I have a question that may have been asked dozens of times before, but I'll ask it anyway.

I'm thinking of getting a 458 WM barrel put on one of my Mauser actions, just to have fun with shooting cast bullets in the 350-450 gr weight range, most likely real close to 400 grs.

I will also want to shoot some mild loads using the blunt jacketed bullets such as commonly seen in 45-70.

My question is should I go with a slower twist rate than the standard 14" twist? Or given the slower speed of the reduced loads, will the 14" twist be preferred? What's been your experience?

Thanks
KB

I have a Mauser with a 22" 1 in 14 twist Douglas barrel chambered for .458 AR. Works well with 400 to 500 grain cast and jacketed bullets.

Typically get about 1 MOA with 435 gr GCFP cast in wheel weights sized to 0.459 and lubed with Carnauba Red.

I always try to caution on more twist than less, as it is more flexible. I've found a 1-14 to be fairly friendly with cast bullets, light to heavy, slow to fast. The 458 win mag is a great cast bullet cartridge. My second 458 lott was built using a ruger #1 takeoff barrel which as I recall was a 1-14, fit to a mauser action. It was a good cast bullet gun.

Well, I picked up a take off barrel from a Mark X. The guy said it was a Whitworth, but I don't know if there is a difference. I'm sure it's 1 in 14" twist rate. Anyway, I think it's a good barrel. I haven't seen it yet, but the seller said it's like new. I've seen only pictures.

Maybe I can have it assembled and shoot it this summer.

I think it's 24". Should I shorten it?

KB

The 458 Win Mag is great with cast bullets from 350 - 550 grains and even 700 grains. I get great accuracy with the 400 grain WFNGC. If you want to have fun, load it with TrailBoss. Max loads with TrailBoss are about 1100 fps. Starting loads are around 800 fps.

I think 24" is a good barrel length. If you like recoil, go with a 20".

Just out of curiosity, do any of you guys hunt deer with these rifles and loads?

Yes I took a deer with the 458, 500 gr cast and 60 gr 4895 this last season, seemed adequate

quote:

Originally posted by Big 5 Encores:
The 458 Win Mag is great with cast bullets from 350 - 550 grains and even 700 grains. I get great accuracy with the 400 grain WFNGC. If you want to have fun, load it with TrailBoss. Max loads with TrailBoss are about 1100 fps. Starting loads are around 800 fps.

I think 24" is a good barrel length. If you like recoil, go with a 20".

With trail boss, is that a very bulky powder, giving little chance of double charge, and filling the case?

I think 1100 fps would make a very interesting load, especially with a suppressor can attached to the muzzel. I can easily imagine a bunch of those east Texas hogs never knowing what is dropping their buddies.

KB

Kabluway

Bear in mind that the 45-70 was developed with a 22" twist and it has been shooting 500 gr bullets farther than most shoot for about 140 years. The 14" twist of the MK X barrel will be fine with cast bullets. You will not have problems until you run over 22-2300 fps. By then you might be having other problems also, like with recoil.

Larry Gibson

The Whitworth barrel arrived and it looks as good as described. I may put it to use, however it was an afterthought, and I bought it because I figured it was a good deal, and I have several Mauser actions to choose from.

The barrel I have had for a while is a PacNor stainless #5 threaded for a Ruger action. It was initially chambered in 450 Marlin, an experiment that didn't work out. It has a 20" twist rate. I am thinking of that barrel, rechambered in 458WM, when I'm talking about 1100 fps and suppressor.

I always figured the 20" twist was sufficient, especially using 405 gr bullets. The reason for the 458, 400gr+ bullets is to get the energy up enough to do some good, but still stay subsonic.

KB