Can I use upper vise block to replace flash hider?

AR/M4 AR Technical Discussion
1

Noob question I know…

I have heard from some say only use a barrel vise which I don’t have.

Can I use an upper vise block to take off and replace a flash hider?
I have seen it done, but it is recommended?

Thanks

2

Yeah, assuming the barrel is already attached to the upper.

3

I wouldn’t… there is a chance of shearing into the index pin - seen it happen more than a few times.

All depends on how tight the barrel is and how much torque you put on the muzzle devise - when we did the testing on how solid the Vltor Front Sight was, we actually sheared off an index pin before the sight budged.

4

I have done shitloads like that. But, it is a very good idea to get a feel for the current flash hider (how hard was it cranked on) and when you install it it is a good idea to apply gradual tightening of the new muzzle device. I also recommend some anti seize or grease on the threads.

5

I wouldnt consider myself an expert but I do have experience. I worked for years doing maintenance for a training unit that fired upwards of 500 personnel a day. We changed out a lot of barrels. The only thing we used to hold everything down was the upper vice block from brownells. In fact, I spent the first 15 years of my career doing nothing for the military but weapons maintenance I have never seen an index pin sheared from using the vice block. Don’t ham fist it and use the right lube on the threads.

6

I wouldn’t do that. I made a barrel vise by cutting some V-grooves in a couple of 3-4 inch pieces of 2x4, wrapping the barrel in a little wet leather and clamping in a vise.

7

Exactly,

Just whip up a barrel block.

8

I prefer an adaptor that secures the upper/barrel at the barrel extension.

While most muzzle devices will pop off with little issue, there are those that are solidly affixed with something that can require ridiculous force to removed, force that can and has damaged upper receivers and index pins.

Sent from my VS980 4G using Tapatalk

9

I wouldn’t either. I had an A2 so locked on it had to be cut off, very unpleasant. Spend a little time and make the barrel blocks.

10

The nylon magnetic jaws at the link below were recommended in another thread that I can’t locate right now. I have used them to remove flash hiders that were hard to remove, but probably not as bad as some of the more experienced posters have mentioned. They are cheap, hold up well, and they clamp a barrel very solidly in my 5" vise.

http://www.lowes.com/pd_209898-52800-BV-NVJ_0__?productId=3070247&Ntt=vise+ja&pl=1&currentURL=%3FNtt%3Dvise%2Bja&facetInfo=

11

I just made a set of vice blocks this weekend. It isn’t too difficult. 2 pieces of hard maple, a 3/4 or 5/8 drill bit depending on your barrel profile, a shim to space the two pieces apart from each other and a couple of C clamps.

12

The upper receiver clamshell has worked for years on easy to remove MDs. If it’s tight, it’s hard to beat an item like the reaction rod. The reaction rod is so easy for this and it’s hard to go back after you have the tool.

13

"The upper receiver clamshell has worked for years on easy to remove MDs. If it’s tight, it’s hard to beat an item like the reaction rod. The reaction rod is so easy for this and it’s hard to go back after you have the tool.

Which is why I ordered one from Brownells. For the money, an item that will last a lifetime and keep me out of trouble, it’s a no brainer.

14

I would also suggest a barrel block.

](http://s656.photobucket.com/user/rgerh913/media/Posted/ARbarrelextension.jpg.html)[/IMG]

If the flash hider is very tight the barrel can unscrew from the extension.

If using either a clam shell type holder or the reaction rod.

15

That worked well for me. I used a rag around the barrel to cushion it. I can’t afford all the specialized tools.

16

It can be done and generally will be fine but I prefer to clamp the barrel. I haven’t run into any difficult removals but the force required to install with a crush washer can be significant.

17

The barrel extension is tightened to the barrel with 150 ft-lbs of torque. It shouldn’t take more than 20 ft-lbs to unscrew a muzzle device.

18

Thanks for the advice. After watching Geissele demonstrate the reaction rod on a youtube video, the physics of the device just made too much sense to settle for anything else. I am not into buyer’s remorse, and I know this will be a keeper.

19

I’ve run into some incredibly torqued flash hiders (LMT) and have had good luck with the homemade barrel vise blocks. I’ve found a piece of leather or rubber in the wood blocks help secure the barrel in the blocks.

20

I have used a block to swap them out before. And finally came to my senses and picked up the Reaction Rod. Never looked back.