Part 4 by Tom Gaylord from Pyramyd Air” /> Part 4, airguns report post” />

Thursday, September 04, 2008

Pro-Guide spring retainer system for RWS Diana rifles
Part 4

by B.B. Pelletier

Part 1
Part 2
Part 3

Today, I tested the Air Venturi Pro-Guide spring retainer in the .22 caliber RWS Diana 48 using a washer spacer to increase velocity. However, as sometimes happens, fate stepped in and changed the test. I had been testing with .22-caliber Crosman Premiers, and you may remember that I mentioned the gun was still more variable than I would like. Well, that turned out to be the pellet fitting too loosely in the breech, so I was unable to continue the test with Premiers.

That being the case, I installed the factory mainspring and spring guide and tested it with a pellet that fits the bore tight enough for credibility. It turned out to be the Gamo Hunter, a 15.3-grain domed pellet.

The washer
As long as I was inside the gun, I decided to add the washer to the factory spring, as well, so we would have a good comparison between both systems. It turns out that we need a 5/16" plain steel washer for the Diana piston rod. The hole in the washer has to be enlarged a few thousandths, which a Dremel tool can do in about five minutes. One washer is 0.079" thick; since I was advised that there might only be 0.10" remaining clearance in the mainspring, I went with just one. I smeared it with lithium grease on both sides and dropped it over the piston rod, then installed the mainspring and guide in the normal fashion.


Plain 5/16" steel washers worked fine for spring spacers, once the hole was slightly enlarged.


Factory spring test
I had forgotten about the vibration of the factory mainspring. It isn't bad, but you do notice it after having used the Pro-Guide system. The velocity range for the 15.3-grain Hunter was 774 to 801 f.p.s., with an average of 791 f.p.s. That works out to 21.26 foot-pounds of muzzle energy, which is right where an RWS Diana 48 belongs.

I removed the factory spring and guide and replaced them with the Pro-Guide system. The washer was still in place, so testing began immediately.

Pro-Guide test
The vibration was gone again with the Pro-Guide. I have to say that it's a nice feeling in a gun this powerful. The cocking effort does feel a pound or two heavier, but not that bad, because the sidelever linkage offers so much advantage.

With the Pro-Guide, the velocity ranged from 792 to 800 f.p.s., with an average of 796. That computes to 21.53 foot-pounds of muzzle energy. Not much more than factory; just like we saw in the original test with Premiers and no washer.

I've had this rifle apart so many times that it's getting to be as easy as stripping a Weihrauch. The T05 trigger deserves the credit for that, but don't forget to pull the trigger before you assemble the rifle and make sure that the safety doesn't slip into lockup as the trigger unit goes in. That happened to me and required another strip-down to correct.

The next step is to install the Pro-Guide in the .177 RWS Diana 34 Panther to see what it does.

34 Comments:

At September 04, 2008 8:00 AM, Anonymous Anonymous said...

B.B.,

Why is it that the same Pro-Guide spring is used in guns of different power? I would think that, since an RWS48 is a more powerful gun than the RWS34, they would require different springs. Are the factory springs different, or is the power difference because of something other than the power plant?

 
At September 04, 2008 8:34 AM, Blogger kevin said...

B.B.,

Very interesting that the velocity range tightened up with the new pro-guide spring. How many shots did you make to create the averages that were used? What is the primary benefit of this pro-guide spring? Eliminate vibration? Make the gun more user friendly, easier to group? The small increase in velocity is noted but narrowing the range of velocity seems more significant to me.

kevin

 
At September 04, 2008 9:45 AM, Blogger B.B. Pelletier said...

Different power,

Why is it that the same car engine block can produce either 135 horsepower or 500 horsepower - depending on how it is set up? It comes down to physics. The 48 has a powerplant better-suited to developing power than the 34.

To really answer this question, we need to take a look at the sliding compression chamber, which is honed inside. The 34 spring tube isn't honed, so there's part of the difference.

One reason that spring guns fascinate so many people is because if their subtle details like this.

Take the TX200, for instance. By making the air transfer port concentric with the axis of the bore, they scavenge the compression chamber much better and produce more power. The Diana 48 does the same thing with its sliding compression chamber - another reason it is more powerful with the same mainspring.

B.B.

 
At September 04, 2008 9:48 AM, Blogger B.B. Pelletier said...

Kevin,

I think the reduction of vibration is the Pro Guide's principal feature. People are paying over one-hundred dollars for custom tunes that do the same thing. Several of them even REDUCE the power of the gun, but the Pro Guide maintains it.

The Pro Guide also offers a drop-in tune for the average shooter who wants to do his own work.

B.B.

 
At September 04, 2008 9:49 AM, Blogger Il Bruce said...

Thread hijack warning.

So, I tried to order the Crosman pistol,as described by bike geek Derrick, and Crosman informed me that they cannot ship to the Ocean State. Argh. Crosman has not returned my call as to options. Ship to and CC info must match, so no shipping to my wife’s office in MA.

Will any retailers (preferably PA) custom order? I asked PA but have not gotten an answer yet.

I am a bit miffed.

 
At September 04, 2008 9:51 AM, Blogger B.B. Pelletier said...

Bruce,

I'm going to send you to a small repair shop that can probably help you.

http://www.bryanandac.com/

B.B.

 
At September 04, 2008 9:53 AM, Blogger Il Bruce said...

Many thanks, BB.

 
At September 04, 2008 11:54 AM, Anonymous Anonymous said...

B.B.

It turns out that my 1911 does have what I take to be a speed bump at the bottom of the grip safety. I guess it makes sense that anyone providing an extended thumb safety would also include everything necessary to shoot it. It still feels a little weird but I will give it a try.

Matt61

 
At September 04, 2008 12:53 PM, Anonymous Anonymous said...

Bike geek indeed. I'm an airgun microbrew bike geek. Just to clarify.

It's really a train wreck when your state doesn't allow you to purchase a simple pellet gun. So much for home of the free.

Derrick

 
At September 04, 2008 1:44 PM, Blogger B.B. Pelletier said...

Matt61,

Try this: hold your shooting handout like you were about to shake hands with it (that really only works for right hands, doesn't it?). Your thumb is pointed straight up. Now, move the grip of the gun into your palm, so the web between the thumb and first finger hits the grip safety at its lowest point.

Wrap your fingers around the grip and put the thumb up on the manual safety. The heel of your hand should be pressing in on the speed bump at this time.

Some people cannot use this grip. Their hands are sculpted to miss the speed bump. For them, Wayne Novak created the Answer - a replacement backstrap that has no grip safety.

B.B.

 
At September 04, 2008 1:51 PM, Anonymous Brian said...

The solution for the ship-to problem is to call the credit card-issuing bank and and ask them to record a second authorized address (your wife's work address in MA, assuming Crossman can ship there).

I'm in the mail-order business and since many merchants will only ship to authorized address, customers "authorize" their work addresses so they can receive boxes they don't want left on their doorsteps.

To emphasize, the banks will record a second authorized address, it doesn't need to replace the actuall billing address they send CC statments to.

Brian

 
At September 04, 2008 1:55 PM, Blogger Il Bruce said...

Derrick,

Micro brews too. I need to buy you a beer (three?).

The State will let me buy, Crosman won't. I have bought air guns from PA no problem. Friends in RI have bought from most of the other big e-tailers with no problems.

I bought a 2100 at Dick's in RI no questions asked. Not so in neighboring MA though. I tols them the CO2 was for my tyre-flater not an air gun and they sold it to me. Had to check with the manager. Bass Pro in MA will sell me pellets and gas but not air guns. I can’t even look at the firearms in MA. I have bought firearms in RI, I passed all the tests and checks.

There are weird RI rules (no slingshots) but the State is actually warming up to air gun hunting after years of prohibiting it.

Crosman cannot come up with WHY they will not sell just that they WON'T.

I dunno...

 
At September 04, 2008 2:29 PM, Anonymous Anonymous said...

B.B.

This all sounds good except that if I put the web of the hand at the lowest part of the grip safety, wouldn't that be right on top of the speed bump? How can that be? Should the web go on the highest part of the grip safety right where it swells out beneath the hammer?

I'm trying to liven things up by doing rapid shooting of multiple targets--not with the 1911 but with the Walther CPS. I know that you are supposed to keep the torso more or less rigid and swing like a turret to engage. So, the only other thing I can think of is the notion of target indexing. I understand this to mean that you look at the next target before you bring the gun to bear so that you can transition smoothly without jerking the gun around. However, I've also heard you're supposed to keep three eyes on the target--the two eyes and the gun--so I guess you're not supposed to move the eyes independently. I guess that leaves you with using the peripheral vision to pick up targets. Is that right?

Matt61

 
At September 04, 2008 2:36 PM, Blogger B.B. Pelletier said...

Matt,

I didn't explain that very well. What I meant by "Lowest" was the deepest, most scalloped-in point of the grip safety. Probably exactly where your hand wants to go anyway. It's right beneath the beavertail, which is where the grip safety swells out beneath the hammer.

As for engaging multiple targets, why don't I let some of our law enforcement readers answer that? I'm not much of a tactical shooter.

B.B.

 
At September 04, 2008 3:05 PM, Blogger Il Bruce said...

I used the alt shipment. No go. No option for alt ship. WIll not take alt address as bill to.

Still no call back from Crosman.

Ton of legalese before you can click "buy"

 
At September 04, 2008 3:17 PM, Anonymous Anonymous said...

B.B.

Actually, I think my own terminology needs work. The beavertail safety is not what I thought it meant. But I believe I understand you.

I just got off the phone from Dewey and was wondering if I could have your opinion on the value of nylon versus stainless steel cleaning rods. I'm having one of those moments of total contradiction. Clint Fowler tells me to get a stainless steel cleaning rod because softer materials like nylon embed particles which can mar the bore. The Dewey person tells me that steel will ruin ("peen"?) rifling and that the U.S. national teams have used nylon for the last 30 years. It's like in martial arts where Master Pang says that there is only one way to do things and Master Po says that the Pang way is utterly wrong and disastrous, and they are both completely credible.

Matt61

 
At September 04, 2008 3:27 PM, Blogger B.B. Pelletier said...

I side with Fowler on the cleaning rod. So does Dr. Beeman. A polished steel rod is believed by many to be the best cleaning rod.

However, for as little barrel as a 1911 has, you could almost use a tongue depressor.

B.B.

 
At September 04, 2008 4:03 PM, Anonymous Anonymous said...

Matt61,

That's weird, I just put the whole mess into the dishwasher. derrick

 
At September 04, 2008 4:14 PM, Blogger scott said...

The rod material doesnt matter much if you invest in a quality (true) bore guide where the guide does not allow ANY play of the cleaning rod. A good example is the bore guides made by Lucas. Do a google search for "Lucas bore guide" and you should find his website. Tolerances so tight that a bore brush has a hard time passing through, which is why you just use a wrap around jag with it and thats it. No bronze brushes, just something like Wipeout or boretech Eliminator. The above mainly pertains to rifle barrels and is a very personal opinion of mine so do what you feel is sufficient. As for my pistol barrels I just scrub/jag then oil it and put it away.

Now back on topic, I get my Venturi spring soon along with my new Evanix AR6 and a chrono.... so I cant wait. Thanks again for doing this write up B.B.

Scott

 
At September 04, 2008 4:17 PM, Blogger scott said...

To add to my above comment.... I wasnt referring to air rifles but regular firearms regarding the rod material/ bore guide/ practices.

Scott

 
At September 04, 2008 5:45 PM, Anonymous Anonymous said...

BB

I just got an Airhog Condor chassis extender. I don't have a Condor but I only paid $120 shipped for it. I put it on a Talon(18inch barrel) .22 and it groups 5 shots just inside 4inches at 50yards. I took it off and shot a quick group of 8 and got 1 3/16inch group. Any ideas to whats going on? Do they make one for .177 only and not .22 and thats what I have?

jeff

 
At September 04, 2008 6:19 PM, Anonymous Anonymous said...

Thanks to all for the cleaning rod comments. Steel it will be along with a bore guide (made out of Delrin). Actually, the stainless rod was for the Garand. For the 1911, I'll go with brass to get some use out of the so-called universal cleaning kit from Winchester that I bought.

Matt61

 
At September 04, 2008 8:47 PM, Anonymous BG_Farmer said...

BB,

I thought only Chinese junk had oversized breeches:)...can't imagine a German product with a sloppy tolerance! I still wonder why it isn't easier to get pellets in different diameters, such as JSB makes.

Matt,

More important than the rod material: don't clean it unless it needs it...you can take several thousand rounds off the life of a barrel with over-zealous cleaning.

 
At September 04, 2008 10:14 PM, Anonymous Anonymous said...

Il bruce,

Makes you want to bang your head against the wall. Maybe Ron Sauls can help.


Derrick

 
At September 05, 2008 2:59 AM, Anonymous Anonymous said...

BG_Farmer,

Thanks, I'll need to restrain this fondness I'm developing for shiny bores which is about as close as I get to tinkering.

Matt61

 
At September 05, 2008 5:52 AM, Blogger B.B. Pelletier said...

Jeff,

Your pellet is touching somewhere inside the device. This is common with European silencers - I've seen a lot of Daystates that did it..

You have to find out where it is touching (a gray mark) and relieve that spot.

The Talon frame is shorter than the Talon SS and Condor frames and I wouldn't have thought it would work with a Condor tube.

B.B.

 
At September 05, 2008 6:02 AM, Blogger B.B. Pelletier said...

BG_Farmer,

Sloppy tolerance? What are you saying? That a sports car gets great gas milage because it's small? What about a Dodge Viper?

The Diana barrel is just not suited to Premier pellets. It's not sloppy.

B.B.

 
At September 05, 2008 7:09 AM, Blogger Il Bruce said...

Derrick,

I have emailed the Sauls clan and am awaiting an answer. I have called them in the past adn teh woman who helped me was VERY nice and they were prompt. I am guessing that they are busy. (I hope busy making money and not buttoning up for the storm).

I may have my father in law in MA buy it. His zip is OK and they live only about 20 minutes away.

I spoke with Crosman's legal dept. yesterday (I am a pest) and she said she's look into what makes RI an exception. You would think anti gun Massachusetts would be a bigger issue...

I am picking up my Ruger Mk II this weekend. That ought to keep me busy.

 
At September 05, 2008 8:58 PM, Anonymous Anonymous said...

This is off-topic, but I hope someone can answer the following:

I have read that it is possible to install a Williams peep sight on a Sheridan/Benjamin Blue/Silver streak pellet rifle. I have some questions.

Since I might want to reinstall the original rear sight later, how is it removed without damaging either it or the rifle?

How is the Williams sight mounted on the rifle? [I notice that there are two holes drilled into a flat area of the receiver just behind the bolt].

Thanks,
--Witt

 
At September 06, 2008 6:45 AM, Blogger B.B. Pelletier said...

Witt,

Those two holes are drilled and tapped for mounting the Williams peep sight.

The rear sight on the rifle is clamped on and must be pried up and off. That will always damage the finish to some extent - no way around it. That's why most folks try to operate the peep sight with the rear open sight left in place. They run it down as low as it will go and sight over it.

B.B.

 
At September 12, 2008 5:45 AM, Anonymous Anonymous said...

I am not shure but after looking around on the Pyramyd air website Air Venturi stuff is Chinese made parts and I would not think of installing Chinese made parts in a German airgun regardless, the stock guns have usually a smooth firing behavior as is and Diana airguns are approaching the poor level of quality themselves of Chinese made products as time goes on here. Would like to see older more durable guns like the FWB 124 and others rather than these self imploding guns with high velocity ratings. Another thing is that ounce a German made airgun is out of production parts usually are as well, so vintage German guns are not the answer either.

 
At September 12, 2008 6:27 AM, Blogger B.B. Pelletier said...

I take it you are new to airgunning. Some of your ideas are mistaken. For starters, Diana guns have never been better that right now! Their parts are so much better than Chinese parts - except for BAM guns that are very close. While there are a few things that go wanting, like spring guides, for the most part, a Diana spring gun is a very well-built airgun.

Second, parts are still available for obsolete German airguns. Have you checked with John Groenewold? He supplies parts for German guns that became obsolete 50 years ago.

John Groenewold, PO Box 830, Mundelein, IL 60060-0830, (847) 566-2365
http://www.jgairguns.biz

The 124 was a fine air rifle, but the Diana 34 series is very close, in terms of quality. It is just as accurate, has a better trigger and the mainspring lasts longer. The finish isn't as good, but the price is less than half what a 124 was selling for 10 years ago.

The reason the 124 is so beloved is because it cocks so easily and the barrel detent is a ball bearing - but so is the RWS Diana 34 series rifle.

B.B.

 
At September 18, 2008 10:45 AM, Blogger waynew said...

BB,
I just got my spring guide today and am going to put it in my RWS 54. Should I put some velocity tar on the main spring, or will this be redundant?

Wayne

 
At September 18, 2008 11:22 AM, Blogger B.B. Pelletier said...

Wayne,

Did the rifle vibrate before? If so, just a light coat on the outside of the spring.

Or are you referring to the new Pro Guide? Because that doesn't vibrate. No tar required.

B.B.

 

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