The Firing Line Forums - View Single Post - Why The Gap In Hodgdon Chart For 300 AAC Blackout?

oldpapps · July 5, 2012, 04:37 PM

Why The Gap In Hodgdon Chart For 300 AAC Blackout?

So many answers....

The 300 BlackOut is new. (SAAMI standardized) Things take a little time to catch up.

Emphasis is on both ends of the bullet weight spectrum in the beginning.

Few suitable mid-weight bullets available from the major manufacturers.

I can think of more but they are less main stream.

Bullet stability and twist. The faster the bullet travels, the greater the needed twist. The revers is also true. So a sub-sonic is traveling slow and the twist can be slower. Push a lighter bullet faster and it could become 'over stabilized' and if the jacket is thin, it could come apart. I have not had this problem but it is feasible. 220 grain bullets traveling slower, stabilize and the jacket thickness is only for controlled expansion. Yes, I know it is not the bullet's weight but the bearing surface that counts. But they both go hand in hand to a large degree. Sticking a steel core in or not putting in any lead does add to the mess.

So far so good. Now to the mid-weight bullets. The 150 to 180 grain bullets with pointy ends, work better when chambering in an AR type weapon, are designed to expand at higher velocities, think 308/30.06/300XX Mag. It will not be long before the major manufactures start pumping out lighter jacketed pointy bullets in this weight range. The new soft tipped bullets for the 30-30 are a step in that direction.

As for now, it is a load your own proposition.

These is what I have been using. NOTE: these are safe in my weapon with my components, in the manner that I load them. These loads are not to be taken as proven or safe. COL is very touchy and minor changes can and do make major pressure/velocity changes.

Reformed Lake City 5.56 brass, CCI SR primers, 17.5 gr of H110 under 147 GI FMJ, no crimp, COL 2.065 inches. Weapon DSA 16in, carbine gas system. Average velocity (@ 10 feet) is 1988 FPS.

As soon/if the weather breaks, I will begin testing with Hornady 150 gr InterBonds. (Sorry, ambient temps of 100 degrees, set on black asphalt makes for temps of over 140 degrees. I've measured it!)

The .300 BlackOut fits in between the .223/5.56 and the .308/7.62 but doesn't begin to replace either of them. Sorta like a 30-30 in an AR platform that does well with lighter (110 grain) bullets and can also be used with a suppressor with heaver bullets. It is a fun gun with lot of possibilities to play with.

Enjoy, I do.

OSOK

July 5, 2012, 04:37 PM	#9
oldpapps Senior Member Join Date: September 22, 2011 Location: Middle America Posts: 518	Why The Gap In Hodgdon Chart For 300 AAC Blackout? Why The Gap In Hodgdon Chart For 300 AAC Blackout? So many answers.... The 300 BlackOut is new. (SAAMI standardized) Things take a little time to catch up. Emphasis is on both ends of the bullet weight spectrum in the beginning. Few suitable mid-weight bullets available from the major manufacturers. I can think of more but they are less main stream. Bullet stability and twist. The faster the bullet travels, the greater the needed twist. The revers is also true. So a sub-sonic is traveling slow and the twist can be slower. Push a lighter bullet faster and it could become 'over stabilized' and if the jacket is thin, it could come apart. I have not had this problem but it is feasible. 220 grain bullets traveling slower, stabilize and the jacket thickness is only for controlled expansion. Yes, I know it is not the bullet's weight but the bearing surface that counts. But they both go hand in hand to a large degree. Sticking a steel core in or not putting in any lead does add to the mess. So far so good. Now to the mid-weight bullets. The 150 to 180 grain bullets with pointy ends, work better when chambering in an AR type weapon, are designed to expand at higher velocities, think 308/30.06/300XX Mag. It will not be long before the major manufactures start pumping out lighter jacketed pointy bullets in this weight range. The new soft tipped bullets for the 30-30 are a step in that direction. As for now, it is a load your own proposition. These is what I have been using. NOTE: these are safe in my weapon with my components, in the manner that I load them. These loads are not to be taken as proven or safe. COL is very touchy and minor changes can and do make major pressure/velocity changes. Reformed Lake City 5.56 brass, CCI SR primers, 17.5 gr of H110 under 147 GI FMJ, no crimp, COL 2.065 inches. Weapon DSA 16in, carbine gas system. Average velocity (@ 10 feet) is 1988 FPS. As soon/if the weather breaks, I will begin testing with Hornady 150 gr InterBonds. (Sorry, ambient temps of 100 degrees, set on black asphalt makes for temps of over 140 degrees. I've measured it!) The .300 BlackOut fits in between the .223/5.56 and the .308/7.62 but doesn't begin to replace either of them. Sorta like a 30-30 in an AR platform that does well with lighter (110 grain) bullets and can also be used with a suppressor with heaver bullets. It is a fun gun with lot of possibilities to play with. Enjoy, I do. OSOK