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KJW 10/22 GBB


Crazybob79

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Modding a real stock to it proved to be much more of a hassle then I'd expected. Well, had to dremmel out a tab in the back of the receiver, then add a bolt hole there. The receiver on the 10/22 was longer than on the stock, so I had to dremmel the front grooved part of the stock another 1/3 inch or so forward. Enlarged the part where the barrel has to sit, as this has a bull barrel and the real one does not. Cut a loooot out where the barrel band sits and trimmed down the barrel band in order for it to actually fit the 10/22's barrel. Ended up being able to do this in about a day with results that I was satisfied with.

 

It appears that you didn't have remove too much material to weaken the stock...or does it? Is the stock you modified walnut?

 

Thanks again for the update.

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I have one on the way from Redwolf (never thought I'd buy a GBBR of all things, but a $250 red gas capable 10/22 proved impossible to resist); in the mean time, can any of the owners elaborate on the takedown procedure to get to the bolt, hop-up and inner barrel? Also, what type of inner barrel and hop rubber are compatible? Thanks!

 

Andyjp's real stock conversion looks fantastic, but personally I prefer the ergonomics of a pistol grip and folding/collapsing stock. The wood rifle stock is far better looking, though.

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I would just wait, as RA Tech is making a full sized barrel.  

 

 

 

 

As for the barrel type, like Horseman said, it's similar to VSR barrels, but is definitely off.  This thread should help with takedown, barrel type, etc. : http://www.arms-cool.net/forum/thread-77695-1-3.html  

 

I'd say the stock rubber will be fine.  Definitely is working great so far.  Couldn't hurt replacing the barrel, as it is true that it only goes about halfway down.  

 

 

 

 

With the structural integrity of the stock, it's still quite solid.  I don't know if it's made out of Walnut, but I'm kind of doubting it.  It's just a factory Ruger 10/22 stock as you'd find on stock Ruger 10/22's.  It definitely isn't weak, just rather a pain to do.  I'll try to get some pics taken here at some point.  

 

 

 

 

Lastly, I have yet to put a silencer on it, as the adaptor seems to be pretty hardcore glued on.  Heating it didn't seem to phase it and I didn't want to break anything, so I left it on.  

 

 

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Got it today. The quality is very nice, all the rails are polymer though, including the top ones. Not necessarily a bad thing.

 

10 shots of .20s on "yellow" gas @ room temp gave the following readings (FPS):

 

447

458

440

444

447

430

458

447

457

411

 

Not the most consistent output, but the power is nice nonetheless. I'll try and clean the barrel and hop-up tomorrow, then do some actual long range accuracy testing.

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After cleaning the barrel and hop rubber, the power output has the same inconsistency, but now 50 FPS lower. What the *fruitcage*. :blink:

 

I did remove a LOT of dirt from the inner barrel, perhaps so much that it enlargened the ID by several .0Xmm?

 

The range test went well though, it shoots very straight over longer distances.

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After cleaning the barrel and hop rubber, the power output has the same inconsistency, but now 50 FPS lower. What the *fruitcage*. :blink:

 

I did remove a LOT of dirt from the inner barrel, perhaps so much that it enlargened the ID by several .0Xmm?

 

The range test went well though, it shoots very straight over longer distances.

 

Do you have another magazine you can test? There's a slight chance that a bad magazine valve or gas routing rubber is causing unusual fluctuations in power (the rubber might be making poor contact with the nozzle/cylinder so a consistent amount of gas is not being fed down the barrel). That range of power fluctuations wouldn't bother me all that much - except for that 411; maybe the result of cool down.

 

Regarding the sudden power drop after cleaning - I assume all the other environmental conditions are identical and your chrono isn't messed up (test it with another gun). Possibly a damaged chamber packing - check if the hop is still effective (fire it at the lowest setting and then the highest setting; see if there is a noticeable difference). Although unlikely, too much silicone oil on the rubber might causes problems. Fire 40 to 50 shots and see if the power normalizes.

 

Without inspecting it in person, it could be one of many different things; hopefully nothing serious.

 

Good luck.

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So, I modified an old PDI ~550mm VSR barrel to fit, resulting in pretty consistent mid 300s FPS output what??? :o

 

I tried another magazine, same story. I have two chronos, an Xcortech x3200 and a Chrony master beta, they show identical readings.

 

Hop rubber looks pristine, but no difference between chrono readings on highest and lowest settings respectively.

 

Derp?

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So, I modified an old PDI ~550mm VSR barrel to fit, resulting in pretty consistent mid 300s FPS output what??? :o

 

I tried another magazine, same story. I have two chronos, an Xcortech x3200 and a Chrony master beta, they show identical readings.

 

Hop rubber looks pristine, but no difference between chrono readings on highest and lowest settings respectively.

 

Derp?

 

I would suggest keeping it stock until you find out what is wrong with it. You've ruled out the magazine so that's a start.

 

Hop rubbers are sometimes very fragile and there are instances where you won't be able to see the damage. One of the most common ways to damage the packing is by inserting the cleaning rod down the barrel with the hop on. You should always turn it off and using something non-abrasive (NEVER use tissue paper). You should also use some silicone oil and clear it with 40 or 50 shots - that usually helps normalize it and clean out all the excess oil.

 

Not the chrono reading, but the trajectory of the bb: is it hitting the target high with it on max and lower when off? If there is no effect, I would think the rubber is damaged (if you can, test it indoors so the wind won't carry the BB off its mark).

 

Another possibility is the cylinder and its valve is dirty or damaged. There's not that many attributes that effect power output like that (since it's a Koba design, I assume its a negative pressure system - if it's positive, there could be a host of other problems). It would be great if another owner can chrono it using the similar environmental condition and source to see if it's a systemic problem (e.g. poor internal design). The tolerances of the parts that direct the gas from the magazine down to the barrel need to be pretty tight - hopefully it's something a through cleaning would fix. It might even be something simple as crappy bb's (low quality BB's in a tight bore is not a good idea - I also like to use .25's for gas blowbacks)!

 

Hope this helps - good luck.

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Thanks for the input!

 

Did the ol' teflon tape mod on the hop rubber, then tested again, same conditions as before:

 

with .20g Golden Ball (or BBKings, not sure, one of those two)

445

420

422

423

417

430

445

435

436

435

Avg: 430.8 FPS, 1.71J

 

 

then with Super King .25g bios:

369

376

390

400

398

370

385

404

406

396

AVG: 389,4 FPS, 1.75J

 

Seems the gun had gas leaks around the hop rubber before.

 

With the 550mm barrel, though, .25g BBs are overhopped even with the hop-up turned off. The cause may be too much teflon tape wrapped around the hop rubber. Will try to correct and test again tonight.

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Right, turns out that the hop cutout in the VSR barrel is larger than the 10/22 one, causing a bigger part of the "bulge" of the hop rubber to protrude into the barrel, causing more hop even at zero hop than the 10/22 barrel does.

 

So, reinstalled the stock barrel, teflon taped the hop-up, then tested (.20g):

427

412

421

419

422

410

411

430

431

426

AVG: 420.9 FPS, 1.64J

 

Still not the very best of consistencies, but it's better than it was out of the box, so I'm happy.

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Still not the very best of consistencies, but it's better than it was out of the box, so I'm happy.

 

It's not the best, but it's not so bad that it would prevent me from purchasing one. About how many rounds have you put through it? Sometimes brand new gas guns have a substantial amount of silicone lubricant INSIDE the nozzle/cylinder and around the floating valve (I see this more with gas guns manufactured in Japan) - it will gradually clear out as you fire more shots and might improve the consistency of the power output.

 

Thanks for posting all the data (definitely much more useful than your average "it's flawless and shoots awesome at 400fps").

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Thanks for all the infos !

 

So there is only the ratech inner barrel that fits in directly :/

 

I'm waiting for the sniper custom and will be using it as a super simple and accurate marksman rifle XD

I don't care the mag look toyish.

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  • 3 weeks later...

Sorry to revive a now somewhat dated thread.

 

Figured I'd put in some info on my 10/22...

 

 

 

 

First, by now I've put about 2k rounds through the gun with no noticeable signs of wear, strain, or other problems. The bolt catch problem (where it would lock back with rounds still in the mag) has gone away by now. It might have just needed breaking in a bit, as I've only had it happen once in the past 500 rounds or so.

 

 

 

 

Next, I purchased a RATech 6.01 full length barrel for it. Drop in fit and was quite easy to install. Definitely ups the range and accuracy and is well worth the money. Until a NPAS is released for it though, I may have to go back to the old barrel. The two shots I chronoed registered 355 and 357 --with Madbull .4's on Propane, equating out to around 505fps with .2's.

 

 

Switching over to duster I'm getting 300-320 fps with .2's. Not really certain why I'm getting a 200fps drop on this, if anyone has any advice on the issue, please let me know.

 

 

 

 

Hope this helps any potential buyers of RATech's barrel. Quite nice, but runs well over field limits.

 

 

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Sadly, the only chrono I have is a paintball chrono. Goes up to 400fps...

 

What I ended up doing was changing out the o-ring on the nozzle. Took the gun completely apart, removed the nozzle, and replaced the skinny little o-ring with a big fat o-ring. Dropped it down to the equivalent of 417fps with .2's. Seemed to help consistency a bit as well. I'll see how it holds up and keep everyone informed!

 

-Andy

 

 

 

 

 

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