SBR and Pistol. Is it the only smart way to go for 300blk?

[MaconGuns]

Ok I gotta ask. I read this. Not sure how accurate it is but the reason I searched for it was I thought 300 BO was designed for suppressed close combat.

"once you drop the bullet weight to gain enough powder to make the 300 Blackout supersonic/high-velocity so that it will actually cycle in your average AR-15, you gain nothing over the .223 round. In fact at the 300-yard mark your typical 68-77 gr .223 round will be delivering more energy than that 300-Blackout/Whisper round, and at the muzzle they are nearly identical."

If you keep it sub sonic at 600 yards won't it loose a lot of power and if you shoot it supersonic why not shoot something else?

For that role, I would have thought something in 308 would be preferred.

Posted while I was writing. I was thinking the same thing

 

[cmshoot]

For that role, I would have thought something in 308 would be preferred.

I've already got plenty of .308's. 600yds is short range for a .308, with added weight, noise and recoil.

The 16" bolt action I'm doing will serve 2 roles. With transonic ammo, my daughter will deer hunt with it. With a mix of transonic and subs, I'll shoot demos with it in my Guerrilla Sniper course. I've also got a 16" Steyr SSG69 that I'll run, and a JPE LRP-07 .308. All about showing the students different tools for the job at hand, along with their pros and cons.

The bolt action .300Blk is a Remington Model Seven action with a tapered, threaded AAC 16" barrel, in a side-folding MDT chassis. It will be topped with a Nightforce 2.5-10x24mm. Lightweight, eminently portable and concealable, and capable of both close range suppressed shots and longer range shots.

 

[cmshoot]

My transonic .300Blk load is a 125grn NBT at 2100fps for 1224 ft/lbe.

Out of a 16" barrel, my 70grn Hornady GMX 5.56 round is doing 2652fps for 1093 ft/lbs.

The 16" .300Blk bolt action gives me a lot of options in ammo used and engagement distances.

 

[Burdy]

My transonic .300Blk load is a 125grn NBT at 2100fps for 1224 ft/lbe.

Out of a 16" barrel, my 70grn Hornady GMX 5.56 round is doing 2652fps for 1093 ft/lbs.

The 16" .300Blk bolt action gives me a lot of options in ammo used and engagement distances.

I met Nathan Foster, who is someone from NZ that does a ridiculous amount of live game ballistic studies, at SHOT this year from NZ, here is some of this takes on .300 BLK from the show. He has sent an email out afterward, I thought it may be of interest to you even if you don't have the same view points. I have a 10" .300 BLK gun that the stamp should be back by next week, so I am on the hunt for a good performing whitetail cartridge for next year as well. It seems the 110 Barnes TSX is popular here on ODT.

From Nathan:
"Later in the event I got to talk with folk from Cutting Edge and also Lehigh. In both instances it was interesting to see that these homogenous copper bullet makers have come to understand the need for a bullet that loses some weight and SD as a means to maximize energy transfer. A main factor has been the .300 Blackout which can be a hopeless hunting cartridge if used with the wrong bullet design. This has pushed many bullet makers towards a deeper understanding of terminal performance. Prior to this, I felt that too much emphasis was placed more on getting the bullet to reach its target and generally expand to create a 'nice looking' mushroom. I very much liked the fact that Lehigh utilize a wide meplat for maximum energy transfer across all of their bullet designs. This is about doing what is right rather than doing what is fashionable (e.g maximum BC)."

Justin Evans from Lehigh defense. I (Nathan) am holding the latest Blackout bullet from Lehigh, showing performance at 1400fps.

 

[rOmiLaYu]

If you keep it sub sonic at 600 yards won't it loose a lot of power

If you keep it sub sonic at 600 yards it won't go 600 yards.

 

[cmshoot]

I don't plan on running the subsonic loads at 600yds.

 

[Johnny B. Goode]

With the price reduction in AR platform based firearms, I began to really consider looking at 300blk. I'm considering this for home defense purpose and read some pretty decent things in regards to ballistics, etc. Nothing earth shattering but, good none the less. I also read that going with a full length setup is pretty much a waste of barrel as the powder will have already burned up, not allowing for velocity benefits of a longer barrel. Also, another point of 300blk is for suppression.

Is all of this true? While a full length barrel may no hurt anything "still assuming it's a pistol length gas system", adding a suppressor to the length hurts maneuverability. With all of this being said, tax stamps, and suppressor, the cost for the rig increases quite a bit. Is it worth it or am I thinking too far ahead? I tend to do that.

I've built a 16" .300BLK and an 8.5" .300BLK pistol -- which is actually in the process of being SBR'd -- and I love them both.

The 16" rifle has a carbine length gas system and is a really soft shooter. I've gotten subs to cycle in it with no suppressor, but YMMV. However, in order to get them to cycle, I had to use a Sharp's Relia-bolt and Balanced Bolt Carrier. The main use for this rifle is to take shots out to around 400 yards max. From everything I've read, you'll still gain a bit of velocity -- and therefore, range -- using a 16" bbl. Coupled with good ammo, you should get some good results. Now, whether or not the extra velocity is worth the extra bbl length, is something you'll have to decide. If you want to stack the odds in your favor as far as reliability goes, my advice is to stick with a pistol length gas system for any .300BLK rifle.

The 8.5" pistol is strictly for home defense. Along with my Form 1, I also have a suppressor that I'll be submitting the Form 4 for on Saturday. Topped with an MRO, it's a sweet setup. If you want maneuverability, stick with something like this. Especially with the added length of a suppressor. When I receive my tax stamps, the estimated OAL of my SBR will be about 31" with the suppressor and the stock fully extended. For reference, it's basically a honey badger build. If you're not sure what that is, google it.

The whole reason I went with .300BLK was to suppress it. To be honest, if I had no intention of spending the extra money to do that, I would have just built an AR in 5.56. Keep in mind that you have to build your rifle to match it's intended purpose. There's really not a single rifle out there that can do everything.

I hope this helps.

 

[MaconGuns]

I don't plan on running the subsonic loads at 600yds.

Just have the dies and want to experiment? Seems like an answer looking for a problem.
If I was gonna dump money in a 600 yard project rifle it be the 6.5 creedmoor,308 threaded or wildcat. I can remember but the cartridge but isn't there a 223 necked up 100%? To each their own I guess. Wish I had 600 yards to play on!

 

[cmshoot]

Just have the dies and want to experiment? Seems like an answer looking for a problem.
If I was gonna dump money in a 600 yard project rifle it be the 6.5 creedmoor,308 threaded or wildcat. I can remember but the cartridge but isn't there a 223 necked up 100%? To each their own I guess. Wish I had 600 yards to play on!

6.5CM doesn't interest me and I own more .308's than I can shake a stick at. I can't make a good .308 as lightweight, compact, and soft-shooting as I can a .300Blk. I've listed the reasons twice in this thread for using the .300Blk. My daughter will use it for deer at deer-hunting ranges. For me, it will be for targets only, so I don't care how much energy it has.....only has to hit the steel.

It's not a question of what is the best round for the job at hand. I want several different types of weapons to show my students during my Guerrilla Sniper course. The majority of the shooting will be at distances of around 300-400yds, I only plan on doing the 600yds to show it can be done.

600yds is short range for a good .308. I don't always need that much cartridge.

 

[MaconGuns]

Ah thanks, I didn't read it all sorry.