Home Forums Hunting & Shooting AR and Tactical Rifles New 300BO setup

10.5" upper from Palmetto. PA 3x Micro Prism with ACSS reticle. Just zero'd at 38 yards to align the ACSS reticle fairly close out to 500.

Seems like a good shooter, I'm liking it.

Cool - I never wanted a 300BO till I started thinking about a SBR suppressed as night stand gun.

I haven't gone down the suppressor rabbit hole. But this is a lot less 'blasty' than a shorty 5.56.

The 110gr VMax expands well from these short 300BO rigs also.

I have a 10.5" 300 Blk upper from PSA, as well. Mine shoots better than expected, and cycles with a variety of my subsonic handholds.

I'm very happy with my PSA SBR in 300. Runs supers and subs flawlessly. I did swap the carbine buffer and spring that came in the lower with a stronger springco spring and H2 buffer. Probably could have gone H3, but the subsonic brass ejects at 4 o'clock and it runs everything great so I'm reluctant to change things.

Currently running a Gemtech Tracker on it but have a Nomad Ti in jail that will be the permanent can.

Got lots of bullets to run through it, but my main supers are Hornady 135gr FTX and subs 200gr SMK. I will eventually move up to 220s for subs but I have a couple thousand 200s to use up first. Lil Gun for the supers and 1680 for the subs.







I never wanted one either until I started shopping for a suppressed 9mm for the home/truck. They are so big I thought might as well just get an SBR. Glad I went the SBR route.

Had a PSA upper and sold it, .300BO in a bolt gun suppressed is a fun time though. Mine gets a lot of back door garden gun duty keeping rabbits and groundhogs at bay at about 50yds off the deck. Wish I had a 6xMQ for it but the 1-4x does ok.

I'm using an H3 buffer and standard carbine spring in this pistol, and in a 16" carbine with pistol gas system. It's smooth running on both rigs.

I only have supersonic ammo on hand. 110gr VMax, 125gr FMJ, 150gr FMJ, and some of that AAC 150gr Saber Blade stuff.

Here's a pic of the Ruger American Ranch,

I like the idea of a .300 Blackout SBR. I need to look into setting a gun trust up for the SBR.

I'd say there's a cheaper way to do this but if you're really wanting the easy button....

From my research a Form 1 is way faster than the Form 4 so I'll be buying a stripped lower and going that route rather than the more expensive DD lower.

Definitely better to buy the upper and lower separately and form 1 trust. Lower does not need to be stripped. Mine got approved in 10 days in November.

No - lower doesn't need to be stripped but I want a Geissle trigger and the Kung Fu grip and specific stock etc - it's easier to just assemble one myself.

Wow. That's incredible.

I have a 10.5" 300BO and I dont think there is a more capable and cool set up in the world. Sweet build man you will enjoy it. Nothing suppresses better or is more fun to shoot that one of these rigs.

I'd suggest the 350 legend subsonic suppressed. I have both. Had the blackout a few years before the legend. Loved the blackout now the legend gets the nod most times. 250 subs and 150 supers, more power and more range.

This is a titanium Form 1 can for my AR 300 BO using 230 gran powder coated cas plain base bullets and 9 grans of H-110 at 900-1,000fps at .38" at 50 with a Thor 4 Does OK on small size hogs.



The 358 MGP and 300 BO cast and powder coated


The 358 MGP is for the bigger hogs, 500-600 pounders, it pushes a 200 RCBS at 2,500 fps and .43" at 100.

I have never seen or heard of this 358 map, but I think I like it. Looks easier to reload than the legend.

Nice setup.

I’m getting ready to buy/build similar, mostly for a truck/range gun.

For those that have both, pros/cons of .300 vs 5.56?

Non-suppressed, ammo availability and cost is non issue.

I've got 10.5" uppers in 5.56, 300BO, and 7.62x39. Here's how they stack up in my experience. These are generalizations, nothing is engraved in stone.

Ammo availability/cost - Advantage 5.56. (However, during one of the shortages, there was still plenty of 7.62x39 at a fair price, and that's when I got into that chambering)

Trajectory/effective range - Advantage 5.56 (if you like to stretch them out past 100 yards or so)

Muzzle blast - Advantage 300BO

Versatility for sub/super - Advantage 300BO

Lethality - either one, choose ammo according to desired effect.

Suppressability - Advantage 300BO

Care to share your powder choice and charge weight? Must be some magical stuff….

When u say less blasts you meaning concussion with supers?

I’d be curious what report to the ears with subs would be on that 10.5” vs regular 55gr at 16”…

Gears spinning but a p&w griffin gp5 on a chf cl the 10.5 barrel would be cheap to shoot, ez on the ears, and be fine on a lot of pests (2 and 4 legged) with supers.