opinions needed for 375 H&H loads

[bpost1958]

I've been working on cast loads for the 375 H&H using the RCBS 375-250. All of my other rifles seem to like 2400 as a go to powder. The Lyman book does not list 2400 for this caliber.

Looking at burn rate charts seem to indicate that I could start at 25 grains safely and go form there. I am looking for 1800-1850 FPS.

Any help is appreciated.

[BerdanIII]

Lyman Handbook #48

Lyman 375248 250-gr Plain base - 18.0 - 2400 - 1650 fps
Lyman 375449 250-gr GC - 24.0 - 2400 - 2195 fps

TFS 82-13, Thoughts on Hollow-points
Lyman 375449 - 29.5 - 2400 - 1838

I can't account for the huge difference in charge weights (24.0 vs. 29.5) and velocities in the above loads.

Practical Dope on the Big Bores
Lyman 375449 260-gr - 19.0 - 4227- 200-yd match shooting (!)

I would think results with your RCBS bullet would be similar.

[frank505]

shot alot of 55 grains of 3031 and the 375449, very accurate until I washed out the rifling with paper patch bullets. oh well, went to the 416 and never missed the 3/8's bore.

[BABore]

35 to 38 grains of XMP 5744 with a CCI 250 primer. I've used that load with 4-5 different cast boolits and it always very accurate.

[Doc Highwall]

Nice shooting BABore, what caliber/gun did you shoot that target with?

[Typecaster]

"Nice shooting BABore"

I'll echo that. That's how I want my #1 H&H to behave when I (finally) grow up!

Richard

[BABore]

The gun began life as a Winchester Model 70 Super Grade in 300 Win Mag. Picked it up for $375. Found out why too as the bbl just wouldn't shoot. Tried every trick in the book. After several years it went to ER Shaw for a 375 H&H bbl, blueprinting and reblueing. After a good bbl break-in it was shot for accuracy with several brands of jacketed bullets. Accuracy ran around 1 1/4 to 1 3/4" for 3-shots at 100 yards. As the H&H is known for accuracy, I wasn't too satisfied. I firelapped the bbl with approximately 35 lapping rounds as spelled out in the Beartooth manual. After a new bbl break-in, I reshot my same jacketed loads. Accuracy was now running 1/2 to 3/4".

I then switched to cast as I was just getting into it then. I bought a RCBS 375-250 mold from 45 2.1 to start with. It only drops about 0.376 with my alloy. I would have preferred at least 0.377. It shot pretty good with 35 grs of 5744 and a CCI 250 primer. Usually an inch and under. I later borrowed a NEI mold from 45 2.1 that cast a 280 gr GC and a 300 gr GC with a DD band. I never had real great luck with the DD banded boolit. It was ok, but nothing better than the RCBS boolit. The 280 gr has a BR section that didn't really touch anything in my gun. It would shoot just under an inch at 100 yards. I took it out to 200 and 300 yards and things just kept getting better. I think I was up to 38 grs of 5744 by then. Accuracy was good enough that I was shooting golf balls with it, at 300 yards. I wasn't hitting every time mind you, as I had to dope our constant breeze and was using the lower thick post of my Burris 3-9x set at 9x. Still it was alot of fun. I finally got serious and adjusted my scope so I was hitting on the main crosshair. My shooting buddies and I were all trying to one-up each other every week. My one buddy even went as far as to paint a white, golf ball sized dot on the post we typically nailed the ball to. I knew it kind of looked funny to me, but 9x at 300 yards can do that. He laughed at each shot until I placed one right on the money and could see the hole.

Later, when I started making molds, I came up with the 300 gr HP that I pictured above. It shot pretty good, but was kind of a ballistic turd becasue I made the meplat a little too big. Long range accuracy suffered a bit. At 100 yards it wasn't too hard to keep it between 1/4 and 5/8" for 3 shots. I later came up with the 378-275 GC I have on my website. It shoots well at all ranges, but I kind of moved on to other guns by that time and haven't shot it as much as I should.

Most everything shot has been 50/50 WW-Pb that was either water dropped or OHT'd. In either case they came out to 22 bhn. All boolits were nose first sized and GC'd, then later lubed in an oversized die. Everything but the RCBS boolit was lubed with LBT soft. I used a simplier lube on the RCBS boolit as it has alot of lube capacity compared to its bearing length. Cases were mostly FL sized and later crimped with a LEE FC die. Several powders were tried, but the best accuracy was always with 5744. It is kind of a touchy powder on charge weight. In some cases, a 1/4 gr difference made a dramatic accuracy improvement. Not really an ideal situation to have. 5744 has a wide min to max loading range. The AA manual only gives you a glimpse of this. A call to their lab opened it up quite a bit. For any given boolit, I found 2-3 accuracy sweet spots when working from min to max. Very cyclic. I wish I had been using a chronograph as I'm sure there was a fps jump that corresponded with it. Some AA literature and load data from other sources show 5744 paired with standard primers. The original AA data I have showed magnum's. I've only used the CCI 250 mag.

[Doc Highwall]

BABor, thanks for the write up!

[bpost1958]

Where can a guy get XMP 5744 and is there a powder with a close burn rate I could try that I might have on my shelf???

[Just Duke]

:popcorn:

[Larry Gibson]

AA5744 is the same as the older XMP5744. I found 36 gr to be an excellent and also very accurate load under the Lyman 377449 at 1850 fps. I use 50 gr of 4895 with a 1 gr dacron filler for 2190 fps and excellent accuracy also.

Larry Gibson

[looseprojectile]

Cause I am Income challenged I got the Lee two cavity mould for the 38 55. It casts 258 grains with my soft metal.
After cutting out the bevel base and lapping it to .380" I was able to shoot ten shots into about five eights of an inch with that boolit at a hundred yards. Thumb seat the boolits into fire formed cases.
I use and like SR 4759. If you just want accuracy at a hundred yards try 20 -- 21 grains and dacron filler for around 1300 fps. Any more powder than that and I get leading. Will try harder metal for more velocity. I use Alox with a coat of wax on top of the LLA.
I also poured a single lead lap and uniformed the bore with 320 grit compound.
I put an old Weaver V9 scope on it and that seems to be very adequate.
My #1 has a 22" barrel and has been Mag Na Ported. Was that way when I got it used. What I really wanted was a 38 55 BPCR.
I have never shot a jacketed bullet load in it.

Life is good