Compensators

[Waylander]

That makes sense, but there's still muzzle rise even if you don't actually hold the pistol grip on an AR. If that's the only thing to cause muzzle rise, then you should be able to hold an AR to your shoulder with your support hand and touch off the trigger without actually touching the pistol grip. It's pretty common to do that from the bench, and there's still muzzle jump.

I'm not even talking about an AR pistol grip. I said hand on a pistol which means the higher bore axis of a pistol relative to the hand means more relative recoil all other things being equal. The center of the butt stock where your shoulder rests is below the buffer tube and so below the centerline of the bore.

If you were in space and were to position your shoulder below the bore line and fire a projectile you would have the same effect due to equal and opposite reactions.

eta:
To put it another way, picture a bare bolt action barrel assembly resting horizontally. Attach say a 3" bar at the back end perpendicular to the bore. On the other end of the bar is a fixed pin so the bar and barrel can rotate. When the gun is fired the projectile will force the barrel backward and it will rise while the bar turns freely on the pin.

[Rayrevolver]

Don't forget about the force due to the gas port. If you want to talk about shooting an AR in a vacuum then the muzzle would get pushed down by the gas port.

It might not be a lot of force, but the result is enough to operate your BCG...

[SomeOtherGuy]

Don't forget about the force due to the gas port. If you want to talk about shooting an AR in a vacuum then the muzzle would get pushed down by the gas port.
It might not be a lot of force, but the result is enough to operate your BCG...

No, because the force caused by gas escaping the barrel would be counteracted by the force resulting from the same gas being turned 90 degrees inside the gas tube.

This discussion is taking on a THR style flavor... I need to go get my Dale Earnhardt pennant and the chart of how many angels can dance on the head of a pin.

[Straight Shooter]

I am looking for a new comp. for a Multi Gun Rifle. What do you recommend as the best muzzle break?

Simple answer: V6 Precision Gamma 556. Period.

[HansTheHobbit]

Simple answer: V6 Precision Gamma 556. Period.

Looks like a good one. My only complaint about that type is that they have a whole myriad of vertical ports when they could simply have a single vertical port in the first stage. That way you only have one or two jets in your sight picture, as opposed to a whole cacophony of fireballs going up everywhere.

[Straight Shooter]

I am looking for a new comp. for a Multi Gun Rifle. What do you recommend as the best muzzle break?

Looks like a good one. My only complaint about that type is that they have a whole myriad of vertical ports when they could simply have a single vertical port in the first stage. That way you only have one or two jets in your sight picture, as opposed to a whole cacophony of fireballs going up everywhere.

I have honestly not noticed one single thing while firing coming out of this comp. Have not done a low light/no light shoot however. But daytime...nadda. And what it did for my LMT carbine was awesome.

[MistWolf]

It's not rocket science

Actually, it is rocket science

[HansTheHobbit]

I have honestly not noticed one single thing while firing coming out of this comp. Have not done a low light/no light shoot however. But daytime...nadda. And what it did for my LMT carbine was awesome.

You're not going to notice anything with any comp during the daytime, unless you get it on high speed camera. From the shooter's perspective, any muzzle flash is very hard to see in the sunlight. It's also highly dependent on what ammo you're shooting. The type of powder and how much there is per barrel length is the biggest factor. Some powders won't throw a fireball even from a bare muzzle.

[Benito]

Yes, a gun would recoil directly backward in space because there is nothing to cause axial force.

Positioning the shoulder, or hand on a pistol, below the bore creates a bore axis which causes rotation about the center of the axis. If the back rest of a gun was positioned directly inline with the center of the bore, the rifle would recoil directly backward on Earth as well.

In space, most guns would recoil backwards with some degree of rotation (muzzle rise), probably including ARs.
For there to be zero rotation, the center of mass of the gun/magazine/optic system would need to be in line with the bore. Every gun I know of (I'm sure there could be some exception) has a center of mass that sits slightly below the boreline. I suppose that if you put a heavy optic, this might not hold true, though.

I have always wondered why ARs have muzzle rise when shouldered, and I do think it's because of the center of mass being lower then the force vector of the recoil. The AR's inline action reduces muzzle rise compared to, say an AK, but it doesn't get rid of it completely.

Back to topic, I installed a Griffin Flash Comp on my AR. It's OK, compared to the AAC Blackout that was on there before, but I was expecting more. I haven't tested it next to other comps, so it may very well be a great comp. Take that for what it's worth.

[SomeOtherGuy]

You're not going to notice anything with any comp during the daytime, unless you get it on high speed camera. From the shooter's perspective, any muzzle flash is very hard to see in the sunlight.

In my experience at competitions, a lot of the conventional brakes (2 or 3 port) produce so much flash that it is quite visible to bystanders from 30-50' away, in cloudy bright conditions close to noon. Not enough to be a distraction at noon, but visible, and it would be awful at close to dusk.

I haven't run that style of comp much on my own rifles, but I have seen obvious flash as the shooter around 1 hour before sunset in fairly bright conditions, on a 16" rifle with common .223 commercial ammo.