I loaded up a few rounds...

[G40MOSHunter]

I loaded up a few rounds...

250 - 115grain, Nosler Competition, 6.8mm SPC II
50 - 115 grain, Remington Core Lokt, 6.8mm SPC II
200 - 180 grain, Rainier Copper Plated FN, 10mm Auto
300 - 180 grain, Rainier Copper Plated HP, 10mm Auto
50 - 400 grain, Speer Flat Nose, .458 SOCOM
40 - 350 grain, Barnes TSX HP, .458 SOCOM
40 - 300 grain, Barnes TSX HP, .458 SOCOM

I think I'm good with ammo for a little while.

[The_Shadow]

G20MOSHunter, how are the 458's doing for you with H4198?  Would you share the load data you have tested?
I have only used Lil'Gun so far in the handloaded 458's...

[G40MOSHunter]

Maybe this should be moved to the general reloading forum vs. 10mm reloading forum...


Once upon a time, I loaded up 5 each Barnes 350 grain TSX HP, .458 projectiles with H4198 with 39, 40, 41, 42, and 43 grains. I settled with  the 40 grain option. The 43 grain load showed primer flattening...

My primary objective was relaiable cycling in an AR, and minimal primer flattening. Accuracy wasn't really that important. Meaning I don't need nor expect 1 MOA from the rifle. I can hit the center of a 6" metal plate offhand at 100 yards. I think it's probably 3 MOA.

As always, with reloading, start low and work up...

[The_Shadow]

Thanks for responding, I did move this into other reloading...Some of the casings show some imprinting of the case head maybe these were multiple used cases?  I have been studying the 458 SOCOM for a while collecting info and data.  I am part of two Facebook groups the 458 SOCOM and Big Bore AR's to also learn or help out.

Have you seen the 458 SOCOM pull-downs I documented and posted on this forum?  Link http://10mm-firearms.com/factory-ammo-pull-downs/458-socom-commercial-pull-downs/

I have loaded several different loadings for my nephew with Lil'Gun, and he's been having fun with them.  I haven't had the chance to run them over the CHRONY yet to verify velocities.  Brass he brought back looks great.

Barnes 250 TSX FN FB
STAR LINE BRASS length 1.5740"  Base Dia. 0.5390"
Hodgdon Lil'Gun  30.0 grains
CCI 350 Large Pistol Primers
Bullet length 0.917"  with 0.5435 outside and 0.3735" inside
HP depth 0.5115"
COAL 2.1430"
Estimated Velocity 1800 fps

HORNADY 500 gr RN 458 SOCOM InterLock®
STAR LINE BRASS length 1.5740"  Base Dia. 0.5390"
Hodgdon Lil'Gun 21.0 grains
CCI 350 Large Pistol Primers
Bullet length 1.3365"  with 0.6260" outside 0.7105" inside case
COAL 2.2000"  ( 2.240" will pass the case gauge)
Velocity 1130 fps 8" and 1280 fps 16"


Sierra 300 .458 JHP
STAR LINE BRASS length 1.5740"  Base Dia. 0.5390"
Hodgdon Lil'Gun  28.5 grains
CCI 350 Large Pistol Primers
Bullet length 0.7825"  with 0.3425"-0.3500" inside
HP depth 0.1925"
COAL 2.0140"
Estimated Velocity 1700 fps

RAINER 350 Grain .458" Flat Point
STAR LINE BRASS length 1.5740"  Base Dia. 0.5390"
Hodgdon Lil'Gun  28.5 grains
CCI 350 Large Pistol Primers
Bullet length 0.8565" with 4260"-0.4305" inside
COAL 2.0000"
Estimated Velocity 1725 fps

HORNADY 250 gr 458 SOCOM MonoFlex™
STAR LINE BRASS length 1.5740"  Base Dia. 0.5390"
Hodgdon Lil'Gun   30.2 grains
CCI 350 Large Pistol Primers
Bullet length 1.0890"  with 0.6260" outside and 0.4630" inside
COAL 2.200"
Estimated Velocity 1900 fps

[G40MOSHunter]

Yep, I noticed and had discussion about the case head imprinting. I ended up buying a barrel and bolt from a mfg that reverse engineered those items, and I attribute the case head imprinting to an out of spec ejector and extractor.

If anyone is thinking about building a .458SOCOM, be sure to buy parts from the legitimate companies that  produce components vs. the companies that don't want to pay the licensing fees to the the inventor and reverse engineer the parts (they are basically stealing from Marty ter Weeme, Founder, Teppo Jutsu LLC). Go to www.458socomforums.com for more information.

Sorry, I don't have a facebook account, so I'm not able to see the facebook groups that you speak of...

I hadn't seen the pull downs that you posted. Good information. Thanks for putting that up there.

The 6.8mm SPC II loads that I made are kind of a known entity to me, 27 grains of AA2200 with various 115 grain projectiles. It's been my deer rifle and it shoots just at 1.5 MOA.

The 10mm loads that I loaded are new to me. Glock Gen 4 G20 is near virgin. It's only had 10 rounds through it. Loading dies are brand new. I ended up loading 9.5 grains of AA#5 with 180 grain flat nose and 180 grain HP. Both bullets from Rainier, and they're copper plated. I guess I'll see how they perform... Any thoughts on my 10mm loads?

[The_Shadow]

I am familiar with Teppo Jutsu LLC and the www.458socomforums.com although I am not a member I have read pleanty.
TROYMIX and Tony Rumore (member here BTW) has barrels, upper & lower receivers as well as parts. 
My nephew's gun is TROYMIX and has 16" and 10" BBL uppers.

He purchased the Redding Die set and I have been teaching him how to load with them...

[Pumpkinheaver]

A .458 SOCOM is on my short list of things to buy. I have a buddy with an SBR .458 and it is one bad mother!!!! It would be a great deer buster for this part of Missouri.