"Best" BCG

[Pasta123]

Just came across this, looks like it isn’t a new thing.

https://www.ssusa.org/content/previe...ense-hmb-bolt/

Eliminates the pass through of the cam pin hole and introduces a tapered cam pin for their

Looks like KE Arms have the latest revision of it. Difference being having radius cuts on the lugs.

This could be the most cost-effective option for enhancements.

[markm]

Not sure if trolling…

He's serious. It's a testament to Stoner's gun how much aftermarket nonsense you can put into it, and have it still function reliably.

[Pasta123]

He's serious. It's a testament to Stoner's gun how much aftermarket nonsense you can put into it, and have it still function reliably.

At least he tried... with a carbine gas.

[lysander]

Looks like KE Arms have the latest revision of it. Difference being having radius cuts on the lugs.

This could be the most cost-effective option for enhancements.

Of course, you realize that by eliminating the pass-through you have increased the bending moment on the cam pin.

Before I believe them about "no more broken bolts...' I'd like to see a stress analysis.

[JediGuy]

Of course, you realize that by eliminating the pass-through you have increased the load on the single open end of the hole, and increased the bending moment on the cam pin.

Before I believe them about "no more broken bolts...' I'd like to see a stress analysis.

Sorry, had to

[Clint]

To borrow Lysander's nice sketch for the benefit of others,

It should be pointed out anything that delays unlocking, also reduces pressure during unlocking and therefore, friction and stress on the bolt and cam pin.

In addition to a longer cam track, these things include heavier buffers, longer gas systems and smaller gas ports.

These two points could easily be labeled

"CAR buffer and H2 buffer"

"CAR gas system and MID gas system"

"067 Gas Port and 063 Gas Port"

and the graph would essentially still be correct.

[Pasta123]

To borrow Lysander's nice sketch for the benefit of others,

It should be pointed out anything that delays unlocking, also reduces pressure during unlocking and therefore, friction and stress on the bolt and cam pin.

In addition to a longer cam track, these things include heavier buffers, longer gas systems and smaller gas ports.

These two points could easily be labeled

"CAR buffer and H2 buffer"

"CAR gas system and MID gas system"

"067 Gas Port and 063 Gas Port"

and the graph would essentially still be correct.

To sum it up, an altered cam track will reduce the chance of cracking through the cam pin hole, but shred lugs is primarily because of maximum chamber pressure. Correct?

[Pasta123]

Of course, you realize that by eliminating the pass-through you have increased the bending moment on the cam pin.

Before I believe them about "no more broken bolts...' I'd like to see a stress analysis.

"It could", not "It will". I'm "trust but verify" here.

If it's so easy, then Stoner would thought about it, but on the other hand, HM would done something if they're reasonable.

[lysander]

To sum it up, an altered cam track will reduce the chance of cracking through the cam pin hole, but shred lugs is primarily because of maximum chamber pressure. Correct?

The load on the cam pin hole is governed by the bolt carrier velocity, which is governed by the piston pressure and buffer weight.

The biggest gain in a longer cam track is increased reliability from easier extraction. it's not intended to be a part longevity improvement.

Bolt life really is kind'a over blown for most folks, unless you do a lot of supressed full-automatic fire . . .

[Pasta123]

The load on the cam pin hole is governed by the bolt carrier velocity, which is governed by the piston pressure and buffer weight.

The biggest gain in a longer cam track is increased reliability from easier extraction. it's not intended to be a part longevity improvement.

Bolt life really is kind'a over blown for most folks, unless you do a lot of supressed full-automatic fire . . .

Double tap