CB Caps, semiauto rifle; would this work?

[jamesbeat]

I've noticed that CB caps are available in 'lr' packages, ie they are powered by a primer only like a cb cap, but are physically the same size as a .22lr round to enable cycling them in magazine fed guns.

They don't have enough 'oomph' to cycle a semiauto, and must be cycled by hand.

I had an idea for a fun, easily reversible modification.

Would it be possible to replace the recoil spring in a semiauto rifle with a weaker version, thus allowing these rounds to cycle the action?

The problems that I can see are:
1. The mainspring and friction between components being too much for the pipsqueak round to overcome.
2. A suitably weak recoil spring would not be powerful enough to strip a round from the magazine and close the bolt for the next shot.
3. The bolt may open before the pressure drops to a safe level.

One would naturally have to be very careful to esure every shot left the barrel before firing the next round, too.

Silly pipe dream, or the funnest little plinker ever?

 

[rcmodel]

Probably not going to work.

The bolt weight in any RF semi-auto provides more opening resistance Inertia then the recoil spring.

The recoil spring only overcomes the feed mechanism or magazine resistance and closes the action.

It doesn't retard the bolt opening much at all, because it isn't compressed to full compressed power until the bolt is all the way back.

A lighter spring would compress easier, but would not have enough stored energy to operate the feed mechanism or push the next round out of a magazine.

I shoot Aguila and CCI CB caps in semi-autos in the basement all the time.

But I expect to hand cycle the action every shot.

You could try your idea.
But it has been tried many times before and it doesn't work that way.

rc

 

[dmazur]

Well, I found this -

http://airgun-academy.pyramydair.com/blog/2011/08/are-cb-caps-as-good-and-accurate-as-pellets-part-1/

First day at the range — a lot is learned
Things seldom go as we plan, and nothing shows that as clear as a day at the rifle range. For starters, I discovered that the semiautomatic 10/22 would not feed any of the CB cap ammo from the magazine — even when I manually cycled the bolt.

So, this introduces a possible concern that you didn't mention. Apparently they are based on a LR case with a shorter bullet. Not the same size as a LR round. And they just may not feed from a magazine...

I agree with your first two concerns, but I have no idea if the third one is valid. If the CB caps contain no powder, how much trouble can the primer cause?

IMO, I would wait until the dust settles and normal LR ammo is available.

Unless you are going down the "prepper" road and trying to come up with something that will kill small game without making much noise...

 

[rcmodel]

So, this introduces a possible concern that you didn't mention. Apparently they are based on a LR case with a shorter bullet.

No, I didn't mention it.
Because it wasn't a concern of mine.

And yes they are a .22 LR case with a shorter bullet.
Sort of like a .22 Long.

I shoot Aguila & CCI CB caps in the basement all the time with three Winchester .22 LR chambered pumps, a Browning .22 Auto auto, three Colt Woodsman auto pistols, one S&W Model 41 auto pistol, and a Ruger 10/22.

It never occurred to me anything that would feed LR's wouldn't feed them manually too.

rc

 

[dmazur]

Sorry, rc. I was referring to the OP's concerns...should have quoted him.

 

[frankenstein406]

i remember people talking about it probably on rimfirecentral and i think it worked but some were worried about forgetting about it and shooting full power then banging the receiver

 

[FIVETWOSEVEN]

Couldn't you just get another bolt and remove material to lighten it?

 

[RustHunter87]

The guy on RFC skeletoned his 10/22 bolt so it was super light, I think he cut some off the recoil spring to, I dont really remember ill see if i cant dig up a link

 

[steven58]

Not to hijack but I found that Aquila 60 gr. Sniper Subsonics are very reliable and accurate out of an AR using a .22 LR conversion kit.

 

[Dave Markowitz]

It never occurred to me anything that would feed LR's wouldn't feed them manually too.

FWIW, CCI CB Longs will shoot and feed fine in my Remington Apache Nylon 77, as long as you work the bolt manually. The Nylon 77 is the box mag fed version of the Nylon 66.

In contrast, they won't feed at all from my tube mag fed Norinco ATD, which is a copy of the old Browning semiauto .22 rifle. In fact, on my rifle if the magazine is loaded with CB Longs, I can't even work the bolt. I haven't figured out why as yet.

 

[VA27]

Want a semi-auto that shoots CB caps? Don't tell anyone I told you this...but, get your wallet out and go looking for a nice clean Remington 550-1. The last ones were made in '71 or '72. They have this nifty little floating chamber that allows them to function with Shorts, as well as Longs and Long Rifles.

When it's clean and well lubed it will also function semiautomatically with CB Shorts. When it starts getting a little dirty just switch to CCI Target Shorts. They're almost as quiet, but still subsonic. It will NOT function correctly with CB Longs, only with CB Shorts. It will be way cheaper than trying to mod another gun to do what you want.