Depending on the length of your barrel and how "fast" it is (some barrels just get higher velocities than others) it usually isn't to difficult to get at or near 2600 fps with a 300gr bullet but I think that's faster than you need to go as, at least for me, recoil becomes more noticable above 2550 fps and the extra 50 fps just doesn't seem to be worth it. My own feelings are that if you can take the recoil of going much over 2600 fps with a 300gr bullet you might be better served going to something like a .416 that will give you 2400fps with a 400gr bullet.

I don't shoot lighter bullets in the .375 as I think they kind of defeat the purpose of shooting the bigger gun in the first place.

My own reloads are just under 2550fps for the Noslers I use as a soft and just under 2500 fps for the solids I use....the 50 fps difference in velocity allows me to regualte the rifle to have the same point of impact at 50 yards for both the softs and solids.

quote:

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Originally posted by D Hunter:
. I understand that velocity can help you extrapolate pressure. "D"

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D, Velocity is only a small guideline, the condition of your primers are the most obvious sign to read here. I think you are at the end of the scale...I would back 'er off a half a grain, myself. I don't know what you are using for primers, but I know the CCI250 and FED215 are hard primers that don't flatten easily. When they do, you could already be in the red-zone. YOUR velocity and load w/ the 270gr. and 21" barrel is what I am getting w/ a 24" barrel. I found that hitting elk and moose bone at 2750-2800fps (m.v) causes over-expansion and LESS penetration in some bullets. I don't use the SAF bullets,,,due to rumors of expansion inconsistancy. (heavy bone vs. viscera)
I cannot comment on the 300 gr. loadings. I might also suggest you try IMR-4895 or 4064 w/ your 270gr.'ers Generally, I'm gravitating more into accurate loads, and away from the higher velocity. Whats another 1" of drop @ 150yds.? No flames intended....cheers

[This message has been edited by D Hunter (edited 11-16-2001).]

[This message has been edited by D Hunter (edited 11-16-2001).]

The factory loads with 270-grain bullets reach from 2,650 to 2,690 fps. Again, Hornady's HM is much faster.

I also like the 300 gr. bullets and 72 gr. of RL-15...260 Nosler and 76 grs of RL-15...270 and 74 grs works fine in all the 375's I have owned. I don't consider the 375 a long range gun, but it will do for 90% of the shots you get...so will a 416 and has the advantage of being a better DGR...

I have never decided if the 375 is the all around best gun OR neither fish nor fowl, it fits both catagories pretty well, but I can't imagine not having one...

If I wanted a flat shooting gun I'd drop down to a 338 or even a 300 Mag. of some sort..If I wanted a DGR I would go with the 416 Rem or 404..but I've allways had a 375 like I said...Now you may think I'm confused, well I am.

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Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

It just is not worth it. The .375 is the queen of them all. It's just right as it is. The reason it's just right is the recoil is about all anyone can take and still make a good hit. Also the bullets stay together at normal speeds. That's why I got rid of the Sauer made .378 that I had. I just knew it was unproven.

Frank N.

If you have a rifle that doesn't display cratering and it starts to as the charge weight increases then that is a true pressure sign.

Headspace and primer pocket fit and primer composition all have an effect on primer flattening. As an example new cases and start loads can often give very flat primers.
indeed. Cases with tight primer pockets will not allow the primer to move to flatten until higher pressures are achieved. Coincidentaly the harder silver coloured primers are also very slightly larger. They therefore not only require a higher pressure to deform but also don't start moving until pressure is higher.

So what do you do if you have a rifle that allways craters (mauser) will flatten primers randomly even at definately low pressure loads. In my case you check with the powder manafacturer, check with a chronograph, check with quickload, leave a margin for error and look for other clues such as report, recoil, ease of extraction and accuracy.

I would be very interested to hear how Saeed decides when enough is enough. Some of his loads are way over book (eg N150 and 100gr nosler ballistic tips in the 6.5x55 data)

quote:

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Originally posted by Atkinson:
I have never decided if the 375 is the all around best gun OR neither fish nor fowl, it fits both catagories pretty well, but I can't imagine not having one...

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Isn't the same true of the 30/06? For any specific task you can probably think of a better caliber than the 30/06, but for everything short of the very largest game it's still arguably the best choice. So also with the .375 H&H for the very largest game too.

Federal primers are thought to be "soft" in the world of Highpower. Some people won't go near them in an M1 or M1A.

Can you back off on the load a couple grains, and/or maybe use CCI or Winchester primers?

How big is the firing pin hole in the bolt, versus the diameter of the firing pin tip itself? Since factory loads are showing signs of cratering, a large clearanc here will contribute to your problem.

The flip side of the "will it work in Africa" statement is that maybe you are planning on taking this to Alaska, and you are in Florida right now.

How many reloads do you get out of a case? Ever have a case head separation? Have you sliced one of your older cases open to see if you are getting near separation?

Sounds to me that high velocity isn't your goal, so much as you like the way the rifle shoots with your load. Keep investigating other ways of obtaining this type of accuracy that won't give you that nagging feeling in the pit of your stomach every time you pull the trigger.

Scott

[This message has been edited by Scott Thornley (edited 11-22-2001).]

I'm getting same FPS with 24" as you are with your 21". Same bullet and powder. I'm pretty sure same Make and model if I remember correctly. I think thats fast in 21" but some are faster than others. What does your bolt face look like and is that neck sized or full length resized case? I know it is hard to come off from your best load.

HBH

I have used 76 grains of Re 15 with 270 Hornady Spire Point in a few 375s that were chambered with JGS reamer, and that will be a tighter chamber than most factory chambers. Velocity from 26 inch barrels was generally over 2850 f/s.

I have also used 73 grains with 300 grain Nosler and accuracy was very good. Velocity from26 inch barrels,just over 2600

As a general rule, calibers with small case capacities for the bore (eg. 308 and 375) rarely give top accuracy at high pressure.

Mike

Hodgdon's loading book gives a max load of 81.5 gr. of H4350 with 300 grain bullets in the 375 H&H, and 83 gr. with 270 gr. bullets.

When I first saw those numbers they made me very nervous because they are considerably heavier loadings than what is recommended as max for IMR4350. But I've used those Hodgdon loadings and they do not show signs of excessive pressures in my rifle -- a Remington 700 Classic with 24 in. barrel. Those loads have given me 2777 f.p.s. with 300 gr. Sierra BT bullets, and 2877 f.p.s. with 270 gr. Speer BT bullets, both with excellent accuracy (sub MOA) and very low shot-to-shot variation in velocities.

I should also say that I use the Winchester WLR (non-magnum) primer for the .375. I did try Federal 215 primers (magnum) but they seem to me to give poorer accuracy. I use Winchester brass.

IMR4064 gave me excellent accuracy with the lighter (270 gr.) bullet, but the velocities were not as high -- they were in the 2670 range. Varget gave me erratic velocities and only so-so accuracy. (In fact, I've not yet found any use where Varget did well.) H-414 also gave me erratic velocities and so-so accuracy.

[This message has been edited by LE270 (edited 11-24-2001).]

quote:

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Originally posted by LE270:
I'm convinced that the best powder for the 375 H&H is Hodgdon 4350

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I haven''t tried it .375 H&H but it's excellent in the .300 WSM and the .338 WinMag, to name just two others. The velocity variation is very low, the temperature effects are minimal in my testing. I to, use Winchester primers and altho they test to be hotter than some others, I like their consistency and ignition.

That load with the 300 Sierra must bwe real compressed unless you are neck sizing and have a large chamber.

I agree with your comments on Varget.

Mike

To me it would make more sense to use a .375 RUM, which can safely push a .300-grain bullet at a factory advertise velocity of 2,760 fps.

Think about this: If it was safe under all hunting conditions to approach 2,700 fps with a 300-grain slug from a .375 H&H, why would Dakota and Remington design their .375 versions? The .375 Dakota can safely push the same 300-grain slug at 2,700 fps.

HBH

That rifle must be a highly unusual one if it is not getting high pressures and those velocities are accurate.

Also, ditto Ray Atkinson on the recommended loads. 72 grains of RL-15 will work with any 300 grain bullet available, at safe and sane pressures, IMHO.

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Rifles And Bullets r us: RAB

Just buy a bigger cartridge if the .375 H&H is not enough for you. And I suggest a bigger bore too as well in that case.

I had a .375 Improved built for fun. I don't load it that hot. I load it just like the others and it does give a little more velocity. I did this on a whim. I would never do it again. I wish that chamber was standard.

quote:

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Originally posted by Mike375:
LE270,

That load with the 300 Sierra must bwe real compressed unless you are neck sizing and have a large chamber.

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No, I am full-length resizing, and my chamber seems normal. The load is compressed, but does not show any signs of excessive compression (and I do know about excessive compression because I've tried to load too much H4831 in .270 brass and had the cases collapse and/or the bullets fail to seat).

quote:

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Originally posted by R. A. Berry:
That rifle must be a highly unusual one if it is not getting high pressures and those velocities are accurate.

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I'm sure the velocities are accurate because my chronograph does not give high readings with other loads. In fact, in my .270, for example, I have trouble getting anywhere near the velocities given in the loading books for given loads -- my loads are usually 100 to 150 f.p.s. lower than published ones. Also, when I load my .375 with Varget, for another example, my velocities from the 300 gr. bullets are in the range of 2400 f.p.s. (I have a partial can of Varget I'd like to trade with someone for an equal amount of H4831, RL22, or IMR7828).

I set up my chronograph about 15 feet from the muzzle, and the figures I'm giving are the actual readings at that distance (not adjusted for muzzle velocity).

[This message has been edited by LE270 (edited 11-24-2001).]

If you want the gun for long range shooting, why not rebarrel with a 26 inch, or longer barrel?

s

First of all, both primers and brass are not very reliable to use in estimating pressure. Secondly, because of its exapnsion ratio, the 375 H&H will also lose less velocity per inch of barrel reduction from, say, 24" than 7mm and 30 magnums and high intensity small-bore cartridges like the 270 Winchester.

Okay, here are some data using W-W brass, Federal 210 primer, 270 gr. Hornady SP bullet, OAL of 3.582".

75 grs. RL-15, 2728 fps @ 60,400 psi.
78 grs. H-380, 2629 fps @ 51,100 psi.
80 grs. H-380, 2692 fps @ 54,000 psi. (Notice the increase of about 3,000 psi to obtain about 60 fps increase in velocity.)
81 grs. H4350, 2559 fps @ 49,000 psi.

W-W brass, Federal 210 primer, 300 gr. Nosler Partition, OAL 3.564": 82 grs. H-4350, 2539 fps @ 58,500 psi.

Hodgdon #27 load manual duplication: W-W cases, Federal GM215M primer, 300 gr. Sierra SBT, OAL 3.600". 81.5 grs. H4350, 2593 fps @ 60,000 psi. (This, by the way, is the single most accurate load in my rifle. Velocity standard deviation was 5 fps and pressure standard deviation was 700 psi.)

Factory ammo test: Federal lot #390005V190, 300 gr. RN, OAL 3.576", 2484 fps @ 56,000 psi.

RL-15 is a good propellant for 270 gr. and lighter bullets, but I consider it a little on the fast side for 300 grainers. With 270 grainers, it appears as though RL-15 is likely to top out at around 75 to 76 grains. Personally, I generally prefer propellants a little on the slow side for the cartridge and bullet combination so lean toward H-380 with 270 grainers and H-4350 with 300 grainers.

The SAAMI maximum average peak pressure for the 375 H&H is 62,000 psi, but I don't have any theoretical problem with taking it to around 65,000 psi in modern bolt actions if the accuracy holds up.

As you can see from the RL-15/270 gr. data, there appears to be a little room to increase the powder charge, but 76 grs. was very erratic in my rifle with wide swings in velocity and the accuracy wasn't worth talking about. The 76 gr. load was so erratic I didn't bother hooking the M43 up to take pressure readings. The 75 gr. load, though, wasn't bad -- giving about 1-1/2" groups at 100 yards.

For the last 3-4 years I have used a load like yours. 76 grians of RL-15 with 270 grain bullets. I know others have said that using less then 300 grian bullets defeats the purpose but I think some may be missing the true beauty of this fine cartridge.

Typically the 270 grain bullet zeroed for 230-250 yards will put the 300 grain bullet dead on at 100 yards with no change of your sights. I know this to be true from reading about this gun in "the old days" and I know this to be true from testing with all the guys rifles I reload this round for. That combination is what makes this cartridge truely versatile.

The 270 SAF at 2800 plus FPS is a magic wand on all plains game. At the typical distances you only need to point and shoot without the worry of hold over or under ever. You also get beautiful full flowing blood trails most of the time(if you even need them).

The 300 grain bullets are fine, I have shot several buffalo, Eland, and big bears with them and watched every one of them fall within a few yards. Including one which crumpled in his tracks. I love the 300 grain bullet, but for the majority of plains game it cannot touch the higher velocity mushrooming effect of the 270 SAF bullet.

There was one part of your "formula" which was missing. You never stated what primer you're using? I have found over long term testing that standard rifle primers are best and give the most consistant Velocities in this cartridge. My load uses Federal 210's with 100% perfect function in at least 6 different rifles without an even tiny problem ever.

When using the 215's my velocity would be higher in some guns going near 2900 on one shot and 2810 the next? Accuracy at 100 yards was "OK" but at 250 it was all over the place. Switching to the 210's kept the velocity consist and the accuracy was magical for such a big powerful rifle.

You don't need a Magnum primer in that slow taperd case. If you were using them, switch and your problem will likely be solved. I have seen this post like the one you wrote before and suggested this many times. It always has worked in the past. If you have already been using standard large rifle primers then you have a finicky gun which I then agree with the others should be loaded down bit to cover the warmer temps and awkward pressure problems. The difference 50 fps will make is not that critical. It's more important to be consistant.

I really doubt you will have trouble if the primers look the same from factory ammo and your reloads. It's probably a characteristic of the gun. Your the one holding the gun though! How lucky do you feel?

I thought the idea of a short barrel was something to use in thick brush, easy to handle, etc.

I also thought the beauty of the H&H was reasonable recoil, with relavtively flat, high velocity rounds? So why load the gun to max?

If you want a kicking, max gun, why not go 378?
gs

When you switch to 200 yards do you have to change shooting position.

The heavier the bullet and powder in relation to the rifle's weight, the more the gun moves back while the bullet is still in the barrel and hecne point of impact is more likley to influenced by different holding.

This one reason why quite often a heavy barrel rifle in say 22/250 or 243 will seem to be much more accuracte in the field than a light barrel rifle in the same calibers, yet there might not be a big difference across the bench rest.

Mike

[This message has been edited by D Hunter (edited 11-26-2001).]

[This message has been edited by D Hunter (edited 11-26-2001).]

I am more than a little perplexed as to why a starting load of H-380 would show definite signs of being greatly over pressure. Assuming the brass was not abnormally soft (doubtful), the pressures had to be up around 70,000 psi. As I said, this perplexes me quite a bit.