I had a load that I wanted to share with you guys for my 338-378 it involves a 300gr. sierra matchking in front of 118 grains of IMR 7828 for a velocity of 3055fps any comments would be appreciated or any loads that exceed this would be cool?

[ 06-07-2003, 05:05: Message edited by: Angeldust ]

My brother shoots his at 3000 fps even, that's with 118gr H870 w/ 300gr SMK at 4.1" OAL with a 32" bbl. Only load he's ever used in it. What length bbl is yours?

My barrel is 26 inches.

i use 106grns of imr 7828 107.5 is listed as max in the barns manual.and a 210 grn barns x bullet.

the uncoated 1's move out at 3150

the coated 1's i can use 109 grns max imr 7828 for 3360fps

26" barrel angel dust 118!!!!wow you must be gripping the bullet by about 50 thousands of a inch since 109 grains fills the case right up to the shoulder and pressures are right up there.

i love my 338-378 if you love the 338 bore size then this gun will give you the most bang for your buck

i have always been a avid 338 fan and with the 338-378 i can really strech out and touch something.

Firing 118 grains 7828 in 338/378 with 300 grainer or standing under the Space Shuttle as it takes off....I am not sure which would be the most dangerous.

I had a 338/378 when they were still a wildcat and the Clymer reamer had longer freebore than the factory Mark Vs.

From memory Reloader 22 topped right out at 110 grains with 200 Hornady. I think 7828 was about 104 grains 250s.

I would expect 118 grain 7828 with 300 grains in the 338/378 to open the primer pocket like a flower and be a ram rod down the barrel while someone else whacked the bolt handle with a big stick.

Mike

Mike,

I think he said 118 gr of H870 and not 118 gr of 7828. But then again, I'm not sure if they have the same burn rate. You may be right.

I suppose H870 is slower by far and if he meant H870 that sounds OK, but it seems to read 118 grains of "IMR 7828" with a 300 grain bullet above. OUCH! Have we had a bit of troll work here?

Correction to my post. I was referring to Brent Moffit's load, not Angeldust's. Angeldust's was edited and I must have missed it before I responded.

I agree with you all too, the H870 at 118gr with it's LONG OAL of 4.1" and LONG 32" bbl is fine "in my brother Derricks rifle," the Oehler 43 shows 65,000 psi average. I never have used 7828, but would guess it's off the chart with 118gr. His MV also indicates he's over book max by a "long" ways, especially knowing he's using a 26" tube.

You're looking for more speed than that in a 26" tube??????? Try a bigger case or a much longer bbl then, and be safe. If pressures are as high as I'd guess they are, you're dooming the actions integrity and it's bound to fail at an unknown point along the way instead of lasting basically forever. It ain't worth it...



338/378 WBY with the 300gr SMK at 4.1" OAL with 118gr H870 in a 32" Pacnor bbl.

I got this load from a website called reloaders nest but at a quick glance back I noticed that the load I described was for the 378 Weatherby Mag instead of the 338-378 Weatherby Mag! I guess there is a big difference.

The difference in data for the 338/378 and the 378 is even greater than the difference in bore diameters would suggest has the Mark V 378 has a lot more freebore than the Mark V 338/378

Mike

Yep gotta be careful with custom chambered rifles with less freebore in the 378 Weatherby also. Mine likes 111 grains of IMR 7828 with 300 grain Sierra bullets for sub-MOA 2860 fps. It will pierce the primers with the factory 378 WBY loads, which are a lot hotter.

That does make a difference between .338-378 WBY and 378 WBY.