Help with custom 30-378, want to shoot HAT, Bergers, SMK, pic included.

[Marine sniper]

I finally got the 30-378 together.
Hall G single shot
33 in. Pac-Nor 3/3 land and grooves 10 twist.
.333 neck.
NF 5.5 x 20.
Jewell trigger.

I have never loaded a 30-378 before. I hope I can get the HAT 210's to shoot. I have two boxes of the 180's that I will start with. I think the Berger 210's my 300 WBY loves might be a little fragile for the 30-378, not sure if they would be accurate at 3300+ fps. Not to mention I would like a little more BC with this conbination. I have a box or two of 240 SMK's, hopeing to see 3200+ with them.

I am looking for tips on what powders to use, how far off the lands to start the Hat's at. Just tips in general for a 30-378 with a barrel this long in a tight neck combination. I am all ears.

I put together a break in load of 110 grs. of H50BMG with the 240 SMK's (just off the lands with .003 nk clearance). I have a bunch of H50BMG, Retumbo, H1000 and 7828. I assume the H50 BMG and maybe Retumbo with end up being the powders of choice. I use nothing but Fed 215's in my 300 Wby and above.

Any thoughts or tips ?

Thanks,
John

 

[Broz]

Watch the Retumbo in a 30-378. It can go hot quick and I have found it happen well below max loads. It can really deplete your brass supply.

 

[Marine sniper]

Thanks, brass for this thing is not cheap....not to mention all the prep time involved with a turn neck case.

 

[MontanaRifleman]

Nice outfit.

I seem to recall the 210 HAT's needing an 8 twist and the 180's needing a 10 twist. The thick jacket 210 Bergers should hold up well???

-MR

 

[Broz]

With a 210 Berger I get about 3120 with 98 gr of H-1000 using a 30" HS barrel. Easy on the rifle , and brass. I have taken lots of game from antelope to Elk with great results. (see very dead Elk below) gun)

.

 

[Marine sniper]

I think the Hat 220's need the 8 twist. I am not going to build a rifle around a particular bullet until I can get 180's or 210's to shoot well first. If I can get them too....I would build a 30-378 with a 8 twist. .9+ BC at 3200-3300 fps !

3120 is pretty mild for a 30-378. I get right at 3000 with my 300, but that elk looks just as dead as the antelope I shot this year with my 300 !

 

[Broz]

Yeah it is a very mild load. But it worked great in both my 30-378's so I stuck with it. I have shot it to 1000 yards with very suitable results. The brass is holding up well, the VLD's seem to work well at this speed too. The only reason I could see to push it was to save some clicks on the scope. So I just shoot it and smile every time a seat a primer and it doesn't fall back out..

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