The TX200-MkIII is a legendary underlever spring-piston air rifle.
This report covers:
- Where were we?
- Seal was shot
- How to fit the new seal
- Most difficult job
- What did BB do?
- End cap
- Cocking effort
- Trigger pull
Readers, I wish you all a very Merry Christmas. I am taking off tomorrow as my Christmas holiday, so this report will be up until Monday, December 27.
Today we revisit the TX200 Mark III for the completion of the tuneup. Listen up, TX owners. You’ll learn some things today.
Where were we?
In Part 1 I showed you the TX teardown and why it is one of the easiest spring piston guns to tune because a mainspring compressor isn’t required. I also showed you a mainspring that had been coated with black tar grease, which is the airgunner’s name for the open gear lubricant that’s used on exposed gears like those found on drawbridges.
But the biggest problem was the cracked piston seal. Several readers offered possible explanations for this. I think it was the black tar. Some of it liquified and went everywhere inside the powerplant.
The presence of black tar told me that it’s been a long time since I was inside this powerplant. I haven’t used black tar for a tune job in I can’t remember how long.
Seal was shot
What you didn’t get to see was when I removed the piston seal it crumbled into many pieces. It was completely petrified! Even without the crack I showed you it wasn’t working. So this report came along at the right time.
I ordered a new TX seal from Pyramyd Air. It arrived about one week later, and I set aside time to replace it and clean and lubricate the powerplant.
The seal goes on the end of the piston, where it has to fit over a mushroomed steel piston head. Naturally the hole through the piston seal is smaller than the mushroomed end of the piston that it has to fit over. And when you receive it the seal isn’t very pliable. What do you do?
The new seal has to fit over the wide end of the mushroom on the piston head.
How to fit the new seal
No doubt there are several methods to do this. I will give you mine. First the seal has to be made more flexible than when it comes from the package. How you do this is up to you but I don’t recommend microwave ovens. A hot water soak would be fine, and maybe a heat gun is going too far.
What I do is flex the seal between my fingers until it loosens up. Another way is to make a tool that allows the hole in the seal to expand gradually and then slip onto the piston head. Let me show you with a .50 caliber BMG bullet.
A tool that’s shaped like this .50-caliber Browning Machine Gun bullet (minus the boattail) will work, as long as the base of the tool is just as wide as the top of the mushroom on the piston head. This bullet is too small but you get the idea.
Stand the base of the tool on the head of the piston and then slide the new seal down the tool and onto the piston head. The hole in the seal will expand gradually and slip right onto the piston head. For the airgunsmith who will do many such replacements, I recommend making such a tool. But for you TX owners who might replace a seal once in your life, I would just flex the seal in your fingers until you can almost “button” it over the mushroom. I then use a screwdriver to pry it over the lip of the mushroom. This stretches the seal, making it more flexible. Sometimes I just press forward on the piston with the new seal in place, then I slowly twist the piston. That usually gets the lip of the seal started and then the pressure forces it onto the piston head.
Yes it’s difficult and takes time, but the new seal will go on the piston head.
Most difficult job
Replacing the seal in a TX200 is the most difficult job in the entire overhaul. Besides that, everything is easy. But I had some cleaning to do and that took a while.
What did BB do?
All of you discussed how I would clean that black tar off the mainspring. Well, I’m going to tell you, but first let me tell you there was a lot more to clean than just that. The inside of the piston where the mainspring lived for more than a decade needed cleaning, as did the last several inches of the spring tube where the end cap lives.
First the mainspring. I used a can of carburetor cleaner. That’s the stuff that comes in a gallon pail with a wire parts basket inside. I know there are spray cans of this stuff and they are probably handier for a job like this, but I used what I had on hand. I use this pail to clean my legal .22 rimfire silencer after shooting several hundred rounds through it.
This removed about 80 percent of the tar, but not all. Then I threaded a paper towel through the coils and wound the spring so the towel got the entire length of the spring — inside and out. That got me to 90 percent clean.
Then I settled down with cotton swabs and a small screwdriver. Some of the tar had hardened on the spring. It had to be scraped off.
The TX200 mainspring has been shot-peened which gives it a rough surface that holds grease quite well. The shot-peening is to remove stress, but the surface it leaves behind has its uses, too.
For the inside of the piston I used more paper towel on the end of the thin-bladed screwdriver and now I was using Butch’s Bore Shine rifle cleaner that is so solvent that it comes with warnings about touching it. In all it took me over an hour to clean out all the tar, and this is the last time I will ever use it in a spring gun. Now that Tune in a Tube exists, why would I ever mess with anything else? For those in other countries, Tune in a Tube is Almagard 3752 red grease, and there are a number of other red greases that are made from the same stuff.
To get the piston seal into the sliding compression chamber I slid the chamber all the way to the rear by pulling the underlever down and then I had to turn the piston many times before it “buttoned” itself into the chamber. While we are on the subject of the piston, let me share something with you.
The rear of the TX200 piston doesn’t fit into the compression chamber. It slides inside the spring tube, where its bearing keeps it centered on the compression chamber. This is one example of the fine engineering that went into this air rifle. I used moly grease on this bearing and the inside of the tube and it is still in place more than a decade later.
As you can see, the rear of the piston (on the right) is larger than the rest of the piston. It slides inside the spring tube, keeping the piston centered in the compression chamber.
Once the piston is in the rifle the rest of the assembly is quick and easy. Press the ratchet to release the underlever with the compression chamber and the piston and chamber slide all the way into the powerplant. Spread a thin coat of TIAT on the mainspring and slide it into the rifle. While it was still outside the gun I checked and both ends felt tight on the spring guide. That addresses vibration to a certain extent. The TIAT takes care of the rest.
The last task in assembling the powerplant is to put the end cap into the rifle. This is the reverse of how we took it out. Simply slide the cap into the spring tube, then stand the tube upright and press down on the tube to align the one bolt hole for the one bolt that you can turn with your fingers. It has 10mm flats if you want to go that way or a Crescent wrench for the rest of you.
The end cap is pressed in until the two holes align. Notice, too, that the mainspring isn’t heavily covered with grease.
Once the powerplant is together the barreled action goes back into the stock. Now the rifle is ready for testing. I cocked and shot it several times to ensure that it was calm and functioning normally. But it’s the chronograph that will tell the whole story. Remember in Part 1 when I ran a baseline velocity test I saw 7.9-grain Crosman Premiers leaving the muzzle at between 786 and 881 f.p.s. That wasn’t the rifle I remembered. How is it now?
Now the TX200 Mark III averages 929 f.p.s. with an 11 f.p.s. spread, from 922 to 933 f.p.s. Apparently that is the way this rifle wants to behave with Tune in a Tube on its mainspring. Did the new seal work? I should say so! My experience with TXs tells me the rifle will speed up as the tune break in.
The cocking effort is 36 lbs. That’s one pound lighter than the HW 50S and the TX develops more power (15.14 with this pellet).
Stage one pulls with 4.8 ounces. Stage two breaks at 9.7 ounces. Not going to do anything to this trigger!
You can safely set the trigger lighter on a TX than a Rekord because of how the unit is designed. Yes, it was designed after the Rekord but it isn’t an exact copy. I’m going to leave this one as it is.
We are now back on track with the TX 200. The next thing will be to test its accuracy. And that beautiful new Meopta Optika5 4-20X40 will get the honors. Stay tuned!
152 thoughts on “TX200 Mark III: Part 2”
Aside from the TX200, I wonder if there are any other modern spring piston rifles that don’t have much preload? I wonder if manufacturers will ever stop over loading the springs in their search for power.
Good question if they will ever learn. Not really good in many ways. The extra preload.
What I have seen is almost all springers I took apart have had more preload than needed.
My Walther LGV Master purchased in 2014 has very little preload. When I tuned it(right out of the box, can’t help myself) I used my spring compressor and was shocked at the slight preload. Going back together I did not use the spring compressor. I also installed the steel “tuning” trigger .To me it is a shame the Twenty-first century Walther springers are no longer made, love mine and have enough spare seals and springs so when it belongs to my Grandson it will still be a shooter.
I had one of the wood stock LGU’s about 6 years aga along side my Tx 200. Both were great guns.
Siraniko – I think there is a trend to make the piston light and preload it heavy to get short cycle and gain more power. The problem is the light piston system will not work well with heavier pellets, even heavy preloaded. Sometimes I use some really “bad words” when I have to assemble the system with 10cm or more preload and need already 50kg to push just to close the system. Impossible without special tool or just to do by myself. You need someone to help.
The TX200 is most wanted for FT competition where there is a energy limit. You can set it properly just on site using only few tools, put some more washers or remove them in a minute.
It’s no wonder that ‘Tuners’ have more work than they have time for.
Maybe an ‘added caution’, like we need another one, would be to add to airgun manuals would be to be ‘your own gunsmith’?
It’s been a while since i have read and posted in your blog but I do lurk on it from time to time.
My method for installing the sea on the piston is by using a socket that’s just a bit larger than the head of the button on the piston and lube the socket and seal with silicone oil then work seal up over socket. Then place the open end of socket right against the piston button and with a quick motion force the seal over the piston button in one easy step. Works very well for me.
I have tuned mine with a new design kit from a fellow in the UK by the name of Tony Leach of Air gun technologies or facebook page of lost volume. It is a 22mm skirtless piston design that reduce the piston weight from around 500 grams to 150 grams and uses a TX355 12fpe spring with one to 2 coils cut off to achieve a very smooth 12fpe tuned gun with virtually no felt recoil at all. It is completely reversible since it uses a sleeve that is threaded into place of the compression chamber front plug to reduce the diameter from 25 to 22mm.
Good to hear from you! I hope you’re doing well.
I am doing well and hope you are as well.
Yes I am, Thanks for asking. Merry Christmas.
Has the blog changed so it no longer sends an email notice that you have a reply to a post you made in the blog or have I possibly done a change on my end.
Couldn;’t tell you. THis blog keeps changing faster than anyone can keep up.
Bummer, that was a feature that I really liked. Made it easy to respond to others replies.
Buldawg! Glad to see you’re back. There are lots of new(er) regulars here now, but not too many of us long-haulers.
How’s it going? Hope all is good with you!
I’ve used the ‘socket method’ back-in-the-day and I was impressed how well it works.
Hope all is well.
Some people get the emails. Some don’t. I get mine still and I use my phone.
Compression chamber and 22mm sleeve
Breech seal made from delrin.
What’s up. Haven’t talked in some time. Good to see you post.
That by chance the Tx you got from me? I tuned it many different ways and it was always accurate.
What pellet you using now with the tune you have on it?
I am going well and still into airguns. Actually, way more than I need if that’s possible LOL. Lost count by now.
Just had to put my .2 cents in this TX report. I have used the socket trick on all seal installations that use a button or lip type of retaining method with great success.
This is the TX I got from GF several years ago and has gone thru many different tune configurations since the but now will keep the 22mm skirtless piston kit in it now since its so easy to cock and shoot like a PCP using AA/JSB 7.9s at 815 fps with a max 4 fps spread. You can place a pellet on the elevation scope turret and fire the gun and the pellet does not move at all. I have cut a red wasp in half at the thorax to abdomen at 30 yards rested on a lead filled bag with it as it’s a laser in its current state of tune. Just an FYI, the 22mm kits from Tony Leach are assembled and lubed completely with STP racing oil treatment from the rear of piston seal, delrin guides to even the spring and rear guide only, no grease of any type inside the TXs at all.
I also have a .22 cal TX with the same 22mm kit that I had in my .177 B40. I removed it from the B40 and put it in the .22 TX and it shoot AA/JSB 16/15.89s at 630 fps with the same 4 fpe spread and laser accuracy as the .177 TX I got from GF. They are such a dream to shoot.
Admittedly I am very likely going to trade with a fellow club member my .177 TX for an older custom made .177 RAW HM1000 that is in mint condition with a one off polygon barrel that was bult by Martin years ago. Just to good a deal to pass up. I can always get another TX but there will never be another RAW made like this one.
I also recently acquired a 1966 model Diana 60 with the GISS system that needed resealed which I have completed and have it shooting right at spec of 575 fps with 7.9s, talk about zero recoil and PCP accuracy out to 27 meter in the benchrest competition we have now started having in our club matches. It’s also a Tyrolean stock beauty that I traded a HW 97 in .22 for even steven.
Hope this find all my friend here in good health and spirits. To all Merry Christmas and a happy New year.
Good looking gun.
Yea it is in very good shape for being 55 years old and just has the normal wear on the bluing and the butt pad is showing its age but all the internals are now perfect with new seals and springs from Macarri. I have the original sights and barrel sleeve but choose to install a carbon fiber sleeve to protect the barrel from my skin oils and help stiffen the barrel as well. Its just a snug fit slipped over the barrel and not glued on at all.
No recoil at all with the opposing piston system and far more accurate then I am capable of.
How long you plan to keep it is the next question. 😉
That I cannot answer for sure. It is a sweet shooter but then if someone makes the right offer, I would let find a new home.
I have got to the point where if they are a nice gun and a good shooter I don’t let them go anymore. The good shooter plays a big part in that. Got a pretty good collection going on again and they are all shooters.
Yea I have the same issue and do have some fine shooters also but then I am running out of room to store guns so would let some go as well. Plus got some other itches needing scratched. To many toys and not enough time to play with all of them.
I definitely need to get probably 2 more gun cases. Going to have to start putting them down stairs I guess.
Out of corners and don’t have stairs or basement so started stacking in corners several deep. LOL
You got o do what you got to do. 🙂
Yep I’m getting 3 deep in the corners in my closet ontop of stuffing too many in the gun safe. Just can’t bring myself to let any go now. Like them all.
Makes me wonder why ‘they’ haven’t come out with something better/more durable for breach seals. With all the new fanangled materials out, there’s got to be something better.
Merry Christmas everybody!
PS underlever cockers are still weird!
And heavy. I kind of like them though. Some of the old gals around here are underlevers.
U 2 Yogi.
Maybe it is because I’m down here in Galveston county and we do not get cold weather but Molycote still works great for me in springers. I my have to try some tune n lube next time I work a springer.
Do so. You will like it. Go easy with it though.
Many AA TX200 fans believe that the Mark I was the best of the lot. I believe even you mentioned that once?
I don’t think I ever said that. There is no basis for it.
The one thing the Mark I has over the others is there is no ratchet to catch the sliding compression chamber. The Mark II has a horrible long ratcheting sound that people object to. Some even held their thumbs on the release as they cocked the gun to keep it quiet. I was one who did.
The Mark III put the ratchets at the end of the cocking stroke and there are only three of them.
I cannot explain why I do not own a TX200 with walnut stock. Yes, they are expensive, but man. I also cannot explain why I did not keep one of the FWB 300s I had.
Oops! First sentence below picture of bullet.
Stand the base of the tool on the head of the pistol (piston) and then slide the new seal down…
I fixed it.
I lucked into my TX200 as a trade – yeah, definitely a keeper! Some might find it to be too heavy to carry around so there may be deals to be had, good luck in finding one!
I still shake my head when I read you letting a FWB 300 (and your 601) go. Took me 30+ years to get my 300, it’s not going anywhere out of my reach.
There are other airguns to try out. When I got rid of the 601, I picked up a Talon SS and an Edge. Another time I sold a Ruger Air Hawk and a 717 pistol and bought my 1906 BSA. Now that one is not going anywhere.
With me many of them come and go. I shoot one for a while and then I sell or trade it for another. There are a few that have found a place on the wall and will be going nowhere in a hurry. My 1906 BSA over the fireplace, a Webley air rifle and pistol from the 30’s, an Original Militia that I believe is from the teens. Soon there will be a Crosman 101 killing feral soda cans around here when I finish rebuilding it.
By the way, I did not let a FWB 300 go. I let two of them go. Yeah, now I wish I still had one of them, but hey, there are other airguns out there for me to play with.
Yeah, I know how it goes. Sell or trade to upgrade or explore new options. Been there, done that.
It’s just that I have a special regard for Feinwerkbaus, …could never part with one.
I’m settled, have the disciples I’m interested in covered.
Cheers – and Merry Christmas!
As fine as an airrifle they are I’ve never been tempted to buy one.
I don’t know of any break barrel that is worth this amount.
Now I’ll sign off and hide to avoid the deluge of rock throwing.
LOL! I have seen some pretty expensive breakers myself.
As I have quite a few breakers and underlevers, I will not be throwing rocks.
I’ve got my share of breaker’s also, but they have become ‘safe queens’ since I’ve taken gone to ‘To The Dark Side’.
Pssssst……..I collect rocks and give them to the grandson, who likes to collect them. Geologist in the making……..not sure.
I’m told as longs as he doesn’t take after me, per his mother, and my son he can be whatever he wants to be…lol.
So, you want me and others to throw rocks, though you would prefer if they were interesting ones. I myself probably would not mind if people threw diamonds at me. What is wrong with being a Wingnut?
Just to put your mind to rest I am keeping one of your 300s that I got from GF warm and cozy here at my place along with all the extra parts and two stocks that had breaks at the wrists. Got them both shooting 650 fps with 8,4s using maccari artic springs. Slowly getting quite a collection of old vintage ladies of my own.
It is hard not to fall in love with that 300. They are real nice made air rifles. LOL! Once you start down the road, it is hard to stop. The quality that is in so many of these old airguns is incredible. That is why if they happen to not be working, they are not so hard to get them that way.
Yea I do love my 2 300s for sure. One is a beater that I can shoot with no worries and the other is the nice one of yours with the walnut stock that only gets shot at home in nice weather.
The Diana 60 was a very easy gun to rebuild once i watched Joe Rhea’s video on rebuilding a model 75 and made me a spring compressor and spring guide rod like he used. Timing the pistons is a piece of cake IMO.
So you still got the 300 with that stock I refinished in oil stain.
If it’s the one in the walnut satin stock then yes I still have it but I did take the o-ring out and put the steel piston ring back in it.
Yep thats the one. I still have the other one I got from RidgeRunner. Got a single Macari spring in it and the o-ring mod instead of the steel ring and lithium grease on the spring. Still need to refinish the stock on it but always got alot going on. Probably going to wait till I retire. Only got a bit under 2 years to go now.
Yep, lubed both of mine with lithium grease a while back and it seems to work better then tranny fluid to give better fps and less spread of fps shot to shot.
Yep I like the lithium grease too.
Merry and Blessed Christmas B.B. and to the airgunners here and everywhere! Hope 2022 will be better for everyone; hope springs eternal. That was deliberate. 😉
You clever double entendre guy! 🙂
Same to you and your family and friends. Merry Christmas.
I hope you are all well.
Here’s a little project that was more difficult and costly than I had anticipated.
It’s a 1979 FWB 300S that was advertised on egun as being in “collector’s item” condition by a guy with 100% positive feedback.
Sadly, this clearly wasn’t the case as the stock had several marks and scratches and there was light rust on the system housing and cocking lever. Also, there was a “twang” in the shot cycle that a 300S doesn’t normally have. At least, I was able to get a little refund.
The twang was caused by two identical mainsprings instead of one left-wound and one right-wound spring.
I tried removing the rust and re-bluing the metal parts with Ballistol and Birchwood Casey cold bluing products, but the results were disappointing, no matter how hard I tried. So I ended up sending the parts to Feinwerkbau for bluing.
In the meantime I lightly sanded the stock (just so the original coat of lacquer came off) which was enough to remove most of the scratches. I then treated it with “Scherell’s Schaftol” stock oil. I think this is the best product I’ve tried so far. At this point, the stock must have absorbed close to 150ml of the stuff which probably shows it penetrates deep into the wood. The stock was looking good when I got it, but now it’s starting to look fantastic. I think it’s also still getting a little better with each application.
When I put the rifle back together, I replaced the seals and mainsprings. I left the piston ring as it was since I figured there was nothing wrong with it and it had probably adapted to the compression chamber. The shot cycle is now smooth as it should be.
So far I managed to shoot pretty decent groups from a rest at 10 meters. The best group was with Qiang Yuan Olympic pellets. I think the rifle and I can do better, though.
Happy holidays to everybody!
The stock looks amazing. Exceptional work!
Very nice Stephen! Thanks for sharing!
Glad the project turned out well!
That thing is beautiful! Thank you for showing us!
Have a Blessed Christmas and a Wonder Filled New Year!
closeup of the stock
best 10-shot group from a rest at 10 meters so far
The very best of holiday wishes to BB and all that visit here.
Be safe and stay well,……………….. Chris
You too. Thank you.
Thank you very much. Wishing you the best on your recovery, a Merry Christmas and a great New Year.
Happy Christmas and may you and all here enjoy good health in the new year.
Miss ya dude! Have a most Blessed Christmas!
Best wishes to you and yours and hope all ids well.
Merry Christmas. May we never forget the reason for this season and may he forever remain in our hearts. Maligayang Pasko!
Merry Christmas to you too..
Praise the Son of God to the highest!
Some good information here for TX owners, thank you again for doing this series. I have a few questions- if you are willing to answer them I would be most appreciative. I numbered them in the hopes that it would make replying easier. Thanks!
1. From my reading of todays article, it seems you reassembled the airgun with a previously applied coating of “moly” grease still in place on the rear bearing surface of the piston, and inside the compression chamber. Is this correct?
2. If that “moly” grease had not been already in place, or if someone were lubricating these places for the first time, are you recommending the use of “moly” grease in these areas?
3. What keeps the piston seal from sweeping the grease inside the compression chamber ahead of the seal? What is the result if this is happening?
4. How about the use of “moly” grease on the spring guide and top hat? Is this unnecessary with the TIAT coating the spring?
5. Does the proper coating of a metal part with “moly” grease leave a visible layer, or should most of it be wiped away before reassembly?
6. Finally, I have seen it recommended from several sources that polishing the ends of the spring can be beneficial. Any thoughts on this?
Thank you for any additional information and clarifications you can provide. I appreciate all of your help.
-Airman of the Board
1. Yes, I left on the rear of the piston and inside the spring tube — not the compression chamber..
2. Absolutely, on the rear of the piston. Not on the front though. The seal is the only bearing surface there..
3.The piston seal only sweeps what it can reach. The moly behind it stays where it is. If it went forward there is no harm done.
4.. I used to put moly on the spring guide but I no longer do. There is no top hat. For me TIAT is sufficient.
5. If the moly is visible, that’s good. Don’t wipe it off. But moly has an affinity for steel and embeds itself in the metal, so after awhile you can’tr see it but it’s still there.
I don’t see any reason to polish the ends of the mainspring. Yes, it does move when it compresses and decompresses, but not enough to matter — in my opinion.
Your the tops! Thank you so much for taking the time to answer my questions and share your expertise. I have many areas of interest, but few where I am able to direct questions to an expert. This is a special place and I commend you for the community service you provide.
I have not yet been inside a Tx200, but the schematic I found on Pyramyd’s website seems to show a forward spring guide. I thought that part could be refered to as a “top hat”. If you feel like indulging me once more, can you help me better understand the terminology, and the distinction between the forward spring guide and the top hat?
Airman of the Board.
Yes, a forward spring guide would be called a top hat. My TX doesn’t have one. I can’t remember if they come with them now or not.
Got it. Thanks again.
I understand the reasoning for polishing the ends of the mainspring. With something like the TX200 where the piston is free to rotate within the compression chamber you are not likely to notice, but I have had sproingers where the uncoiling of the sproing is quite noticeable when you pull the trigger. It is especially noticeable with the light, powerful sproingers.
This is also why the FWB 300 series has counter wound sproings. If you can allow for the sproing to twist freely when it is being compressed and released, you eliminate one of the factors that make sproingers difficult to master. Unfortunately, that usually calls for an extra outlay of assets which most companies are unwilling to do.
I polish all my spring ends to a mirror finish regardless of gun they will be installed in since I feel it just make the guns shot cycle all that much smoother and it takes only minutes with some sandpaper and a granite flat plate but then I am perfectionist and anal both at the same time. It’s just habit from years as a mechanic that I learned early in my career that if you don’t have the time to do the job right the first time when you are getting paid to do it where will you find the time to do it right the second time when it’s for free. My work ethic is slow is fast and fast is slow and incorrect.
like I was saying, anything that alleviates the sproing torque is a good thing. Many sproingers that I have shot I could not notice the twist though it is always there. Some I have shot would try to twist right out of your hands. My Gamo CFX had a bad twist.
BB, Great photos of the TX piston. A question sir, is that a shiny wear band around the circumferance from the comp chamber caused by vibration at the end of stroke? Buttons..?
I too wish I got the nice wood stock break barrel Walther, it had a fancy ‘muzzle brake’ on it too.
I keep looking.
That’s not a shiny band. It’s a piston ring that’s in the piston.
No, an inch to the left of the larger nylon ring.
Gotcha. That is where the piston goes no farther into the compression chamber. Some fluttering of the compression chamber?
Folks I would like to give an update on my development of a low pressure pellet gun. It has been quite a journey so far. Lately I have been tuning the gun to improve accuracy.
I did a test to find out the optimum compression of the hammer spring. In the beginning I maximized the hammer spring compression to be sure I had the valve open long enough to maintain all the pressure the valve can deliver till the pellet leaves the barrel. I have discovered after many test the valve is larger than necessary, and now have found the hammer spring compression can be significantly reduced. The reduced hammer spring load reduces the kick and resulting harmonics of the entire gun.
Here is the data from incrementally decreasing the hammer spring compression and measuring the resulting velocity. The air pressure used for the test was 130 psi.
load … Velocity
inches … fps
1.24 … 465
1.15 … 467
1.01 … 467
0.90 … 472
0.79 … 475
0.68 … 475
0.56 … 473
0.48 … 474 this should be a good hammer compression
0.34 … 475
0.23 … 0 did not fire
Based on this testing I think the air pressure in the valve is pushing against the valve stem holding the valve open until the pellet leaves the barrel. The low air pressure then allows the valve return spring to close the valve.
Based on the design of my trigger I could only reduce the hammer compression to 0.75 inches, I was hoping for .5 inches. It did make a significant reduction in the in the kick and harmonics of the gun. The barrel movement was easily noticeable with 1.24 inches of hammer spring compression and was barely noticeable with the 0.75 inches of hammer spring compression.
Up to now I have been using the AA .22 caliber Falcon pellets they are 13.43 gr. I was finally able to order some of the .22 cal RWS Hobby pellets, at they are the lightest .22 lead pellets I have found. I was hoping the Hobby pellets would get 500 feet per second with 100 pounds per square inch pressure; they did not. Below is a graph of the velocity vs pressure for the Hobby and Falcon pellets.
Up till now I have been using the Falcon pellets, they are a good fit I can seat them with my finger and get good consistent velocities. The Hobby pellets fit tight, and I did not get consistent velocities and at low air pressures they did not even move. I had to deep seat each pellet to get stable velocities.
I have not had a chance to test the hobby pellets for accuracy yet. With the Falcon pellets my best groups are around .33 inches center to center, 10 shot groups at 25 yards. Maybe the Hobby pellets will be more accurate, but I don’t think so.
Here is a picture of the low pressure pellet gun as it is today. I have been using the FX radar chronograph; see it at the end of the barrel. It is very easy and handy to use. Well worth the money, especially after I shot my Beta Chrony. The Beta Chrony still works after I put it back together.
Congratulations to your work in progress! Merry Christmas to you and your family!
Thanks, and Merry Christmas to you and your family.
And I wonder if reducing the barrel length would increase the velocity?
I would expect a lower velocity with a shorter barrel. At some point with a longer and longer barrel the velocity will start going down. I did some tests earlier with three barrel lengths and the velocity was still increasing with a 24 inch barrel.
I am not ready to start cutting down my Lothar Walther barrel. If I had a cheap barrel 48 inches long even a smooth bore I would give it a try.
Then maybe the longer barrel is the trick. I guess you chose the Lothar Walther barrel for accuracy.
You know Crosman makes a bunch of different length barrels and they are pretty accurate too. Maybe you could adapt them to your gun.
You know, that looks like something Lloyd would put together. He once built a tabletop proof of concept air rifle that would shoot a special made pellet at over 2000 FPS.
That would be 2162 fps to be exact using if i remember correctly a 1.7 grain pellets and 4500 psi with a dump valve setup.
LOL! So, you remember that rig! I sure do miss going to those Fun Shoots! I like hanging out with Lloyd. We just had a fun shoot at his place last month. He, Marty and I try to get together at least once a year.
Lloyd is always tinkering around with something.
Right now, he is building hail guns for a siding company. These airguns shoot large balls of ice.
Nice Diana. I notice you also use UTG scopes and those bikini covers. 😉
Yea Lloyd had a big thread going on the GTA about his high speed gun that was a very cool experiment. Those fun shoot sound fun indeed. He made me some parts for one of my guns years ago, great fellow airgunner for sure.
Yea I like the UTG small scopes for their size and it just seems appropriate for the model 60 and I do lie the tight fitting bikini covers. I do have the original sights and barrel sleeve but my old eyes prefer scopes these days.
Most of my scopes are UTG. I have one Hawke.
I have an old 3x9x32 BugBuster and a 3x12x32 BugBuster.
You kinda get the idea that where I am, 100 yards is a long way.
P.S. I also have one of the original SWAT Compact before illumination.
I have several UTG scopes as well as Hawkes and others. They all have their purpose for the guns they are on.
I do shoot at mostly from 10 to 55 yards with the majority of my guns but also shoot out to 100 yards with my Mutant and Brod.
The Mutant is by far a dedicated 100 yard gun that if I can do my part will keep sub 2 MOA or under groups, Have had perfect weather condition and stars aligned for me to get a few sub 1 MOA groups but those are not the norm for me. The gun is capable of them just i am not on most days.
This project of yours is so amazing. I know your goals are not yet met but the performance you are getting is still remarkable. I am humbled by your results every time I stop my fills at 3,700 psi!
Merry Christmas to the Master Elf of Low Pressure ;^)
Looking forward to your successes in the New Year.
Great stuff Don!
A very interesting project, suspect that it’s changed the way you look at a PCP!
Cheers and Merry Christmas!
First let me say Merry Christmas and Happy New Year to everyone.
This is a bit off topic but I couldn’t help myself. I found this adult beverage today and thought you would get a chuckle from it.
Watched the movie last night!
Enjoy your well-earned day off! Merry Christmas.
Enjoy the Hubs!
Have a most Blessed Christmas and a Wonder filled New Year!
Well — thanks for not having your name put on the card! It said Merry Christmas with no name and I hadn’t a clue who sent it. I finally thought that I must have sent it to myself.
Thank you very much! They were delicious! 🙂
LOL! My bad! Have a most Blessed Christmas and New Year!
Merry Christmas B.B.! I have a TX MK I manufactured in 1992 (4 digit serial number) non FAC model. At first, I tried the Vortek SHO kit. I didn’t like the firing characteristic of that kit. Recoil was harsh and Tom never replied to my emails to try and solve the problem. I finally took the kit out and got a Tony Leach 21mm kit. What a difference! Recoil is almost non existent velocity in the 760’s. Tony was very helpful in explaining the kit as well as offering tips regarding the TX. He had mentioned the TX is most accurate at fps in the mid 700’s. Joel Goodwin won the Canadian FT Nationals beating all PCP’s! His TX’s velocity? 755fps! I looked at other FT results and the winning TX’s had velocities in the mid 700’s. There may be advantages to higher velocities that others prefer but, I, for one, prefer accuracy above all else. Next project for the TX is bedding the stock.
Enable, enable… You’re after my job! 😉
Hahaha! Not at all interested in your job! I only have 3 airguns–the TX; Baikal 46M for plinking; and FWB65 MK I.
I believe that would be a 22mm kit not 21mm unless Tony has made a special one for the mark 1 TXs. I also have a 22mm kit in my MK111 TX as well as one of only 2 B40s with the 22mm kit ( Tony owns the other one) I contacted him about one for mine and he gladly made one up for me. I admit I did remove it from my B40 and installed in in my .22 cal TX since the .22 cal is actually more efficient with the 22mm kit than the .177 is with it. But either cal is a dream to shoot for sure. The only difference between the MK1 and 2 and the Mk 3 is the piston strokes, with the 1 and 2 being a bit shorter at I believe 94mm versus 98 for the MK3. The 22mm kits are all at 96 to 98 mm depending on how far the piston rod depth is set in the shirtless piston. It’s been a while since I built my two so I may be off on the numbers by a mm or 2. I got just unassembled kits that I had to remove the piston rods from OE pistons and install into 22mm pistons to a predetermined depth. I know my B40 kit has 2mm more stroke than the 22mm TX kit per my choice.
Nope, it is a 21mm kit. From Tony when I purchased the kit “You just bought my last 21mm kit I had 4 left before new stock in a fee weeks 21mm is faster still and less recoil still”. It is set at 84mm stroke.
Well, that’s interesting for sure. I was not aware he made them in 21mm but then also being at the shorter 84 mm stroke it makes sense. I bet it is fast and snappy shot cycle since it has to be a few grams lighter than the 22mm kits.
BB and Everyone,
MERRY CHRISTMAS! and a HAPPIER NEW 2022!
Been up since about 5:30 this morning getting things ready to cook for the Christmas meal later.
And looks like Santa came. And I see a long skinny box under the tree with Gunfun1’s name on it. Hmm I wonder if Santa brought me a air gun. We will see later.
Merry Christmas everybody.
Well it was a air gun. Another Marauder. A synthetic stock .25 caliber. And it is real accurate for some reason. Tried the trusty JSB 33.95’s and some FX 33 grain pellets and it loves them. Getting 24 usable shots from 3000 down to around 1750. Put several 24 shot groups in 3/4’s of a inch at 50 yards with each brand pellets yesterday. Me and my daughters and the oldest daughters husband was hitting bottle caps at 25 to 50 yards plus yesterday no problem.
And I ask myself why Santa chose another .25 caliber air gun. Thinking about it old Gunfun1 has several .177 and .22 caliber air guns and only one .25 caliber air gun. Guess Santa figured that the one .25 caliber air gun was lonely. No complaints here. 🙂
Still have your first 25 I got from you although has gone thru some changes over time. Now a bottled Teryx chassis tactical gun.
Forgot about that gun. But do remember you was in the process of building it. I like it.
One of my most fun guns I got a little while back is my SAM (Semi Auto Marauder) in .22 caliber. Reminds me of back when I was a kid blasting my semi-auto .22 rimfire rifle that’s factory regulated. Definitely a fun gun.
And I also got one of the factory regulated. 177 Marauder FT with the factory Lothar Walther barrel. It is very accurate. It gives my .177 Gauntlet a run for the money.
Oh and like I mentioned got some Marauder’s now. I got a Prod with a dot sight on it that is a excellent starling popper out to 50 yards. Love their 2 stage triggers with the trigger stop.
And the list doesn’t stop. 🙂
I have had a Prod awhile back and sold it then bought another with an AR stock that is a nice shooter as well and also got a 1720T that I use in FT that in a Tom West stock and has a huma reg in it. I now have the Prod in a Rapid-70 bullpup stock from a vendor from Spain that makes its a very compact varmint gun.
How does the SAM do since I have heard there has been some issues with the cycling in semi auto mode.
I still have my gen 1 .177 Mrod that I used in FT for years now and am going to be getting a LW barrel to put in it first of the year. Got it in a nice stock now as well.
Here’s some pics of the Prod and 1720T
Love the 1720T you have. I had 2 1720T’s and they both shot as good as yours looks. Again love that 1720T you have.
And the Prod is cool too. I had been thinking it would be cool if Crosman made a bullpup SAM.
And as far as my SAM goes I eliminated the charging handle and machined the breech and tapped the bolt and used a Allen bolt to cock the bolt and I changed the pin in the striker to contact directly to the bolt. Mine is a true semi-auto action now. Absolutely no mis fires now plus I modded some SAM and regular Marauder magazines the mag advances sooner when the bolt is retracting. There is pictures on one of the SAM reports BB did on the SAM in the comments. Forget what part blog now. But yep done all that within the first week I owned the SAM.
Yep i do like my 1720T and have it tuned to get 45 shots with 10.34s at 12fpe per fill and also have a custom shroud that has bafflers in it similar to the Mrods so it’s very quiet as well. The Tom West stock really makes it comfortable to shoot.
I should have figured you would fix any feeding issues with the SAM to make it fully functional semi auto. Glad it is working good now.
Did you use the bigger inside diameter transfer port orafice. The 2 different 1720T’s that I had came with 2 different orafices. I always used the bigger inside diameter one for more power but less shots. I bet that orafice would work good with a regulator.
And here’s a picture of the breech now on my SAM after I milled it for the Allen bolt cocking handle. And a picture of the modded mag on the inner part that advances the pellet. I also went one notch tighter on the spring so the pellet will advance faster. I can pull the trigger as fast as I can and empty the clip no problem.
Yes, do have bigger transfer port in the 1720 and actually drilled it out to the 3,5mm that the instruction with the lane reg stated to do so the port from valve to barrel is all 3.5mm straight thru. Reg is set to 90 bar to get most shots at 12fpe with 10.34s and have tuned hammer spring in it also.
Nice mod on the SAM to get it working properly.
Here is the inside of the mag.
Basically just filed a angle on the part where the pellet fits in then chamfered those openings.
That sounds like a nice setup on your 1720T.
And yep for sure glad I modded the SAM. The charging handle system they used was a joke. It was even made out of aluminum. If you didn’t pull straight back you would end up bending it or cracking it or both. Anyway all good now.
Your forgot your comment. ???
While FM has been known to blank out on occasion, did not put a comment there because that was not where I wanted to put it. Tried deleting the whole thing but format would not allow it.
Yep the blog commenting has been screwy since they started the new format.
Not a big fan of it for sure. But Gunfun1 is living with it.
Merry Christmas everyone!
Merry Christmas to you and your family and hope all are doing well.
Enjoy the day with all.
Today is only the beginning of Christmastide! We celebrate and rejoice for all twelve days until Three Kings Day!
Tomorrow is Boxing Day; don’t forget to fill those boxes with lots of rubber mulch!
May the New Year be bright for all of us,
For those interested here is a link I found to a through history and info on Air Arms. Lots of useful and interesting info and schematics.
I hope all had a wonderful Christmas, I saw a Ralphie upgrade meme that I just have to share enjoy this silly image.
I also found a short video under a minute of the BrickWurX Mfg. Lever Action AR-15, a strange take on the AR platform in the form of a Red Ryder.
Mike in Atl,
No place to reply directly below.
At 72 very soon to be 73 my competition days are over; even at the Masters level, since at most all Masters events there would sadly be no one to compete against.
I volunteer to give back to the sport and get to ski around a bit for FREE!.
Best to you and I hope you have fun, the getting old thing can be a problem but you seem to be holding on and in good shape, hope that continues for you.
Just setting off on my 69th trip around the sun and hoping all will go well.
Mike in Atl,
Best wishes on your 69th orbit. I think investing in two sessions a week with a Personal Trainer since I was 65 is the best return on my money I have ever gotten. Plus I almost never use elevators, park away from my destinations and generally walk if under a mile.
All packed for the morning going to get my beauty sleep ;^)
Well did Santa bring anybody some guns or such for Christmas?
Glad you got a precise .25 Marauder with the synthetic stock…any ‘yotes will be in trouble with the right power tune and ammo choice!
My DAQ. 410 Shot Pistol was just really an early Christmas arrival; now half of the reloading supplies (especially the Nickel plated shot and .410 wads) showed up. Dennis has promised to make 25 of the Brass shot shells when he produces the next batch in January. Those extra shot shells will make reloading for testing/patterning much more efficient. I also have some #000 Buckshot on order to see what two or three pieces of that will do in the Camp & Garden DAQ.
It has a bit of BARK when launching full Sugar Pearl Loads! Don’t know yet if they come out of the muzzle Supersonic; haven’t bothered to set up the LabRADAR to get velocities. The Sugar Pearls patterned really well out to eight yards.
More in January when I get back from the mountains.
I was wondering if you was getting anywhere with your .410. I imagine if you shoot any bugs with those pearl sugar shots there won’t be anything left. Probably won’t be good on screen doors or windows. And probably might break the glass. 🙂
And yep this Mrod is accurate. At 50 yards it’s like a magnet when it shoots. I think I pull a shot and it still hits. Most happy with it.
The Sugar Pearls are so light for volume that I doubt they will break windows much past three yards, I really am clueless on just how much to expect. I will act as if it was just as powerful as a .410 firearm until I get some actual numbers and more importantly some real World experience. The various length and shaped wads in the Brass Shot Shells are going to take time to figure out what works with what while being driven by an air charge just for starters.
The snow falling this evening and forecast for almost all of this week has my mind on the skinny skis, base prep, wax choices, and most of all the wonderful young people taking part in a major Biathlon competition.
There will be lots more Air Shot Pistol FUN in the New Year!
You know what surprised me.
I have been using the #8 shot in my Wingshot ll and recently got some #6 shot.
The #8 shot likes the high power cocking and the #6 shot likes the low power cocking.
Like you said. Real world shooting tells the story.
And I wouldn’t underestimate that pearl load. I bet there is some good energy there that close.
Will you be in the competition or just an observer?
Anyway it sounds like fun however it works out.
Waiting for delivery of the Axeon 1RDS sight you and I discussed – should be in before the New Year. 🙂
Somehow these comments don’t seem to post where they should. This was meant to reply to GF1’s question about what goodies Santa delivered. Another MISS by FM!
There are so many replies to the main comment it keeps putting replies to the bottom of that bunch of comments. It does make it a pain in the butt commenting sometimes.
But is this the dot sight you ordered if I remember right. You will like the 11 different brightness settings. I have one on my old Winchester 190 semi-auto .22 rimfire rifle that is the same but branded under a different name. The brightness level will slightly change the dot size which helps in certian circumstances.
And notice there is a size written on the dovetail clamps. One side when placed up is for 3/8’s inch dovetails and when the other side that say’s 5/8’s is placed up it will work on the slightly bigger 11mm dovetails. But that is about the only 3/8 -11mm dot sight made now days. Everything else is picatinny or weaver.
But here is the link. Look at the pictures and you can see the writing on the top of the clamps.
Yup, that’s the one. Think that will work nicely with the Max and FM’s Mr. Magoo eyeballs.
I wear my everyday prescription glasses when I shoot. Scope or dot or peep sight. If I didn’t the sights and object would not be very sharp at all. I would probably not be a very good shot without them.
Let me know when you get the dot sight and maybe a picture of it mounted on Max.
Did you try any of those JSB 10.34 Hades pellets in Max. How about the .177 caliber Winchester pellets. They all worked good in Max when I had it.
This is for you.
I just read your blog. I also just rebuilt an original 1st version of the 101 I picked up at an estate sale. All I have at the moment is Crosman premier hollow point hunting pellets. I ordered some RWS Superpoints after reading your blog and can’t wait to try them. My 101 has the steel barrel and the rifling looks pretty strong so we will see. Anyway nice blog. Thanks PS I wish I could post pics?
You should have no problem posting images. Look down below the RED “SEND A COMMENT ” box to see what types of files you can add to your posts. Give it a try! Not difficult at all.