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Suppressors 30 cal Suppressed Bolt Build

Mbaysinger89

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Minuteman
Feb 13, 2017
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KS
Just got done with one rifle build and am starting to think of another. I would like to go with a caliber that is subsonic capable. Right now between 300 BLK and 308. Primary use will be plinking but will probably see some use calling coyotes at night in tight areas.

I like the 308 for its multiuse capabilites, could keep a mag with full power loads and select a different zero in the thermal scope for coyotes that hang up. I do not know the case fill with some of the powders used in 308, really dont want to play around with possible double charges or hangfires.

Pros for the 300 BLK is I a have a Howa .223 bf action sitting around and a couple thousand .223 Lapua brass laying, and plenty of CCI 400s. Would have to find powder.

Either rifle would be cut at 16.5, running a TBAC Ultra 7, and a chassis. I will need a chassis that can collapse to a very short LOP for a dedicated thermal scope, but can extend out for daytime plinking with a day scope.

What direction would you go for the cartridge and chassis? Any holes in the build I haven't considered?
 
Seems .300 blk fits the bill if the yotes aren’t 400 yards away. You already have most components. Barrels are readily available. I have no problem to 300 with an 8” barrel supersonic. Accurate 1680 is great for both super and sub. Fairly clean. Throws extremely consistently being ball powder so you can load fast and accurately. Best yet it’s been available periodically recently. 🍻
 
300 BLK seems more efficient. I would love to find a worthy sub 308 that feeds in mags. If you could replicate the Tubbs 2 hole loads, that would be out of sight! I am waiting on 8.6 BLK to come to market; It should be out by Fall.
 
I built several 300BO SBR chasing the perfect quiet thermal setup. At the end I've decided that there are big tradeoffs.

The softball like trajectory of subs makes shooting beyond 150yds quickly a challenge. I was unimpressed by 300BO groups both in subsonic and supersonic. My thermal is a clip on- 1.5" to 3" typical subs and 1" to 2" typical super.

I'm also not convinced that you need to shoot subsonic for hogs and coyotes. I'm not very experienced night hunting, so take that for what it is.

Where I am now, is I put the thermal on a 6.5 Grendel 18"AR and run suppressed. Flat shooting, fast follow ups and quiet enough for me.
 
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This has got me looking at 308 again.......

Trail Boss with 200, 208 and 225gr bullets are appealing; I assume a 1:10 twist will support them. Confirm without can first, though.
 
I had Caleb over at Alpha & Omega spin together this one for me last year.

16.5” 300 Blackout
Zermatt Origin
KRG Xray
Topped it with one of the Crimson Trace 1-5 scopes.

It does everything I need it to do.

0CB64A32-21C8-4FBD-B337-99F69979F726.jpeg
 
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I don't think you are missing anything. Really just figure out how much you are going to shoot sub sonic.

I'd pick the 308 because plinking sub sonic can get boring pretty fast in my experience. After the thrill is gone, you'll have a 308 which you can do anything with and can always, like you said, change the zero for back to subs when you want to play again.

For me, I found that subsonic or super sonic doesn't make a difference and sub sonic only limits your ranges. Hogs and deer run after the first shot regardless. I haven't tried subsonic at night based on what I saw during the day. Also, I shot some deer way high because of the flight path of the subsonic round when they were closer than 100. Not ideal. I had a 300BO but had mediocre results. It works but I found better rounds for my shooting ranges.

I've got a bergara ridge 308 cut to 16" with tbac ultra 7. Awesome truck gun. Got 4 hogs last time I went down to the farm just driving around.
 
I also have designs about doing a 12" 375 Raptor in a pork sword chassis. That would be real fun.

I have a 458 SOCOM 16" that I use with a Silencerco Hybrid. Fun, but loud even with Subs. I'm on an AR platform so bolt should be quieter. To my ear 458 subs sound like suppressed supers out of a 6.5 or 7.62. Supers are LOUD. Of course when I shoot at the range with no suppressor using the break I just piss people off. ; )

I had hoped for the quiet hammer of death, more like Thors hammer from the sound of it.

It is an absolute blast to shoot, wife loves it, she likes rifles that push back.
 
Just got done with one rifle build and am starting to think of another. I would like to go with a caliber that is subsonic capable. Right now between 300 BLK and 308. Primary use will be plinking but will probably see some use calling coyotes at night in tight areas.

I like the 308 for its multiuse capabilites, could keep a mag with full power loads and select a different zero in the thermal scope for coyotes that hang up. I do not know the case fill with some of the powders used in 308, really dont want to play around with possible double charges or hangfires.

Pros for the 300 BLK is I a have a Howa .223 bf action sitting around and a couple thousand .223 Lapua brass laying, and plenty of CCI 400s. Would have to find powder.

Either rifle would be cut at 16.5, running a TBAC Ultra 7, and a chassis. I will need a chassis that can collapse to a very short LOP for a dedicated thermal scope, but can extend out for daytime plinking with a day scope.

What direction would you go for the cartridge and chassis? Any holes in the build I haven't considered?
Subsonic .308 Win is a tricky beast. I've been making them for years. For case fill, use Trail Boss powder (large donut grains).

Prefernce over the 2 for mostly subsonic and plinking, I'd go .300 BLK. It utilizes all the powder and potential with subsonics at subsonic velocities, and isn't wasting any potential. Running the .308 Win with subs is a whole different beast. Like I said, for ease of use, I'd just stick with a .300 BLK and H110, CFE-BLK, Lil Gun, or 300-MP powder with subsonics. Because a .308 caliber bullet being pushed to 1,050 FPS will function the exact same, regardless of whether it's being shot from a rifle chambered in .300 BLK or .308 Win. Best efficiency is a cartridge designed to do that from the start... Like the 300 BLK.

Plus, making brass from cheap surplus (or your once-fired range) 5.56 brass is SUPER cheap and easy to do. Get the VZ57 jig, and the Harbor Freight 2" mini chop saw, a Little Crow WFT2 trimmer w/ 300 BLK head, and you're ready to rock and roll. Chop, Form, Trim, polish in the tumbler... You can pump out 250 pieces of high-quality & ready-to-load 300 BLK brass in an hour (taking your time while watching TV in the background).

I love my .300 BLK and 6.5 Grendel AR's I built, so I plan on getting Ruger American Ranch rifles in both cartridges soon, as well. Something about shooting a suppressed bolt-action that just gives you so much satisfaction... Not to mention the added sound suppression and DB drop being a bolt-action and not a gas-powered AR with port-pop.
 
I'm also not convinced that you need to shoot subsonic for hogs and coyotes. I'm not very experienced night hunting, so take that for what it is.
Definafely don't NEED. Just fills a gap in the arsenal I'm trying to find. I shoot 22-250, 20 Prac, 204, 243 for coyotes. The blast usually doesnt keep doubles from coming. Don't need thermal either, just have to be able to somewhat justify the expediture to the wife for her to sign off.
For me, 30 cal subs are for plinking fun. If someone suggested to me building a 16" 308 to hunt with outside of the discussion of subsonic use, I'd probably give them the stink eye. Why not just a Grendel? It's my favorite cartridge for deer and pigs.

The Grendel is a neat round, but I already have lonely deer caliber rifles and don't need anymore plinking or hunting ARs. If I were going to do something like that in a bolt rifle I would build a 6.5 BR or 6.5x47 , but theres no subsonic fun with those.
 
9 twist 308. Run any standard pet load for supersonic and a 220 grain/Trail Boss sub load for quiet close range stuff.
 
I have a 458 SOCOM 16" that I use with a Silencerco Hybrid. Fun, but loud even with Subs. I'm on an AR platform so bolt should be quieter. To my ear 458 subs sound like suppressed supers out of a 6.5 or 7.62. Supers are LOUD. Of course when I shoot at the range with no suppressor using the break I just piss people off. ; )

I had hoped for the quiet hammer of death, more like Thors hammer from the sound of it.

It is an absolute blast to shoot, wife loves it, she likes rifles that push back.
I almost built an AR in 458. I ended up building an AR in 45ACP, mainly because CMMG had a delayed blow back and it makes a world of difference with sub play. The cycling of an AR alone is not quiet, FWIW. I have not noticed that they have made a 458 or any rifle calibers with the delayed design; Perhaps the pressure is too much past pistol cartridges? Maybe you could speak with them in regards to doing one in 458? The modification seems like something a person with basic machining experience could pull off. You basically lose the gas system and angle one side of the lugs. The recoil impulse is transmitted to the carrier by the time the pressure is safe.
 
I almost built an AR in 458. I ended up building an AR in 45ACP, mainly because CMMG had a delayed blow back and it makes a world of difference with sub play. The cycling of an AR alone is not quiet, FWIW. I have not noticed that they have made a 458 or any rifle calibers with the delayed design; Perhaps the pressure is too much past pistol cartridges? Maybe you could speak with them in regards to doing one in 458? The modification seems like something a person with basic machining experience could pull off. You basically lose the gas system and angle one side of the lugs. The recoil impulse is transmitted to the carrier by the time the pressure is safe.
The 458 is direct impingement, so the bolt is locked until the gas from the barrel releases it.

The delay blowback is better than non blowback, but this only applies to pistol caliber carbines.