[smokey]

I am loading the >375 now and wish to use up some powder. I have 10 lbs of H870 and am wondering if anyone has some experience with the powder and possibly the .375 win, 30-30 win, 444 marlin, 8x57m or 50 bmg with this powder.
My bullet wieghts are as follows:
.375=200, 220, 240, 255, 265, 300gr
.30-.30= 150, 162, 165, 168, 180, 200gr
.444=240, 265, 285, 300, 325gr
8x57mauser= 180, 190, 220, 225, 265gr


Thanks in advance!!

 

[ribbonstone]

Suspect you'll find that H870 is a bit slow for all of those rounds, with the possible exception of the 8X57...it will be too slow here, but not horribly so and should work reasonably well.

In the others (the .375Win. and not the .375H&H right?) will find that all you can seat under the heavy weight bullets would still earn pretty low velocity, some unburned powder littering the bore, and perhaps an occasional "blooper". May come close to BP ballistics, but believe the vel. would be a bit under that.

Don't let that stop you...may find great accuracy...but loading data will be missing from the manuals. IF you get "bloopers" (where about 1/2 the charge is blown out the barrel along with the very low vel. bullet) STOP. If you get a suck bullet...where the primer ignites, the the powder actually doesn't burn well enough to get the bullet to exit...STOP. If you get a "dud" wher the primer is well dented, but the bullet didn't move, STOP.

Have had that last happen with some slow powder loads in the 45-70. No bullet movement, but the case was kind of warm. I broke the round down to find a mass of 1/2 melted/clumped powder..some of which i had to pick out with a rod. Evidently, the powder never really got burning at all.

 

[smokey]

Ribbonstone,

I have several pounds of the H870 and would like to find the right caliber for it rather than let it ruin. I am thinking more seriously lately about buying one of these big single shot .50BMGs. I haven't settled on the exact specs regarding the .50 I am still looking for dies, brass and so forth. I am wondering if it will be possible to effectively load these?

I also have found a good source for H870 pulldown powder. Any words of wisdom/caution I should be aware of?
Thanks!

 

[ribbonstone]

H870 is a very slow powder, so would be useful in large cases (doesn't have to be as large as 50 Browning) with a bottle neck...say, every thing from .264WM to the big super 30's and .338's. Would have to use heavy bullets in these rounds to get more out of the powder, and it may not be the fastest possible in any of them, but it would burn clean and give reasonably high velocity.

It would probably work (to a degree0 in the 8X57 with a heavy bullet...wouldn't be the fastest of loads, but would probably burn clean enough not to be an embarassment.

Know folks that use slow rifle powders with some cast bullet loads...were they want low pressure and lower velocity. I'm not one of them, but have used stuff as slow as 4831 in the 45/70 with big heavy cast bullets (+500 gr.). Usually it isn't the best of loads...that unburned powder does collect, and as it litters the bore, the bullets have to plw though it, and often that degrades accuracy.

Nothin much to be too aware of...it just does a crappy job in small cases (know it's had to think of the .444 case as small, but in these terms it is) and tends to burn real dirty when used in low pressure loads. If too low a pressure (as would happen with a full case in that .375) may get some ignition problems.

 

[loader]

H870 and AA 8700 are for shooting heavy bullets out of overbore cartridges. The best application I have come across is 220 gr bullets out of my 300 RUM. 3000 to 3100 fps is a breeze in the 26 inch bbl, and accuracy is the best of all powders and all bullets tested - 0.75 MOA.

Its too slow for my 338 RUM - even 300 gr Hawk bullets need R25, and the 870 is 200 fps slower.

As a test, divide case capacity in usable grs of water by the square of the bore in inches. You need a number exceeding 1200 before 870 and 8700 make sence as full pressure powders (300 RUM is 117/(.308X.308) = 1244. If you plan to shoot a bullet with a sectional density of more than 0.330, you can drop the number to 1000 or so.

The smallest case I can think of that might work is a 270 WSM shooting 180 gr barnes bullets, or the 264 Win Mag shooting 160 gr Hornadys.

 

[Jack]

Hodgdon 870, and it's twin, Accurate Arms 8700, are about the slowest powders you can find. H870 and a 375 Winchester is a real mismatch. Doubt if you can get enough powder in the case to do much good.
Hodgdon 870 is the perfect powder for the 264 Winchester with 140 grain bullets. 870 would be good in some of the other really big case magnums, too. 870 is even too slow for best results in the 7mm rem mag. It's better in the ultra mag type cartridges.
Hodgdon has recently discontinued 870, BTW, although I believe AA still makes 8700.