I have an ace skeleton stock. I recently bought a carbine H buffer from BCM. is it worth it/safe to use the carbine length H buffer in a full size stock, or is the regular full length buffer heavy enough? The buffer is the original from the full size A2 stock, a bushmaster XM15.
Don’t use a carbine buffer or spring when you are supposed to be using a rifle buffer or spring. They don’t swap nicely.
The carbine buffer in a rifle receiver extension will allow the bolt carrier to travel too far to the rear and may damage your rifle.
You can use a carbine buffer and action spring in a rifle receiver extension with a spacer, but there is no good reason not to just use the rifle spring and buffer.
Rock River Arms sells a delrin 9mm spacer that will allow the use of a CAR length buffer and spring.
The only reason I would ever use such a set up would be to use a CAR buffer and spring in a 3gun rifle where I wanted a fast cycling low mass BCG to keep the rifle as flat as possible. I did use such a set up for quite a while for the ‘gun games’. They proved to me that they aren’t 100% reliable. Getting the gun sideways and or in bad weather, dusty conditions or dirty would cause stoppages. I’ve since went back to full gas, M16 BCG groups and rifle weight buffers.
The rifle spring and buffer would be more reliable and smoother than any CAR length buffer and spring you could come up with using a spacer in a rifle length stock.
An H buffer is nowhere near heavy enough to adequately slow down the bolt. Even with a carbine stock and buffer, a three quarter inch spacer should be used in the receiver extension to limit bolt travel. That three quarter inch of over travel gives the bolt a running start at the bolt catch and can lead to bolt catch failure.