Desirable Powders For 300 Grain Swift A-frames, For .375 H&H Magnum?

[Trogon]

I'm preparing for loading the referenced bullet for my new rifle. I have ordered the Swift manual but it's on backorder. Suggestions for powder for optimal loads with your own reloading efforts are greatly appreciated. I realize this is a poor time for reloading in general but found a new place to check into this weekend. So I can certainly use some pointers what to be on the watch for. Thanks in advance for your comments and advice.

 

[PHOENIX PHIL]

My M70 loves 300gr A-Frames with IMR4350 behind them. My load actually exceeds max listed in their manual, but no pressure signs and very accurate.

 

[Wyatt Smith]

IMR 4350, H4350, W760

 

[TOBY458]

Try RL-15. It usually works quite well in the 375 H&H.

 

[fourfive8]

Right now with the "powder" outage, I'd grab a pound or two of most any powder listed for the 375 HH. Those would include: IMR 4064, Varget, RX15, N160 or N150, any 4350, RX19, H 4831 or H4831SC, any 4895. I just looked in my log and a few powders worked pretty well with the 300 gr TSX and A-Frame bullets I spent time/effort on for serious hunting loads. The powers that seemed to work best with those bullets in both the Win M70 and the BRNO 602 were: Varget, H4350 and RX19. Also grab any LR Mag primers you find including CCI #34s.

 

[flatwater bill]

I get the best velocity with IMR 4350, but hands down, IMR 4064 has produced the best accuracy in my 375's. You may, however, have to take what you can get. Have had very poor results from all the 4831's.............FWB

 

[Aussie_Hunter]

I'm preparing for loading the referenced bullet for my new rifle. I have ordered the Swift manual but it's on backorder. Suggestions for powder for optimal loads with your own reloading efforts are greatly appreciated. I realize this is a poor time for reloading in general but found a new place to check into this weekend. So I can certainly use some pointers what to be on the watch for. Thanks in advance for your comments and advice.

I'm running RL15 with 300 grain Hornady DGX Bonded in my 375 at 2560fps from a 23" barrel. Swift reloading manual lists a max load of RL15 at 2546fps with 300 grain A-frames.

 

[Whacker]

Right now with the "powder" outage, I'd grab a pound or two of most any powder listed for the 375 HH. Those would include: IMR 4064, Varget, RX15, N160 or N150, any 4350, RX19, H 4831 or H4831SC, any 4895. I just looked in my log and a few powders worked pretty well with the 300 gr TSX and A-Frame bullets I spent time/effort on for serious hunting loads. The powers that seemed to work best with those bullets in both the Win M70 and the BRNO 602 were: Varget, H4350 and RX19. Also grab any LR Mag primers you find including CCI #34s.

I would also add Winchester Staball 6.5 to the list. Reloading data can be found for it on Hodgdon website and it can be found some places still since it’s a newer powder and not a lot of people have loads worked up with it yet

 

[375 Ruger Fan]

Sent a PM to you with a photo from the Swift manual. Good luck trying to find any powder and LRM primers.

 

[Frederik]

If you do get hold of it and can't get the other powders mentioned Norma 203B works like a charm.

 

[machinistbutler]

I have , the same as many others , had fantastic results with IMR 4350 with the 300 grain bullets. RL15 is my favourite for the 260 grain.

 

[bruce moulds]

h4350 is probably the optimum powder for 300 gn bullets in the 375.
the reason is that the slowest burning powder that will give the velocity also has the least pressure.
so you get best velocities at lower pressure, AND h4350 is fairly temp stable.
this powder burning rate has a tipping point with 270 gn bullets in 375, working well with them, but lighter than that a faster powder is preferable.
in the old days, the next slowest powders were re15, varget, and 4064.
these are ideal for 235 gn bullets in 375, but too fast for 250, 260, and definitely 270 gn bullets.
now there are powders in between that will suit 237 to 260 gns.
yes re 15, varget, etc, will give the speed, but at what pressure compared to slower powders?
bruce.

 

[arizonajake]

I've been using Varget (ADI 2208) for over 20 years in my .375 H&H with 270 and 300 gr. bullets with top notch precision and consistent velocities.

 

[bruce moulds]

yes but at more pressure than necessary.
once you get 300 gn bullets up to and over 2550 in the h&h you are talking pressure potential.
h4350 (ar2209) makes this issue go away.
bruce.

 

[arizonajake]

yes but at more pressure than necessary.
once you get 300 gn bullets up to and over 2550 in the h&h you are talking pressure potential.
h4350 (ar2209) makes this issue go away.
bruce.

Agreed to. However, this propellant works well in my rifle and keep my 300 grain loads under 2500 (2480) fps, since I am not too fond of hard recoil and more velocity, in my humble opinion is not necessary. My 270 grain Barnes X loads chronograph at 2660 FPS and everything I have properly shot with them, at distances between 75 and 200 meters, has gone down with 1 shot. The exception was an eland, shot low in the front leg, which my PH Jaco Pauer was lucky enough to spot from 1 Km. away the next day. Another 2 quick shots in the chest area got him. I have not used the 300 gr. Woodleighs on animals yet.

 

[dchamp]

My current load is using 300gr SGK's and VVN550. I average about 2585 f/s with good precision. I think RL16 would also be a very good powder to try with 300gr bullets.

 

[Firebird]

I had best success with Norma powders-but good luck finding any. . .

 

[Ridgewalker]

Page from Swift manual. 76.0 H4350 worked best in my MRC at 2,582 fps. 5 in 1 1/4”.

 

[Trogon]

Just got back from working out of town; Somerset, Kentucky had nothing to be found. A store pick of Eagle Rare was a consolation prize though.
I really appreciate all of the responses.
Of all of the powders mentioned, I have H4350. I have exactly one hundred Winchester WLRM primers, so not dead in the water...I'll see if I can find someone local to trade some other primers with.

 

[Wyatt Smith]

That’s a good start at least.