Mak-90 Brake Advice?

Uberdillo · May 22, 2009

Long story short, fleetingly industrious relative installed a pin on muzzle brake to a Norinco match Mak-90 with JB Weld without accounting for gravity and the relatively loose fit of the brake while it dried. Now Mak looks like a sure candidate for Viagra. It keyholes ~3 feet to the left at 25 yards and develops an increasingly shiny, polished copper mark on the mouth of the brake.

I enjoy projects, especially those firearm related, so I'm going to consider this an opportunity. I also end up shooting the piece a good bit so there's the rest of my personal interest. The two ideas bouncing around my brain have been:

1. I've heard you can heat JB Weld up to a certain point at which it might release so that I can reset the brake properly. I'm posting here to figure out if I can learn how to do that without ruining the barrel or if I ought to stop here and pay my favorite gunsmith to let me watch him. This would be more aesthetically appealing, i.e. no more limp bizkit effect.

2. Bite the bullet and use my mad Dremel skills to carve a path for the bullets to go.

How hot do I have to get the JB Weld to release and compare that to how hot I have to get the barrel to permanently damage it?

What would you do?

Deavis · May 22, 2009

If it were me - I would cut the barrel at 14" behind the front sight. Use a carbide cutter with a pilot to true the crown.... then install the front sight housing behind the new cut barrel and a Krink style break after drilling the break so once installed you could fill the hole with weld and make it permanent at 16" for ATF.

It would look like this (middle one) when done:

OR.....

cut all the front end stuff off and thread for a flash suppressor and then weld on HK sights.... would look like this:

candyman · May 22, 2009

use a torch with map gas

you should be able to get the brake hot and off befor the barrel even really heats up

jb weld ...... i dont really need to say it do i

you can thread the barrel in 1/2x28

Uberdillo · May 30, 2009

Thanks for the insight so far! The idea of cutting the barrel is alarming to me at this stage in the game. I do appreciate the pics. I'll look into the map gas. I don't think I've dealt with that kind of heat, just silver brazing, so I've got some familiarizing to do. And yeah, JB weld, ick... If I do find a way to get this off or I send it to the smith, the 1/28 threading would end the project nicely in my mind too.

Deavis · May 30, 2009

I used to be tentative about taking irreversible steps too... but after a little sucess... I got over it

You could contact 7.62llc.com and have him thread it to 14x1 LH like the original and put on a slant break.

gunluvver · Jun 1, 2009

Threading a MAK90 14X1mmLH or 1/2-28 depends on if the original threads were removed or there never were threads on the barrel. If never threaded, go 14X1. If the threads were ground, go 1/2-28. Here's a pic of one of my MAKs that got de-banned and threaded to 14X1.

This one got threaded to 1/2-28 and got a Yugo grenade launcher gas block and front sight. I put an AR bird cage on it until I got a slant brake with the right threads.