Bumping back the shoulder - 375HH?

[rookhawk]

So I've never reloaded 375HH before, or at least haven't in so long I can't remember anything. Do you set up the dies as normal and try to bump the shoulder back .002" compared to a once-fired case? Or since 375HH headspaces on the belt is it irrelevant?

 

[Edster]

That depends on who you talk to. Been doing a bit of searching on the topic myself. Some say yeas some say no. I’ll try to dig up
The article I was reading and pass it along.

 

[Edster]

I did find this during the process. I did buy the collet die, waiting for winter to subside so I can make some empties to try it on. https://larrywillis.com/index.html

 

[BourbonTrail]

It helps with chambering on Weatherbys.

I imagine it’s similar on the 375 despite it’s smaller shoulder. The first couple shots may not matter, but eventually, the shoulder to belt dimension matters.

 

[C.W. Richter]

Never had an issue w/ 2 diff 375s simply FL sizing them via std method (even using hotter, higher P handloads in hot climates.) Super accurate and consistent way beyond 3 or 5 shots (likely due in large part to the heavier barrels.) I could see high pressure, previously fired, blown out, neck-sized only brass hanging up in some chambers, causing issues, etc. but for a DG gun (or a non-bolt action for any purpose) it's best to FL size for ease of loading/extraction. Never measured head to shoulder dimensions. Just FL size and trim. No problems.

 

[Wyatt Smith]

It can go either way. I normally just full length size. The primer pockets loosening are normally the reason I discard 375 H&H brass, not overworking.

 

[IvW]

I just fl resize...no issues...ZKK602 Brno's

 

[Sarg]

I would used the neck to help head spacing as I had a custom .375 H&H that would near have case separations on first firing as I believe the chamber was too long, even though head space off the belt was correct, I get this a bit with .303 Brit to !

 

[rookhawk]

So the conclusion is what, go ahead and bump back the shoulder .002" as normal and reload as is customary, ignoring the fact it headspaces on the belt?

 

[mdwest]

I just fl resize...no issues...ZKK602 Brno's

I do the same.. I just use a full length sizing die... no issues at all... Win M70 classic

 

[davidg8480]

i believe if you're looking for sub .5 moa then go the neck size / shoulder bump thing?... But its a
375 hh for shooting big critters. FL is just going to be fine its a belted case. imho.

 

[shootist~]

Bumping the shoulder back a moderate amount is still Full Length sizing.

Based solely on my 338 Win Mag:
Measuring the shoulder on Federal factory ammo compared to fired cases in a couple of rifles was something like .013" to as much as .017". Scary.

I would be happy with .002 - .003", but I defer to those with more experience with the H&H.
Maybe see how your fired cases compare to factory new first.

 

[Inline6]

So the conclusion is what, go ahead and bump back the shoulder .002" as normal and reload as is customary, ignoring the fact it headspaces on the belt?

For practice yes that's fine. When you go hunting please use new brass. Brass can let go right at the belt and you would not want that in a hunt. Like someone else mentioned also full length resize.

 

[F. Vaccaro]

If you’re loading for one rifle neck sizing is usually fine. If you run into chambering problems you could full length resize, be sure seating bullets out too far isn’t the reason if you have chambering problems. I really don’t like setting the shoulder back with any ctg.

 

[Pheroze]

I bump the shoulder 0.002 and I have great results.

 

[The Engineer]

Many belted magnums I have had long chambers which did not impact headspacing (Headspace on belt.) but did impact brass life. If you full length size for one of these rifles the case stretches significantly on each firing and tend towards head separation after a very few reloadings. For practice round I neck size on these rifles to avoid as much of the case stretching as possible. However, any reload that is not full length resized needs to remain with the rifle it was fired in as the round will have expanded to the chamber size and will exceed the SAMI head to shoulder length.

The above being said, I use new full length sized and trimmed brass for DG reloads. I also adhering to the admonition to cycle each round through the rifle before heading off on a long journey to hunt. The round cycling applies whether it is a handload or factory load as I have found oversize factory loads. It only takes a few minutes to remove the firing pin from a bolt rifle and cycle the rounds.

 

[Rick HOlbert]

I would used the neck to help head spacing as I had a custom .375 H&H that would near have case separations on first firing as I believe the chamber was too long, even though head space off the belt was correct, I get this a bit with .303 Brit to !

Had the same issue. Case head separation on the 2nd loading. Pulled the barrel, cut back 2 threads and recut the chamber. no further issues. I full length size my brass but do not bump the shoulder back. Doing so allows for the brass to stretch/flow forward and greatly shortens case life.

 

[450 Fuller]

I have a 1950s Winchester Model 70 that easily tolerates neck-sizing and FL sizing .
With 350 gr original Barnes bullets, one has to be a bit careful of OAL.
The Model 70 rifles seem to have forgiving chambers, but it is wise not to push
velocities into 375 Weatherby territory. Easier to get away with that in Alaska-not Africa.
But some African countries still do not smile on anything but factory ammunition.

 

[Ray B]

The belt is a carry-over from the sloping bodies that needed something perpendicular to the bore to set the headspace. The 375 has enough of a shoulder to hold the headspace, so the belt is not needed. Since I only shoot one 375 H&H i partial resize the cases- that is I set the die by taking a fired case, smoking the shoulder, then insert case into die, in & out while turning the die into the press. when the neck is sized but the soot on the neck in not touched, then I set the lock-ring on the die at that spot.
As long as the loads are not so hot that the case has melting/stretching, they will chamber fine and the greatest potential for accuracy is obtained.

 

[450 Fuller]

That sounds similar to the practice adopted by PO Ackley decades ago. I also only have one 375,
and neck size practice or load developing rounds. But I managed to obtain a separate neck sizing die.
The original British loading of the 375 H&H
used long strings of cordite powder. This also contributed to the belt and sloping case design.
Interesting that the 416 Rigby case did not incorporate that principle and appears modern, though developed close to the same time as the 1912 Holland cartridge. Both used cordite. The 416 remained a proprietary cartridge with Rigby-while H&H released the 375 to the rifle trade, Kynoch may have
helped Holland with case design. The 300 H&H came later, a necked down 375 case that still used cordite powder.