Finally got to the range after doing the last little bit of bedding on the .458 AR ... had to relieve the front of the recoil lug. Have been developing a practice load with cast bullets. They are 435 gr GCFP WW slugs from a Ballisti-cast mold driven with 50.0 grains of XMR 5744. Haven't chrono'd them yet, but should be in the 2100 fps range.

First two rounds were needed to foul the barrel from clean. Next 4 made a 1.598" group at 100 yards ... with a 2.5x Leupold Compact scope. Given that I don't see all that well ... I think these'll work for practice and piggies




Now I can afford to practice with the fella!

Nice work Mike!!

my practice load is with rem405s, but it works out to being the same
jeffe

Can you post a pic of your cast boolet? As soon as my supply of 405 rem runs dry its on to cast.

Guys,
Your thoughts ... the load I'll be trying as a reduced plinker will be a cast 385gr with a 458WinMag "max load" of 2400. The Alliant manual lists about 20gr of 2400 behind a cast pill. You reckon there might be enough "oomph" in these to fireform??

Still ... we need to get our rifles back from being inletted, then steel bed, wait for it to cure and then do some fireforming!! Can't be too long now!!
Cheers...
Con

72 hours MINIMUM con!!!
I dunno what the 2400 will do... have fun with that.. when I am fireforming.. again, not using that powder, a shotgun patch in the case works very well

jeffe

Con,

I really don't think 20 grains of 2400 behind a 385 is going to do a full fireform. I can tell you that a bunch of Bullseye behind a couple of grains of dacron does not do as well as the 50 grains of XMR 5744 and the 435.

ptaylor,

Here is a pic of some bullets I make. The .458 is in the middle:

What lube are you using?
Nice.

Using LAR45's Carnauba Red. Doesn't smoke much and does a heckova job as lube. Usually takes three patches to get a bore clean. Not much worse than jacketed bullets.

His lubes are one of the very unusual cases where great quality is not expensive! I use the Red for everything from 38 Super to .470 NE

+1 on the lube. I use it on all of my gas check loads.

What are the other two bullets in the picture?

Rich
DRSS
Knowledge not shared is knowledge lost...

The other two bullets are:

Left: .375 285 gr from a 375449 GC Lyman mold sized to 0.377" Shoots well in my .375 H&H M70 SS Classic

Right: .470 500 gr Ballisti-cast Custom mold sided to .476" Shoots very well in my Searcy.

I also make a .366 290 gr bullet from a 366-260-GCDD NEI mold.

Fellow 458AR shooters,
At the moment I'm about to load up fireforming loads which will consist of AR2206H (H4895) and a Rem 405gr projectile. ADI lists the start load for the 458WinMag as 72gr with a max load in the 458WinMag of 77gr for a 400gr projectile. I'll probably split the middle for the first few shots just to get a feel of what the cases will do ... in some ways I'm unsure whether to hit the fireforming cases with a short/sharp rap with a faster powder (AR2207 - H4198), or a slower more gradual rap with a medium burn rate powder (AR2208 - Varget). I figure AR2206H will do okay as its listed as being a bit slower than H335. My other concern is that because we've opened 300RUM cases ... the necks have taken quite a stretch ... they may try splitting on us as I haven't annealed them and some cases are showing striations where the neck/shoulder join is. If they show splitting we have 375RUM brass to use whilst I anneal the 300RUM cases. I can also fireform with a Red Dot equivalent and bran ... done that before too! So much fun and education coming up real soon!!

TrailBoss is also now available here and is listed as 21gr in the 458WinMag with cast pills. Hoping to try this one too in the fireformed cases as "light plinkers" for 45/70 velocities from the 458ARs.
Cheers...
Con

I don't have a lot of experience with this rifle yet. Only has 70+ rnds on it, so take the experience with a grain of salt

I was given a bunch of 300 RUM cases by a very nice person on AR, so that's pretty much what I've used. I do try to to take the necking up process slowly .308 ->.338 -> .366 -> .416 -> .458 with good inside lubrication of the case neck.

The only cases I've lost were those that were fireformed with Bullseye and dacron wads (which doesn't give a real full form), and then fired with stiff loads of H335 behind cast bullets. What I saw were small holes in the necks ... not splits.

I think annealing is a pretty smart thing to do unless you have a huge supply of brass.

i have FINALLY started loosing cases form splits... and some of these are the first ones i did... i did anneal them, after fireforming...

rem 405gr and 77gr of i4895 makes for about 2020 or so... or 75gr of h335

quote:

Originally posted by mstarling:
What I saw were small holes in the necks ... not splits.

I think annealing is a pretty smart thing to do unless you have a huge supply of brass.

mstarling,
The above is exactly what I think they'll try and do.

We have almost 200 300RUM cases I bought at a give away price, plus S&F has x50 375RUM brass ... so we're okay to split a few in experimenting.

jeffe,
Hopefully by Monday we'll have pictures of the first 458AccRel's loaded and awaiting fireforming south of the equator.
Cheers...
Con

quote:

Originally posted by mstarling:

ptaylor,

Here is a pic of some bullets I make. The .458 is in the middle:

Where do you crimp these? Are you worried about having lube exposed in the case? Are they seated below the neck junction?

ptaylor,

The bullets are crimped on the front driving band. The crimp groove is for 45-70 ammo (we use the bullet in 45/70, .458 Lott, and .458 AR. The OAL is 3.100". This should leave a little of the back grease groove at the GC exposed within the case.

The lube does require heating in cold weather. Is useable in the lubrisizer in hot weather without heating but does not seem to move on bullets during warm weather. So I have not worried about that exposure ... and it has not caused problems so far. The 500 gr GC bullet I am experimenting with at the moment will have an even greater exposure.

This is a 4200-4400 lb-ft load that I intend to use these for piggies from a blind and for practice I don't view this as a problem. If I need more and more assured temperature stability in North America I'd use the 425 gr Rhino at 2350 which is a 5200+ lb-ft load. (The 2350 is easy to make with H335 from a 22" bbl.)