How do I tighten the flash hider when the barrel is covered by a rail?

[RAM Engineer]

This is going to be a stupid question, but: How do I clamp my barrel in vise blocks when tightening the flash hider after installing a full-length rail?

Do I just use receiver blocks and not worry about stressing the barrel indexing pin/barrel nut area? :confused:

[Texas Patriot]

I just hold the receiver area between my knees and tighten it up a bit. I'm not so sure it needs to be tightened up as much as you may be planning to do.

[RAM Engineer]

I just hold the receiver area between my knees and tighten it up a bit. I'm not so sure it needs to be tightened up as much as you may be planning to do.

What if I'm going to be using the FH as a suppressor mount?

Thanks,
Jason

[Robb Jensen]

This is where Brownells wrench which holds the barrel extension is really nice. Ideally you should clamp the barrel itself into the vise. There are times that are less than ideal such as in this case. As long as you don't go over around 40 Ft lbs you should be fine just holding by the receiver. Be very careful, if you can't get it off then take the rail off or weaken the flash hider by cutting slits in it but not all the way through or you hit you muzzle threads. You can always try the freezer trick to.
I've changed several hundred flash bidets on SBRs where I had no access to the barrel and haven't caused any damage to any of them.

[eternal24k]

I use the DPMS claw mount, it works great solong as you have a decent vise.

http://www.dpmsinc.com/store/products/?prod=1675&cat=1450

[Robb Jensen]

I use the DPMS claw mount, it works great solong as you have a decent vise.

http://www.dpmsinc.com/store/products/?prod=1675&cat=1450

Cool. Great tool, I use one too.

However it does nothing to protect the aluminum upper receiver from the steel indexing pin on the barrel extension as you're twisting the barrel inside this receiver by cranking on the flash hider which also put pressure on the barrel indexing pin against the aluminum receiver.

[RAM Engineer]

Cool. Great tool, I use one too.

However it does nothing to protect the aluminum upper receiver from the steel indexing pin on the barrel extension as you're twisting the barrel inside this receiver by cranking on the flash hider which also put pressure on the barrel indexing pin against the aluminum receiver.

Mil spec for FH torque is (I believe) 15-20 ft-lbs.
KAC spec for the Triple Tap is 20-30 ft-lbs

Looking at the length of barrel protruding on a 14.5" barrel with a DD RIS II, it looks like there might be enough to grab onto if I cut down a set of barrel blocks.

However, one of THESE (http://www.bravocompanyusa.com/BCM-BFH-11-5-Upper-Receiver-Group-KAC-p/bcm-urg-11%20bfh%20urx%2049.htm) might require the use of the Brownells tool.

What prevents the barrel from turning inside the barrel extension when using the Brownells tool? Don't they just thread together too, with no locating pin?

[Robb Jensen]

Mil spec for FH torque is (I believe) 15-20 ft-lbs.
KAC spec for the Triple Tap is 20-30 ft-lbs

Looking at the length of barrel protruding on a 14.5" barrel with a DD RIS II, it looks like there might be enough to grab onto if I cut down a set of barrel blocks.

However, one of THESE (http://www.bravocompanyusa.com/BCM-BFH-11-5-Upper-Receiver-Group-KAC-p/bcm-urg-11%20bfh%20urx%2049.htm) might require the use of the Brownells tool.

What prevents the barrel from turning inside the barrel extension when using the Brownells tool? Don't they just thread together too, with no locating pin?

The barrel and the barrel ext. themselves. These are both RH threads and the indexing pin is drilled and pin installed after the bbl ext in torqued.

[Iraqgunz]

There is no torque value when installing a military type flash hider using a crush washer. You simply turn the flash hider until the center slot of the hider is in line with the center of the FSB.

You should be able to use an upper receiver vise block to do it. I have several times.


Mil spec for FH torque is (I believe) 15-20 ft-lbs.
KAC spec for the Triple Tap is 20-30 ft-lbs

Looking at the length of barrel protruding on a 14.5" barrel with a DD RIS II, it looks like there might be enough to grab onto if I cut down a set of barrel blocks.

However, one of THESE (http://www.bravocompanyusa.com/BCM-BFH-11-5-Upper-Receiver-Group-KAC-p/bcm-urg-11%20bfh%20urx%2049.htm) might require the use of the Brownells tool.

What prevents the barrel from turning inside the barrel extension when using the Brownells tool? Don't they just thread together too, with no locating pin?

[BudJr]

Originally Posted by eternal24k
I use the DPMS claw mount, it works great solong as you have a decent vise.

http://www.dpmsinc.com/store/product...=1675&cat=1450



Cool. Great tool, I use one too.

However it does nothing to protect the aluminum upper receiver from the steel indexing pin on the barrel extension as you're twisting the barrel inside this receiver by cranking on the flash hider which also put pressure on the barrel indexing pin against the aluminum receiver.

Mount the upper to the dpms claw, then put it in the vice at 90 degree angle, so the vice is contacting the bottom of the claw and the top of the upper (use wood or something to protect the rails).

This is very solid and allows zero twisting of the upper, as apposed to relying on the pins. I had an extremely tight barrel nut I was about to give up on. This did the trick, nut came right off with no worry about the upper.

Actually this is such a solid method they should include instructions and an additional piece for the top of the upper specifically for this.

With regards to how tight you need to torque the FH, it's not so much a matter of how tight is enough, it's that you sometimes need a lot of force to get that last bit for a proper index.

[Robb Jensen]

Mount the upper to the dpms claw, then put it in the vice at 90 degree angle, so the vice is contacting the bottom of the claw and the top of the upper (use wood or something to protect the rails).

This is very solid and allows zero twisting of the upper, as apposed to relying on the pins and magwell. I had an extremely tight barrel nut I was about to give up on. This did the trick, nut came right off with no worry about the upper.

Actually this is such a solid method they should include instructions and an additional piece for the top of the upper specifically for this.

With regards to how tight you need to torque the FH, it's not so much a matter of how tight is enough, it's that you sometimes need a lot of force to get that last bit for a proper index.

I think you've missed my point entirely.
Tightening the barrel nut does not hurt the upper receivers indexing pin notch. Tighenting/loosening the flash hider could because it's in turn turning the barrel within the receiver. (The receiver is aluminum the barrel indexing pin is steel....which do you think will win?) As long as you don't go nuts on the torque of the flash hider you'll be good. Like I said earlier ideally you want to clamp the barrel into barrel blocks into the vise when cranking on flash hiders.

[BudJr]

I think you've missed my point entirely.
Tightening the barrel nut does not hurt the upper receivers indexing pin notch. Tighenting/loosening the flash hider could because it's in turn turning the barrel within the receiver. (The receiver is aluminum the barrel indexing pin is steel....which do you think will win?) As long as you don't go nuts on the torque of the flash hider you'll be good. Like I said earlier ideally you want to clamp the barrel into barrel blocks into the vise when cranking on flash hiders.

Oh shit, you're right sorry. I'm so used to people refering to the potential twisting of the upper and didn't read your post carefully enough.