Muzzle Brake Removal, Arsenal AK47

The brake has a right hand thread and is held in position with a spring loaded pin. I have tried Aerokroil, carbon remover, and Breakfree. While supporting and protecting the ears ofthe sight, I have applied a lot of torque. The brake refuses to move. I am hesitant to apply more than 100 ft-lbs of torque. If I apply 100 ft-lbs of torque, the end of the sight is getting about 1200 lbs of force. (The supported part of the sight is about 1 inch long.) This is like running over the sight with a car. I have two more methods in mind:

1. Submerge the brake thread in boiling water. I will use a large kettle so that the rifle does not cool the water. This has the advantage that the brake will be heated rapidly. The idea is to get the brake to expand while minimizing expansion of the male threads.

2. Use an impact wrench. I'll fashion a steel bar with a double nutted bolt. put the bar through the brake, put the wrench on the bolt and carefully pull the wrench trigger in short bursts. I'll also start with the wrench at minimum torque.

Unless someone tells me that the impact wrench technique has been done without damaging the rifle, I may just accept the fact that this brake cannot be removed without destroying it. I can cut the brake off with a band saw then use a Dremel tool to cut two slots down to the threads. I suppose, as a last resort, I could take it to a gunsmith, but, how am I going to find a gunsmith who has experience in removing brakes from AK's?

I would guess that threaded shotgun choke tubes have this same problem if they are left in too long. Maybe I should post on shotgun forums too.

?'s answered

The rifle is about 2yrs old and I cannot see any difference between it and my one year old AK74.

I know it is RH thread because I can see the threads in the slot which accepts the holding pin. Nevertheless, it will loosen either way because there is about 1/16th inch more to go (over a full turn screwing on) until the brake contacts the sight. I can turn either way to loosen.

I think boiling water will heat the brake faster than a torch. I intend to plug the bore with a rubber stopper so that the hot water cannot get to the barrel and heat it from the inside. I will try both a paint removing heat gun and a mapp gas torch. I have a surface thermometer and won't let anything get over 300 deg F.

I have placed a brass shim between the pin and the brake so that the pin cannot get into the slot.

Nut splitter

I have a splitter, but it requires so much force to split steel that I would be afraid of deforming the barrel or severely damaging the male threads. The Dremel tool with take a while, but should be safer.

I have had Kroil and Silikroil in the threads for a few weeks now, but have not tried soaking in penetrant. I have an old gallon can of 5-56, I'll try that next.

I wonder if an ultrasonic cleaner might loosen whatever is freezing the threads.

edfardos said:

Soldering iron?

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Too slow. Irons do not transfer heat efficiently unless there is molten solder between the iron and the workpiece. With painted surfaces solder will never wet the surface.

briansmithwins said:

The standard for 14mm thread AKs is LH, the 24mm muzzle device standard is RH. Without knowing the model we can't tell which you're dealing with.

Before going crazy with the Dremel have you called Arsenal?

BSW

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I called Arsenal originally. She said she would call back, but never did. I'll try again.

Not welded or pinned

Kp321 said:

It really sounds like the brake is welded, soldered or pinned in place. Look very closely and see if there has been a pin inserted and welded into the threaded area.

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It is not welded because welding would show. It is not pinned. It could be soldered; it could also have thread locking adhesive. It is identical to my AK74 which is new. The brake on the 74 removes easily. I can see a few threads in the recess for the spring loaded pin. There is no sign of solder or adhesive. But that does not mean that they are not present on another part of the threads.

Solder and welding are unlikely because the barrel and brake were painted separately.

Restoring Ferrari's

AK103K said:

If thats the case, I would say its even more likely.

Ive removed blind pinned brakes on a number of rifles, and you couldnt tell they were pinned and welded, until you took a file to them.

.

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If someone ground a weld on this brake, he should be restoring Ferrari's not welding AK's. The surface is perfectly smooth and round with uniform surface texture.

Water treatment

I put the rifle in the freezer overnight, then plunged it into boiling water. The water raised the temp to 180 deg in 15 seconds. Applied 80 ft-lbs torque - dead tight. The problem here is that 150 degrees difference between the male and female threads amounts to only 0.001 inches per inch. And the threads are only a little over an inch diameter. 0.001 inch is only 0.0005 all the way around. Apparently, this is not enough to break a bond of carbon. Oh well, it was worth a try.

Anyone ever see

Has anyone ever seen a rifle which came from the mfgr. with BOTH a spring loaded pin AND another means of preventing a brake from unscrewing: solder? locktite? pin at right angle to the barrel axis?

I can think of no rationale for doing this except to deceive someone (like me) into thinking that the brake is easily removed.