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

[Jakalas]

Good morning. Kindly help me with your stats on using 300gr TSX with H4350. I am looking for a guideline on a new ZKK602 custom built j just received. I use 300TSX in another 375 h&h of mine but with local Somchem propellant which is now unobtainable. Hence my move to H4350 which is pretty much all I can get in South Africa now.
Thank you.

Good morning, did some load development and would like to share.
300gr Barnes TSX,

H4350 72g
CCI 250
2400 ft/s
PMP brass (3.2% less volume than Norma)
Lightly compressed load
.49 MOA

72.8gr
2423 ft/s
.61 MOA

Will be doing some more fiddling - only because I can

 

[Jakalas]

Good morning, did some load development and would like to share.
300gr Barnes TSX,

H4350 72g
CCI 250
2400 ft/s
PMP brass (3.2% less volume than Norma)
Lightly compressed load
.49 MOA

72.8gr
2423 ft/s
.61 MOA

Will be doing some more fiddling - only because i can

Please note that I worked up to 74gr H4350 with no pressure signs. The load was compressed but not over the top for 2466ft / s
I have no need for higher velocities. If need be I can change to Norma brass with 3.2% more case capacity but will then have to start afresh with load development.
Hope this can help someone out there.

 

[RockSlinger404]

I'm still waiting for my 375H&H and playing around with potential loads on Quickload. The rifle in question is a CZ550 with the standard 25" barrel.

Using the 300gr A-Frame, it looks like VV N540 produces the best results. It reaches the 5th node at 2535 fps with 69.6gr powder for 92.8% case fill and 58531psi pressure.

With IMR4350 it can only reach the 6th node at 2442 fps with 71.5gr powder for 96.9% case fill and 48954psi pressure.

This is all theoretic, however it does sway me to at least start with VV N540.

 

[davidg8480]

I'm still waiting for my 375H&H and playing around with potential loads on Quickload. The rifle in question is a CZ550 with the standard 25" barrel.

Using the 300gr A-Frame, it looks like VV N540 produces the best results. It reaches the 5th node at 2535 fps with 69.6gr powder for 92.8% case fill and 58531psi pressure.

With IMR4350 it can only reach the 6th node at 2442 fps with 71.5gr powder for 96.9% case fill and 48954psi pressure.

This is all theoretic, however it does sway me to at least start with VV N540.

Hey Rock Slinger, sorry to bother you with a greenhorn type question what do you mean by reaching the 5th node ?
Thanks David

 

[RockSlinger404]

Hey Rock Slinger, sorry to bother you with a greenhorn type question what do you mean by reaching the 5th node ?
Thanks David

@davidg8480 I think the best would be to read the paper regarding optimal barrel time, that explains it a whole lot better than I can...

Optimal Barrel Time Paper

 

[Spearhead]

Please note that I worked up to 74gr H4350 with no pressure signs. The load was compressed but not over the top for 2466ft / s
I have no need for higher velocities. If need be I can change to Norma brass with 3.2% more case capacity but will then have to start afresh with load development.
Hope this can help someone out there.

@Jakalas much appreciated . Perfect timing with your post.

 

[Spearhead]

Just my 10 ¢
300 A-frame
H4350 78.9gr federal 215 primers
BTW...rifle Winchester m70 safari
View attachment 475732

David, what kind of velocity are you getting with this load please?

 

[davidg8480]

David, what kind of velocity are you getting with this load please?

Of the top of my head 2450 I believe I'll need to look at my notes

 

[steve white]

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

If you don't mind paying hazmat shipping and full price, at least Southwest Ammo in old downtown Mesquite Tx HAS all of the above...

 

[davidg8480]

@Spearhead according to my old notes I was getting 2619 fps

 

[SRvet]

I have good results with Reload Swiss RS60 which is also sold as Reloader 17. 2550fps with a 300g TSX

 

[F. Vaccaro]

I have had great results with WW760 (which is the same powder as H414 I called Hogdons to verify), IMR 4064, & Varget. The .375 is not picky!

 

[revturbo9967]

Good morning, did some load development and would like to share.
300gr Barnes TSX,

H4350 72g
CCI 250
2400 ft/s
PMP brass (3.2% less volume than Norma)
Lightly compressed load
.49 MOA

72.8gr
2423 ft/s
.61 MOA

Will be doing some more fiddling - only because I can

View attachment 477564View attachment 477565

This is great info. I've been loading A frames with H4350 with not much success with accuracy. 1 moa is about is good as I can get, but I have not gone past 74.5 gr. I have had good results with factory loaded 300gr Barnes so I plan to switch over to the Barnes. I know this is a fairly old thread, but do you happen to know your starting load with the 300 gr Barnes and H4350?

This is factory loaded Barnes.

 

[Frederik]

Norma203B and Vita N540 works like a charm but if you want to add more speed N540 is the one.
Both of these I enjoy previously it was Somchem S355 (South African Powder) but cannot get any.
Fills the case nicely close to 100% depending on your case and burns 100%

I can but don't like to push 300gr bullet over 2550fps its plenty enough.
Anything between 2450 and 2550fps will kill anything as long as you use the right bullet.

 

[Puddle]

I only use A-Frames, and in the .375 H&H I load to a target ME of 5.4kj.

If where you're hunting temperatures are balmy then most any powder will do. If, however like my most recent hunt temperatures were well past 95 degrees F then you might consider a temperature-resistant powder. I use H4350.

The Swift manual says 73.9 gr. H4350 will get you 2,464 fps for a starting load. Uhh, not out of my barrel. My load is 74.6 gr. H4350 which chronographs an average MV of 2,455 fps and meets my target ME of 5.4kj.

Plenty enough lethal and all up in a 9.5 lb rifle fast handling for follow up shots as well.

 

[Mark A Ouellette]

I have a bunch of H4350 and used that for my South Africa hunt last October. My rifle shot Barnes 300 gr TSX, factory seconds 285 gr Grand Slams, and Cutting Edge 270 gr Safari Raptors smaller than MOA. Their points of impact were also each very close to the other loads. I stuck a square of blue painters tape on my scope and wrote the dope for each load (POI information) on it.

I don't go to Africa to shoot long range. I did however kill an Impala at 200 meters off the sticks, and three monkeys at 150 meters. The H4350 produced accurate enough ammunition. I am certain I could hit larger animals much further away if I had to.

I also like H4895 for 375 H&H but haven't been able to find any recently.

Both H4350 and H4895 are very temperature stable.

 

[Luvthunt]

Long time 375 user and IMR 4350 and IMR 4064 with 300 gr any bullet. Lighter bullet 260 Nosler Part (269gr) I prefer Re 15 at 2800 fps.

 

[dchamp]

In my 375H&Hs I am getting 2560fps+ using 299gr Hammer Bullets with GM215M primers and 71.0gr’s of CFE223 @ 3.60”oal. Accuracy has been around 3/4” at 100yds in both my Blaser R8 and Winchester M70. The Winchester is giving me closer to 2600fps. I have had it up to 72.5 grains of powder without any pressure signs.

I don’t know how temperature sensitive CFE223 is but I have had good luck with in the 9.3x62 and 8x57 also.

 

[charlieB12345]

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.

Can you tell me what it is I have that same rifle and powder and bullet

 

[PHOENIX PHIL]

Can you tell me what it is I have that same rifle and powder and bullet

Well I'm not inclined to do that. But I started at 73.5gr which is roughly the midpoint between max/min per my manual. I worked up from there, and particularly slowly when I reached maximum and kept going. Your rifle is not my rifle and as such, your maximum load may be different. So for both of our sakes, you need to go through the same process.

As always, particularly when approaching/exceeding max loads, you need to be paying attention to bolt lift and the expended brass after firing looking for high pressure signs.