If you have a threaded barrel, I believe the pin is not to stabilize the muzzle device but to make it "permanently attached". If you installed the muzzle device on a 16" barrel no pin would be required. I don't see how adding the pin could possibly cause "play". Am I misunderstanding something? Has anyone else had this problem with a pinned muzzle device? I have at least 4000 rounds on my pinned Epsilon and it is solid.

If you have a threaded barrel, I believe the pin is not to stabilize the muzzle device but to make it "permanently attached". If you installed the muzzle device on a 16" barrel no pin would be required. I don't see how adding the pin could possibly cause "play". Am I misunderstanding something? Has anyone else had this problem with a pinned muzzle device? I have at least 4000 rounds on my pinned Epsilon and it is solid.

You’d have to ask the guy for more detailed info. I was asking questions, but he and I both had other things to do. That said, the way I understood it is that the pin sits in a dimple in the barrel. That that interface gets stressed repeatedly as there’s torque applied to the connection between the device and barrel. If just a crush washer or shim, both have some give to it and it absorbs some of torque applied to the connection of the device to the barrel. That the way the pin sits in the dimple, that gets “fatigued” from that repeated stress and the play develops.

I was trying to ask if the device was tightened down properly, howit could come loose, but never got there. I’ll ask when I go back for the follow up. I beleive the crush washers help keep things from working loose. But since this device uses shims, it doesn’t react the same.

The SLR was installed with leftover shims from the set that I bought for the AFAB and the SLR comp is still on there solid. That upper is a 16” barrel, so no pin. I shot prob about the same round count with the SLR after switching to it. The SLR was also used in the part of the course where the pace of shooting was higher.

That sounds kind of sketchy dude, especially after only 300 rounds. I’ve had six pinned 14.5 uppers and every single one has been rock solid. My current Noveske has about 4k rounds on it and won’t budge.

That sounds kind of sketchy dude, especially after only 300 rounds. I’ve had six pinned 14.5 uppers and every single one has been rock solid. My current Noveske has about 4k rounds on it and won’t budge.

Are those installed with crush washers or shims?

I emailed Precision Armament and got a reply first thing this morning.  Awesome responsiveness and feedback from the co-CEO and President of the company.  Gotta love that!

Anyways, the feedback was that if followed the instructions for the accu-washers, there should have been enough "pre-load" on the comp that it shouldn't have moved.  They also recommend application of high temp Loctite 272 or Flexbar Rocksett.  I have printed out all the various instructions and feedback and will present them to the installer. 

When I picked up the upper after the install, the person who did it mentioned that they had to try an alternate method (not their usual method with a reaction bar) to torque down the comp.  I made sure that issue was taken care of for this go around, so maybe that will help. 

Overall still not sure in my mind what happened and definitely see what dogman and Wake indicated and really that's what I had expected.  Hopefully things will get done right this time.  Again, the guy is working with me to make it right, so that's always important. 

I am no engineer, but I don't like the answers either.  Good, it is being addressed.  Any issues, please let me know and I will help.

I am no engineer, but I don't like the answers either.  Good, it is being addressed.  Any issues, please let me know and I will help.

Yeah, the explanations given left me scratching my head.  I mean I'm no expert at pinned and welded brakes/comps, but the play thing definitely didn't sound right.  Hopefully things will get put together properly this time. 

Shot the gun with the AFAB in a carbine class yesterday and seems like this installation is holding.  I had shot the gun after getting it back after the comp was taken off and new one installed (with pin and weld), but just to zero and didn't get the gun that hot.  I believe thread locker was applied as well.  Don't recall what was used, but it left some clear red residue.  The class included may drill that got the gun pretty hot, which is where I noticed the muzzle device working lose.  Checked it here and there during the class and after and seems to be on there solid. 

Still not sure what happened with the initial install.  The first time, the installer mentioned not being able to get the light off of the rail, so had to use an alternate method of securing the upper than he typically does.  So maybe he was not able to torque the comp down properly.  For the reinstall, he used threadlocker as recommended by the manufacturer, but not sure if that was the issue as I believe shooting will get the comp hot enough to affect the threadlocker. 

When the comp worked loose, in between courses of fire, I had leaned the gun up against a tree when I reloaded mags.  I recall resting the comp on the tree.  While I wouldn't think that would cause anything, something that I figured I would avoid from now on.  So yesterday, when I put the rifle down, I made sure to rest it on the handguard. 

For the reinstall, he used threadlocker as recommended by the manufacturer, but not sure if that was the issue as I believe shooting will get the comp hot enough to affect the threadlocker. 

Loctite Red is rated between 300-450 degrees depending which version you have.

Loctite Red is rated between 300-450 degrees depending which version you have.

I don’t recall what he used. He told me the product, but can’t tbink of it right now. PA recommends Loctite 272 (red) and Rocksett. I do recall it wasn’t either of those.

Some feedback on the AFAB.  I was able to shoot my Colt with the AFAB and a BCM with the BCM Comp, which is closer to an A2 than most other comps on the market.  Pretty similar setups and weight.  Probably the only main difference was my gun has an M4 profile barrel and the BCM had a lighter profile barrel.  Otherwise, pretty close to the same setup for comparison.

When I tried the BCM, we were doing drills that included multiple shots on multiple targets.  I was actually trying this gun for the trigger, but then I noticed how much the dot was jumping around between shots.  We were shooting on smaller targets and trying to ensure our hits were in the selected target and accounting for the proper holdover.  The target areas were maybe as small as 1" wide by 3" tall in some instances, so you could definitely notice when the dot moved off the target.

When I went back to my gun with the AFAB, I immediately noticed how much easier it was to keep the dot on the target.  I wouldn't say no muzzle jump, but much less and mostly was able to keep the dot from jumping out of the target area. 

That was a good side-by-side comparison of the muzzle devices and how effective the AFAB is at controlling muzzle jump, which is what I wanted.  It also made me wonder if shooting the gun with the AFAB will make me lax on solid muzzle control techniques.  Before about 3 months ago, I mostly shot with the A2 and what I was used to.  I certainly see the benefits of using a comp, but I also will make time to shoot the guns with the A2 to work on solid muzzle control techniques. 

Tried dogman's AR with the VG6 Epsilon with the CAGE thing and I was pretty impressed.  Was shooting with irons and the front sight wasn't jumping around very much at all.  Think the rail was 13" ish, so the front sight was way out there.  Even then, it seemed like the front sight stayed pretty close to on target. 

Then I observed when dogman shot it to get a feel for the blast with the CAGE device, which is supposed to help mitigate the side blast.  It wasn't bad at all.  I would have liked to have observed that side-by-side with the AFAB.  I would say that the VG6 Epsilon was a little louder than the AFAB, but not that much.  I was standing about 3 feet left of the muzzle and it wasn't bad. 

A few weeks ago, I was shooting next to someone with the Lantac Dragon and that thing vented a LOT of gasses sideways.  Felt like someone was blowing compressed air at me. 

Tried dogman's AR with the VG6 Epsilon with the CAGE thing and I was pretty impressed.  Was shooting with irons and the front sight wasn't jumping around very much at all.  Think the rail was 13" ish, so the front sight was way out there.  Even then, it seemed like the front sight stayed pretty close to on target. 

Then I observed when dogman shot it to get a feel for the blast with the CAGE device, which is supposed to help mitigate the side blast.  It wasn't bad at all.  I would have liked to have observed that side-by-side with the AFAB.  I would say that the VG6 Epsilon was a little louder than the AFAB, but not that much.  I was standing about 3 feet left of the muzzle and it wasn't bad. 

A few weeks ago, I was shooting next to someone with the Lantac Dragon and that thing vented a LOT of gasses sideways.  Felt like someone was blowing compressed air at me.

what is the CAGE thing?

I guess I should focus and google

what is the CAGE thing?

I guess I should focus and google

CAGE = Concussion Altering Gas Expansion Device

"The CAGE is the pinnacle of concussion reduction technology. Its primary essential task was to disrupt side concussion while keeping or enhancing the characteristics of the Gamma and Epsilon series of muzzle devices. It accomplishes this with ease."

http://www.vg6precision.com/muzzle-devices/60-cage-device.html

You have to work on your Googlefu 

CAGE = Concussion Altering Gas Expansion Device

"The CAGE is the pinnacle of concussion reduction technology. Its primary essential task was to disrupt side concussion while keeping or enhancing the characteristics of the Gamma and Epsilon series of muzzle devices. It accomplishes this with ease."

http://www.vg6precision.com/muzzle-devices/60-cage-device.html

You have to work on your Googlefu 

heads


the way I tell how effective a muzzle device is, how many people on either side of me say "what brake is THAT!" or if people move benches
lol

heads


the way I tell how effective a muzzle device is, how many people on either side of me say "what brake is THAT!" or if people move benches
lol

I've shot next to one of the range regulars when he was shooting his Savage .338 Lapua with a pretty "effective" brake.  The side blast from that thing would knock over my spotting scope!     Luckily he would shoot like 5 rounds at the start of a relay and just cruise for the rest.