TexasCHLforum.com

psijac wrote:IWI has released a 300 blk conversion kit for the Tavor. Also Sig MCX can be converted to a 300 black with a barrel and rod change. Both of those rifles are piston.

That's good information, thanks. Unfortunately, I've already registered the SBR for an AR lower, so for this build I'm committed to that platform. Perhaps when I decide on a 7.62x39 platform I'll take a look at the Sig. I know the TVOR is a fine weapon, but I just don't have a personal desire for a bullpup.

Weg wrote:

"One thing..... and others can correct me if this is wrong.... but it seems that the only way to get a suppressed .300 Blk SBR to cycle reliably in an AR platform is to (A) avoid gas-piston systems generally and (B) to stick to pistol-length gas systems specifically. That first one breaks my heart as I've become a devotee of gas-piston systems, and the direct impingement SBR upper will just end up pooping all over the innards of my 'til now pristine AR15...... which of course is perfect justification to build out another Spikes Tactical/Timney/MFT lower to keep my 5.56 carbine upper mounted on.

"

Mine has a pistol length gas system with a 16" barrel and it functions fine with everything, and yes, it gets very dirty, especially with the suppressor on it.

Weg, how dirty is "dirty"? I have noticed that when shooting my 5.56 upper suppressed, even with the gas-piston system, if I remove the magazine while it still has rounds in it, the metal of the remaining cartridges is dull and obviously dirty with something, although it is more like a dulling of the metallic sheen, rather than visible crud. The magazines appear to get dirty faster too. The dirty cartridges feed just fine. Unsuppressed, the gun runs clean as a whistle with the GP operating system. It just gets a little noticeable dulling of the metal finish on the barrel around the gas block (it's a matte finish stainless barrel), which wipes right off. I'm asking all of this, because I'm curious how much of the dirt in your gun is from the pistol-length gas system, and how much is from the suppressor?

Surgeon wrote:

Weg wrote:I have a .300 Blackout AR. I bought it for suppressed shooting, both target and hunting. I started hand loading it and have found it to be reasonably affordable. I have a Gemtech HVT-QM on it. I have shot 3 deer thus far using hand loaded sub-sonic Lehigh Defense 194 grain Maximum expansion bullets with no issues. Overall, if I was not wanting to shoot suppressed and as quite as possible I probably would have just stuck with a 5.56 AR, but for what I use it for it is great. I have never had jamming or feeding issues with it, and my subsonic hand loads work fine.

That's want it for as well plus my hearing is starting to go. I've heard the recoil is less and allows you get back on target sooner too.
Thanks for the feedback.

I e-filed a Form 1 for a .300 Blk SBR a couple of weeks ago. Like the OP, I own other .30 caliber rifles (except mine are all in .308 Winchester except for a single Mosin Nagant and an old M1 Carbine), but I specifically wanted something that would be useful in the following two situations: (1) Home Defense; and (2) Hog & Deer hunting at shorter ranges. My hearing has suffered over the years too, and they ring all the time. That was one reason I bought my first suppressor - an AAC 762-SDN-6, which was originally developed for the .300 Blk cartridge, but works just dandy for 5.56 NATO and .308 Winchester.

My upper will have a 10.5" barrel, and I imagine that I will almost exclusively shoot suppressed subsonics in it....since that is the whole point of the project. Like the OP, I've been doing my research and talking to those who know more than I do. It appears that a 220 grain HPBT or ballistic tip bullet at subsonic velocities will knock the bejabbers out of whatever it hits inside of 300 yards. I found this graphic while surfing around:


#16 sounds magical.

One thing..... and others can correct me if this is wrong.... but it seems that the only way to get a suppressed .300 Blk SBR to cycle reliably in an AR platform is to (A) avoid gas-piston systems generally and (B) to stick to pistol-length gas systems specifically. That first one breaks my heart as I've become a devotee of gas-piston systems, and the direct impingement SBR upper will just end up pooping all over the innards of my 'til now pristine AR15...... which of course is perfect justification to build out another Spikes Tactical/Timney/MFT lower to keep my 5.56 carbine upper mounted on.