How can a BCG change recoil impulse?

[markm]

Why on earth are you boys installing strange aftermarket springs into your bolts? You're getting me cranky on my Saturday morning.

[me2hootyhoo]

Why on earth are you boys installing strange aftermarket springs into your bolts? You're getting me cranky on my Saturday morning.

Is it strange and aftermarket if manufacturers are using these parts?

http://www.defensereview.com/the-big...m4-unreliable/

[AndyLate]

Is it strange and aftermarket if manufacturers are using these parts?

http://www.defensereview.com/the-big...m4-unreliable/

I know Sionics uses the Sprinco extractor springs, and IG recommends them, along with Colt copper washed and BCM enhanced springs.

Npena84, I would never have thought of extractor springs affecting felt recoil - are you pulling our collective legs?

[me2hootyhoo]

I know Sionics uses the Sprinco extractor springs, and IG recommends them, along with Colt copper washed and BCM enhanced springs.

I would never have thought of extractor springs affecting felt recoil - are you pulling our collective legs?

I'm not too sure I believe an extractor spring changes recoil, but anything is possible and I won't argue or bet against it. So, yeah, if IG and Sionics run em, I will too. Just ordered 6 more last night actually. I run Sprinco extractor springs and Tubb buffer springs all around just for the reliability and longevity.

[Vegasshooter]

I’m surprised it has taken 3 pages to get an explanation on how the recoil is affected by the bolt/BCG. It all has to do with the timing of when the cam path is allowing the gun to unlock, and come out of battery. The LMT Enhanced BCG alters the cam path to keep the rifle locked up a nanosecond longer. By staying locked up that longer time, the pressure curve is altered. That causes the pressure from the round firing to drop quite a bit. By the time the gun unlocks, the pressure has dropped quite a bit. This will absolutely cause the gun to feel lighter in the recoil. It will also be easier on your brass, reduce the chances of a case head srperation, and allow parts to last longer. I’m not trying to sound like an advertisement for any particular brand, because I don’t even use them. I shoot all stock sandcutter BCG from KAC.
The logic is there, and the pressure spike being lower at unlock makes perfect sense. I just haven’t felt a need since KAC are by far the softest guns I’ve ever shot.
SureFire JUST released their new BCG that, among other things, does exactly this. The cam path is altered to stay locked up longer.

If this did get answered in the prior pages, I apologize. I didn’t catch it. It’s Sunday morning, and I got cheated an hour of beauty sleep last night.

[C1-2DG]

I’m surprised it has taken 3 pages to get an explanation on how the recoil is affected by the bolt/BCG. It all has to do with the timing of when the cam path is allowing the gun to unlock, and come out of battery. The LMT Enhanced BCG alters the cam path to keep the rifle locked up a nanosecond longer. By staying locked up that longer time, the pressure curve is altered. That causes the pressure from the round firing to drop quite a bit. By the time the gun unlocks, the pressure has dropped quite a bit. This will absolutely cause the gun to feel lighter in the recoil. It will also be easier on your brass, reduce the chances of a case head srperation, and allow parts to last longer. I’m not trying to sound like an advertisement for any particular brand, because I don’t even use them. I shoot all stock sandcutter BCG from KAC.
The logic is there, and the pressure spike being lower at unlock makes perfect sense. I just haven’t felt a need since KAC are by far the softest guns I’ve ever shot.
SureFire JUST released their new BCG that, among other things, does exactly this. The cam path is altered to stay locked up longer.

If this did get answered in the prior pages, I apologize. I didn’t catch it. It’s Sunday morning, and I got cheated an hour of beauty sleep last night.

This man is right on the money. Beat me to the reply.

Elongated cam pin slots (actual term) are valuable for configurations outside of what the gun was originally meant to be, such as 10" 5.56s, and even large frame gas guns shooting hotter 7.62 or .260/6.5

To a point, longer dwell time and case contraction is a thing.

S/F