Short cycling

[MadRabbit]

Using Wolf ammo?

[FireMoth]

OK, guys, here's a new one:

How about an unknown brand 'mil-spec' receiver extension that was too short in internal dimension?

Tried backing it off a revolution, but would not retain the buffer retainer. Replaced with a proper mil spec tube, and problem solved.

This was of the variety that has a finish that looks like paint (not anodized).

So be careful on inexpensive parts. Even some of the less regarded but known name makes at least keep this spec right.

[DeusExMachina]

So the bolt wouldn't physically go back enough, not just when fired?

[FireMoth]

Correct. Dialed out one revolution, it would go back to lock, but the lip to retain the buffer retainer was too short, and let go of the retainer the first time it was manually cycled.

New receiver extension, problem solved.

[DeusExMachina]

That must have been pretty short.

[FireMoth]

Hey, hey, hey... lets not talk about the length of a mans equipment, ok...

[SAnd]

Some numbers from my notes made about a year ago-

Measured from the long part where the buffer retainer sits.

Colt A2 rifle stock, 9 3/4 inches to the square bottom.
ArmaLite A2 rifle stock, 9 5/8 inches to the square bottom.
Armalite Adjustable A4 carbine stock, 7 11/16 to the square bottom.
Tapco Adjustable T6 stock (#1), 6 3/4 inches to the top of the bottom cone.
Tapco Adjustable T6 stock (#2), 6 5/8 inches to the top of the bottom cone.
Short "Tactical" stock, 7 inches to the top of the bottom cone.

The bottom of the hole is tapered like the point of a drill bit on the two Tapco stocks.
The bottom of the Colt and ArmaLite stocks have square flat bottoms.
The Tactical stock has a square shoulder with a pointed center of about half the diameter.

The external over all length dimensions of the ArmaLite and Tapco adjustable stocks are the same.

[spleify]

Yep, that was definitely a strange one. Rob(like always) figured it out and I bought a new buffer tube and he installed that, a new castle nut and end plate, and she in back in service again!

Thanks again Rob, and I'm looking forward to running this baby!

[FireMoth]

Some numbers from my notes made about a year ago...

Good data. Thanks. We'll have to measure the offending tube to see what was different, though i should say it was at least .250" too short, and maybe even .5".

Where did you measure out to? bottom retaining lip, or the short part of the threaded ring? I want to have a realistic comparison

[ldmaster]

Given that if they made ONE like this, they made a LOT like this.

How many people have this on a rifle, and don't know of the problem because they have never shot their rifle?