Has anyone tried loading 130 to 140 gr bullets in the 6.8 SPC ?

[300RUM]

Last year I started working with magazine length heavy bullet loads in a 6.8 SPC AR carbine with the goal of obtaining more energy. There is generally no load data for bullets over 115 gr. A 110 gr bullet at 2525 fps with 1034 ft/lbs at 200 yd was my best by the book load. I have been able to load a 130 gr bullet to 2400 fps for 1189 ft/lbs at 200 yd. a nice improvement in energy. Today I made my first attempt with 140 gr bullets and got 2360 fps for 1133 ft/lbs at 200 yd. I still have a few more powders to try with the 140 gr. It would not take much more velocity for the 140 gr to exceed the 130 gr load in energy. Has anybody else experimented with heavy bullets in this round?

[452b264]

Have you looked at the Barnes bullets for the 6.8? This is for the 95 gr. TTSX they also make a 110 gr. bullet. The 6.8 SPC makes an interesting cartridge for the AR platform. Maybe even perfect?

 

Bullet Weight: 95 gr Case Trim Length: 1.676 " S.D. 0.177 Bullet Style: TTSX BT Primer: Rem 9 1/2 B.C. 0.292 COAL: 2.240 " Barrel Length: 16.5" Case: Remington Twist Rate: 1:10 "

Maximum Load Mi Ld 6.8 Remington SPC Starting Load St ti L d Charge Velocity Charge Velocity Powder (grains) (fps) (grains) (fps)

 

A-1680 (Accurate) 24.0 2521 26.0 2702

 

H4198 (Hodgdon) 25.5 2542 27.5 2767

 

IMR 4198 (IMR) 24.0 2479 26.0 2694

 

A-2015 (Accurate) 28.02435 30.0 2583

 

RL 7 (Alliant) 26.0 2534 28.0 2713

 

X-Terminator (Ramshot) 30.5 2561 32.5 2723

 

RL 10X (Alliant) 27.5 2581 29.5 2750

[Saguaro]

Is that rifle a Stag? I wanted to buy the 7L Hunter for years. The carbine should be a lot of fun too.

[300RUM]

Is that rifle a Stag? I wanted to buy the 7L Hunter for years. The carbine should be a lot of fun too.

It is a carbine I built off a bushmaster lower when the 6.8 first came out. I wanted a quality stainless barrel, something not readily available at the time, so I bought a 1" Douglas blank and turned my own barrel. Unfortunately mid- length gas systems were not real common and I used the carbine length. At first I had a short extractor life span with hotter loads but switching to an H3 buffer and building a restrictor for the gas system solved the problem. The next barrel will be mid-length.

 

I use the rifle to hunt so additional energy is desirable. I felt the cartridge was capable of more than the loads in the manual were producing. The 130 gr load I worked up produces 15% more energy at 200 yards than the 110 gr load from the book. That is a healthy increase. It will be interesting to see if a 140 gr load can top that.