I just joined the .375 H&H club
Bought a Sako Finnbear Mannlicher with 20.5 inch barrel
I will use this on deer ,elk , moose hunting and Grizz protection in Mt.
I have selected the newer Barnes 250 grain and am need of advice regarding powder selection in the short barrel.
I figure the Barnes 250 is enough for the species listed and should give me some range.
So , any advice on loads ,powder selection etc is welcomed

Not actually loading for an H&H at present, but have heard some very good reports on RL 15. Used WW760 in my old H&H (was great), but don’t know who we’ll it would perform in the 20.5” Barrel. memtb

I reload a lot of .375H&H. I am a big fan of RL 15. Currently I have worked up to a load that is 1 grain under the max listed in the Barnes book.

My rifle has a 20" barrel I am getting about 2700 FPS with the 250 gr TTSX and about 2700 FPS with the 270 gr TSX. The 270s group tighter out of my gun so that's what I use.

If your magazine is 3.6” and you want to get max velocities from the 250 TTSX, you’ll have trouble getting enough RL 15 stuffed in the case. I use IMR 4064 for that load of you are limited to 3.6” OAL. I load to 3.59” OAL to ensure good feeding.

all good info

I have a few pounds on 4064

ANother question is , Barnes recommends to load so many thousands of an inch off lands.
Excuse my lack of knowledge on this point , but how do I measure that distance?
Do I just stay with the top crimping groove ?
Should I stay with 3.59 and be ok with it?

I favor the 250 gr bullet in the 375 H&H, Sierras or Bitterroots. IMR 4064 works well with either.

quote:

Originally posted by SILVERBUZZARD:

ANother question is , Barnes recommends to load so many thousands of an inch off lands.
Excuse my lack of knowledge on this point , but how do I measure that distance?
Do I just stay with the top crimping groove ?
Should I stay with 3.59 and be ok with it?

There are a number of ways to determine the length of your chamber and throat. Easiest is to load a dummy round to something like 3.8” and see if it will chamber...but don’t force it, just lightly try the bolt. Keep seating deeper by a few hundredths until it will chamber, then you have your chamber/throat length.

Next, seat deeper by the amount Barnes specifies. If that will fit in your magazine, you have your starting point. If it won’t fit in your magazine, then your max overall length is determined by the magazine, not the chamber.

great stuff thank you

Problem with using a dummy round to determine the chamber/throat length is that the ejector, if it is in the bolt face, or the extractor slipping over the case rim into the extractor groove both create feel as you attempt to close the bolt on the dummy round.

The better way is to close the bolt on an empty chamber and put a cleaning rod down the barrel until it touches the bolt face then mark the rod at the muzzle (ballpoint pen up against the muzzle). Remove the bolt and then insert a bullet into the chamber and push it to stop at the rifling using an empty case, finger, pen etc. Again let the rod touch the bullet nose and mark rod at the muzzle. The distance measured between the marks on the cleaning rod is the maximum overall length, COAL, of a loaded cartridge with the bullet lightly touching the rifling.

Deduct Barnes' 'off the lands' measure from the COAL and load your rounds to the "Barnes" COAL. Of course as mentioned by Trademark, your magazine length may dictate your COAL.

oky doke
WIll get started on this
thanks all for the help

quote:

Originally posted by eagle27:
Problem with using a dummy round to determine the chamber/throat length is that the ejector, if it is in the bolt face, or the extractor slipping over the case rim into the extractor groove both create feel as you attempt to close the bolt on the dummy round.

The better way is to close the bolt on an empty chamber and put a cleaning rod down the barrel until it touches the bolt face then mark the rod at the muzzle (ballpoint pen up against the muzzle). Remove the bolt and then insert a bullet into the chamber and push it to stop at the rifling using an empty case, finger, pen etc. Again let the rod touch the bullet nose and mark rod at the muzzle. The distance measured between the marks on the cleaning rod is the maximum overall length, COAL, of a loaded cartridge with the bullet lightly touching the rifling.

Deduct Barnes' 'off the lands' measure from the COAL and load your rounds to the "Barnes" COAL. Of course as mentioned by Trademark, your magazine length may dictate your COAL.

Rather crude resolution on the measurements that way, but a good method to get an idea of how deep that CZ .458 Lott throat really is.
I'll try that.
Thanks.


Anyone who claims the .458 Winchester Magnum is ineffective has either not tried one, or is unwittingly commenting on their own sheepishness.
Rip...

I have a Sako AV in 375.

I've only ever used the 285 and 300 grain bullets, but W-760 is the powder that delivers the best accuracy for me.

Not 250s but 71 grains of RL-15 is my go to for my 375 using 270 gr Hornady's. Very accurate load. It's my go to powder for 300 grains as well.

I NEED MORE POWDER !

Another vote for Reloder 15. I'm using 73 gr. and a 270 gr. Hornady.

quote:

Originally posted by RIP:

quote:

Originally posted by eagle27:
Problem with using a dummy round to determine the chamber/throat length is that the ejector, if it is in the bolt face, or the extractor slipping over the case rim into the extractor groove both create feel as you attempt to close the bolt on the dummy round.

The better way is to close the bolt on an empty chamber and put a cleaning rod down the barrel until it touches the bolt face then mark the rod at the muzzle (ballpoint pen up against the muzzle). Remove the bolt and then insert a bullet into the chamber and push it to stop at the rifling using an empty case, finger, pen etc. Again let the rod touch the bullet nose and mark rod at the muzzle. The distance measured between the marks on the cleaning rod is the maximum overall length, COAL, of a loaded cartridge with the bullet lightly touching the rifling.

Deduct Barnes' 'off the lands' measure from the COAL and load your rounds to the "Barnes" COAL. Of course as mentioned by Trademark, your magazine length may dictate your COAL.

Rather crude resolution on the measurements that way, but a good method to get an idea of how deep that CZ .458 Lott throat really is.
I'll try that.
Thanks.


Anyone who claims the .458 Winchester Magnum is ineffective has either not tried one, or is unwittingly commenting on their own sheepishness.
Rip...

two drill stops on a brass rod. tighten outer one on empty chamber to bolt, inner one on bullet touching lands. calipers to measure between the stops gives Cartridge Over All Length to lands

I've had very good luck with the Barnes 235 gr and the 250 gr Sierra Game King.

RL 15 and 4064 plus many other powders work great in the 375 H&H, its just not picky...My only hunting load for anything with the 375 is the 300 gr. bullet at low pressure 2500 FPS. If your looking for flat shooting use the 300 gr. Sierra btsp, it shot flatter than any other bullet at longer ranges (400 and 500 yds) in my tests..also is a dandy elk round and deer just flop at any range.

Ive never understood this business or a big ole gun and a little short bullet..If I intend to shoot 250 gr. bullets then I'll do it in my .338 win. and so fourth with most all calibers..The same reason I don't shoot a 30-06 with 125 gr. bullets!

Ray, I’ve been told that the Sierra 300’s are much improved since the early 80’s....I certainly hope so. I bought about 3 boxes for my H&H,developed a load that I was very happy with. Later, broadside shots (under 100 yrds.) on a deer and a slightly larger than average black bear, showed that neither bullet exited. A thorough autopsy on the bear found the empty jacket (only)!

A test of the Sierra shot right beside a few Hornady 270 SP, into my available test medium (soft, loose, sandy soil)dirt bank.....gave these results. The Hornady gave text-book perfect mushrooms. The Sierra’s would have required the soil to be “sifted” through a screen to find any jacket/ lead material. The remainder of those were used on jack rabbits and prairie dogs while fire-forming for my new (in 1990), AI.
volt
The Hornady 270 is my “go to” bullet in my old H&H. They upset too quickly and lost too much weight in my AI, soon I discovered Barnes’ in the early ‘90’s....and never looked back! memtb

I love this forum , years of experience on guns and loads !
I am going to try the 300 grain Sierra and the 270 Barnes ,like Ray pointed out ,the Sierra is the flattest shooter.
Just tried a couple 250 Barnes and some 4064 ,there is promise there but as you all are pointing out , heavier is preferred
RL 15 looks to be popular here too

quote:

Originally posted by eagle27:
Problem with using a dummy round to determine the chamber/throat length is that the ejector, if it is in the bolt face, or the extractor slipping over the case rim into the extractor groove both create feel as you attempt to close the bolt on the dummy round.

The better way is to close the bolt on an empty chamber and put a cleaning rod down the barrel until it touches the bolt face then mark the rod at the muzzle (ballpoint pen up against the muzzle). Remove the bolt and then insert a bullet into the chamber and push it to stop at the rifling using an empty case, finger, pen etc. Again let the rod touch the bullet nose and mark rod at the muzzle. The distance measured between the marks on the cleaning rod is the maximum overall length, COAL, of a loaded cartridge with the bullet lightly touching the rifling.

Deduct Barnes' 'off the lands' measure from the COAL and load your rounds to the "Barnes" COAL. Of course as mentioned by Trademark, your magazine length may dictate your COAL.

eagle27,

Thanks for goading me into trying that.
I use a cold-rolled 3/8" steel rod in the .458-caliber rifles.
I hold a fine-point Sharpie marker against the rod, precisely at the muzzle crown, and spin the rod to mark it.
Then I cover the mark with transparent tape to preserve it, prevent smudging.



When the rod is marked twice, the data is one number: The distance between the two marks.

If the bullet-caliber slug is flat on the end going into the rifling,
then that one number is the "Throat Jump" of a bullet going from maximum length brass to the bullet-caliber diameter of the throat.

If there is any nose projection of slug/bullet ogive beyond the full-caliber diameter of throat,
then that projection must be measured and subtracted from the distance between the two marks on the rod.

I measure the spacing of the two rod marks on the muzzleward side of each mark, as precisely as possible with calipers.
Not with a ruler vaguely somewhere in the middle of each mark.

Take care and you can get some good results using this method,
repeatable and reproducible for me within +/- 0.005",
plenty good enough for my purposes.

Thanks for the idea.

Here is another method more simple-minded that might be OK for small bores and short throats:



http://bulletin.accurateshoote...ngth-to-lands-gauge/

I load my 375 H&H with IMR 4064 and use Fed 215 Magnum primers in Win cases (WW Super, Win, SuperSpeed, Super X, etc.) Pre 64 Win 70 with 25 inch factory barrel.

I believe 375 H&H and bigger need crimped at the cannelure with a moderate crimp.

I use 70 grains in 260 Grain Partitions
69 grains in 260 Grain Solids
2710 fps

and 66.5 grains in every 300 grain bullet I have tried: Nosler Partition, Win Silvertip, Hornady RN, Hornady DGS, & DGX for 2450 fps

I loved the 250gr NorthFork SS until michael458 got me interested in CEB. Now I use Barnes loading data and Viht N540 under a 235gr ER Raptor. Makes 3000fps in a model 70 and is supremely accurate. CEB has a few new Maximus bullets in .375, 175gr(which I think is too light), 250, and 300. If I didn't already have a fantastic load with the 235, I'd try the 250.

Andy

quote:

There are a number of ways to determine the length of your chamber and throat. Easiest is to load a dummy round to something like 3.8” and see if it will chamber...but don’t force it, just lightly try the bolt. Keep seating deeper by a few hundredths until it will chamber, then you have your chamber/throat length.

That method works but it works even better if you take out the firing pin assembly - the bolt closes with zero resistance in this case.

quote:

Originally posted by Atkinson:
RL 15 and 4064 plus many other powders work great in the 375 H&H, its just not picky...My only hunting load for anything with the 375 is the 300 gr. bullet at low pressure 2500 FPS. If your looking for flat shooting use the 300 gr. Sierra btsp, it shot flatter than any other bullet at longer ranges (400 and 500 yds) in my tests..also is a dandy elk round and deer just flop at any range.

Ive never understood this business or a big ole gun and a little short bullet..If I intend to shoot 250 gr. bullets then I'll do it in my .338 win. and so fourth with most all calibers..The same reason I don't shoot a 30-06 with 125 gr. bullets!

I agree Ray; I shoot nothing lighter than 270s in my .375s...