300 blackout

[samson7x]

Anyone have experience with this round? Particularly with subsonic rounds and suppressor? I plan on either building an upper or buying one to run with my TiRant 45 until I can afford a more appropriate suppressor. I was wondering what you all may have and if it runs well with subsonic rounds. What should I look out for? I was looking at a core15 barrel for ~250 with 1:8 twist for a build. This will be a 16" barrel as I don't want to mess with the SBR process at this time.

[atlas3025]

I have one that I run a 9mm can with a 10 inch 1:8 twist AAC barrel with a pistol length gas system on. I never have tried especially hard to shoot tight groups. I like to shoot steel plates with it at 50 and 100 yards, and it does that wonderfully. I use an EOTech 512 and 3x magnifier on it. It isn't especially quiet with the 9mm can, but it is hearing safe. I have a 30 cal can coming for it when the stamp comes back that will be much quieter.

I haven't played much with supersonic, only running 1 box of the remington supersonic ammo, but I have played with subsonic a lot. The factory Remmie 220 gr sub ammo only clocks around 875 FPS out of my short barrel, but will probably be close to 1000 for you out of the 16".

I have been playing with 10.5 grains of 4227 and a 200 grain hot core bullet and a light factory crimp with Tula small primers, and I have been pretty happy with it, as it clocks around 1050fps. Strangely, when I use that same load with 208 grain AMAX's, it goes supersonic...no idea why the heavier bullet is going faster with the same charge, unless there is a little compression, but I can't imagine that would add another 100fps.

Either load cycles the gun fine.

I think some are doing a 1:7 twist now, which works with bullets over 220 grain better. I would probably try that if I had it to do over because there are some 240 cast lead bullets out there which would be cheaper to load.

There is a lot of info on 300blktalk.com

Edited June 5, 2012 by atlas3025

[samson7x]

I have one that I run a 9mm can with a 10 inch 1:8 twist AAC barrel with a pistol length gas system on. I never have tried especially hard to shoot tight groups. I like to shoot steel plates with it at 50 and 100 yards, and it does that wonderfully. I use an EOTech 512 and 3x magnifier on it. It isn't especially quiet with the 9mm can, but it is hearing safe. I have a 30 cal can coming for it when the stamp comes back that will be much quieter.

I haven't played much with supersonic, only running 1 box of the remington supersonic ammo, but I have played with subsonic a lot. The factory Remmie 220 gr sub ammo only clocks around 875 FPS out of my short barrel, but will probably be close to 1000 for you out of the 16".

I have been playing with 10.5 grains of 4227 and a 200 grain hot core bullet and a light factory crimp with Tula small primers, and I have been pretty happy with it, as it clocks around 1050fps. Strangely, when I use that same load with 208 grain AMAX's, it goes supersonic...no idea why the heavier bullet is going faster with the same charge, unless there is a little compression, but I can't imagine that would add another 100fps.

Either load cycles the gun fine.

I think some are doing a 1:7 twist now, which works with bullets over 220 grain better. I would probably try that if I had it to do over because there are some 240 cast lead bullets out there which would be cheaper to load.

There is a lot of info on 300blktalk.com

Thanks a lot for the info. What 9mm can are you using?

Side question: Can you give me more info on the 3x magnifier? Im not versed on optics. I just put a cheap red dot on my 5.56.

[Shorty]

I have one I built with the Wilson lightweight tactical barrel, believe it was about $250. I've run about 100rds thru it with zero issues, but I've only shot supersonics out of it so far. When my buddy's suppressor comes in I'll try some subs. Took it to the range over the weekend to sight the irons and my scope with the Rem 115gr UMC and PNW 147gr. I prefer the PNW, seems more consistent.

Edited June 6, 2012 by Shorty

[nightrunner]

Admittedly i have very little knowledge of suppressors or details of how they work but wouldnt the extra pressure difference between a rifle round and a pistol round be enough to possibly damage a pistol suppressor? Or is the fact that its a subsonic round bring pressures low enough it to not matter?

Just curious

[samson7x]

Admittedly i have very little knowledge of suppressors or details of how they work but wouldnt the extra pressure difference between a rifle round and a pistol round be enough to possibly damage a pistol suppressor? Or is the fact that its a subsonic round bring pressures low enough it to not matter?

Just curious

Yes, the use of supersonic rifle rounds could damage the blast baffle in a pistol suppressor. Subsonic, on the other hand, is safe to use given that you are using a quality can. The TiRant is a quality can and AAC supports the use of subsonic 300 blk through it. Obviously performance will be greater with a 30 caliber can, but that is another 6-7mo wait so this will suffice for now.

[atlas3025]

To echo Samson, supersonic through a pistol can will likely seize the threads up and you will never be able to disassemble your pistol can again. Heat would become an issue if you did rapid fire. With a rifle can, no issues. I have shot ONE supersonic round through my pistol can (ammo got mixed up) and it made my can REALLY hard to take apart. Another few super rounds and I probably would have ruined it.

I am just using a cheapish Vortex 3x mag. It is MUCH better than one of the knockoffs or a Sitemark, but doesn't have quite as much eye relief as an Aimpoint of EOtech, but enough for the Blackout, even supersonic. Of course, it is a third of the price of those high end pieces. The optics are clear and it is adjustable so you can center the reticle in the picture. It really helps out to 200 yards, but isn't going to help much beyone that.

Edit, I should ad that a magnifier may not work all that well with a cheap red dot, depending on the dot clarity. I used my mag with a Tasco ProPoint red dot, and the dot was so blurry that it wasn't useful (with no mag I love the Tasco, and it looks clear).

Having said that, I used it with a cheaper BSA red dot, and it worked fine. The dot is smaller and tighter in the BSA sight that in the Tasco. The EOTechs have a VERY well defined reticle, so it still looks crisp through the magnifier.

Edited June 6, 2012 by atlas3025

[samson7x]

To echo Samson, supersonic through a pistol can will likely seize the threads up and you will never be able to disassemble your pistol can again. Heat would become an issue if you did rapid fire. With a rifle can, no issues. I have shot ONE supersonic round through my pistol can (ammo got mixed up) and it made my can REALLY hard to take apart. Another few super rounds and I probably would have ruined it.

I am just using a cheapish Vortex 3x mag. It is MUCH better than one of the knockoffs or a Sitemark, but doesn't have quite as much eye relief as an Aimpoint of EOtech, but enough for the Blackout, even supersonic. Of course, it is a third of the price of those high end pieces. The optics are clear and it is adjustable so you can center the reticle in the picture. It really helps out to 200 yards, but isn't going to help much beyone that.

Edit, I should ad that a magnifier may not work all that well with a cheap red dot, depending on the dot clarity. I used my mag with a Tasco ProPoint red dot, and the dot was so blurry that it wasn't useful (with no mag I love the Tasco, and it looks clear).

Having said that, I used it with a cheaper BSA red dot, and it worked fine. The dot is smaller and tighter in the BSA sight that in the Tasco. The EOTechs have a VERY well defined reticle, so it still looks crisp through the magnifier.

Of course, I have no intention of using it with my cheap red dot. In the (near?) future I plan on buying an Eotech and would reserve its use for that.

[atlas3025]

I think you would be happy with it then. If you look at the Vortex, you can find packages with a nifty American Defense Swing Mount online for a good deal cheaper than I have seen them at gun shows. I think that combo runs around $250 online, but I have seen it $100 more at shows.

Of course, it the funds are available, the EOTech or AimPoint are top of the line. There is also the Burris Tripler that is about the same cost as the Vortex, but I have no experience with those.

[Guest BungieCord]

The problem with the 300 Blk right now, from my slightly lopsided point of view, is the lack of suitable bullets for subsonic hunting ...or SD. The heavy bullets are only ~220-gr, and most of those are pointy-nosed, high-BC bullets that will not expand properly at subsonic velocities. The Hornady Interlock bullet (to include the 220-grainer) supposedly tumbles after 2" of penetration, but where have we heard that before?

So I looked at the .338 Spectre, which also runs in the AR15 platform. At least then you have the option of the excellent 300-grain Woodleigh bullet. But a 300-gr subsonic bullet still does not to me seem enough of a step up from a 231-gr .45 to be worth the extra expense, weight and complexity of a long gun (accuracy, of course, is a different kettle of fish).

Next stop after that is the big bores, the 450 Bushy, 458 SoCom and .50 Beowulf. There's no shortage of heavyweight bullets there, but they do tend to be ridiculously expensive.

The Engel Ballistic Research 7.62x39 Jackhammer round will run in an AK (after a little ramp work), which got me to thinking I could cook up my own loads for my AK, which I already run suppressed, but with a less blunt bullet so I don't have to modify my ramps. Maybe that would soothe my subsonic jonesing until the Blackout draws enough attention that somebody starts building suitable heavyweight bullets specifically for it.

[atlas3025]

That's a good point. Not to be combative at all, but why would you hunt with a subsonic load anyway? With any subsonic 30 cal round, I would think that 100 yards would be about the limit for a humane kill, regardless of bullet performance. Would you want to limit your range to that?

I don't hunt anymore, but even in East TN I think you'd like to be able to kill at 200 yards, thought that may be about the outer limit for what is typical here.

[Caster]

That's a good point. Not to be combative at all, but why would you hunt with a subsonic load anyway? With any subsonic 30 cal round, I would think that 100 yards would be about the limit for a humane kill, regardless of bullet performance. Would you want to limit your range to that?

I don't hunt anymore, but even in East TN I think you'd like to be able to kill at 200 yards, thought that may be about the outer limit for what is typical here.

Well, depends on your style of hunting. I don't hunt anymore either but I let anything past 75-100 yards or so walk. Much prefer to get closer. It takes more skill, or in my case dumb luck, to get in close.

[samson7x]

The problem with the 300 Blk right now, from my slightly lopsided point of view, is the lack of suitable bullets for subsonic hunting ...or SD. The heavy bullets are only ~220-gr, and most of those are pointy-nosed, high-BC bullets that will not expand properly at subsonic velocities. The Hornady Interlock bullet (to include the 220-grainer) supposedly tumbles after 2" of penetration, but where have we heard that before?

So I looked at the .338 Spectre, which also runs in the AR15 platform. At least then you have the option of the excellent 300-grain Woodleigh bullet. But a 300-gr subsonic bullet still does not to me seem enough of a step up from a 231-gr .45 to be worth the extra expense, weight and complexity of a long gun (accuracy, of course, is a different kettle of fish).

Next stop after that is the big bores, the 450 Bushy, 458 SoCom and .50 Beowulf. There's no shortage of heavyweight bullets there, but they do tend to be ridiculously expensive.

The Engel Ballistic Research 7.62x39 Jackhammer round will run in an AK (after a little ramp work), which got me to thinking I could cook up my own loads for my AK, which I already run suppressed, but with a less blunt bullet so I don't have to modify my ramps. Maybe that would soothe my subsonic jonesing until the Blackout draws enough attention that somebody starts building suitable heavyweight bullets specifically for it.

I see your point, but Im not particularly interested in hunting with this cartridge. It will almost exclusively be used for subsonic suppressed plinking. If I do decide to take a deer with it, I would likely use a supersonic round unsuppressed. If I was using it for hog hunting, I would think about the 240gn Sierra round that seems to be getting a great deal of hype. It appears that it's performance is more than sufficient for hogs, but sadly I do not have a place to hog hunt back home (in AR.)

[hlb14]

is a 300 blk barrel all that is needed to go from .223 to 300 on an ar? or is it more involved?

[samson7x]

is a 300 blk barrel all that is needed to go from .223 to 300 on an ar? or is it more involved?

That is all that is needed. 300 uses the same BCG and mags. My only concern is using subsonic rounds both suppressed and unsuppressed.

[Dolomite_supafly]

is a 300 blk barrel all that is needed to go from .223 to 300 on an ar? or is it more involved?

That is pretty much it

You might have to get a different gas tube depending on the location of the gas port. Some barrels have a pistol length system and some use carbine length.

Dolomite

[hlb14]

thanks!