by B.B. Pelletier
Today’s guest blog is so fantastic, I jumped at the chance to use it. Brian has been making precision aircraft and missile parts for over 30 years, so he knows quite a bit about the subject of manufacturing tolerances. Take it away, Brian.
by Brian Saada, aka Brian in Idaho
If you’re a regular reader of the Pyramyd AIR blog, then you probably read BB’s article of May 21, Pellet Variation What Do You Do?
The simple answer to that question is — not much! Or, as BB noted, you can weigh, sort and package your pellets with some semblance of order as to actual weights. Still, some of us may want to know more about these types of manufacturing variation(s) and what causes them. Is there no perfection to be had out there? In production manufacturing, there’s no perfection — only allowable tolerance or deviation from the norm.
Manufacturing tolerance
So, what is this tolerance thing anyway? Simply stated, a tolerance is an allowable range of dimension or weight or other measurable feature of a part or product. If the part or product falls within the “tolerance,” then it’s assumed to be fit for the application or use for which it was designed. As an example, if the head diameter of a .177 lead pellet can be functional or useable in a range of sizes (tolerance) from .175 through .178 diameters, then the manufacturing tolerance allows for pellets inside the tins we buy at Pyramyd Air to be .175 or .176 or .177…and also .178 in diameter. In plain, old-fashioned drawing or blueprint terms, we would see this written as .175 / .178 diameter for the nominal size .177 pellet. In practical terms, we feel these variations in our single-shot guns each time we push a pellet into the breech or barrel.
Nominal size
Wait a minute…what’s this nominal size stuff? A .177 diameter pellet or pellet gun barrel diameter is .177. Right? Not exactly. A nominal size simply means the size that can be normally expected or used in relation to some industry standard or design standard. As many of us know, the infamous steel BB that is called .177 is not .177 at all. It is typically .173 diameter but its tolerance allows it to be as small as .171 and as large as .177 (almost never at .177 diameter, per Daisy data). The nominal size of .177 is used in labeling and packaging for pellets, BBs and guns. It is not the actual or as-measured size of much of anything!
Weight and size relationship
As we know, a lead pellet is more or less a tube, depending on the style of the pellet. I say tube because, it has an outside diameter and an inside diameter too. Sure, it may not be totally hollow, but at least on the skirt surfaces we can see the inner and outer diameters. So, if a pellet diameter can vary (tolerance) does that affect the weight too? Potentially, it does. Both the inside and outside diameter can vary, and not always at the same time! Whew, more variation and larger tolerances? No, more often than not, it would be the changes in the forming die that squeezes the pellet into shape from lead wire that affects or controls the weight (along with the inside and outside diameters). Larger outside diameters or growth in the head size = greater weight. Given the density of lead, it doesn’t take much change in diameter to affect the weight of the pellet. Remember, we’re talking tenths of grams or less, and a significant change to the pellet diameter is a lot of additional surface area (weight) for an object as tiny as a lead pellet!
OK, enough on the math lesson and tolerance talk. What BB did not mention in his article about pellet weight variation was the somewhat-related topic of pellet sizing. Years ago, pellet sizing was a fairly common practice among serious airgunners. A pellet sizer was simply a hand-held steel die that forced the pellet into a specific diameter. Since then, these pellet sizers have lost their popularity except for certain die-hards (pun intended) who demand ultimate control over their pellets (wait, isn’t that us?). Now, unless the sizer sheared off some material when used, it did not affect weight. Then, as now, the only way to deal with weight variation was through sorting. Back then, we also sized the pellets after sorting out the weights. A lot of work for (arguably) little gain.
Summing it up
Manufacturing tolerances allow for mass production. Otherwise, we would handcraft each pellet to within .0001 grams of weight to each other, and we would probably manufacture two or three tins of pellets per day at a cost of, say, $150 per tin. Oops, can’t do that, now can we? Still, BB’s advice about weight-sorting your pellets is the most practical and useful piece of advice on this subject.
Enough for now, I’m off to send some of my pellets to the local testing lab to check on the standard deviation of the chemical and physical elements as relates to the density and weight of the lead alloy. Right! Typical airgunner!
Hello bb i was thinking do you think you can give the air guns that you review, a rating like “3 bbs out of 5”
Thanks David
On the subject of tolerances I recently found that two tins of H&N Baracuda Match each had one pellet that had its top smashed against something such that it deformed the top, and there was a indent in the side. Both tins are from the same batch. I emailed H&N and they said:
“We are sorry that one pellet has had the top smashed/sliced and the lead is smeared to the side. However, it may happen that one pellet is defective. For that reason there are always 2 or 3 pellets more in one tin.”
I then counted the number of pellets in each tin and I came out with 198 + defective pellet in one and 202 + defective pellet. So I am not too happy nor too upset. I am just a bit put off on H&N and their idea of striving for 100% defect free production. I hear it, but I don’t see it. JSB on the other hand, I haven’t seen an issue yet. I am a lot more amazed by their standards to quality. Anyway, I still like H&N, but for the price, it leaves something to be desired.
-Ryan
I have bought about 20 tins of Barracuda Match 177 (Beeman Kodiak Match) over the last couple of years and could never find a thing wrong. Since I buy 4 or 8 at a time I get them all from the same batch. I test fire a dozen and know I’m good for the next 4000 rounds.
The Crow Magnum pellets are a different story. I bought two tins and hand sorted for defects and removed about 40%. The remaining 60% shoot reliably and accurately.
Don’t get put off by this bad experience. I suspect mishandling in shipping. I had two dishwashers from Lowes damaged somewhere from manufacturer->store. A pain in the butt to be sure but nothing wrong with the product.
Hi Dvid from AZ,hi all of you!I assume that AZ is Arkansas,if i am wrong correct me couse i am “Balkanien” 😉 I was thinking what ALL OF YOU think about GAMO ROCKET 17 cal ?I only bought it becouse i was curious and my opinion is that is interesting stuff but too expensive for what it has to offer ps-this will not stop me buying 22cal rocket (if i find it here ) just to try ps- question for RYAN have you started your “pellet tide” work of art 🙂
Croatia-Serbia,
On the subject of .177 cal Gamo Rocket, I think they are kinda cool if you need something with decent knockdown power in medium power airguns. The hard steel tip will help deliver the energy to the target. I agree they are not the best manufactured pellet out there for the price. The remind me of Crosman or less quality and more expensive.
On the subject of “Pellet Tide” TM, I haven’t started yet. I need a surplus of Kodiak Double Gold, and more Baracuda Match. I will stockpile them as soon as I can and then go about considering the logistics and what not. 😛 Thanks for getting the naming part done. That was a big help.
-Ryan
David from AZ only we here call arkansas -Asrkanzas so my bed 🙂 Ryan i think that pellets made from “white lead” are better, tuffer(so far i did not find so much-or any smashed pellets in a tin) and cleaner ps: only my opinion
C-S
AZ stands for Arizona. Arkansas is AR. Incidently Daisy Outdoor Products is headquartered in Arkansas. They make the Red Ryder, the model 25, 853 etc. Are American made airguns available where you live?
Cheers
Lead -yes we have DAISY over here and WHINCHESTER -so far i know.People over here i noticed mostly(recently) buy Diana,Slavija 631-634,Gamo,DAISY lesser brands i did not mentioned
Ryan-buy collor spray(gold) and cheat with “lesser brand”of pellets 😉
Now you’re thinking! Genius!
I could do the collage in .177 cal and buy Baracuda rather than Baracuda Match. I can also spray paint some of them for the sand. Woot 😛
Just ask man I AM artistic genius-you know what, when you finish THEN you can actually shoot a litlle bit 😉
Edith
I noticed this a while back but I thought I would comment on it.
Now, when you post a link to a webpage there is no need to add the html tags, the WordPress software does it for you. Nice touch!
Now, if they could only figure out when I am kidding, and automatically add winking smileys in the appropriate places. Oh well, you can’t win em all.
In a perfect world…
Brian in Idaho,
Some food for thought to be enjoyed with my morning pot of coffee. Thank You! You’ve got me wondering about sizing pellets–worth it or not? Do the FT guys size theirs?
Mr B.
Brian in Idaho,
Nice work putting tolerances in lay-mans terms. By the way I was weighing and sorting my change and it turns out that RWS holds tighter tolerances than the US mint.
Caveman
BB and Edith:
Absolute cracking photographs on yesterdays Topic.Almost as good as having the pistol in my hand.Cheers.
Ryan:
I am sorry I don’t know if H&N still make the Coppa points.
I hope they do because in my old Logun PCP they were ‘toppas notchas’ and still shoot quite well out of my cheap Chinese springer.
I get/got mine from an army surplus guy who has a stall at our local market.
For such a small stock this fella carries,he still manages to have tins of the more unusual type of pellets.
I normaly avoid town on markets days but when I do venture down there, you will find me lurking around this blokes stall 🙂
Brian:
I find manufacturing processes real interesting.
I must have seen every episode of ‘How it’s made’on TV.
Not only what they make but the machines that make them.
There are sure some clever folk out there.
Thank you for a very enlightening article mate.
DaveUK
DaveUK,
I found some available on Ebay. Not too expensive, considering they don’t seem to make them anymore.
I too am amazed by manufacturing processes. I like to see quality control too. I have looked for a “how its made” for pellets, but to no avail. I would love to get a nice video from JSB, H&N and RWS, about how they make different pellet types. I think its all very fascinating. If anyone does find any videos, or even some good written stuff, let me know.
-Ryan
Ryan,
I believe I remember reading in an earlier post late last year or early this year that BB visited an airgun factory. I don’t remember if it was Crosman or Daisy but they gave him a tour of the factory except for the pellet making process, which they keep secret, which means there probably won’t be any videos.
-Chuck
Darn it. I really want them to show videos of some of the process. Like some basic stuff. I would love it if they could figure out a way to do it without harming themselves. I for one just want some education, not out to make my own pellet manufacturing plant in my garage…
-Ryan
DaveUK,
RE: How It’s Made
I could watch that show for hours…
– Orin
Brian,
Nice introduction but there is the rest of the story. Imagine a bolt and a nut each made with a wide tolerance. You could start off with a big bin of bolts and a big bin of nuts. You pick up a bolt the rummage through the nuts until you find one that you can spin on the bolt. Repeat of course. Now the customer can only use that bolt with that nut. This is “inspecting” quality into the product.
The alternative is to tighten the tolerances on both the bolts and nuts. Thus both will vary, but the variation in either is such that any bolt will work with any nut. This is the desired outcome.
Thus manufacturing is all about error propagation. If you add up all the errors in making a car engine will the parts fit together and still make a working engine?
Weight sorting (and the Harry roll ect) are both sorting for “normal” variation as well as sorting out “abnormal” pellets. Imagine throwing 6 CPL pellets into a tin of CPH. The 6 CPLs are not within the “normal” variation and are thus outliers. Get rid of ’em.
Now for the “normal” variation. I can’t shoot one hole groups at 10 yards much less 25. So an acceptable weight variation will be greater for me than the folks who can shoot one hole groups at 25 yards. I did a quick back of the envelope calculation based on Wayne’s data. +/- 0.075 grains for a range of 0.15 grains seemed about right.
/blog/2010/05/mass-production/#comment-1730
The other thing that was fascinating to me was to look at the error in ranging the distance. With the pellet’s flight at a steep downward angle the distance estimation has to be very very good. +/- 0.5 yards at 50 yards.
The overall net result is that there are a lot of factors that go into shooting error. Ultimately if they are all about the same size, then eliminating any one does you no good. The overall error stays about the same.
Herb
Brian,
Great article. Thanks.
kevin
Brian,
nicely explained! good reading for the morning’s first cup.
Brian,
Nice write up. I use my scale to determine the consistency of pellet brand \ types, but don’t actually weight individual ones for shooting. The worst ever, .25 caliber Milbro Rhino’s. The advertised weight on the tin is 19 gr. They actually run 17.1 to 18.4 grains. This means not only would the energy calculation be way off, at any distance the accuracy will be terrible shot to shot. So they become a pellet I no longer buy.
On the other hand, .22 caliber Heavy JSB’s all go 18.0 or 18.1 when I weigh a few so they are keepers, then I just need to determine if individual rifles will shoot them well.
PA,
My article today includes pellet weighing and seemingly pertinent information to this post, so I will add a link to it. If it is deemed irrelevant to the topic, please feel free to delete it. Thanks. http://namericanairguns.blogspot.com/
This tolerance range is about what I expect. I suppose that increased precision goes with higher cost. However, there are two notable counterexamples. The first is, I think, a B.B. comment that JSB has somehow managed to manufacture its pellets to an extremely high tolerance (as found through inspection) without a corresponding increase in price. The results are also proved in shooting my B30.
Second, is the brilliant Savage technique of headspacing their actions. I expect that most manufacturers, fabricate their parts according to a template. For Savage, the procedure involves something like inserting a dummy round, and then screwing the barrel down on to it for an exact fit for the specific action. It’s custom-level precision on a mass-produced basis. Brilliant. That’s how they get custom accuracy out of budget rifles. So, this isn’t exactly pellet production but it is related to manufacturing tolerances. No doubt there are still some good ideas somewhere in manufacturing that can make a difference.
PeteZ, I finally figured out the stock adjustments with the aid of an Allen wrench that I overlooked. For some reason, length of pull does make a big difference for me. But I also enjoyed rotating the cheekpiece into place and sliding the buttplate up and down. Edith, you should get one of these! You can fit your rifle perfectly to yourself. Another reason I got this rifle is to have a custom job (by way of adjustment), a rifle fitted exactly for me and like no other in the world. 🙂
rikib, the gunstore in question is not Bud’s. I thought BG_Farmer gave them a good report. BG_Farmer, it looks like gun purchasing is unavoidably an adventure. I’m just glad I survived this one with my equipment intact. But that gunsmith does deserve to be reamed out by somebody.
Weatherby does similar with their actions and they also bed the barrels or precision float them and 100% inspect the stocks for visual and structural and, and, and!
I think Savage was smarter than most when they began to off-shore their production. They also sent their very best machinery, QC and mfg experts to manage the process. I have several Savage shotguns and they are great weapons, both cosmetically and as practical shooters.
It mostly comes down to top management philosophy in mfg. go offshore and run by remote control and suffer the quality? or… go offshore, save cost but use hands on QC and insure the product and company integrity!? I think Savage got it right.
Brian in Idaho
Brian in Idaho
Where is offshore for Savage?
Matt61,
My length-of-pull doesn’t seem to be too sensitive to changes of less than 5mm or so, plus or minus. But the trigger position is sensitive at the +/- 1mm level. This isn’t too surprising, as there are ways the LOP can be compensated in the hold, but the distance from grip to trigger is crucial. I’m still trying to fiddle the last millimeter out of the cheekpiece.
Fun!
my pellet testing procedure.
1. buy pellets.
2. shoot pellets
3. measure groups
4. buy more pellets
5. shoot pellets
6. measure groups
7. buy more pellets
8. shoot pellets
9. measure groups
10. buy pellets.
11. shoot pellets
12. measure groups
13. buy pellets.
14. shoot pellets
15. measure groups
repeat as often as you can.
You left out “chrony pellets”……
/Dave
I like ajvenom’s testing method best of all.
To All; thanks for the comments on my short article.
To Herb; Good points,and I could have written 10 more pages on those subjects! Bottom line, the average shooter (including me) has more influence on his shooting variation than all of the tolerances and variation in the ammo and the gun stacked together! We can still argue that it’s a noble cause to reduce all the other variation as much as possible but, at some point the return is dimiinished or overwhelmed by the shooters capability (or variation, aka shaky shooter syndrome).
Other things to consider regarding variation and tolerances;
1) The pellet lead alloy weight per unit of measure? Wonder what the weight tolerance is in the actual alloy recipe?
2) “Zero Defects” a concept that has evolved into “No Escapes”. Zero defects is a noble goal but… very near impossible. No escapes means no defects that GO to the customer. This is more of a QC issue that assumes some methods of gauging or inspection that is repeatable and consistent to keep any out of tolerance product from getting to the customer. Of course, this could mean a pile of defects for the mfgr. but, at least the product is not sent to the customer. However, keep in mind that Toyota is (was?) the gold-standard of Zero Defects mfg. and we all know what the gas pedals have been like in Camrys?
And on and on and on.
See ya on the range!
Brian in Idaho
Brian,
I’m sure you could have written 10 more pages… an entire book even! That would be the over-detailed “Dad answer”.
The overall point was that all of the error sources add up. The back of the envelope calculations that I did based on Wayne’s data should give Wayne a good idea as to how closely he needs to weight his pellets. Of course if he shrinks his group size then he might need to weigh more closely.
In the beginning of adjusting a process there is typically one error source that controls the overall error. But as you tweak the process multiple error sources start the control the overall error. At that point eliminating just one of the error sources does you no good. You have to improve all of them simultaneously.
Again, pellets which are really “off” of the nominal are apt to be aerodynamically weird as well. they could go anywhere.
Differences due to the alloy should be insignificant. Crosman pellets have a very small amount of antimony. Not enough to change the density of alloy from that of pure lead significantly. Also assuming that all the pellets in a tin were of the same alloy, the effect cancels. But if one machine has one alloy and another a very very different alloy, then mixing the pellets would be bad news of course. (I looked for a few minutes and couldn’t find densities of lead alloys on the web.)
Herb
Herb, man… I love this stuff! Process control, fool-proofing, error reduction, it’s all good stuff.
Chuck; Yes, you would think that (at least) H&N would have the good old European/German mfg. skills at play but… anymore, I’m not sure that some of these products just have German labels on packages of Chinese mfg? As for Beeman, I think the current ownership is far less precision oriented given the “Marksman” heritage of the company?
Herb, the density of lead (99.7% pure) is 11.34 grams per cubic centimeter (gpc). As a comparison, Iron is about 7.5 gpc. Antimony 6.74 gpc and Tin is at 7.31. Assuming that some small fraction of the total lead alloy is either of these, the alloy to alloy variation would be negligible in a .177 pellet. My quick calc tells me that it would have a nearly un-measurable influence on weight variation, at least 4 decimals to the right and not weigh-able on any scale I know of, more like mass-spectrometer type measurement.
Hi everyone,
Sorry, I am a bit off topic here.
First, I’d like to thank everyone for giving me advises and information about the Bronco. I’ve finally got one and tested it out with some 200 shots. And I’d like to share some of my personal observations (and have some more questions too). Please note that I am new to airguns and this is my first spinger. I’ve only experienced with Crosman 1077 and a couple of pistols, Crosman 1377 and 357.
1-The best thing first, the trigger, wow, I’ve really enjoyed the trigger, given my experience with the 1077’s. The tag attached to the gun says, 1 lbs 17 oz.
2-The metal finish is nice.
3-The stock is only fair, less than I expected. See more explanation below.
4-It is quite muzzle heavy, probably due to the long muzzlebrake. Is it removable?
5-The overall weight is just above 6 lbs on my scale.
6-The noise level is a bit louder than I’d like. Hopefully, it would quiet down a bit more with more use.
7-There is a little kick when fire. Somehow, I like this little recoil as a good feedback.
8-Cocking is easy.
9-It is very addictive. I just wouldn’t want to stop.
10-Accuracy is my top priority and so far, I am really happy with it. Given that I am still learning “artillery hold” from BB’s video from youtube, I’ve been able to stack pellets with open sight at 10m. I can see this clearly with my homemade silent pellet trap (similar to BB’s). I’ve done 10 10-shot groups at 10m (open sight) with each group with different pellets (Beeman Coated HP/WC, H&N Baracuda Power (copper coated),H&N Baracuda 10.65gr, Crosman lead-free WC 4.0gr, Beeman FTS Dould Gold, Skenco Blue Arrow 6.4gr, RWS Superdome, JSB Exact 8.4gr. It seems to like most of these pellets even the cheap ones like, the Beeman Coated HP/WC, and light weight ones like, the Crosman lead-free WC 4.0gr. It does not like the Skenco Blue Arrow 6.4gr. But the best group of all was from JSB 8.4gr. One single hole with the diameter a little more than two N0.2 pencil’s erasers.
So overall, I am really happy with the Bronco. Sorry for this long post, but I have some questions here.
I’ve mentioned the stock being only fair. But I’ve looked more closely and noticed that it is not even. The two side screws that hold down the gun to the stock in the front, one of them is deep in the hole and one of them is sticking out, and cannot be screwed in any further. Then, with an even closer look under the stock, I’ve also noticed that the cocking mechanism (not sure what to call it, but it is the moving part when cocking) is on one side of the inner stock. So when cocking the gun, that moving part is really touching on that inner side the stock and creating some additional resistance too. After about 200 shots, I can see a deep carving mark. So, I am not sure if this is normal? Or should I be concerned about this in the long run? Please help.
Thanks.
tdung,
After reading your Bronco comment I looked at mine closer to look for similar discrepancies. Looking at the rifle from the bottom, with the barrel pointing out in front of me, I do see the right screw is in slightly deeper than the left and that the cocking mechanism is closer to the right side of the stock. It doesn’t touch on mine, however, so I don’t get any rubbing, but it is pretty close. It sounds like yours may be somewhat out of tolerance and maybe got tightened too much on the one side or not enough on the other since you say the screw is sticking out. Is the deeper screw on the side that is rubbing?
I agree with Mr B that you ought to at least call PA and tell them what you have. Maybe you can suggest to them that you can send them a photo of the linkage and screws in an email.
Chuck,
Yes, the deeper screw is on the side that is rubbing.
One of the front sight screws is missing on mine too. I’ll give PA a call. I’ve just got it last Friday.
Also, by looking from the bottom, I can see the main string too. I thought the spring wouldn’t be visible and would be contained within a tube, the compression chamber? I don’t anything about this, I am curious here.
Thanks Chuck and Mr B.
Sorry, I meant “main spring”.
tdung,
If I look under the cocking mechanism I can see the main spring on mine, too, but just a little of it. It looks like it’s contained in a tube that is slotted and I can only see the spring through the slot. The cocking mechanism looks like it runs in this slot also and forces the spring back towards the butt of the rifle during cocking.
-Chuck
tdung…
Check the two tabs or areas on the mechanism that mate with those two stock screws. If they are tabs, they may be bent? If they are female threads in the main tube or breech area, then ther may be a bad therad that is not allowing the one screw to fully seat or… the hole may not be fully tapped/threaded?
There should not be mis-alignment of that degree in your gun. Let Pyramyd know about this right away and… I’m sure BB would agree that it sounds like you should get a replacement rifle from Pyramyd. There customer service is very helpful, I know, I have had to return items and all they need is some good detail of the problem and they will help you.
I completely agree with Brian of Idaho fame 😉
I highly doubt that in most instances, no one but the top shooters is really going to be affected by minor tolerance differences.
I run into the same thing in my profession (photography). I always have people asking if they should buy the top dollar pro camera (part of what you’re paing for is better manufacturing) so they can get better family/vacation snaps.
I suggest to most of them to use what they got and spend some money on a good evening photography course at their local community college.
That will do far more to improve their pictures.
HOLY TOLERANCE MISSILE MAN!!
Brian,
Excellent article and very well written. Very informative, putting our OCD passions in perspective. I think H&N and Beeman need to read this so they understand the definition of nominal and tolerance in regards to Kodiacs and Baracudas.
Thanks for your time well spent.
-Chuck
tdung,
If that was my Bronco, purchased within the last 30 days from PA, I’d be on the horn explaining your stock issues. I’d be looking for an exchange for a new one. Sounds like a quality control problem..
You’re right about the 1077. It’s a great teacher of trigger control. Nice group with the Bronco.
Mr B.
I need a very accurate springer or pump pistol in .22 for rodent control at distances less than 25 feet. Accuracy is a little more important than power. Can anyone suggest what some good choices might be. Crossman poducts are prefered, but i’m open to other manufactures as well.
Thanks,
Mike D.
My most accurate rifle is the Air Venturi Avenger 1100 in .22. I also have a Mendoza RM-600 in .22 and it is accurate as well. With minor differences, they are both the same gun but the Avenger 1100 is about $3 less expensive and has a fancier stock.
–Witt
Mike D,
If you can live with a .177 you cann’t go wrong with a 1377 from Crosman for small rodents.
You’ll have to give us some guidence on your budget. Cause you can spend 60 to over 500 dollars. Also, how big are these rodents? Are we talking mouse, squirel, woodchuck, nutra??
Mr B.
I want to spend less than $200 and the rodents are squirels
Mr. B,
I just looked up nutra, having never heard on it. Dang. That’s one big rodent.
– Orin
Also I prefer .22 over .177 for hunting
also considering RWS and Beeman and weirauch products
Mike D.
Do you live in a warm climate? If so I would go to the custom shop on the Crosman website and build a .22 CO2 pistol with the 14.6″ barrel. If you live in a cooler climate the CO2 won’t have the velocity for hunting.
Alternatively, if you are moderately good with tools, you could buy a Crosman 1377 and convert it to .22 caliber. You would need to order the following from Crosman:
.22 caliber bolt part # 1322-063
18″ barrel part # 2400-102 or
14.6″ barrel part # 2289-001
Barrel band part # 788B011
Barrel band set screw part # 781A012
Front sight part # 760-201
I would also order the steel breech if you plan to use a scope or red dot sight on your pistol. You could set up either the CO2 or the home-customized 1377 for less than $200 dollars.
The 1377 project may sound intimidating, but it is very straightforward, and you could get plenty of help on this blog.
Keep in touch.
Slinging Lead,
Orin has a question for you over by Funkytown on the TX200.
A question to all airgun nerds/wiseheads!
How precise and reliable is the gamo SOCOM carbine? I would use it for hunting pests. I would need a precision of 1″ at, say, 25-30 yards? And what is the most precise pellet for use with the SOCOM? Scope? any mil-dot, reliable springer scopes?
Jozef
Given Gamo’s penchant for repackaging the same basic rifle in different stocks, I think it’s fair to say that the SOCOM is gonna comparable to other similarly rated Gamo’s – Varmint Hunter, Whisper, Shadow Sport, Hunter Sport, Big Cat, etc. So I would suggest that Tom’s results with the Big Cat:
/blog/2009/3/gamo-big-cat-part-4/
…are probably indicative of what the SOCOM would do.
Jozef,
I can’t help you on the accuracy of this rifle and I see on Pyramydair’s website that no one has reviewed it yet. As for pellets, typically, domed pellets such as JSB Exacts, RWS Superdomes and even Super H points (for me) and Crosman Premiers Magnums have been found to work pretty well but here’s the thing – each rifle will like a different pellet due to, yes, manufacturing tolerances. Buy a couple of tins of pellets and see how tight a group each pellet shoots at maybe 20 or 30 meters. As for scopes, everyone on this blog has had excellent experience with the Leaper’s brand of scopes. Typically look for 3 x 9 x 40mm with adjustable objective lens so you can dial out the parallax error.
Fred PRoNJ