Short stroking caused by BCG

[Captains1911]

1 of 2 problems, and I’m pretty sure they’ve been mentioned...

Gas key on BCG

OR

Under gassed gun and some tolerance stacking

Under gassed gun, even though it locked back with an H3 buffer and a different BCG?

[Captains1911]

Delete

[Clint]

For anyone who needs an upgrade, we have a few of these in stock now.

[ViniVidivici]

I hope that the Toolcraft NiB bcg I stuck in my last build is gtg. (DD lw 16” middy). Haven’t run it yet. Wouldn’t have been my first choice but with parts availability being what it is, I went with it.

I’d love to get my paws on a REBCG but I’d likely win the lottery first, and I don’t play.

It'll most likely be just fine.

[davidjinks]

Anything is possible, that’s why I added the tolerance stacking part.

At this point it’s a SWAG without being able to actually shoot it myself.

Under gassed gun, even though it locked back with an H3 buffer and a different BCG?

[wanderson]

I had a similar issue with a PSA 8” .300bo upper and a PSA premium phosphate BCG.
Cycling by hand I could feel the BCG carrier had more resistance in the upper than any other AR I own.
It would cycle supers but not subs unsuppressed.
Swapped it with the Toolcraft nitride BCG in a PSA 16” .300bo 16” upper. Now both run unsuppressed subs just fine.

Just tolerance stacking.

[Averageman]

Tolerances stack.
A bit here and a bit there can make for a questionable/or even wrong result, move some pieces around and "There you go, everything works."
I used to work on Abrams Tanks, it was sometimes maddening,....
There are times when it makes sense and others when it enters the realm of voodoo.

[DG23]

For anyone who needs an upgrade, we have a few of these in stock now.

Curious if you guys are a 'commercial only BCG supplier', make your own BC's in house, and how long you guys have been at it. I did visit your website and the 'about us' info was big time lacking in details in my opinion.

"Value"' priced commercial only BCG suppliers tend not to do a good job holding these critical dimensions with any sort of regularity.

WHY would a BCG from BRT be an 'upgrade' to anything I have from ToolCraft?

[ViniVidivici]

I had a similar issue with a PSA 8” .300bo upper and a PSA premium phosphate BCG.
Cycling by hand I could feel the BCG carrier had more resistance in the upper than any other AR I own.
It would cycle supers but not subs unsuppressed.
Swapped it with the Toolcraft nitride BCG in a PSA 16” .300bo 16” upper. Now both run unsuppressed subs just fine.

Just tolerance stacking.

I've seen a Bear Creek Arsenal BCG that was that way....stiff as hell moving inside the upper.

Turns out the "head" of the cam pin was out of spec, too big, and was binding inside the top of the upper.

Filed it down to spec, all was smooth as glass, that BCG now functions flawlessly.

You sometimes see wierd things with lower tier manufacturers.

[lysander]

Anything is possible, that’s why I added the tolerance stacking part.

Just tolerance stacking.

Tolerances stack.
A bit here and a bit there can make for a questionable/or even wrong result, move some pieces around and "There you go, everything works."

If the design is properly toleranced on the drawings (and the M16 is), and the parts made to the tolerances specified, then stacking of tolerance will have no effect on operation. The only time "tolerance stacking" causes problems is if the tolerance are not designed correctly, or the parts are not made correctly.

That's the whole point of interchangeability. A rifle made from parts all at one end of the tolerance band should work just as well as ones made at nominal, or a random mix.