.338 ARC load data available
- Thread starter 5pins
- Start date
Here is some 338 ARC Improved loads, with only slightly more capacity, 32.9 GR H2O capacity for higher velocity supers, that does not affect subs.
6.5 twist barrel.
350 gr Maker only 650 fps ejected did not lock back.
300 SMK 2nds full function.
272 gt fmj.
250 gr Hornaday RN
175 gr HP 2200 fps average
200 gr Speer hot core 2100 fps
338 ARC case fireformed in 338 ARC imp chamber.
6.5 twist barrel.
350 gr Maker only 650 fps ejected did not lock back.
300 SMK 2nds full function.
272 gt fmj.
250 gr Hornaday RN
175 gr HP 2200 fps average
200 gr Speer hot core 2100 fps
338 ARC case fireformed in 338 ARC imp chamber.
Attachments
So after owning and shooting the 338 Spectre, the 8.6 Blackout 3 twist and 6.5 twist....and now the 338 ARC, I decided to make improvements to the 338 ARC platform as introduced by Hornady.
First a 6.5 twist barrel instead of Hornady’s 8 twist. Blow the case out a bit for a small gain in super velocity, but retain same sub velocity.
Fireformed the Hornady brass, then went to Starline Grindel brass shortened to 1.370" .
So now the 338 ARC improved hangs with the 12" 3 twist 8.6 Blackout in about all categories, plus it can shoot lead bullets at full velocities, without bullet blow ups destroying your suppressor or your chronograph .
Even out shoot the 3 twist 8.6 blackout with accuracy and velocity with cheap lead factory 2nds in am AR15, hanging close to 2000 ft/lbs of muzzle energy in the 16" AR 15. Modified 347 gr (weighed 350 gr) Maker 344 grs over 1200 fps, about 200 fps faster than a 3 twist 8.6 BLK.
160 gr Barnes tipped reached 2300 fps.
165 gr Maker averaged 2276 fps.
175 gr 2202 fps, 200 gr SST 2025 fps, 200 gr Speer 2100 fps.
Work up and take atleast 1.5 grs of powder out of the regular factory case and Keep Same COAL, these should be helpful with regular factory 338 ARC reloads.
Today I shot a variety of 338 ARC imp loads.
160, 165 Maker, 175, 200 SST, 250 RN, 272 fmj, 300 SMK, 300 Atips, and 350 Maker.
All bullets were stabilized in the 6.5 twist.
The CMMG 338 ARC specific magazines really work with every bullet tried.
Like the Hornady 250 gr RN at 1760 fps
The 300 Atips were a little too fast for subs.
Here are the loads as fired...the 350 Maker has various powder charges and many loads exceeding COAL... mag length are around 866 fps with maybe just 900 fps attainable at 2.295" ...so do not try the bore riders at mag length you'd be way over pressure.
This may or may not be of interest as the 338 ARC is a bit lackluster when it comes to supers.
So that's why the improvements, to get a bit more zip on the supers and with the 6.5 twist shoot the long heavies....not just their flat nose 307 gr.
For informational purposes.
Remember small capacity case pressures jump drastically with fairly small increments of adjustment in COAL .020" and .030" makes a big difference at max pressures in small capacity cases.
First a 6.5 twist barrel instead of Hornady’s 8 twist. Blow the case out a bit for a small gain in super velocity, but retain same sub velocity.
Fireformed the Hornady brass, then went to Starline Grindel brass shortened to 1.370" .
So now the 338 ARC improved hangs with the 12" 3 twist 8.6 Blackout in about all categories, plus it can shoot lead bullets at full velocities, without bullet blow ups destroying your suppressor or your chronograph .
Even out shoot the 3 twist 8.6 blackout with accuracy and velocity with cheap lead factory 2nds in am AR15, hanging close to 2000 ft/lbs of muzzle energy in the 16" AR 15. Modified 347 gr (weighed 350 gr) Maker 344 grs over 1200 fps, about 200 fps faster than a 3 twist 8.6 BLK.
160 gr Barnes tipped reached 2300 fps.
165 gr Maker averaged 2276 fps.
175 gr 2202 fps, 200 gr SST 2025 fps, 200 gr Speer 2100 fps.
Work up and take atleast 1.5 grs of powder out of the regular factory case and Keep Same COAL, these should be helpful with regular factory 338 ARC reloads.
Today I shot a variety of 338 ARC imp loads.
160, 165 Maker, 175, 200 SST, 250 RN, 272 fmj, 300 SMK, 300 Atips, and 350 Maker.
All bullets were stabilized in the 6.5 twist.
The CMMG 338 ARC specific magazines really work with every bullet tried.
Like the Hornady 250 gr RN at 1760 fps
The 300 Atips were a little too fast for subs.
Here are the loads as fired...the 350 Maker has various powder charges and many loads exceeding COAL... mag length are around 866 fps with maybe just 900 fps attainable at 2.295" ...so do not try the bore riders at mag length you'd be way over pressure.
This may or may not be of interest as the 338 ARC is a bit lackluster when it comes to supers.
So that's why the improvements, to get a bit more zip on the supers and with the 6.5 twist shoot the long heavies....not just their flat nose 307 gr.
For informational purposes.
Remember small capacity case pressures jump drastically with fairly small increments of adjustment in COAL .020" and .030" makes a big difference at max pressures in small capacity cases.
