Would fluting a bolt carrier increase it's reliability? The buffer would probably have to made heavier to compensate for the weight reduction of the carrier.

Good idea, bad idea?

More weight usually means more reliability, not less.  That's why you see H, H2, H3, 9mm buffers being used.

Think about it, it's the sum of the moving mass weight - the bolt, carrier and buffer - that make up the system, not any one piece.

Now, a lighter system may make for lighter recoil, like in the case of JPs light carrier, light hammer and light spring combo.  I've shot a rifle with all of this and they are smooth, but it's not something I'd take to a gunfight.

I'm with mongo here


I suspect it takes a certain amount of mass to lock up the second round, and moving that weight rearward  to the buffer would be ..................well just moving the weight.

I like the creativity aspect though .

Quoted: Would fluting a bolt carrier increase it's reliability? The buffer would probably have to made heavier to compensate for the weight reduction of the carrier. Good idea, bad idea?

Id leave it as it is. Designed that way for a reason.

Id leave it as it is. Designed that way for a reason.

Ditto...why mess with something that's not broken........So you can create a problem down the road.....

I got to go with the bad idea side.

When I built some 80% receivers the buffer hole was to low, so I ground off the tops of my bolt carriers so they could go in the tube, they work and I really can't notice a differance between them and my other ARs. (one of 'em won't cycle WOLF ammo, but I think it just needs ether (A) the gas hole drilled bigger, or (B) the recoil spring shortened till it works, I'll monkey with that another day.)

Quoted: I got to go with the bad idea side.

+1

[McNamara whiz kids] If the carrier needed to be fluted, Stoner would have designed it that way. [/McNamara whiz kids]  

I dunno.  I think it may have some merit.  I suspect you could mill some really shallow transverse flutes that would only take off maybe .5 oz max.  What you'd gain would be some debris/sand cuts to provide a space for gunk to move to, out of the way of the carrier-to-receiver clearance.  If needed, you could bump up to the next heavier buffer to compensate.

I suspect it takes a certain amount of mass to lock up the second round, and moving that weight rearward to the buffer would be ..................well just moving the weight.

What about adding weight to the inside of the rear of the carrier like the weight Oly puts in their pistol caliber bolt carriers? We're not talking pounds here and the flutes don't have to be very deep to have an effect. If adding a heavier buffer makes a 9mm and .45 set up run better, reduce the fire rate why is it such a bad idea in this case? There seems to be a lot of guys running heavier 9mm buffers in there 5.56 carbines. Why is this different?

Id leave it as it is. Designed that way for a reason.

It may not have originally been designed that way maybe because they never thought of it or didn't think it would be needed. It must have been an issue at some point as they came up with the forward assist to help seat a sticking bolt/bolt carrier.

Ditto...why mess with something that's not broken........So you can create a problem down the road.....

If this train of thought had prevailed, there wouldn't be any pistol caliber AR's and it wouldn't currently made in about 16 calibers, there wouldn't be piston uppers, better mags, and a host of other improvements just because someone thought of a different/better idea.

I'm not syaing it is the cure all to end all cure alls but I haven't heard a convincing argument as to why it's a bad idea. Maybe this just needs someone to make one, check the weight loss, and add the lost weight somewhere else if needed.

If it upsets the time space continuum, then ok, that's a technological reason not to attempt it.

I think it is a good idea! The manufacturers probably don't do it due to time and labor expenses.
This may just solve some problems with dirty ammo and direct gas impingement.
I may do it myself. I have a friend who is a machinist.
You may want to consult a gunsmith just for safety issues.
A thought just occurred to me. What if you started the flutes about 1/8" behind the bolt face?
This would in theory, channel gasses and dirt away from critical areas.
If you kept these flutes shallow  (10 or 15 thousandths), I would not think the weight reduction would be enough to fowl anything up.
Let me know if you pursue this. Please!