Author Topic: What powder for 375/350 Rem Mag? (Read 1251 times)

HHI 812 · « **on:** March 08, 2006, 04:55:37 PM »

I got a 375/350 Rem Mag barrel for my single shot, and wondering if there is a way of figuring out which powder to use, as well as minimum and maximum charge? e-mail at dennis.madriaga@gmail.com Thanks!!!

Nobade · « **Reply #1 on:** March 09, 2006, 02:20:54 AM »

Hi Dennis, good to see you're still out there in cyber land! As for powder, I would use about the same powders you'd use in a 45-70 since that case is similar in size and shape. 4198 to 3031 in IMR, 2015 in Accurate, maybe H335, etc. you get the drift. Perhaps someone with Quickload could give some load recommendations, but that's where I'd start. That sounds like a fun cartridge, I've been thinking along the same lines myself.

HHI 812 · « **Reply #2 on:** March 09, 2006, 08:05:04 AM »

Nobade-not doing a whole lot like I use to. When I got laid off, it kind of drained my gun collection and funds. Have to cautiously watch what I spend, but just can't stay away from my favorite hobby. Odd you gave a couple of those powders, because the 3 I was seriously looking at was IMR 4198, 3031 and Rel 7. Not familiar with the AA powder? Problem is, not sure where to start? Was considering looking at 350 Rem loads, or 416 Express, but not sure how to really estimate the charges? Never worked with a belted case before, so not sure how I should really tell my max loads? As far as the .375, had a few .375 JDJ's in the past, and liked it. Looked at the 411, 416 and even the 470, and just sold my 4" S&W 500, and an unfired 6.5" PC 500 S&W, but shooting them 700 grainers wasn't fun anymore. Must be getting old? Anyway, figured the 375 would be a good middle?

Nobade · « **Reply #3 on:** March 11, 2006, 03:21:50 AM »

Well, I'm sure you're not going to get into trouble using book loads for the 350 Rem mag. This case will probably allow you to use powder that's one step faster than you could in the 350, but amounts are going to be about the same. Can't fill it up more than full, huh? Of course it'll depend on the throating your barrel has, and how much the bullet is in the case but shouldn't be too tough to figure out. If the book lists a compressed load for the 350 there's no way you're going to get in trouble with the 375 and that same powder. As for pressures with belted cases, since I assume you're using this in an Encore I wouldn't load it any hotter than having the case fall out with the extractor removed, and it ought to be going plenty fast. Can't do the normal pressure signs like a bolt gun, so there's no need to really push things since it's not going to be very flat shooting no matter what. It sounds like a fun cartridge, similar to what I was dreaming up a while back - 300 win mag case, sized in a 338 win die and blown out to 375. Yours is about the same, just a little shorter.

HHI 812 · « **Reply #4 on:** March 11, 2006, 01:58:26 PM »

This barrel I have is for the Competitor Corp single shot pistol. He also chambers these caliber all the way up to a 470 Nitro. This site has a list: http://www.competitor-pistol.com/ I just took some photos of my Competitor with a 16" barrel, over my Encore with a 15" barrel, and the encore overall length is still longer by 2 1/2".

Golsovia · « **Reply #5 on:** May 13, 2006, 04:20:39 PM »

I never quite get down this far in the forums so I haven't seen this before. I do shoot a 375-350 though. Mine has a 20" Pac-Nor and they did a fine job including bolt face work on my Ruger 77 which was a 243 at birth.

I have tried a number of powders using 250 loads for the 350 with 270s in the 375. My initial results with 350 powders: 4320 and 4064 gave results too slow with case fulls so I went down a bit. I have tried H322, Varget, H 4895 and IMR 4895. Of them, the 4895s seem to work best and IMR 4895 gives very fine accuracy and good velocity. I get 2400 fps with 270s and 2300 with 300s. The shot to shot variation in velocity is very low with these combinations. It's a great cartridge.

HHI 812 · « **Reply #6 on:** May 13, 2006, 07:20:24 PM »

I have to check my data, but the heaviest bullet I tried so far, has been the Sierra 250 SPBT, and I think it was H4895 that gave me 2500+fps average, out of my 16" pistol barrel. Have stopped any more testing since I have a buyer for the Competitor. Now I have a bunch of .375 bullets to sell like 220FP, 225SP, 250 Sierra, 260 Accubonds, to name a few. Have to admit, the cartridge is a thumper, but quite comfortable in the Competitor.

Golsovia · « **Reply #7 on:** May 14, 2006, 09:43:31 AM »

That sounds about ballpark or perhaps even a bit hotter than I've gone. I have never felt like I've pushed my rifle hard - never a hint of pressure trouble but getting useful velocities which seem about right for the case volume and barrel length. I am using 58.0 grains with 270s and 56.5 with 300s. Don't take that as recommendations obviously.

How much H4895 are/were you using with 250s to get 2500?

My rifle is very accurate with Hornady bullets, especially the RNs. Barnes and this Pac-Nor seem to really disdain each other.

HHI 812 · « **Reply #8 on:** May 15, 2006, 08:30:55 PM »

When I got the barrel, there wasn't much load data. I've gone to the range with this barrel only twice, so haven't done much testing. But with the few powders I've tested, this is what I got with the Sierra 250 SPBT: 56.0 3031/2357fps, 60.0 Varget/2303fps, 361.0 IMR4320/2420fps and 61.0 H4895/2531 fps. These loads were worked up in "my" Competitor pistol, and not to be used in any other firearm. Didn't have time to see how much more I could get, nor did I test for long range accuracy.