10.5" SS Noveske 300BLK build questions

[redirt78]

Going to build one as a pistol and use the Sig SB15 brace. Just got the barrel and have most of the other parts but I need to know if anyone out there knows a good starting point for a buffer/spring combo with the 300BLK 10.5" Noveske barrel setup as a pistol. Will it run on regular carbine length parts? Looking at the newer Phase 5 pistol buffer tube also.

Anyone out there have this already? Any help is appreciated.

 

[TygerAR]

Good starting point. Noveske came out with their 300blk barrels very early. I have the first version of their 8.2" and also a later version. That said, they have so much experience, just about any carbine spring/buffer combo will work. I've run my pistols with a DPMS carbine spring/buffer, but now i run them with a Spike's ST-T1 with a Spikes spring. I've never had a issue and neither will you. From what I've read, the barrels are causing the cycling issues and not the spring, buffer, or mag.

You're good. Have fun

 

[komishe]

Noveske 10.5" and phase5 tube has had ZERO issues with carbine spring and standard or heavy buffers for me.
Shoots AA1680 and Lil'Gun supers and subs without a hiccup.

Now if only I could find more Lil'Gun.......I was squeezing a bit more velocity out of it back in the days when it existed

 

[redirt78]

Good to hear, thanks guys

 

[redirt78]

Good starting point. Noveske came out with their 300blk barrels very early. I have the first version of their 8.2" and also a later version. That said, they have so much experience, just about any carbine spring/buffer combo will work. I've run my pistols with a DPMS carbine spring/buffer, but now i run them with a Spike's ST-T1 with a Spikes spring. I've never had a issue and neither will you. From what I've read, the barrels are causing the cycling issues and not the spring, buffer, or mag.

You're good. Have fun

Was it smoother with the ST-T1 and/or worth the extra money?

 

[TygerAR]

Was it smoother with the ST-T1 and/or worth the extra money?

Yes, the small gains in the action/cycle and quality, make's it worth if for me.

 

[komishe]

I also prefer the Spike's heavy buffer in mine. Smooths out the cycling a little and is easier on the brass.

Just wanted to add that I had to hammer my sb15 onto the phase5 tube pretty hard. I don't think it's coming off without a fight
I saw there was a company that makes a specific pistol tube to use with the sb15 brace that does not require so much force. I cannot recall who makes it.

Using the Sierra match king 300blk specific bullets with Lil'Gun, I was surprised to get ~3/4" average groups at 100y and less than 2" @200y.
It was neat to see but now I just load cheap stuff for plinking and hunting bullets for max safe velocity.

 

[redirt78]

All good info. I think the KAK tube is the one you're talking about but the tight fit on a Phase 5 actually sounds good. I like the end cap too

 

[komishe]

I think you're correct.
The sb15 brace ain't going anywhere on the phase5 that's for sure.
I do think it may crack with age as it's stretched out pretty good to fit over the tube........

You're gonna like the setup. It's sure a handy little pistol with surprising accuracy with the right loads.

 

[Birddog6424]

We started buying the Sig brace in mass quantities about 5 months ago. When the ATF came out with their "official" ruling that it was compliant, pistol carbine sales here at the shop exploded.

We've built and sold more of these in various length barrels than you can beat with a stick since that happened. We have used carbine buffers and springs on all of them without issue. Lots of different buffer tubes as well. Though the foam padded ones are suddenly out of style and no longer sell.

 

[Aye-Are-10]

I have used my brace/phase 5 tube for about two thousand rounds now and actually the thing im running into is that the brace is stretching! Its not moving quite yet but the front edge is rolling up just a bit. Im betting by 3k rounds it will be flopping in the wind. As soon as that happens im just going to SBR it as that was my plan in the first place. If youre not shooting it often, I wouldnt worry about that.

As for buffer, I believe im running a DPMS factory carbine spring with the spikes T2. Cycles subs without a can. Oh, I have a 9" AAC upper also.

 

[MSTN]

Keep in mind that the .300 BLK is a fairly low pressure round, just over half the chamber pressure of a 5.56MM. I've had much better results with lighter buffers in SBRs using Noveske .300 BLK barrels. Here's an early .300 BLK blaster built for testing by a certain suppressor outfit, utilizing a standard carbine recoil system with the lightweight carbine buffer:

Of course, your results will vary based on gas port diameter, location, ammo used, suppressed - yes/no, etc.

With the Vltor A5 recoil system, you definitely need to drop back to the A5-1 weight buffer with a Noveske .300 BLK SBR barrel. But, I prefer the A5-1 buffer for all my applications, anyway, regardless of caliber, and special order my Vltor A5 lowers so equipped.

My 8.2" Noveske .300 BLK runs like a top with the NEA stock and abbreviated recoil system:

Frankly, I was as surprised as I was pleased. Thank you, Eugene Stoner, for such a forgiving operating system!

 

[redirt78]

I know you've built a bunch of AR's, seen a lot of cool ones from you. I have a 16" 5.56 build with one of your N4 barrel/matched bolt that shoots great. I'm probably going to be mostly running factory supersonic ammo around 115 grains and factory 220 subs when I finally get to take my suppressor home. Since I already have a spare carbine buffer and spring I'll try that first and see how it goes.

AA10, I might run the SB15 brace for a while then apply for the SBR stamp also.

 

[Aye-Are-10]

I know you've built a bunch of AR's, seen a lot of cool ones from you. I have a 16" 5.56 build with one of your N4 barrel/matched bolt that shoots great. I'm probably going to be mostly running factory supersonic ammo around 115 grains and factory 220 subs when I finally get to take my suppressor home. Since I already have a spare carbine buffer and spring I'll try that first and see how it goes.

AA10, I might run the SB15 brace for a while then apply for the SBR stamp also.

Thats a good plan, you wont regret it. These things are a blast!