300blk In Precision SBR Bolt Action

[vinniedelpino]

What’s the go-to setup for a 12” bolt gun in 300blk that will be 100% suppressed?

This will likely be in a pork sword folder chassis with a bighorn origin and tbac 7.

I used to have a factory 16” remmy that was a blast to plink cans with and stupid quiet with underpowered loads that couldn’t come close to cycling a gas gun. Even though it was painfully inaccurate it was still fun.

Any feedback helps.. twist rate, load data etc.

Is MOA even achievable with this kind of setup?

 

[Snuby642]

Moa in a 300 blk subsonic shorty.

Definitely not a given, good luck.

 

[corsairpilot62]

Bro, Q mini fix. Done.

 

[264win]

I have been doing a lot of load testing in a cheap Ruger American 300 BO with 16” 1-7 twist barrel. It’s not the easiest to shoot and is very rough but I have been able to get sub moa 5 shot groups @ 100 yds. I can’t imagine you would have any trouble replicating that in a quality rifle.

 

[redbullitt]

I have a decently high round count on an 8 inch mini fix, cz527 wlth a 16 barrel , and an 8 inch encore in 300 blk. I mention the cz because I really like the controlled round feed for the 300blk with odd bullets etc.

Accuracy has been easily moa or better with supersonic jacketed and typically 1.5 to 2.5 moa with cast loads. 3 inches at 100 yards is realistic for lots of sub loads. Some will do better and usually can get some combos close to moa or a little better. Accuracy with subs is typically similar to a normal .22 lr unless you get lucky or do some decent load development.

The mini fix or something similar is an awesome setup, if you can afford one go for it. Youll love it.

If you can cast bullets you have an insane amount of options from round balls, 50g buttons basically up to 300g or more.

For twist it's gonna depend on what bullet/s you're planning to use. I've shot both 8 twist and the faster 7. No issues with typical bullets. If you plan on subsonic for the suppressor then I think the 7 twist is better for typical 220smk and similar cast use vs. the 8 twist, give a little more wiggle room on stability hopefully. If shooting a longer bullet, then may need to speed up the twist.

As far as loadings, a light cast coated bullet is the ultimate little plinker. Hornady makes a little semi jacketed bullet ( i dont trust through a can fwiw) and an awesome little xtp. The xtp is great on pests at 1000fps and is very quiet and plenty consistent. Suppressed it will be mousefarts, especially so if you're closer to 900 to 950 fps with fast powder.Trailboss can be fun and effective here as well as the fluffy fast stuff.

Don't neglect the middle weight bullets. A 175smk 180rn can be very quiet and shoot well, and the 30 30 bullets, too, like the ftx.

 

[Zigjib]

Dunno how useful this will be to you but we did testing in the 300blk. This is our 12.5" barrel results.

There's no accuracy results here but this is the energy.

Accuracy wise, the hand loaded nosler 125gr was the best, but the 110gr V-Max was awesome as well for the light and the Winchester Deer Max ammo was really good close range too for that middle weight.

The Remington Factory 220gr was all over the place FPS wise. ES was massive but impacts on plate were 10/10 at 200m on a 20cm plate. We had it out to 300 and 500m as well, but i'd be lying if I listed impacts for those ranges. Wasn't as bad as you'd expect.

The shorter barrels were done for comparison sake but the 18.5" gun is the bomb with 300blk ammo. We are able to hit targets at 1000y with the 125gr Nosler ammo.

our 18.5" is a remington 700. Platform wise, i can't really help there sorry.

 

[Hoser]

Best I had found was Vhit N-110 under Berger 230s or 215s. 8 twist Benchmark and Bartlien.

With my 16 inch DTA Covert I still get occasional weird fliers but out past 300 yards it is still holding under 1 MOA. I got so pissed that I could not figure out the flier issue, I took the S&B 5-25 off tossed on the Kahles 3-18, got a zero and pushed it to the back of the safe.

 

[264win]

Best I had found was Vhit N-110 under Berger 230s or 215s. 8 twist Benchmark and Bartlien.

With my 16 inch DTA Covert I still get occasional weird fliers but out past 300 yards it is still holding under 1 MOA. I got so pissed that I could not figure out the flier issue, I took the S&B 5-25 off tossed on the Kahles 3-18, got a zero and pushed it to the back of the safe.

My testing is by no means conclusive, but in trying over 100 different loads recently, it seems to me that eld/vld secant type bullets are much more finicky and very prone to flyers in subsonic loads.

Switching to more conventional tangent type bullets made a big difference in the two rifles I was testing.

Btw, 700x is a very underrated powder for this use, especially in the 160-200 gr weight bullets. 5-6 gr has given great accuracy and very low noise for me.

 

[SkyScrapin]

Ive had the best luck with lighter bullets in the 180-190g range than the heavies when it comes to subs. The faster twist didn’t work great for accuracy but a standard 10T was perfect. Not sure if it was a fluke, but no problem hitting steal at 300y.

 

[SkyScrapin]

My testing is by no means conclusive, but in trying over 100 different loads recently, it seems to me that eld/vld secant type bullets are much more finicky and very prone to flyers in subsonic loads.

Switching to more conventional tangent type bullets made a big difference in the two rifles I was testing.

This was my experience. Berger Juggernauts and 190 SMK worked well.

 

[FuhQ]

Bro, Q mini fix. Done.

 

[Snuby642]

I run 220g round nose flat base bullets. Cfe blk at max recommended load. 1015 fps from 16 inch barrel. Cold day.

Both barrels are 1/7 twist one a rem 7oo bolt gun and the other a 10 inch sbr gasser. Both suppressed.

The bolt gun gets 1 moa the sbr gets 1 1/2 at best.

I didn't buy iether of them for shooting past 100 yards.

This is just for a comparison as some guys have put a lot more development into thier loads.

I could put a few more tenths of powder in them to get to 1050fps but Texas is running 100 degrees Fahrenheit with 115 heat index and I don't want them to pop in the summer.

 

[wind gypsy]

What about subs that actually expand for dispatching coyotes and other vermin in the yard when noise is a concern? Anyone have any recommendations for that application?

 

[hlee]

What about subs that actually expand for dispatching coyotes and other vermin in the yard when noise is a concern? Anyone have any recommendations for that application?

Maker Bullets makes 30 cal bullets that expand at subsonic velocities.

 

[FuhQ]

Maker Bullets makes 30 cal bullets that expand at subsonic velocities.

Hornady Sub-X bullets are, as well...

 

[FuhQ]

Subsonics at distance (200 yards)... I'll just leave this here...

 

[AMMOWASTER]

I bought a Howa to put together for the same thing. One of these days I might get around to it.

 

[Dead Eye Dick]

We built a 300 Whisper to shoot handgun silhouette. Beautiful gun, spent a fortune. Never got it to shoot. Extreme spreads of 100FPS which is a ten percent spread. When it hit the 65 pound steel rams, they went down like hit by Arnold S. Using a heavy sledgehammer. But hitting them was the thing. Fun to watch the bullets, not the trace, the bullets fly down range. Really wish I could have gotten it to work, virtually no recoil, great momentum, it had everything but accuracy.

Tried every bullet I could find including cast bullets. Used every powder even close to WW296 on the reloading charts. Tried cotton stuffing to keep the powder charge stable.

Funny thing I never could explain. When fired with the cotton wadding in front of the powder and behind the bullet, the cotton would fly out of the barrel, completely clean and white without a touch of scorching or burn marks. Good enough to use again, but I didn’t. Strange.

We have a Ruger Ranch in 300BO. Basically only use 110 and 120 grain bullets. Killed at least one deer with the 120 grain . Not impressed with the bullet. pencilled right through the deer. And the deer ran quite a ways. But we got em.

Some day, I’ll dig out that XP100 from the back of the safe, load it up with some 110’s super sonic and see how it shoots. Problem is, my XP100 in 7TCU is super accurate, super easy to shoot and does the job. however, kind of a moot point, as they are dedicated IHMSA handguns and my going back to that event is highly unlikely

 

[padom]

I run 220smk with CFE Black in a 10.5" sbr AR. Stupid quit and crazy accurate.

 

[Hoser]

My testing is by no means conclusive, but in trying over 100 different loads recently, it seems to me that eld/vld secant type bullets are much more finicky and very prone to flyers in subsonic loads.

Switching to more conventional tangent type bullets made a big difference in the two rifles I was testing.

I also tried Sierra 175, 190, 220 and some Berger 185s. Several other powders as well.

No matter what I did, the first round from a "cold/warm bore" always went low. At 300 yards the rest of the magazine (5-10 rounds) would go into a 2-3 inch group. All charges weighed to within .02 and stuck into Lapua brass.

I gave up and just kinda accepted the fact that the first round is most likely going to be a miss on small targets past 150-200 yards.

 

[padom]

I also tried Sierra 175, 190, 220 and some Berger 185s. Several other powders as well.

No matter what I did, the first round from a "cold/warm bore" always went low. At 300 yards the rest of the magazine (5-10 rounds) would go into a 2-3 inch group. All charges weighed to within .02 and stuck into Lapua brass.

I gave up and just kinda accepted the fact that the first round is most likely going to be a miss on small targets past 150-200 yards.

I dealt with this same.issue and random flyers on several 300blk AR barrels when doing accuracy testing with supers and subs. I went through 3 barrels and almost gave up saying 300blk wasn't accurate until the last barrel I tested is a tack driver. I have since tested 2 more of these same barrels and just as accurate as the first one.

Rainer Ultramatch 300blk 10"

Rainier Arms Ultramatch MOD2 300BLK Barrel - 10\

Rainier Arms Ultramatch MOD2 300BLK Barrel - 10\

www.rainierarms.com

125 TMK H110 Supers






220 SMK CFE Black Subs

 

[Hoser]

I did not try CFE. I will give that a try. Many thanks.