Gunsmithing Seized Surefire Brake

[Phylodog]

Need some advice here. I just got in a Rainier Arms match barrel today and a brand new Surefire muzzle brake yesterday. After installing the barrel I began the process of getting the brake timed properly. It was a tight fit so I confirmed that both the brake and barrel were 1/2 x 28, which they were. I put some oil on the threads and slowly worked the brake on, stopping when things got tight and backing off a turn then tightening further. It was tight but nothing I wouldn't attribute to tolerances. I removed the brake which came off easier than it went on and looked for burrs or anything on the threads, all looked clear. I then went to reinstall the brake to determine which shims I would need to add to time it properly and it seized up on me 1/8" shy of full seated. I've added penetrating oil and at this point I know the threads are wet but it won't move more than about a half turn in either direction.

I've got it in the freezer now. The only thing I know to try is to get it good and cold then hit the brake with a MAP torch to heat it up quickly to see if that will allow it to come off. Any other suggestions?

 

[bptactical]

Stainless barrel? If so it has seized and SureFire stainless is tough stuff.
Your going about it the right way, slowly and with lots of penetrant. Easy on the heat, if you fry the finish on the brake it will be a bear to redo. You should be able to weasel it off.
When you get it off use some anti seize.

 

[1SMALLJOHNSON]

I think you're right there, but maybe one alternate step: Using a heat gun, get a hold of some bees wax. Orient the barreled action vertically, and heat up the threaded union. Let the bees wax melt into that union, as far as you think you can get it. Now, freeze your parts. Once guten-cold (german word for freezing), insulate the barrel with a towel or something. Keep it cold. Heat the can with either a heat gun or your MAPP gas. Loosen AND tighten that joint, working it back and forth, until the thing spins off.

Worst case is you cut off your threaded stud, and have somebody re-thread the muzzle.

Are the can threads aluminum? Forgive my ignorance.

 

[Phylodog]

I tried the freezer then heat once and it appeared to make no difference. The barrel is stainless but I'm not sure of the material Surefire uses for their brake, hard stuff I'm sure. I sent an email to Rainier to see if they have any suggestions. If I have to cut the barrel and have it threaded again I don't think I'm going to be able to get the suppressor to clear the rail. I've got a 14.5" barrel and 14" Centurion CMR.

 

[Alpine 338]

I think you have issues with the tolerances on the barrel and or threads, shouldn't go on that tight. All my Surefire brakes I've had, all spun on freely by hand until it hit the shoulder stop. I've installed them on LMT barrels, Sako TRG barrels, and GAP built Bartlein barrels and never had an issue.

Good luck.

 

[Alpine 338]

Surefire brakes are made with hardened stainless steel, much harder than most barrels.

 

[Phylodog]

Carnage

 

[300sniper]

^^^Unfortunately, that is the result I was expecting.

 

[Bill Larson]

Both those parts can be yet saved..... with careful rethreading..... and use of ANTI-SIEZE lubricant......

 

[Phylodog]

Both those parts can be yet saved..... with careful rethreading..... and use of ANTI-SIEZE lubricant......

I am not a machinist by any means but I'm not sure how they could be made to mate up properly again. As far as anti seize, Surefire includes and recommends the use of Rocksett when affixing the brake to the threads, it isn't going to work with anti seize on there. I was attempting to follow the manufacturers directions, obviously something was off. I looked through my limited supply but I don't have a 1/2 x 28 tap to use in determining where the issue was (assuming there is any evidence left).

 

[kish]

Stainless to Stainless will gall easily, In some applications (not firearms) I have had the stainless threads Teflon coated to ease disassembly. Don't know if anyone else ever has done this or not it worked but that was years ago

john

 

[1SMALLJOHNSON]

Bummer. Soooo......how'd you get it apart?

 

[Phylodog]

I let it set for about an hour after the cold/heat attempt, went back out and it actually gave pretty easily. Not sure what the heat did but something gave.

 

[SONIC SAAMI]

Pure Nickel Anti Seize is a good friend of mine
Bostik Pure Nickel Products - Industrial Supply Group

 

[Phylodog]

Again, Surefire specifies the use of Rocksett which is not possible with anti seize on the threads.

 

[ZombieMonkey]

Ouch. Lesson learned hopefully, never force something on like that. If it doesn't want to thread, stop as something is out of spec. Sorry to see the end results.

 

[Phylodog]

Took some measurements but I don't know if these are indicative of what they issue may have been.

Unaffected OD of the barrel threads

Unaffected ID of the brake

 

[300sniper]

Again, Surefire specifies the use of Rocksett which is not possible with anti seize on the threads.

Was there Rocksett on the threads?

 

[Phylodog]

No Rocksett yet, I was in the process of getting it timed with the shims when it seized.

 

[chipsfan]

Do you have a micrometer?

 

[chipsfan]

I cut and pasted a link to thread specs below. As a rule, most dudes cut the major diameter of threads .002" under.

Class 3 thread specs for 1/2-28?

 

[Phylodog]

I may have one, I'll check when I get home. I inherited some tools a few years ago and it seems like I remember there being one in the lot. What should I measure with it?

 

[chipsfan]

I may have one, I'll check when I get home. I inherited some tools a few years ago and it seems like I remember there being one in the lot. What should I measure with it?

The major diameter of the threads. Calipers aren't as accurate.

I'm going with the barrel being out of spec.

 

[Phylodog]

.5025-.503 OD on the threads measured with two different micrometers.

 

[Killswitch Engage]

Pm sent phylodog

 

[chipsfan]

.5025-.503 OD on the threads measured with two different micrometers.

Oh boy...

Give them a call and a chance to make it right.

 

[Phylodog]

I've got an email in to Rainier, hopefully they'll get back with me Mon or Tue. They've got a great reputation for CS so I'm hopeful they will work with me. I appreciate the assistance in determining where the problem was.

 

[bptactical]

Spec for 1/2 x 28 is .620. I have found that some devices are short threaded so when I thread a barrel I typically go to .600.
The brake is fine, the SureFire stainless is hard as hell and the only time I have seen one damaged is when the remnants of a hardened pin rolled the first 3 threads.
The barrel is saveable, a couple of different things can be done.
1- cut back, re crown and thread.
2- cut the barrel back removing only the damaged threads, re crown and turn the barrel back enough to get you to .600. Pick up the existing good threads and thread the remainder.
3- turn down the shank and fabricate an oversized bushing, silver solder it on and turn and thread as normal.

 

[chipsfan]

So what happened?

 

[JJones75]

I'm pretty sure that Surefire brakes are made from 17-4 PH steel with is harder than wood pecker lips and is known for galling very very badly.
those male threads are way out of spec on the big side just looking at the outside measurement. the best way to measure them would be with a set of thread wires but I doubt you have those. The major diameter maybe have been to large OR it could have been that the threads just were not "cleaned up"
I'm sure Rainier will make it right.
Invest in a quality tap and die for any threads you have , if for nothing else to clean any loc tite or grease from the threads

 

[SPEAK338]

.620 wtf? 1/2-28 major is .493-.500

 

[jasonk]

.620 wtf? 1/2-28 major is .493-.500

I'm guessing he meant from the muzzle to the shoulder.

 

[Mike_Honcho]

Sorry that happened. As others have noted the SF should screw on hand tight with no real resistance. In the past it seems like the shimming process was to screw it on by hand, look how out of whack it was, add shims to get it to 11 on the clock face, pull it all off one more time, Rockset, then torque it down.

If it were me, I'd probably gently (by hand) run a tap through that SF, or at minimum take a tooth brush and some solvent and clean any and all chips / shavings / grease out of those threads.

 

[chipsfan]

I'm guessing he meant from the muzzle to the shoulder.

Yeah, that's what im thinking . That's what the drawing included with those brakes show

 

[Phylodog]

So what happened?

Had a local machinist offer to help out. I took it to his shop Sunday and we ran a tap through the SF brake. Aside from pulling the leftovers from the barrel threads out the tap went in without issue. He tried to run a die on the barrel threads but didn't like how it was going so he chucked the barrel up into the lather and spent about an hour manually cleaning the barrel threads up to include those which weren't damaged by the brake seizing. The result was a pretty loose fitting brake on the cleaned up threads. I timed the brake and put a small amount of Rocksett on it and tested it out. I wasn't seeing the accuracy I was expecting (guaranteed MOA or better) so I contacted Rainier and explained the situation. They advised me to send it back and they would contact me about a replacement (I mentioned possibly upgrading to one of the Ultramatch barrels). They should have the barrel back in the next day or so but it appears they intend to stand behind their product. It's unfortunate but I have no complaints if they send out a new one.

 

[chipsfan]

Had a local machinist offer to help out. I took it to his shop Sunday and we ran a tap through the SF brake. Aside from pulling the leftovers from the barrel threads out the tap went in without issue. He tried to run a die on the barrel threads but didn't like how it was going so he chucked the barrel up into the lather and spent about an hour manually cleaning the barrel threads up to include those which weren't damaged by the brake seizing. The result was a pretty loose fitting brake on the cleaned up threads. I timed the brake and put a small amount of Rocksett on it and tested it out. I wasn't seeing the accuracy I was expecting (guaranteed MOA or better) so I contacted Rainier and explained the situation. They advised me to send it back and they would contact me about a replacement (I mentioned possibly upgrading to one of the Ultramatch barrels). They should have the barrel back in the next day or so but it appears they intend to stand behind their product. It's unfortunate but I have no complaints if they send out a new one.

Wow, that's pretty decent of them.

 

[Phylodog]

I don't disagree but they did ship a barrel with out of spec threads on it.

 

[bptactical]

I'm guessing he meant from the muzzle to the shoulder.

Sorry guys, I should have clarified that dimension. .620 is generally the length of the threaded shank.

I would not be the least surprised if Rainier denies your claim due to the machinist tinkering with the threads. He destroyed the evidence of the faulty threads.

 

[Phylodog]

They gave no indication that replacement was questionable. They asked me to return it and they would contact me about replacement. It'd be pretty shitty to refuse to make it right but I'm not worrying about it at this point.

 

[CS223]

.5025-.503 OD on the threads measured with two different micrometers.

That's after you threaded the brake on & off. Whomever threaded the barrel must not own a proper set of GO/NO-GO ring gages.

 

[Phylodog]

Heard from Rainier today. They were going to replace the barrel so I paid the extra to upgrade to one of their Ultramatch barrels. Wish it hadn't happened at all but I have zero complaints with Rainier, they handled it as well as could be expected. I'll be checking this barrel out a little better before installing (or test fitting) the Surefire brake.

 

[chipsfan]

Heard from Rainier today. They were going to replace the barrel so I paid the extra to upgrade to one of their Ultramatch barrels. Wish it hadn't happened at all but I have zero complaints with Rainier, they handled it as well as could be expected. I'll be checking this barrel out a little better before installing (or test fitting) the Surefire brake.

Good for them. Go buy yourself some anti sieze

 

[SONIC SAAMI]

Good for them. Go buy yourself some anti sieze

What he said^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

 

[19Scout77]

Guys...stop recommending anti seize for the installation of a Surefire brake. Surefire brakes are to be mounted using rockset...a heat resistant product intended to hold the brake even after heating up the barrel. Surefire brakes are intended to be used as suppressor mounts. Anti seize is the wrong product for such use.

 

[chipsfan]

Guys...stop recommending anti seize for the installation of a Surefire brake. Surefire brakes are to be mounted using rockset...a heat resistant product intended to hold the brake even after heating up the barrel. Surefire brakes are intended to be used as suppressor mounts. Anti seize is the wrong product for such use.

My comment was a reference to galling stainless parts when the major diameter is .005" over.

 

[SONIC SAAMI]

I dont see anyone suggesting the use for install,just the first fitting

 

[19Scout77]

Or better yet, skip the antiseize all together and when threading on a Surefire brake, if you encounter any resistance whatsoever, stop.

 

[Phylodog]

Or better yet, skip the antiseize all together and when threading on a Surefire brake, if you encounter any resistance whatsoever, stop.

That lesson has been learned. Hopefully this new barrel will be threaded appropriately.

 

[STR]

Since you're getting a new barrel and test fitting agian. This is a little trick that works very well, and I'm 100 % will be criticized. First off, if you encounter any interference at all, STOP! Put a very small amount of 1000 grit lapping compound on the barrel threads and very slowly work it 1/4 to half turns in and out. The compound is suspended in lubricant which helps. If you're unsure with this, just send your Surefire part to the barrel company so they can see what the issue is because they where very good to you with a replacement without question. I don't think that might be the case if it happens agian. Best of luck.

 

[Phylodog]

I definitely won't allow it to happen a second time