help sizing .30-378wby brass

30-378shtr

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I'm fairly new to reloading and I have some questions about sizing brass. I know the .30-378 is considered a "free-bore" caliber. I've been reading alot about using bushing style dies and I want to try it out. My question is: Does this caliber work better to neck size or use a full length sizer? Do I need to bump the shoulder back? I got a new bbl for my gun and I now want to make sure I feed it the highest quality reloads I can produce. What do you guys think?
 
I full length resize everything including my competition fodder. I have sized many a 30-378 and in my experience they shot outstanding in the factory rifle while being full length resized.
 
Agree with the others. For hunting you want to set your dies for a FL size. You might as well do your load developement the same way you are going to hunt. Most benchresters are FL sizing nowadays because they don't want feeding problems at the bench. (although they have special dies that do a minimal resize all the way around). In a normal hunting rifle with a well set up fl die you will get excellent accuracy....probably much better that the average guy can shoot in the field.
 
here's what I do, in your case run an over sized expander ball into one case, say an 8mm or 338, lube it well!
then start with your resizer screwed way up and resize, trying it in the rifle as you go, when you can close the bolt with just a lil resistance, screw the die in 1/8th to 1/4 turn and lock it down.
your cases are now sized to perfectly fit your chamber. then you can do your normal case prep and load.
RR
 
Not trying to knit-pick but don't go a 1/4 turn...that would probably be about .012" and that's a good chunk of headspace. Keep it to 1/8 turn using the method above. BETTER YET----get a stoney point (now hornady bought them out) headspace bushing kit for all your calibers. Probably the best $35 you'll ever spend if you do any amount of reloading. I could load without it but I use it all the time now that I have it.
 
Not trying to knit pick but 7/8"x14 thread (which most dies are) has 14 threads per inch, which means the one full turn moves it .0714", which 1/4 of that is .0178". That's almost .018". Now 1/8 of a turn is .0089" which is all but .009".

I would say that somewhere around 1/16th of a turn or slightly less (closer to .003") would be more appropriate. Just my opinion!

But, then again. If your not going to be pushing the pressure limit, then there's no real big reason to FL size unless it's entirely necessary. Aside from being less work, it will make your brass last alot longer.

I've pushed full power loads to 5 loadings, never resizing, before the primer pockets gave out. And when i say never resizing, I mean none at all. Just fire, decap, recap, drop powder charge, seat bullet, and fire again. But i always check every single loaded round in the chamber just to make sure there is no problem. At least for that rifle anyway.
 
I load .30 x .378 and .338 x .378. Full length resize both. The sizer die is set by screwing it down until it stops on a fired case that has the neck cut off in the middle of the neck radius (depending on where you cut the neck, you may want to pull the expander plug). Turn the die in handy on the case, and lock it down. This only works if you shoot the brass in the same rifle. The shoulder won't wrinkle or cave in this way. The .30 by shoulder is a little more fragile than the .338, but both require thin sizing lube inside and outside and thorough cleanup. You may booger up a few cases before you get it like you want it.

Ditto on the primer pockets; mine get loose at 4-5 firings. If I knew how to tighten them up again, the rest of the hull would probably make 4 or 5 more firings.

My go-to hunting rifle is my .30 by, Henry Wayne, (you might be a redneck if you name your rifles). #2 is my 7mm-08 named Ugly Baby. Henry Wayne is sub 1/2 moa, and Ugly Baby is sub 1/4 moa. Both are way better than I am.

Got long winded again, good hunting, Tom
 
30/378

Sounds like a lot of good advice.

The trick to Weatherby or any belted magnum case is that the
head space needs to be .001 or less and the chamber needs
to be concentric. Then size as close to full length as possible
with out touching the sholder of the case.

By doing this everthing is aligned prefect an the problems with
freebore are eliminated .

If the head space is more than .001 or .002 thousandths thenI would
recomend neck sizing only."BUT" before you go hunting try each round
to make sure they will go ( A common practice with dangerous game
rifles even with full length sizing to avoid a problem at the worst time).

So start by checking the head space on your rifle and go from there.

All you need to check head space is a small peice of brass shim stock
.002 and some grease to make it stick to the bolt face . Cut several
pieces small enough to fit in the bolt face without touching the extractor

Being very careful use a new factory round and close the bolt on it
with one of the brass shims stuck to the bolt face if you feel a slight
resistance then take the shim out and try it with out the shim. If it
feels the same add two of the shims( You should'nt be able to close
the bolt with out forcing it"DON'T" .

Of course if you have access to a head space gauge please use it first
to avoid using a live round.

One of my Weatherby's shoots a .091 5 shot group set up this way.

Good luck
J E CUSTOM
 
For 30-378 I use a full length bushing die, I do not like dragging an expander through the neck.
I also have a 30-378 neck sizing bushing die and don't use it because with max loads they need to be FL sized. If I was going to shoot mild loads I'd use the 300Wby.
James
 
I load .30 x .378 and .338 x .378. Full length resize both. The sizer die is set by screwing it down until it stops on a fired case that has the neck cut off in the middle of the neck radius (depending on where you cut the neck, you may want to pull the expander plug). Turn the die in handy on the case, and lock it down. This only works if you shoot the brass in the same rifle. The shoulder won't wrinkle or cave in this way. The .30 by shoulder is a little more fragile than the .338, but both require thin sizing lube inside and outside and thorough cleanup. You may booger up a few cases before you get it like you want it.

Ditto on the primer pockets; mine get loose at 4-5 firings. If I knew how to tighten them up again, the rest of the hull would probably make 4 or 5 more firings.

My go-to hunting rifle is my .30 by, Henry Wayne, (you might be a redneck if you name your rifles). #2 is my 7mm-08 named Ugly Baby. Henry Wayne is sub 1/2 moa, and Ugly Baby is sub 1/4 moa. Both are way better than I am.

Got long winded again, good hunting, Tom
Try to look up swaging with the Rcbs , swagger #2 (?) unstaking military brass dies and a few homemade aids.. I found something a while back that makes tightening up the 30-378 doable ! Saves the brass , money etc .
 
Seeing that this thread is from 2007 I will go out on a limb and say that 30-378 barrel is shot out by now. 😉
? Depends , Newbies here , I got so many to play With , I can't shoot a 30-378 over em All 🤪🤣😂
 

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