Considering getting a .458win mag and all the load data that I am seeing online is for compressed powder charges; does anyone have modern load data that would help me get maximum velocity out of this round without going to an extremely compressed powder charge?

I have read about the original loads, even factory ones being so compressed that ignition problems were occurring(while rare); and I was thinking that modern powder developments may lead to improved performance.

FYI - I tried to PM ChadTRG about this issue but his inbox is full.....

Long action magnums, I tend to go straight to H-1000, and H-Retumbo, depending on barrel length.

What does Hodgdon.com say?

Thr 458 Lott solves the problem and was chambered by Ruger and still by CZ. Sorry, no help with your original question.

Only loads I saw on hodgdon sit that weren’t compressed was H4198.

Yeah I'm looking at a Winchester Pre 64 Super Grade Safari..... Not exactly the type of rifle I want to have a smith take a chamber reamer too just yet

What bullet and weight are you looking at. Being a basically straight big bore it will take faster powders than the bottle neck magnums. H4895 is almost as fast on the Hodgdon sight as any of the others and not compressed and is an easy to ignite powder often used in reduced loads. One of those powders that gives good results in a lot of different loads.

H335 is the fastest with 500gr that Hodgdon lists and is not compressed but not as temp stable as the H4895 which with the compressed load listed is only 2fps slower than 335. I would also consider Varget or 8208 even though compressed at max loadings.

A lot will also depend on bullet weight. Powder burn is also enhanced with a good consistent strong crimp in straight walled cases

Not a buffalo/elephant load but I tried 400 grain cast with Trail Boss and it becomes fun to shoot. Will shoot through a hog..
I have found with full power loads a 450 grain works better than a 500.

M

Sorry Dewayne, my mail box filled up over the weekend. What bullet are you planning on shooting?

On most of the big bore rounds, you will be a compressed load. That's ok. With a crimp and good neck tension, there's nothing wrong with a compressed load, as long as it's not overly compressed. You can go to 100% to 105% case fill and be fine. When it gets into the 110% case fill, that's where it gets too much. Just like any magnum round, if you ignite it with a magnum primer, like a Fed 215, you should be fine. I wouldn't push 75 grains of double base powder and try to ignite it with a standard primer. There's many good powder you can use, depending on which bullet weight you want to run.

AA2230 and H335 are the usual suspects. I'm a big fan of H335 myself.

Bullet Weight..... I would like to have 450-500gr for actual big game hunting load & a lighter reduced load for the range that I could also use for pig hunting ect.