Big 338 powders??

[Broz]

Hey Jeff,

A friend sent me this today for my TRG-42 LM, I am a Lapua fan because it's a MIlitary round, but it is not even close in capacity to the Wby. which I could care less about, the recoil is already a lot with a 14 1/2 lbs. gun.

Cartridge : .338 Lapua Mag.
Bullet : .338, 300, Sierra HPBT LR MK 9300 G7 Litz
Useable Case Capaci: 92.057 grain H2O = 5.977 cm³
Cartridge O.A.L. L6: 3.681 inch = 93.50 mm
Barrel Length : 27.0 inch = 685.8 mm

I chose to brake in the barrel w/IMR 4350 since Sierra showed in a most accurate, which in my case it was rather accurate, but slow as snails pace; 78 grains only produced 2525 fps but put three out of twenty in the same hole even with cleaning the barrel.

I have on hand H1000, RL 22, 25 and 33, IMR 7828 and 7828 ssc, N170, 780 Supreme and almost anything else except the really slow stuff.... US869, and such. What would you suggest I try for shear accuracy and nothing else, bullet drop means almost nothing. I have 28.5 Mils of scope adjustment even with the 2525 fps 300 SMK round.

"Usable case capacity" and case capacity are different. For an accurate comparison I fill em to the top and the standard Lapua holds about 112 to 114 gr.

My most accurate load with both 300 SMK's and Berger OTM's were around 92.5 gr of H-1000. """ Work up from 88 gr""" Some rifles will max at 90 or 91 depending on the rifle and powder lot. Do your group tests at 200 yards or beyond.


Jeff

 

[longrangehunterII]

I wondered if that was the difference in case capacity? From everything I've read I hear H1000 is the-go-to powder for the Lapua Magnum? So based on your opinion and what I've heard I'll start with H1000 and see what happens. I also have Lapua 300 gr. Scenar, and the Hornady 285 gr. BTHP Match bullets if the Sierra Matchkings don't seem to work well enough?

I've had great luck lately using the Berger Juggernaut OTM Tactical Bullets in my 300 Jarrett, but I haven't been able to find any of the 300 gr. 338" Berger's in stock anywhere. If these suck I'll move on to them.

Thanks Jeff,