New 300 BLK Build, Inevitable Questions

[Coronach]

I'm new to the forum and the caliber, and I'm trying to do my homework. I am, however, reaching the point of information saturation. Rather than just starting off with a "please tell me what to do" post, I'll try to break it down into a couple of specific questions. First off, an overview:

I'm looking at building a 300 BLK rifle for home defense and predator hunting. I live out in the country and we have coyotes. A nice little quiet thumper to knock over the yotes that doubles as a nice quiet little thumper to knock over home intruders would be very interesting. I'm envisioning a 0-100 yd primary usage envelope. Naturally, the gun and round can reach beyond that, but 99% of it's non-range-toy usage would be 100 and under.

I'm very familiar with the AR in .223, but I have no experience with 300 BLK and very little experience with suppressors (which i why I've been doing a bunch of reading). My current spitballed design ideas are as follows:

SBR upper with a 8-9ish (?) inch barrel
12"+ rail/handguard system with the can recessed underneath (yeah, I know, stand by for more on that)
The can would be dedicated to the gun, so I was thinking screw-on for attachement method.
Not sure which can, not sure which handguard, not sure which upper, not sure which barrel.

My concern with recessing the can is heat, less than appearance. On the pro side, I like the idea of keeping the can under the handguard, due to the fact that if this IS to be a HD gun and it gets used, I have small kids that I would be herding to safety and I want to try to protect the environment from a hot can. The con side is that I know cans get hot hot hot, and it is therefore possible (probable? inevitable?) that the guard around the can will get hot hot hot as well. That's my first question: is this at all practical?

Second question is the upper. Is it worth it to go all fancy and go with something like the Grizzly side-charging upper, in order to cut down on gas in the face, or not?

My original intent was to go piston, but I think I've scrapped that. The gist I got was that they don't work that well, they don't cut down on the crud in the action that much (if at all), and they're another piece to break or go wrong. Correct?

The barrel is obviously an issue as well, but I imagine I should sort the first two issues out first. I've read a couple of threads where users were putting (or considering putting) cans under the handguards, but I never really saw much about how it turned out. I like the idea, but I'm not married to it. If it's not practical, it's not practical. FWIW, Seekins has a 13" BAR rail that allegedly accommodates a AAC can, and if you went with a 8" bbl with screw-on attachment that SEEMS to give you plenty of length to recess the can under it...you might even be able to go with a longer bbl or shorter rail. Dunno.

Thanks for any help,

Mike

[nolwark76]

Welcome. Hopefully my opinion will be of use. I have a 9" AAC upper on a pistol lower. I have an SAS Ti suppressor and really enjoy this combo. I went this route because I wanted a rifle to do the same thing. I didn't go for can under hand guard for a few reasons. First, I don't really care about the look of it. I don't have a problem with it but not a feature I was seeking. Second, if you ever have a problem with your can and need to take it off, your rifle looks silly with a recessed barrel. The 8-9"+ factory uppers that have a full rail work great. I was looking piston too but LWRC only makes one DI gun, their 300 BLK. I went AAC instead of Noveske just because the Noveske is not designed to cycle subs without a can. My thinking was this; I have a can and don't see a point in shooting subs unsuppressed unless that's all I have for some reason and my can is on a different rifle. I don't have a problem shooting my 9" with a can as far as gas in my face. Maybe there is something you can do to make it better but it wasn't really more noticable. Shooting lefty, I'm sure it would. I also like the 9" upper with its carbine hand guard because I can take the can off and put it in my eberlestock pack with it as small as it can get. As far as heat goes, get a TAB gear or any number of suppressor covers. That's my opinion, and its what works for me.

[zimm17]

I think recessing the can is more trouble than it's worth. I just built a 8.2" noveske barrel into a spikes upper and BCM Bolt carrier group (because I couldn't find a spikes at the time). I think just about any mil spec upper is fine. The spikes just has the cool laser etched logos. Then put on a carbine 7" quad rail. I like daniel defense lite rails or omega X. If you go AAC, you can put the 51t muzzle brake on there (on backorder for a few months) and a 7.62 SDN-6 can (tough to find too). The cool thing about the SDN-6 is that it works on .223 and .308 as well. So you can get an AAC 51t break, breakout, or flash hider for your .223's and swap the can at your leisure. That's what I plan to do. If you just get a threaded can for the 300 which is 5/8" thread, it won't screw onto the 1/2" threaded .223's. The 51t AAC mount fixes that. Then someday when I ever get a .308 bolt gun with threaded barrel, it'll work on that too. Then you're good out to 600 yards!

Oh yeah, you're going to engrave the lower and get a stamp before you put it all together right? I built my upper, but I can't keep it my house until I get the stamp back. You can have a relative hold it for you as long as they don't also have AR-15's in the house.

I should add that the newer SR7 with 90T mounting system is coming out in the near future, but it could be awhile.

[Coronach]

Yeah, I didn't know the specifics of having the SBR'ed upper and what was allowed and what was not, but I knew there was an issue. I wasn't going to order anything until I had squared that away. I certainly don't want to screw around with any potential NFA violations.

As to recessing the can vs not, I agree that not doing it makes more sense as long as you can effectively insulate the can. The suppressor covers work, then? If so, that makes everything easier.

What length barrel do you recommend? 8-9"? That would put the OAL, with can, at shorter than a 16" carbine, correct? If so, that would be a nice way to go. I am used to maneuvering with a 16" gun, so anything shorter than that would be fine. Weight ... eh, that's another matter. No matter how you cut it, I'll be hanging about 1 lb at the end of the barrel.

Thanks for the input, it's very helpful.

Mike

[ataris121]

I agree the can under hand guard is more trouble than its worth. though id say go with a Vltor Casv and barrel that terminates right at the edge, or just short. add on a fast attach muzzle brake (AAC brake or blackout) that way you get functionality and look. As for the piston you can get a ops-416 to work you just need to drop in a lighter buffer and lighter spring or a JP silent power(im currently considering this). and i cant say for suppressed but as far as unsuppressed supers the change in the build up in the action is highly noticable. all i have to do these days is run a bore snake and its good to go

[Coronach]

I'm perfectly happy to NOT run a piston. My understanding is that it doesn't help with suppressed usage, which is what this platform is going to be. My general sense, from dinking around with several on unsuppressed ARs, is that whatever it brings to the table for standard use (easier cleanup) is outweighed by the negatives (increased complexity, expense, parts breakage, carrier tilt and buffer tube erosion). Those comments are directed at pistons in the AR design in general, not this particular one.

And, I'm aware that the idea that they don't really help with fouling from cans is based upon the same info that led me to believe that recessing the can was better than wrapping it, so I'm taking that for what it's worth. Can anyone comment upon that idea?

Thanks,

Mike

[300Blk]

The benefits of a piston rifle not getting as dirty are less of a benefit when a can is used as the dirty gasses go back through the bore - even on an MP5 which is not a gas operated design.

Then there is the weight, cost, etc - like you mentioned.

[rjacobs]

I would say skip trying to run a can under the rail.

Yes, cans get hot, but in your hypothetical "situation" of having a hot can around your kids you are talking about shooting 3-5 rounds, the can aint going to be that hot, especially with subsonic ammo. Its not like you are going to dump 30 rounds into a guy and be trying to get your kids to safety. Plus you are talking about protecting the base of the can(if you put it under a rail), not the end so no matter what you do you will have hot can sticking out the end of something. And I would hope you have good muzzle discipline around your kids anyway so they shouldnt be getting close to it. My other thought is a burn is easy to deal with and if a burn is your biggest concern in a situation like you are imagining, you are doing pretty well. Hell that would make a cool story: "how did you get that burn on your leg" "I got it from a hot silencer when our house got broken into and my dad shot the guys that broke in in the middle of the night while carrying me to safety".

QD cans under a hand guard are also a PAIN IN THE ASS to take off because you have to push down on the detent tab to get them off the locking mechanism while unscrewing it. Not saying it cant be done, but its a pain from what I understand.

Screw on cans are better for this application, but I wouldnt do it personally.

I have never been impressed with any of the can covers I have seen. Thats just me.

I would run a short Noveske or AAC upper as they come, dont try to run a long rail to tuck the can under. Get yourself a can like an AAC 762SDN-6. Perfect setup IMO.

[300newb]

I understand that this is a slim chance, but I would hate to have a rail that hid the base of a can enough that if you removed the can, the rail(or your hand) would be subject to muzzle gasses. Just a thought.

[Coronach]

Well, the original plan was to have the whole can recessed under the rail. Nothing sticking out. That would make it a no-go to fire without the can, since your muzzle would be back about 4-6 inches under the rail.

As fas as muzzle discipline goes, I'm a cop. I search houses with long guns for a living. In training, it is very easy to have outstanding discipline and never touch anyone with a gun, never sweep anyone, keep your reactionary gap, etc. When you do it for real in a dynamic fashion, some of that goes out the window pretty fast. People move in unexpected ways, the untrained people in the house will be freaking out and not listening to verbal commands and popping out of unexpected spaces. Having someone get up against your muzzle is still pretty unlikely, but it can happen. In a home defense scenario, where you're on defense, you don't know where your opponents are, and your kids are involved and probably in blind terror, it can happen.

Incidentally, I was in a building when a rifle was discharged. I was two rooms away, and it still stomps your skull flat (it also slams your sphincter shut too, incidentally). I hope to never have to discharge a rifle in a house, especially my own, without earpro. Sure, I can thow a set of Peltors in with my rifle, but what of everyone else on the Home Team? Sucktastic. This is why I'm researching this.

Doing a little more reading, I think that the probable low roundcount of an exchange and a suppressor cover would probably be sufficient to make sure no one got burned. As long as the cover can keep its surface below the injury threshold for a handful of shots, I'm golden. If I have to change magazines in that scenario, I'm having a bad enough day that a second degree burn is the least of my concerns.

Thanks,

Mike