After waiting what seems like forever, the last of the parts have arrived for my 458 SOCOM build, both for reloading and the rifle.  I thought a post a picture here showing the relative size of the ammunition to other rounds.  The number of choices for heads for the 458 seem to increase by the month.  From 100 to 500 grains.  The one here is a Hornady 325 FTX.  I have some Speer 400 SPFN yet to do and looking at some Lehigh Defense Controlled Fracturing.  Estimated speed for this round is 1800 FPS.  I'll post up the rifle when I finish it under new ARs.  Nothing special sort of a plain jane, built for hogs in Florida again in late winter.

 

 

Left to right. 22lr, 9MM, 45ACP, 55FMJ 223/556, 150FMJ 300BLK, 123FMJ 7.62x39, 325FTX 458 SOCOM.

You made that .458 cartridge? Just curious why the bullet is not seated with the cannelure in the case mouth

You made that .458 cartridge? Just curious why the bullet is not seated with the cannelure in the case mouth

 

My guess is to establish a proper OAL.  That bullet, I suspect, was never intended for that cartridge.

Old School you are correct.  458 SOCOM has not been SAAMI approved yet, so there are only a handful of heads designed for this round. Most are used for the 45-70.  As it turns out there are a bunch of heads that perform with amazing accuracy in the 458, this 325FTX is one (at a much cheaper price point too!).  Other 458ers are getting sub MOA with this configuration (.800 at 100 yards). 

 

Shocker, yes, all in the picture except the 22LR are handloads.  The 458 performs best at this COAL for most.   Wishing my ladders will prove likewise.  Handloading the 458 brings the first round cost to about $36/box 20.  Reloads will be about $15/box 20.  Way better than the $60-70 box retail.

What is the .458 brass formed from?

What is the .458 brass formed from?

 

The case is not formed and must be purchased.  The body is larger than the case head and you could never blow out a case that much.

I didn't think there was anything close enough to make it work --  

how many rounds do you get per 15rd AR magazine?

Five if your lucky, ten in a standard 30 round AR Magazine.

Tough brass to find in quantity.

So is it legal to use a 30rd mag and fill it with 10 rounds of .458?

So is it legal to use a 30rd mag and fill it with 10 rounds of .458?

No --  that mag is not intended for .458 --  Unless it's modified and labeled .458 socom --

 

I'm wondering if a follower that would limit the feed of double stacked bullets installed in a standard mag would make it legal -- looking at the size of that case it's a single stack mag when loaded with .458

 

You would still probably need to permanently seal the magazine -- so it couldn't be easily altered with a standard follower

How did this rifle turn out? Any update on range time, load data?

The rifle has been done since the middle of November.  The first load ladder has been built but not fired yet.  Because I got an 8lb bottle of Lil Gun the preferred load should be 29 grains over a 458 325 grain FTX Hornady at COAL 2.20 (YMMV).  I'll try to load up pics of the rifle, but there has been a lot of personal/family health issues over the last 4 months that have delayed trips to the range and enjoying my hobby. In fact the last project I started in September along with this one was putting a bull barrel on a 10/22 TD.  That should be here the 2nd week of January finally.  With a little luck I'll be back on the range in a couple of months just in time for spring.

very cool, this is an AR platform ?  so the bullet is seated to the same length as 223/556  bullet to be used in an ar ?

The rifle has been done since the middle of November.  The first load ladder has been built but not fired yet.  Because I got an 8lb bottle of Lil Gun the preferred load should be 29 grains over a 458 325 grain FTX Hornady at COAL 2.20 (YMMV).  I'll try to load up pics of the rifle, but there has been a lot of personal/family health issues over the last 4 months that have delayed trips to the range and enjoying my hobby. In fact the last project I started in September along with this one was putting a bull barrel on a 10/22 TD.  That should be here the 2nd week of January finally.  With a little luck I'll be back on the range in a couple of months just in time for spring.

Very sorry to hear. I hope you and everyone else recovers well. Look forward to hearing about this beast.

The rifle has been done since the middle of November.  The first load ladder has been built but not fired yet.  Because I got an 8lb bottle of Lil Gun the preferred load should be 29 grains over a 458 325 grain FTX Hornady at COAL 2.20 (YMMV).  I'll try to load up pics of the rifle, but there has been a lot of personal/family health issues over the last 4 months that have delayed trips to the range and enjoying my hobby. In fact the last project I started in September along with this one was putting a bull barrel on a 10/22 TD.  That should be here the 2nd week of January finally.  With a little luck I'll be back on the range in a couple of months just in time for spring.

 

Put the powder in the case first! 

 

Can't wait to see load data and results.

 

Good luck with all the issues.