I managed to chronograph some loads I worked up over the weekend and I'm quite surprised. I worked up to max 81.5gr of H4350 with a 300gr Hornady RN and was getting 2700fps at about 20 feet from the chrono. This roughly calculates to about 2725fps at the muzzle. The 375RUM in Hodgdons book tops out at 2733fps with 90gr of H4350. What's the deal here? I had zero signs of excessive pressure. The cases extracted just as smooth as could be, the primers aren't even flattened a little, no bolt lift, etc... This is out of a 24" barrel. Any insight???

Hodgdens list 77 grains of H-4350 as maximum and a velocity of 2545 from a 26" barrel with that charge.

your load of 81 grains is in tune with the 2700 you chronographed...... have you checked to see if your primer pockets are loose.....in other words have you resizeed and seated new primers?

Hodgdons lists 81.5gr. How old is your reference? And no, primer pockets are just as tight as they were the first time around.

I got the info from Hodgdon's Data Manual #26 the second printing of May 1 1993

their website confirms your number

Hodgdon #27 indeed does list a .375 H&H load of 81.5 grains of H4350 under a 300 grain Sierra boattail for 2645 fps and 49,500 CUP. My only concern would be that you substituted the bullet component and exceeded the velocity of that load by 55 fps. It might be prudent to back off until velocities averaged 2645 fps at the muzzle. Just because you are not experiencing the classic signs of excessive pressure doesn't mean you should exceed the velocity of a published load. JMHO

By the way, our resident reloading expert jeffeosso believes this particular Hodgdon load for the .375 H&H is dangerous and will cause "steel rain." https://forums.accuratereloading.com/eve/forums/a/tp...1043/m/814105601/p/1

Holy Crap Jackfish!!! I read the first page and saw there were two more pages... WOW!! No thanks. I don't need an argument like that. I'm just going to take my data and run. When I blow up, I'll have my next of kin write in about the load I was using

If I saw no pressure signs including no opening of the primer pockets...seriously flat primers...volcanoed...pierced, good extraction of cases then I'd assume the load was safe in my gun.

It might actually be over SAAMI specs but I'd still shoot it as I have no way of proving it.

Possibly the chrono is a bit off but I've not seen this before either.....personally, I'd believe the chronograph.

I believe strongly in the following two statements
1. My modern bolt action rifle is far stronger than my brass cartridge cases.

2. If my cases are not showing signs of excess pressure then I do not have excess pressure for the current set of circumstances

Sorry about that, but I always have a box of salt ready for that old wound.

quote:

Originally posted by jackfish:
Sorry about that, but I always have a box of salt ready for that old wound.

You're just upset about the Packers dismal showing this past weekend.

vapo, You got me! I've been a Packer Fan for 40 years so its nothing new. Ya got yer ups and ya got yer downs. Down for a while I think.

Hello ManCannon,

Would you mind sharing information on your rifle? I'm not surprised you are getting over 2600 fps with H4350. I would back down to 2650 fps as it is the max book velocity but hey, Bob Hagel use to shoot up to 84gr of 4350 in a 375H&H!!!! In my case all I want is 2600 fps with a 300gr and I am a very happy dude!!!

Jackfish I feel your pain. I also have been a packer fan for longer than I care to remember. I will be riding with a bunch of Panther fans down to Charlotte in a few weeks. It will be a sad ride home for someone.
Back to the question at hand. I am only getting about 2745 out of a 270 gr bullet. I guess I had better get me some of that H 4350 for my 300 gr pills. I am with the rest of the responses; I think I might stop at 2650. The critters will not tell the difference and I bet you can't tell any on the trajectory out to 3-400 yards either.

I've got an M70 Safari Express, 24" barrel. In the Hodgdon's data, it uses the 300gr Sierra SPBT, which upon examining the bullet, has a fairly long bearing surface. The bullet I'm using is a Hornady 300gr RN which has quite a bit less bearing surface, thus reducing friction. I'm guessing that the reduced bearing surface is the reason for the increase in velocity. AND seeing how this exact rifle is also chambered in the 416RM SAAMI'd @ 65,000psi, I'm feeling pretty safe running 2725fps with a 300gr. I highly doubt it will accomplish much except for more recoil and alot of bullet/meat destruction. I just thought it was cool how the old 375H&H, loaded to Hodgdon's specs, meets the 375RUM in terms of velocity and power.

I know this much. If I had your rifle and planned to use it in Africa, I'd back off a couple of grains. You'll have velocity to spare anyway. A 375 H&H firing good 300 gr. bullets at the 2550-2600 level is giving you everything you'll need out of that cartridge, and fits into the original ballistic parameters of that cartridge.

Velocity isn't everything........

AD

I've seen the load of 81.5 grains of H4350 on Hodgon's website, what's the opinion of using that load or close to it with the Barnes banded solids?
Since the Barnes uses the driving bands and has so much less bearing surface, it makes sense that it could handle that load well. Since this is a compressed load would the longer Barnes bullets not fit at all?

Allen, I wholey agree with you. I just thought it was "cool" how powder and bullets have evolved that would allow the 375H&H to reach new levels of velocity. Like I said before, what that gains, I don't know. Just a neat tidbit, nothing more.

You're right, powders and bullets have indeed come a long way!

I was reading a piece by John Barsness on loading the 375 H&H, and he stated that his favorite powders were Reloader 15 and H4350. He stated that in his experience these powders were the most consistent at all temperatures, besides producing the best combination of velocity and accuracy.

So it sounds like you're on the right trail!

AD

Many times that first shot with new brass holds together with a good overload, then problems crop up with brass fatigueing very quickly...shot one round and reload it untl you see how long it lasts....

But in reality I never load a .375 over 2600 FPS as bullet failure starts beyond that on big animals....2550 being the perfect combo of speed and expansion for full penetration and leaving two holes....

quote:

Originally posted by Atkinson:
But in reality I never load a .375 over 2600 FPS as bullet failure starts beyond that on big animals....2550 being the perfect combo of speed and expansion for full penetration and leaving two holes....

Ray, may I assume then that you're not a fan of the .375 cartridges larger than the H&H case....such as the .378 Weatherby.....?

I called Hodgdon this afternoon and spoke to one of their ballistic engineer. I asked Mike (the guy I spoke to) about using H4350 with 300gr bullets in the 375H&H. I asked him if it was normal to see velocities as high as 2700fps with this combo out of a 24" barrel. He replied that I was not the only one reporting such speeds and that he does get over 2600fps with his 375H&H which is based on a Remington Classic. I also asked Mike if he thought that H4350 could be used with other bullets like Partitions or A-Frames and obtain such velocities. He believed that it should work out but of course one should always start 10% below maximum. I asked him if he had heard of Bob Hagel's loads using up to 84gr of 4350 in a 375 H&H case. The words that came out of his mouth were, and I quote "how did he get that much powder in that case, I can't"... He told me that most rifle can shoot up to 81.5gr of H4350 and such load generates less than 50000 CUP. He said that the 375 H&H case is a big and strong case that it was perfectly safe. He said that the only exception would be using Barnes bullets or other monolithic which require special loads.

I would love to hear what Ray Atkinson gets out of his 26 inch tube with some H4350 behind a Nosler partition...

Enigma

Gentlenen:
I also get excellent velocity and accuracy in both of my Sako 375HH's with 79.0 GR.of H4350 @ 2600 fps.It is also my powder of choice in both my 338WM,s with 250 GR. Nosler Partion's.

Paul K

Hello Paul K,

Are you getting any signs of excessive pressure with that load in your rifle? Are you getting 2600fps out of a 26" tube?

Enigma

I have been using 79 gr of H-4350 with 300 gr Partitions, Hornady solids and Sierra boattails for over 15 years and get around 2560fps out of a 22" barrel. Should expect 2600fps with a 24" barrel or close to it. I have seen the 300 gr Hornady solid penetrate to the skin on the chest from a Texas heart shot on more than one cape buffalo.

465H&H

WOW!!!!

I did not think that a 300gr out of a 375H&H could penetrate a cape buffalo lengthwise!!! 465H&H do you think that a flat nose solid would of exited that buff? Do you have any experience of such a thing occurring?

Enigma

I have never seen a flat nosed solid used on a buff so can't say. From what I read here from african hands that have used flat nosed solids, it would appear that they do penetrate further then round nose solids but I'll let someone with flat nose experience answer that question.

465H&H

Enigma:
The velocities were out of a 24" barreled Sako deluxe.

78.5 gr. H4350- 300gr Horn RN- 2548 fps
79.0 gr. H4350- 300gr Horn RN 2600 fps
79.5 gr H4350- 300gr Horn RN 2610 fps
Win. brass and Fed. 215 primers.
Chronographed at 15 ft from muzzle. Temp. 78 degrees. Brass is on third reload and no excessive case stretching or case head expansion. Very easy extraction.

Paul K

Maybe this is a bad time to mention the 380 grain Rhino bullet.....

You better hide behind that sofa Vapodog!!! I was ready to through a few rotten tomatoes in your direction...

Cheers,

Enigma

I'm not near my reloading data, but I got near 2700 FPS with H4350 before I quit, and well before I got to 81.5 grains. I backed it off to 2550, but I had no problems with the 2700 fps load. Too much compression for me, though, and I figured there was no need to push beyond factory ballistics.

I don't remember what charge I settled on, but I know that my M-70 (24") will do 2700 with H4350, with less than 81.5 grains. This is with the cheap Hornady 300 gr. bullet.

It's the only gun I own that chronos higher speeds than what's shown in reloading books.

Pertinax