General silencer discussion. If you want to talk about a specific silenced rifle or pistol, it is best to do that in the rifle or pistol section for that brand.
So I ordered a Remington SPS AAC-SD in 308 to take advantage of a 762SDN6 suppressor I have pending. I went to install the 51T brake on it yesterday and noticed something odd about the factory threading. There was no thread relief at the shoulder. This probably wouldn't be an issue since the brake can screw all the way on up to the shoulder, but when I tried to use the supplied AAC peel washers to align the brake I noticed they get caught up on the round filet and cannot sit againt the barrel shoulder.
I know I don't want to try and torque it like this or I'll just get a ruined crush washer and poor shoulder contact. My lathe is not big enough to take a barreled receiver through the spindle bore and add thread relief. I'm not sure what to do at this point because I kind of figured the Rem700 SPS AAC-SD would be compatible with an AAC silencer...
I guess I could try and remove some material from the back of the brake mount to try and align it the traditional way to the barrel (no washers). But frankly, that sucker is HARD and I'm not sure how easy it would be to take my time and shave it in several passes until it times correctly. I pinned a brake mount to a 14.5" AR barrel earlier this week and I had to use a endmill to make the hole. Any suggestions?
I reject your truths and substitute my own realities
If you've got a lathe why not make the spacer that would align the brake anyways long enough to skip over the missed thread relief?
Something .100 long plus whatever length you need to align the brake with an O.D. the same as the barrel, I.D. ~.530 or whatever the diameter is down there. I wouldn't turn anything off of anything.
I didnt have any issues with mine and if I recall it looked exactly like that. I also run the full brake. I think I used 2 shims. They say not to use more than 3.
I have run a few thousand rounds through it with no issues.
I didnt have any issues with mine and if I recall it looked exactly like that. I also run the full brake. I think I used 2 shims. They say not to use more than 3.
I have run a few thousand rounds through it with no issues.
counterboreing the brake isn't the issue, it already has enough of a small chamfer to be able to butt up against the shoulder without any washers. it's the peel washers that hit the base of the treads before the shoulder. It doesn't matter how big of a counterbore the brake has if the washers can't make it all the way to the shoulder - the brake rests on the washers.
I think I'l just get some 0.001" shim stock from the grainger store and make my own peel washers. Either that, or I'll put the brake in the Lathe and shave a few thou off at a time until it fits.
Are the brakes just 14-4PH or 17-4PH steel Nitride treated, or just blackened some other way??
I reject your truths and substitute my own realities
Have used precision shim washers from McMaster-Carr in such instances. Not a good solution if you're trying to index the muzzle device.
Does the barrel have a front sight mounted? If not, remove the gas block and dismount the barrel from the upper ... should then go through the head stock of the lathe I would think.
How many shims is it taking to properly align the brake? Like I said, I think I used 2 and had no issues like this. With only 1 washer I could see it being a potential issue.
pneumagger wrote:counterboreing the brake isn't the issue, it already has enough of a small chamfer to be able to butt up against the shoulder without any washers. it's the peel washers that hit the base of the treads before the shoulder. It doesn't matter how big of a counterbore the brake has if the washers can't make it all the way to the shoulder - the brake rests on the washers.
I think I'l just get some 0.001" shim stock from the grainger store and make my own peel washers. Either that, or I'll put the brake in the Lathe and shave a few thou off at a time until it fits.
Are the brakes just 14-4PH or 17-4PH steel Nitride treated, or just blackened some other way??
with added counterbore, the washers had room to conform to the rounded shoulder (on my setups). YMMV.
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New rifle, with factory threading? I'd call Remington Customer Support and keep explaining the issue until you get hold of someone that understands what you're saying. Heck, get an email address and send them the pictures.
I certainly wouldn't start cutting on the barrel or anything...cutting the brake would be less risky dollar-wise, but I'd still let big Green fix it if there is a problem. It will also give them another data point, in case there is a systemic problem. Believe it or not, they don't read forums like this very much, and rely on the customer's input to find and address issues.
If they say its in spec or they won't do anything on it, chuck it up and cut wherever you need...but I'd spend some time on the phone first.
JasonM wrote:
with added counterbore, the washers had room to conform to the rounded shoulder (on my setups). YMMV.
Well, I went ahead and gave it a go with the "deform the washers" strategy, Jason. The .008+.015 was a just a hair past aligned when torqued a fair amount... almost unnoticeable, but bothered me knowing it wasn't perfect. So I pulled it off to use the .010+.015 shims instead, added a bit more rocksett because I'm not sure if I should've just left what I had on before and put a ton of torque on it to get aligned. Between the rocksett and the torque, this aint goin nowhere. And the washers pretty much mushed flat against the shoulder... so my worries are gone.
I'll probably be pretty frustrated when it comes time to remove it and get a super quiet dedicated thread-on suppressor for this rifle.
I reject your truths and substitute my own realities
JasonM wrote:
with added counterbore, the washers had room to conform to the rounded shoulder (on my setups). YMMV.
Well, I went ahead and gave it a go with the "deform the washers" strategy, Jason. The .008+.015 was a just a hair past aligned when torqued a fair amount... almost unnoticeable, but bothered me knowing it wasn't perfect. So I pulled it off to use the .010+.015 shims instead, added a bit more rocksett because I'm not sure if I should've just left what I had on before and put a ton of torque on it to get aligned. Between the rocksett and the torque, this aint goin nowhere. And the washers pretty much mushed flat against the shoulder... so my worries are gone.
I'll probably be pretty frustrated when it comes time to remove it and get a super quiet dedicated thread-on suppressor for this rifle.
It bothered the heck out of me too, but once mounted, I promptly forgot and have never bothered thinking about it again.
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Interesting. I actually have an SPS in .308. Have not decided which can to mount on it so had not noticed the thread shoulder. Was going to wait until the new trust rules are instantiated ... may not be able to acquire anything then anyhow. Would have to use my only 30 cal can after buying another muzzle adapter.
