That Didn’t Go So Good: 300 Blackout Attempt

[Gargoyle]

Groups at FIFTY (50) Yards with 300 Blackout in 16” bbl AR.


16” AR platform with 115 Red Mountain Lehigh Defense controlled Chaos and Nosler brand 125 BT. 50yds.
115gr @2367 11SD
125gr @2153 11SD
Used a 3-21X50 scope on 12X.

 

[LVLAaron]

300 BO isn't an inherently accurate round

 

[Gargoyle]

300 BO isn't an inherently accurate round

I'm running back to my 350 Legend!

 

[David Milisock]

View attachment 1380445
16” AR platform with 115 Red Mountain Lehigh Defense controlled Chaos and Nosler brand 125 BT. 50yds.
115gr @2367 11SD
125gr @2153 11SD
Used a 3-21X50 scope on 12X.

Who built the AR?

 

[Gargoyle]

Who built the AR?

I did.

 

[X-Caveman]

Mine hates Lehighs and Barnes. See if you can get your hands on some 150 gold dots for hunting or 125 TNTs for plinking.

Still, your accuracy is plenty good for me. Shooting pigs at night from 20-70yards.

 

[Forum Boss]

Unless you were shooting off-hand with military iron sights, I’d say that something is wrong with that barrel. I have S&W .44 mag pistol that shoots better than that, using a rest and custom lead bullets with light loads.

 

[69mach]

i had a shilen barreled ar15 one time that looked about like that. i tried several things including different bolts. finally i replaced the entire bcg and that fixed my issue. might be worth a try for ya.

 

[Gargoyle]

Unless you were shooting off-hand with military iron sights, I’d say that something is wrong with that barrel. I have S&W .44 mag pistol that shoots better than that, using a rest and custom lead bullets with light loads.

Yeah, I'm not used to this. LOL

 

[joshb]

Good home defense gun for shots under 50 feet. Me? I have a shotgun that groups like that with buckshot.

 

[Gargoyle]

Mine hates Lehighs and Barnes. See if you can get your hands on some 150 gold dots for hunting or 125 TNTs for plinking.

Still, your accuracy is plenty good for me. Shooting pigs at night from 20-70yards.

If this thing won't shoot the light & fast coppers I'm done with it! I got a 350 Legend build that's nuts on accurate. KISS! LOL

 

[ebb]

What twist is it most are 1in 8 or 1in 7. good for subs not light and fast. A barrel with the right twist for supersonic may make all the difference.

 

[Gargoyle]

What twist is it most are 1in 8 or 1in 7. good for subs not light and fast. A barrel with the right twist for supersonic may make all the difference.

1/7 Twist. I guess I would need a faster twist for the longer coppers?

 

[ebb]

No slower. The fast twist 7 or 8 is to stabilize the very heavy subsonic bullets that are best for shooting quietly and having enough power to kill something. Most 30 caliber bullets shoot at normal supersonic velocity are 1 in 12 or 1 in 10. i may be off a little on that cause i have never shoot a solid copper bullet. If it won't shoot a 125 BT I would think something is way off, as the 125 BTs are easy to make shot small groups.

 

[Gargoyle]

No slower. The fast twist 7 or 8 is to stabilize the very heavy subsonic bullets that are best for shooting quietly and having enough power to kill something. Most 30 caliber bullets shoot at normal supersonic velocity are 1 in 12 or 1 in 10. i may be off a little on that cause i have never shoot a solid copper bullet. If it won't shoot a 125 BT I would think something is way off, as the 125 BTs are easy to make shot small groups.

Welp, that explains things. My 350 Legend is a 1/16 and I plan to try 125gr Hammers. Hope those work. It shoots 145 and 160 really good.

 

[dellet]

Are those commercially loaded?

If not what was the load data?

The twist rate is not the problem.

 

[Gargoyle]

Are those commercially loaded?

If not what was the load data?

The twist rate is not the problem.

Yassir. Factory loaded offerings. Nosler ammo and Red Mountain. Can one over stabilize a round?

 

[dellet]

Controversial, but depends on your expectations and definitions. If it’s truly stable. Spinning it faster won’t make it unstable. The problem is finding that perfect bullet.

Consider you’re spinning those bullets 240-250,000 rpm they need to be well put together.

Knowing how many people use those bullets and get MOA or better results with hand loads I have trouble blaming the bullets, or spin. That leaves the load or the barrel. Something simple like a burr at the gas port, sharp edges on the feed ramps damaging the bullet with a new barrel might be a good place to start.

For what it’s worth I shoot everything from a 1/5 to 1/10 and the accuracy really isn’t any different until you get past 200 yards. As long as the bullets will hold up at 350,000+ rpm. It’s certainly easier to tune a slower twist. It off the bullets hold together it works fine.

If you want Factory loads and all copper, it’s tough to beat the Barnes 110 load.

Here’s what I expect from off the shelf ammo. This was. 7” 1-6 twist. Bipod off a bench, no rear support.

 

[Dusty Stevens]

I think you were shooting too long of a distance for that round.

 

[David Milisock]

I did.

From multiple parts or factory assembled upper?