458 socom 350gr alliant unique

[Rwilson18]

Hey guys this is my first post on here. I've reloaded 5.56, 45, and 12 gauge. However 458 socom is a new beast. I would like to use my alliant unique powder with some rainier 350gr bullets rated at 1500fps. The 458 has a max pressure rating of 35k and unique has a tendency of high pressures (from what I've read, I've only gone by reloading book data for 12 gauge and 45, never experimented). Anyone have some recommendations on starting weight for the powder? And a possible oal if you've used this bullet. Black Butterfly (458 socom ammo distributer) uses this bullet for their plinking ammo. All the help I can get would be great considering the lack of info there is for this particular set up.

https://www.midwayusa.com/product/1016226330/rainier-leadsafe-bullets-45-caliber-458-diameter-350-grain-plated-flat-nose

[M-Tecs]

Not sure how many here load for the 458 Socom. More here http://458socomforums.com/

[dkf]

Unique is a fast powder, not ideal for the .458. It will never be able to cycle an AR but that is not an issue if you have a bolt gun nor expect it cycle a semi. I have not come across anyone whom uses Unique in the .458 on forums and on the FB group in the 3 years I have been into it. I believe someone posted some quickload data with unique on request but the numbers were not pretty nor ideal. Also the Berrys and Rainier plated bullets are not know for their accuracy either, but that is at supersonic velocities. If you want to fool around with light loads I would use Trail Boss. But trail Boss won't cycle an AR either unless the gas port is opened up significantly.

For the Berrys I would start with IMR 4198.

[hicard]

I agree with dkf on IMR 4198. That is what I use. Unique will only lead to failure, especially in an AR-15.

[Smoke4320]

I have a great load using 2400 powder and a 350 gr bullet if interested

[Rwilson18]

Thanks guys, ill get some imr 4198 or lil gun tomorrow and use some known charges. I can't register on 458socomforum and I need to set up an isp email to register on ar15.c0m. I have unique on hand so that's why I asked, couldn't find load data for it.

[dkf]

IMR 4198 is all around a solid performer. Just be aware there is H4198 which is not the same but will also work. In case you don't already know Lil Gun is a temperature sensitive powder that burns really hot. A lot of guys use it but I don't find it to be anything special and I avoid it for the reasons listed. Too many other good powders out there.

The 458 socom forum can take a while for the registration to be approved. The site has some quirks but once you become a member it works well. There is bunch of quick load data for different bullets on the Teppo Jutsu website that you can download if you do not already have it. I find the data to be pretty darn close with the powders I use. I often use this data as a basis for an "educated guess" of starting loads for bullets that there is no data for, cast included.

[32 ballard xl]

Thanks guys, ill get some imr 4198 or lil gun tomorrow and use some known charges. I can't register on 458socomforum and I need to set up an isp email to register on ar15.c0m. I have unique on hand so that's why I asked, couldn't find load data for it.H-m-m. I've loaded 45-70 with Unique for over 60 years, if that means anything. Important to be careful loading Unique. Make sure you never double load a case!!

[pakmc]

what is you data for the .458 socom with 2400 powder, Im using H-110 and I don't like the way it pours or fouls up my powder thrower(Cheap Lee).

[44Blam]

H4895 is also a good choice... If the gun has a longer barrel you might also look at a slower powder like Varget.

[44Blam]

H4895 is also a good choice... If the gun has a longer barrel you might also look at a slower powder like Varget. Problem I have with 4198 is that the recoil is sharp. The slower powders tend to make the recoil a little more like a push.

[pakmc]

how much of 4198 are you using with what weight bullet. I started with 37gr.s of H-4198(and the recoil is brutal) and a 353gr. Lee bullet. I powder coated the bullets after I poured them. I"m down to 27.5 gr.s of H-4198 and my accuracy is getting better and the gun is still working and spiting out the brass. I've used H-110 but I don't like it. it clogs up my cheap Lee powder thrower and spills out the side of the slide. I was hoping Smoke4320 would let me know how much 2400 that he used on what size bullets he used? me and a friend are jsut wanting to get a load that might Kill a hog and/or still be fun to shoot!

[pakmc]

I'm very interested in you load data for the .458 socom with All. 2400!
Pat

[dkf]

This thread has some data for 2400. As always work the load up. http://castboolits.gunloads.com/showthread.php?206462-Any-one-have-458-socom-load-data-using-2400

I use a lot of IMR4198 and I never thought the recoil was bad. A powder that has some recoil is Norma200. Full power 300gr jacketed loads have a decent pop to them.

[boman250]

I have done a bunch of research on this subject OP. I do not have any physical experience as I have been trying to get my standard loads GTG first. The test I am planning on trying is a start load of 10 to a max of 13.6g of Unique under a 300 gr PCC bullet.

Like I said, I have not tested this. But, I probably will soon. Maybe even load them up today... Who knows.