Bolt spring change for Cci quiets

[68sixspeed]

Has anyone tried or found a softer bolt spring to let the 15-22 cycle on Cci quiets? I have a bunch of them, they are cheap ($30/brick) and they are a lot quieter even with a sparrow vs std velocity. Plus I'd like to save my std velocity for handguns.

I managed to do it with 19 out of 20 cycling on a 10-22, so I figure it might be possible... Thx

 

[Majorlk]

Even with a lighter spring, the possibility of the bolt cycling is doubtful, due to the mass of the bolt itself.

If my memory is correct, CCI specifically says Quiet is for bolt, lever and single shot actions. Even with .22 Short slide on my High Standard Trophy SupraMatic, it won't cycle the action.

 

[little_airwolf]

Couldnt you just shoot it like a bolt action?

 

[68sixspeed]

Couldnt you just shoot it like a bolt action?

Yes, that does work but isn't as fun.

I think it can be done, as the bolt assembly in a 10/22 is surprisingly heavy, I'm going to pull both down this week and weigh the bolts, do the math on the springs, preload, etc and I'll post the findings. Maybe even I can get lucky and find a few springs to try once I know the rate of the stock and the one in the 10/22 and the bolt weights.

 

[cosmose]

I think it can be done, as the bolt assembly in a 10/22 is surprisingly heavy, I'm going to pull both down this week and weigh the bolts, do the math on the springs, preload, etc and I'll post the findings. Maybe even I can get lucky and find a few springs to try once I know the rate of the stock and the one in the 10/22 and the bolt weights.

keep us updated! I had the same idea but didn't where to start. mine will almost feed them, sometimes evening chambering them but not cocking the bolt.

 

[little_airwolf]

Iirc the pistol bolt it lighter. Maybe try that with a lighter spring?

 

[Smitty357]

I have an old winchester model 190 semi auto. Only rifle I've found yet to cycle the cci quiet. None of my others will cycle it, but the 190 does it just fine. Then again I've had this 190 since I was a kid. It's had its share of abuse and wasn't maintained a while bunch over those years. Never the less it's never let me down. And continues to work flawless ro this day.

 

[68sixspeed]

Just a quick update, I took some time to reverse engineer the springs and bolt weights and did a spreadsheet on forces at bolt closed and bolt open on two 15-22's and my modified 10/22 which runs pretty good on cci quiet ammo.

A few observations, In the case of the 10/22 the trigger will reset without full bolt travel. 1.25" travel is enough to just catch another round and reset the hammer. The 15-22 basically needs full travel (1.625")

Bolt weights are similar, the moving mass (bolt plus charge handle) on the stock 10/22 is just over 6-1/2 oz. The lightened bolt I'm using is right at 6 oz.. The 15-22's moving portion (front of bolt and top pin) is 5.95 oz. I didn't count spring weight in either condition.

I have two 15-22's, an early model and a performance center from about a year ago. The older one has the silver spring which is slightly stiffer (higher spring rate) than the newer blue spring in the newer 15-22. Also the older one has 1/10" additional preload on the spring. That results in ~2.55 lbs closed force on the older one, 2.34 lbs on the newer one. Open force (calculate) is 5.52 and 5.30 lbs. Note, it just hit me I assumed all the springs are music wire and not stainless, I should check that.

Anyway, for comparison the 10/22 spring I'm using on quiets give me 2.0 lbs at bolt close, 3.0 at 1.25" stroke which will reset and load the 10-22, 3.6lb at 1.6" which is full travel on the 10-22 bolt.

So I'm targeting around 2lb bolt closed, 3lb bolt open for my new spring for the 15-22. Surprisingly the one out of the 10-22 might work, that would give 1.78 and 3.06 installed in the 15-22, I also have another one just a bit stronger, 2.3 and 3.9 lbs, so I'll try both of those hopefully this weekend. If not I'll get something out of Mcmaster and keep trying.

Of course there are other variables, but friction seems similar, but I have not measured the added force to reset the trigger. The reset on the 15-22 comes on later and at the point where the bolt will have less energy than the 10-22 which resets more linear and sooner. So that could be a problem in my next test...

I had never taken the 15-22 bolt fully apart, but there are some similarities to the tried and true 10-22 that are likely not by accident. The extractor system is almost identical, stock spring rates, and bolt weight too. Then again with nearly the same bolt weight the spring rates would have to be close to function properly. -Dan

 

[68sixspeed]

Slight holdup, new spring doesn't fit the 15-22 rod, so I'll have to order something next week... Doh!

 

[68sixspeed]

quick update, so far no luck with a spring combo for cci quiets. The latest one (5th combo I've tried) will cycle the bolt, eject, but doesn't get the new round all the way out of the magazine and into the chamber. so close... I have the bolt/closed for the same as the std spring but the part open and full open forces lower, apparently too low. I'm going to order and try one more spring with a higher rate next weekend...

 

[97catintenn]

Dang, it doesn't get any closer than that 68six!

 

[68sixspeed]

Struck out again, I'm about ready to give in... Or make a tungsten bolt for more weight/inertia going forward. If it had a forward assist like a true ar15 I'd be ok, so close...