458 Win Mag Loads

novega

novega

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Anyone have a working load for 325gr Hornady FTX projectiles?
I have three boxes of them but can't seem to find a 458WM load, only 45-70... can I just use 45-70 or 45-90 load data even though the case volumes are different between the two calibers? My gut says "No"

I also have the following cast bullets from Jet Bullets: ...so if anyone can share a recipe for these, I'd appreciate it.
  • 350gr RNFP Gas Checked
  • 400gr RNFP Gas Checked
  • 485gr RNFP Gas Checked
  • 500gr RNFP Gas Checked

Most of the recipes I've come across are for 450- 500gr bullets and there doesn't seem to be much for the <450gr ones

And finally, should I be using a filler (such as starch packing peanuts, or toilet paper) to take up case volume on these loads? where do I draw the line and stop using fillers? Is it according to the volume of powder vs case capacity?

Sorry for all the questions, but I like to take things slow when loading a new caliber, and ask around more experienced folks to make sure I'm doing things safely... even if it makes me look like an idiot :p
**My main reference is Lymans 49th, and Barnes #4**
Thanks!
 
4fifty8 said:
I've loaded 325gr FTX/458WM by adapting load data following 300gr and 350gr guidelines. For reduced loads with appropriate powders dacron filler works not too bad. Lyman Cast Bullet Handbook has load data could adapt for safe use.
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Yeah, that's what I was thinking about doing. Just split the difference between starting loads for 300gr and 350gr and work up from there, continually watching for issues and being extra cautious as I approach the max loads for the lighter bullet.

icehunter121 said:
Couldnt you just go online and use load data from Hornady for their 350 gr. round nose?
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You're right and I'm probably overthinking it...but wouldn't it be safer to use the load data from the lighter bullet because it's the lighter of the two powder charges?
Honestly, it's 25gr difference in bullet weight, it shouldn't make a huge difference as long as I begin with starting loads and work up...right?

I've been lucky in that all my pistol and rifle reloading up to this point have had several published load data for the components I want to use. This is my first time kinda deviating from the recipes.
 
H4895 is probably a good powder to use with cast bullets or for reduced loads. You can reduce the charge as low as 60 % of the listed maximum load for that bullet. There is good info on the Hodgon website. I don’t know that fillers are such a good idea. Following this thread too. I have a bunch of 405 grain bullet barn hard cast I am trying to find a good reduced load for.
 
.I've dabbled in cast, up to the 416 Rem Mag. it is fun to shoot cheaper and with less recoil. I usually look at what powders Speer uses for reduced loads and consult the Lyman manuals. The 458 Win Mag is a straight walled big bore cartridge, not a bottleneck small bore. It is also a small capacity case, WRT the bore size and expansion ratio. It need fast powders to obtain velocity. IMR 3031 is a mid burn rate powder in the 458, for jacketed.

IMO your best results will be with SR4759, if you can find it, 5744 or 4198. IMR 3031 may work for you as well. Lyman 50 lists loads for those powder with cast bullets from 292 gr up to 500 gr. Cast seems to work well in the 1600 to 1800 fps range without too much fuss.
 
H4895 or imr 3031 wil be awesome. I shoot 460 weatherby and 500 jeffery with cast. They are great powders for cast in big cases.

I also like 5744 a lot as a powder in my 43 mauser and 43 express. Works awesome for low volume loads. But i also use h4895 and imr 3031 in both those cases as well. H4895 is my favorite powder.
 
Your 325 FTX bullets. If you get to see SAAMI chamber drawings, quite a difference in throat and leade between a 45-70 and a 458 Win Mag - same diameter bullets, I think, but use a somewhat different shape bullet. Jethunter has the moulds for each - he knows about that throat difference. So a bullet made for a 45-70 can be loaded in a 458 Win Mag case and will go "bang" in a 458 Win Mag, but would be more surprise than good planning, if they worked well? Is possible why you can't find 458 Win Mag load data for it?? Was why I bought the 485 RNFP from Jet Bullets for my 458 Win Mag attempts at "light loads" - those ones, for sure, are of a shape for the 458 Win Mag throat.

I went looking in Hornady 9 manual - so they do list loads for that 325 FTX in the two lower pressure levels for 45-70, and for the 450 Marlin, but do not list it for Ruger #1 pressure levels in 45-70, nor in the 458 Win Mag section. Also a note for the 45-70 and the 450 Marlin about trimming the cases shorter than normal to use them.
 
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With the cast bullets you usually want to limit velocity to about the 1800-1900 fps or lower. That's relatively easy with the heavier bullets but the lighter bullets under 400gr it limits the suitable powders. A faster powder will burn better than a slower powder for those.
 
I've loaded up 50 of those 325gr FTX with 50-65gr charges of RL7, 3.34" OAL

I'm hoping to shoot a few today. I'm not expecting much, but hoping to break-in the rifle and at least get sighted in onto the paper.

In the future I'm hoping to find a more suitable bullet (next 50 rounds will be Jet's 485gr RNFP)
 
novega said:
I've loaded up 50 of those 325gr FTX with 50-65gr charges of RL7, 3.34" OAL

I'm hoping to shoot a few today. I'm not expecting much, but hoping to break-in the rifle and at least get sighted in onto the paper.

In the future I'm hoping to find a more suitable bullet (next 50 rounds will be Jet's 485gr RNFP)
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In most 458win rifles you can seat a 45-70 cast bullet further out. Try seating between the 1st and 2nd lube grooves, see if it chambers. You'll need to give it a hard crimp if you're using a magazine rifle so the bullets don't burrow into the case on recoil but that's not hard to do with cast bullets.
 
novega said:
I've loaded up 50 of those 325gr FTX with 50-65gr charges of RL7, 3.34" OAL

I'm hoping to shoot a few today. I'm not expecting much, but hoping to break-in the rifle and at least get sighted in onto the paper.

In the future I'm hoping to find a more suitable bullet (next 50 rounds will be Jet's 485gr RNFP)
Click to expand...

If you fired jacketed bullets, then use a real good copper remover to clean barrel shiny clean - all copper residue must be gone - before trying lead cast bullets. Had read that any copper left likes to strip off lead as the bullet passes over - get build up - was something that I read - so have been pretty fussy about that - might be "busy work", since I have never knowingly fired lead bullets down a bore with copper jacket residue...
 
Potashminer said:
If you fired jacketed bullets, then use a real good copper remover to clean barrel shiny clean - all copper residue must be gone - before trying lead cast bullets. Had read that any copper left likes to strip off lead as the bullet passes over - get build up - was something that I read - so have been pretty fussy about that - might be "busy work", since I have never knowingly fired lead bullets down a bore with copper jacket residue...
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All that, for sure. If it's a brand-new barrel, shoot some jacketed bullets first to smooth out minor tool marks and working edges before switching to cast. Some barrels are better than others but you can avoid or reduce leading by "breaking it in" with jacketed bullets in some rifles. Shoot 10-20 jacketed, clean the bore well, then start on cast.
 
Does anybody have any recommendations or experience for .458 405 grain bullet barn hard cast with trail boss powder for a .458 win mag? Was thinking of around 1600 FPS to keep barrel leading down.
 
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