I had originally settled on a 14.5" w/pinned mount for my dedicated silenced build.
I planned on a Noveske 14.5" Light Recce w/VIS and Switchblock.
Now I am not so sure. It’s only 1.5" more to 16", and I am planning on running a Surefire FA556-212. Surefire does not recommend pinning very many of their muzzle devices due to the precise dimensions of them and the intended interface points, and not the 215 mount at all, which is the one I want to use.
-Will a 16" with an FA556-212 feel that much more clumsy than a 14.5"?
-How much added length does this can add FROM THE BOLT FACE. I have seen all sorts of measurements, but nothing indicated from the bolt face.
-Will the 16" be better or worse gas-wise for this build (Both would have the switchblock and be complete Noveske rifles)?
-Is proper torque and Rockset enough to keep a flash-hider permanently attached (for practical, not legal purposes) so that it doesn’t unscrew from the weapon while the can is mounted?
***I do not want a 2-stamp gun, so SBR is not on the table.
Honestly, that’s for you to decide, no not really.
With a 16" barrel, that’s measurement from the bolt face to the crown of the muzzle. Because the crown sits ahead of where the rear of the muzzle device where the suppressor ratchets to, let’s use the FA556-212A for example, which is 2.33" long, but about 1/2" of it is the threaded portion, so take that 1/2" back, so 15.5", plus 6" of suppressor, 21.5" total length.
It won’t matter with a switchblock, you will have a suppressed setting, which is ported correctly for suppressor use on a 16" barrel.
The mount should come with a crush washer, sufficient torque to crush the washer and time the muzzle device is plenty enough to keep the mount attached. I personally would skip the rocksett. If you want to use it, go for it, but with the heat of the rifle, especially running suppressed, I wouldn’t think that rocksett would hold up anyway and would just degrade from shooting. (you hear stories of people taking blowtorches to heat it to remove something that is rocksetted, same theory here, I think)
Either way you decide, Noveske can pin you a surefire mount, and it will be fine. They are a top quality shop. If you want to go with the 14.5" rifle, contact Noveske and set something up. Todd, Sherri, and the people over at Noveske take care of their customers. If you want to go with the 16" instead, go with the 16". Either way, you’re going to end up with a quality, top tier rifle that will serve you well for a long time.
Just remember, the 16" will turn into a 21.5", the pinned 14.5" will turn into 19" overall barrel length with suppressor attached.
-I don’t see why not. The issued KAC NT4 suppressors have always been run on our M4s that use a peel washer to attach the mount and haven’t had issues. Granted, it might not be what is recommended or advised, but I’ve seen it done. I don’t claim to be an expert in these things.
I was looking at I think the 212. I can see where the 215 would be extremely hard to pin.
I’m a moron. I saw 14 and 16 and thought two. 20" overall. :dance3:
You are correct. The 4" I was talking about is the overall length added to the weapon after the muzzle device, I mistakenly added that to the end of the muzzle. This can get confusing if you sit down and think about it. Like thinking about how big the universe is and stuff
However, there will be no crush washer included with a suppressor mount. It will be peel washers/shims.
I said crush washer (I actually think I said it in my second post as well), I meant peel washer. I’m a little tired today, you’ll have to bear with me. :jester:
Good luck with your decision. I’m assuming that you’re going with the 16" barrel. Another thought I had is the weight of the Magpul UBR stock. Noveske will factory install one if you order directly from them for the added cost of the difference between what the rifle would come with and the UBR. It would add a little bit of extra weight to the rifle on the ass end and balance it a little better. Something to concider if you are worried about the front end being a little bit heavy.
I’m not exactly sure on the weight difference between the two. From what I know the UBR is one of the heavier stocks on the market, because it uses it’s own reciever extension, which is why I say to get it factory installed instead of buying one outright and installing it yourself.
Honestly, there are so many different offerings out there, that you can’t go wrong with whatever you decide. I just thought I would throw the idea out there. You could always get that SOPMOD stock and load the storage tubes with either good or dead CR123 batteries to add weight to the ass end as you need. Kind of a home made variable weight stock type thing. :lol:
Personally, with the setup you’re thinking about doing, I think it would be perfect for the UBR, plus I think it looks sweet, and have used one and like the ergos of them. That would be my choice, but you won’t go wrong with the SOPMOD either.
The National Firearms Act, Title 26, US Code, Chapter 53 IRS Code, subsection 5854(a)(3) defines a firearm subject to this law in part as “a rifle having a barrel or barrels of less than 16 inches in length”.
Thus, ATF determines barrel length from the receiver end of the chamber to the end of the muzzle. If you permanently attach a device to the muzzle, it is now part of the barrel by ATF rule. Thus, you measure chamber length (including throat), bore and the length of the permanently attached muzzle device beyond the crown to determine barrel length.
If you measure from your breechface as you suggest, you derive “total headspace” and not “barrel headspace”. This will provide you with an inaccurate measurement for the purposes of defining barrel length in order to comply with the NFA. You could potentially end up with a barrel shorter than 16" and have an unintended NFA item. Yes, we are talking thousandths of inches here, but, ever wonder why many barrel manufacturers manufacture a 16.1" barrel when 16" is considered a non-NFA item? You don’t want to come up on the short end on the ATF’s ruler!
You mention a “2 stamp” rifle.
NFA Branch issues a “Letter of Exception” which amends your original approved application to include any additional barrel lengths you may wish to put on your registered lower receiver. These days, NFA Branch will only except a Form 1 or 4 with a single barrel length listed in Block 4e. My last “Letter of Exception” took 2 years, 3 months to receive! However, there is no charge/fee for the letter.
I cannot not find the administrative ruling, but, I seem to recall permanently attached was defined by BATF as a welded pin extending from the exterior surface of the device into the barrel.
As always, you should direct your questions regarding NFA device legalities to NFA Branch, (304) 616-4500. Ask the rep to cite the code or ruling. I generally send a letter via first class mail asking for a return letter answering questions while citing references. The Tech Division has likely been down darn nearly every device iteration you can think of.
14.5 pinned mount isn’t a bad option. I’ve found myself saying… why didn’t I just perm this mount since I’m never taking it off and it’s been there for years?
Rockseting a mount is fine. One drop on the threads and one drop on the mount after cleaning both and you won’t have a problem.
Pinning’s only point (in this discussion) is to avoid sbr status… If you shoot a lot, i’d always avoid pinning- brakes and flash hiders are wear items.
