Friday, January 29, 2010

ka-POP!

So I mentioned that I fired my CMMG rimfire kit for my AR while I was at CCA, right?

I had a couple of failure-to-feed issues, say four or five in fifty rounds, most likely due to the fact that I neglected to lube the conversion kit before dropping it in the upper, which caused it to be rough as a cob, and the springs that run those things are pretty feeble.

More exciting is the fact that rimfire conversions on the AR are straight blowback rather than locked-breech, and that they will fire when out of battery by a fairly significant amount. With some of today's .22LR ammo running higher chamber pressures than .45ACP +P, stuff can be expelled from the ejection port rather forcefully when this happens.

In my case, a round of Aguila Interceptor fired with the bolt not fully closed. I was fine, the gun and conversion kit were fine, and I was mostly just glad I was shooting right-handed. The kit has since been sprayed with Strike Hold and cycles a lot more smoothly; I'll be shooting it more extensively this weekend.

9 comments:

Justthisguy said...

Sounds like you're leaving something out there, Ma'am. How far did the pieces fly, how big were they, etc.?

New Jovian Thunderbolt said...

what HE said

Tam said...

Nothing flew that I could tell. The spent case looked like one of those booties you put on the end of a turkey drumstick, though...

New Jovian Thunderbolt said...

yowza!

multigun said...

I've seen the same thing with the Tactical Solutions AR22 upper, and have heard other similar reports on these .22 conversions.

One thing that seems to help is paying a higher-than-average amount of attention to cleaning the chamber after each range session. Instead of just running a bore snake through it, consider using one of the more traditional brass bristle brushes with a decent amount of elbow grease.

Mad Saint Jack said...

You didn't mention if the magazine was Ok?

I had an AR-7 fire out of battery, and the bottom of the mag bowed out.

I assume you checked yours, but I'm posting just in case.

Tam said...

Yup, the mag was fine.

loren said...

I once had a very old .22 semi auto that occasionaly went to full auto and spewed out the entire magazine in the wink of an eye. Really got my attention as I shoot left handed. Got rid of it quick.
Anyone know of an AR or HK type rifle that a lefty can shoot without gyrations and brass zipping across his face?

Tam said...

Stag Arms makes a lefty AR.