Where should I start with 458 socom?

[brasscollector]

Reloading for a 16" 458 socom with carbine gas. Looking mostly for cheap range fodder for now. A load that gets me in the 1400-1500fps range and cycles the action would do just fine if possible.

This is what I have to work with:
once-fired starline brass
WLP primers
Acme 300gr RNFP hi-tek coated
OAL close to 2" seated to the cannelure

My real question is which powder & where to start for a powder charge.
I have on hand:
H4198
IMR 4227
A1680
W296

thanks in advance

 

[GunnyUSMC]

I use IMR4198 and H110.
The H110 is faster burning and will most likely work best for light loads.
I like IMR4198 for heavy loads because recoil is not as violent as it is with H110.

 

[Blue68f100]

I use mainly W296 but have used IMR 4198 with CCI 350 primers. When I started loading for the SOCOM CCI 350 primers were the only ones recommended, others showed over pressure signs and failures. 35.5 gr of IMR4198 or 31.5 gr of H110/W296 will get you close to the 1500 fps with 300 gr RNFP HiTec. Have not used the other powders for lead loads.

 

[markr6754]

Thanks for posting this. I’m at the start of acquiring parts for a SOCOM build for my son. I have a 16” barrel, stripped SOCOM upper, lower, lower parts kit...meanwhile, trying to decide which die set to buy. I’ve just started loading for .300 AAC Blackout, and haven’t mastered that yet...so .458 SOCOM will definitely be a challenge to overcome. At least I already have the H110 on hand. Considering getting some Shooters World SOCOM, as it has more loads for .300 AAC Blackoit, plus SOCOM loads, vs the Shooters World Blackout.

 

[adcoch1]

37.0 grns imr 4198 with a Berry's 350 grn plated bullet designed for the 45-70 is what I'm using for cheap stuff. It cycles good in both my rifle and pistol, haven't tried it over a crono, or for groups yet but it blows chunks off of tree stumps.

 

[alfsauve]

With 325gr bullets I've been using LilGun

 

[Blue68f100]

For your dies go with the Redding. There are a lot of dies out there that the mfg went upon them selves to make it their way and not to the developers spec. Redding is one that will work the first time and every time. When I got into the SOCOM over 3 yrs ago there were a lot of people having problem sizing the brass. The only ones not having problems were Redding.

You may want to take a look at the www.458socomforums.com - Index

 

[brasscollector]

I guess I did fail to mention I had Hornady dies and a Lyman MSR ammo check block already. I have sized 20 cases and made 1 dummy round which chambers in the block & the rifle. One thing I am a little concerned about is those slippery coated bullets moving upon chambering so I was thinking about crimping. I've read a few people recommend the LEE FCD.

When I started loading for the SOCOM CCI 350 primers were the only ones recommended, others showed over pressure signs and failures.

Is there a reason I should be concerned with the Win primers? I'm not opposed to buying something specific but I did see accurate had used the WLP in their loading data.

It looks like I have enough 296 and 4198 to make about 4 or 5 rounds each so I guess I can check out both.

 

[Blue68f100]

Just keep a eye on them. If they show over pressure signs then switch over.

I've shot the MB HiTec coating in mine and did not crimp. Did not have any problems with setback. The shoulder is so short on the SOCOM that it's hard to crimp without buckling the brass. But the good thing is there is a lot of bullet contact with the long neck. Try if first without and see if you need it, I didn't. I don't own any LFCD, learned decades ago if done right it's not needed. I never could them to shoot very accurate in my gun but did not work very hard on it.

To tame the recoil look a the GL-Shock stock. This is spring loaded shock, works good. Takes the big impact out and makes it a big push. I run a adjustable gas block on mine along with a heavy bolt and buffer.