338 Rem Ultra 30" barrel loads-wanted

knc1105 · #1 02-23-2010, 12:47 AM

I found a post online here from 8-9-2001 on 338 RUM loads and it was the best I have ever seen and I joined LRH. I have a new rifle coming day after tomorrow and it has a 30" Lilji heavy barrel and brake ( scaled down 3-chamber 50-BMG style brake ). All the data I have found is for a 26" barrel. The bullets I got to try first are Sierra 250 gr. GameKings and MatchKings and Hornady 250 gr Match (675 B.C.) I will have them Boran Nitate coated before I start. I have H4831, IMR4831, and H50BMG in stock, I am looking for 7828 also. I have Federal Large Rifle Magnum primers, I could not find any match primers. Any help would be greatly appreciated.

RJ338 · #2 02-23-2010, 10:47 AM

The powders best suited for those bullets are 7828, RL25, Retumbo and Ramshot Magnum. The 215 primers are fine, likewise the WMLR and CCI250.

knc1105 · #3 02-23-2010, 11:26 AM

I am told the longer barrel would not add chamber pressure, but would like the slower burning powders and have increased velocity with the slower powders. I got a e-mail from a 50 shooter that there was not enough case capacity for H50BMG and Retumbo was the slowest burning powder that I could use, those max loads were compressed loads. So I'll get some of the listed powders to start. I wonder if anybody has every loaded for a 30" RUM barrel, I can't be the first. The 30" is kind of the standard with the 50BMG and the Lapua shooters, maybe I screwed up. I got this for long range Elk hunting.

JD338 · #4 02-23-2010, 05:32 PM

My stock M700LSS 338 RUM shoots well with Retumbo. With the Nosler 250 gr AB, this was the second target I shot with the load so I never bothered to try going up. Hodgdon web site says 101.0 grs is MAX.

The same powder and charge weight with the Nosler 250 gr PT gave me an average of 3024 fps.

JD338

knc1105 · #5 02-23-2010, 06:03 PM

WOOOOOW! now thats the kind of secret recipe to try. My scope and rings came in Friday, all the reloading stuff that I did not have came in this afternoon and the rifle is scheduled for tomorrow. It's hard for a old hunter to not get exited like a kid. I probably won't sleep much tonight. Ain't it great!

knc1105 · #6 02-23-2010, 06:15 PM

Alot of my buddies call the 338 Ultra Mag a working mans Lapua, I always called it a Hunter's Lapua. The group posted above would make a bunch of S.W.A.T. teams jealous, and old Elk bulls shake in their hoofs.

JD338 · #7 02-23-2010, 07:31 PM

This is a good load and not too hard on brass either. Same load from a clean barrel. Note the dark oil ring from the first shot.

Rifle is a stock 700 LSS with a Pachmayr Decelerator recoil pad and the trigger lightened to 2.5 lbs.
Scope is a Mark 4 4.5x14x40mm with M1 dials added.

JD338