458 Winchester Reduced Load Info

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I just purchased a Whitworth 458 Winchester off Gunbroker. I’m interested if anyone has any recipes and or powders that won’t need filler. Thanks for the info. I plan on using it on hogs until I can afford a buffalo hunt. I shoot at night with an AGM thermal was hoping to try it on the Whitworth. It will be impossible with full house loads. If the recoil is stiffer than 308 in an AR10 it won’t be feasible. Thanks for the help.
 
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I tried some reduced loads that would allow my daughter to shoot mine. She shoots a 338 federal with 180 grain bullets loaded max and a 7mm Remington mag with 140 grain bullets. I never found any load that she could have shot. Sorry for the bad news.
 
A couple very mild, accurate loads you might try if you happen to have either of the powders (scarce now). One is Trail Boss w 400 or 405 gr jacketed flat nose bullets. Hodgdon had the instructions online (basically fill to bottom of bullet, cut back to 70% (not cut 70%) and work up from there). The other that has been very mild and very accurate for me w the same bullets is around 28 gr of IMR SR 4759. I used mag primers w both. I happened to have enough of both powders to still be going strong, but realize they are scarce to nonexistent now. Check Hodgdon and others for reduced and subsonic loads.

Final sugggestion would be something like that w lead bullets but I use the above (a lot) and defer to someone else on that.
 
I am currently working on light 458WM loads.
PM sent.
 
You may find this helpful:
 
As per Hodgdon published recommendations…
60% of listed max H4895 load.

I would not mess around with Trailboss in this type application. It’s burn rate is comparable to Bullseye.

4759 has been out of production for years. It’s closest comparable is 5744. 5744 is designed for low vel loads for cast bullets… it’s best use.
 
I just purchased a Whitworth 458 Winchester off Gunbroker. I’m interested if anyone has any recipes and or powders that won’t need filler. Thanks for the info. I plan on using it on hogs until I can afford a buffalo hunt. I shoot at night with an AGM thermal was hoping to try it on the Whitworth. It will be impossible with full house loads. If the recoil is stiffer than 308 in an AR10 it won’t be feasible. Thanks for the help.
Sorry, I don't have any reduced loads for the .458. I do want to congratulate you on getting one in the Whitworth though. I have had one for the last 42 years. It has been to Africa twice and I took a buffalo on both trips. The rifle is a little light for the .458 cartridge and after the first trip I had it Mag-Na-Ported. It will still get your attention, but it is much more manageable. I hope you enjoy your new rifle as much as I have enjoyed mine.

Doug
 
TrailBoss is quite different from Bullseye. Burn rrate may be simular but TB is a much more voluminous powder. Hodgson lists Min and Max loads w cast bullets under subsonic loads. They and ADI also have info for jacketed bullets and use in general. Right now though, not really back yet. 4759 was very accurate if lucky to still have or find any. I've heard some have turned to and like 5744 but I've no personal info to share on that. Reduced loads are a lot of fun. They're only shooting around 1100 fps. Very mild. Should work w your thermal. Would be a great time on pigs. Good luck.
 
TrailBoss is quite different from Bullseye. Burn rrate may be simular but TB is a much more voluminous powder. Hodgson lists Min and Max loads w cast bullets under subsonic loads. They and ADI also have info for jacketed bullets and use in general. Right now though, not really back yet. 4759 was very accurate if lucky to still have or find any. I've heard some have turned to and like 5744 but I've no personal info to share on that. Reduced loads are a lot of fun. They're only shooting around 1100 fps. Very mild. Should work w your thermal. Would be a great time on pigs. Good luck.
I’ve loaded all the powders mentioned in all manner of calibers, bullets and loads - 4759, 5744, Trailboss, H4895. I know the density and burn characteristics of Trailboss. I would not use it for applications where no published pressure data exists. Trailboss is an energetic, very fast burning double base powder that happens to have a very unique and different bulk destiny. Proceed and recommend as you will.
 
Perhaps the attached may help. The significant note re is that with TB, you can go to the bottom of the bullet and still be in good pressure, but you're not after velocity anyway with reduced loads. With TB, you're loading up/working up to find an accurate load. Hope that helps. Both ADI and Hodgdon have been pleasantly responsive and helpful if you'd like more information.

20240827_063520.jpg
20240827_063149.jpg
 
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I thought the 458 winmag was considered by some a reduced load:)
That Whitworth is a very nice Express rifle but as mentioned, I find my 458 a tad light, the 375 is a bit better...
Good one :-). Yes GoexFFG, it is a fine rifle. Enjoy.
 
Nosler 300 Ballistic Tip with 60.0 grains H4198 and filler to bullet base, CCI 200 primers. Super accurate load.

20241113_120630.jpg
 
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I tried to develope reduced loads for a Ruger no.1 in .458. The only load that gave acceptable accuracy was a 350 gr. slug launched at 2200 fps. That one shook my molars. I gave up on it and found out later they have a .600” throat, which might have been the problem. Looks like it was meant to only fire long heavy bullets.
 
I just purchased a Whitworth 458 Winchester off Gunbroker. I’m interested if anyone has any recipes and or powders that won’t need filler. Thanks for the info. I plan on using it on hogs until I can afford a buffalo hunt. I shoot at night with an AGM thermal was hoping to try it on the Whitworth. It will be impossible with full house loads. If the recoil is stiffer than 308 in an AR10 it won’t be feasible. Thanks for the help.

Welcome to the IMO intermediate big bore class...

The reduced loads I'm working on are 45-70: +P, +P+, +P++: aka the area beyond the max load data of 45-70 and well below the minimum load data for 458WM with 300, 350, and 405 grain bullets and using IMR4227 and RL7 powders.

Most likely my test load results will be above,... well above, 308.

Just Saying: ....You are now in the big bore class with the 458WM. You need to invest in a big bore scope setup. Leave your small 308 bore setup on the AR10.
 
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Nosler 300 Ballistic Tip with 60.0 grains H4198 and filler to bullet base, CCI 200 primers. Super accurate load.

View attachment 647662

NOTE!!! (For the community)

Do NOT use this load for hunting!

I shot a doe yesterday with it and the bullet failed in spectacular fashion. It hit a rib just behind the should in the ideal location, but the bullet literally exploded on the rib, the hole going in was 3" in diameter but the fragments went through heart, lungs, liver, paunch and also forward in the shoulder. It was a disastrous mess, the bullet did not exit and I recovered the jacket and a flat button of lead from under the hide on the offside, I will weigh it when I get home, but it is surely not more that 60-70 grains, down from 300.. It is an extremely accurate load, but at the speeds it is travelling this particular bullet (all-be-it, designed for the .450 BM) does not hold together. Fortunately I brought a backup rifle for the next deer. Back to the drawing board for a light load. I am going back to one slightly stronger than my .450 Marlin load and using the Hornady 350 RN. In the neighborhood of 54 grains H4198 with filler to the base. If that struggles, I will fall back on H4895 reduced loads... I just want a pleasant but potent deer/bear load for this .458 WM Carbine.

I
20241118_184519.jpg

20241118_184455.jpg
 
NOTE!!! (For the community)

Do NOT use this load for hunting!

I shot a doe yesterday with it and the bullet failed in spectacular fashion. It hit a rib just behind the should in the ideal location, but the bullet literally exploded on the rib, the hole going in was 3" in diameter but the fragments went through heart, lungs, liver, paunch and also forward in the shoulder. It was a disastrous mess, the bullet did not exit and I recovered the jacket and a flat button of lead from under the hide on the offside, I will weigh it when I get home, but it is surely not more that 60-70 grains, down from 300.. It is an extremely accurate load, but at the speeds it is travelling this particular bullet (all-be-it, designed for the .450 BM) does not hold together. Fortunately I brought a backup rifle for the next deer. Back to the drawing board for a light load. I am going back to one slightly stronger than my .450 Marlin load and using the Hornady 350 RN. In the neighborhood of 54 grains H4198 with filler to the base. If that struggles, I will fall back on H4895 reduced loads... I just want a pleasant but potent deer/bear load for this .458 WM Carbine.

IView attachment 648339
View attachment 648340

The remains of the bullet were 144.7 grains, that means 155.3 grains of shrapnel did the nasty damage. I pulled the remaining bullets and loaded 350 RN's in their place... I will try these at the range before putting them to use on bears in the spring. I used this bullet in a slightly weaker load in my .450 Marlin and swatted a bunch of bears effectively, so I am confident this.bullet will hold up.

20241123_072818.jpg
 
It comes reduced with factory loads.....
 

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