Home Forums Hunting & Shooting Custom Rifles & Wildcats .458 Catastrophe

.458 Catastrophe (aka .458 CAT) is named accordingly...

IF YOU CHAMBER (AND FIRE) THIS ROUND IN A .300 WM, .300 WEATHERBY ETC. YOU WILL SURELY DIE!!! (Genesis 2:17).

With that said and with proof of concept completed last year in a .45-70 and a .458WM...



We are planning 458 CAT AR-10s... this year.

Brass is 7mm RM brass (or any belted magnum brass) that has been zipped down with a stepped drill bit.





Final trim...

Pills are any .458 pill...

I happen to like the absurd...





WAG on stability from various sources and testing... "1 in 10 twist shows stabilization at 550 to 650fps, 1 in 14 is 800-900fps, 1 in 20 twist shows 1400-1600fps."

Rebated rims are done on a lathe... I am looking for ideas on how to do them faster (i.e. some kind of World's Finest Trimmer or "Pencil Sharpener" idea.) SEND ME YOU IDEAS PLEASE!!!



A "blended" Sammi PDF...



The belt is super important on headspace lock-up... being a straight wall case that is NOT TRIMMED TO ANY PARTICULAR LENGTH (UNIMPORTANT) AND THE CHAMBER BEING A .458WM... HEADSPACE WOULD BE A KILLER OTHERWISE.

IF this concept works further... we will modify (REBATE) .450 Marlin brass. Why? The belt on the .450M is longer and will prevent the gun from closing battery... that new cartridge would no long have Catastrophic potential. We will call that one .458 Meerkat (or whatever).

FYI... the 730 gr. subs tested so far are UBER QUIET. Yes they fall like rocks, but 2 ounces of lead is still a serious gate crasher. Recoil is quite mild... LR potential is very possible with 250s-325s (think .45-70 +P capable).

I will update this project as we go forward... plan to do a 16-18" and a 10" SBR. Cans are Lane and Bowers.

Why???????????????????

Just because I can.

You're an entertainer !!

One thing for certain is that this is very interesting. Please keep us informed as you progress with your project.

I used to use a tubing cutter to cut 30-30 brass back to make 30 Herretts.

30 Herrett - that's dating oneself . . . . . . . .

Ha ha...probably right. Wonder how many are going to google 30 Herrett now.....

Game on Bill Wilson...

.458 CAT vs. .458 Ham'r

http://shopwilsoncombat.com/Ultimat...wist-Fluted-Black/productinfo/RIFLE1384/

Get one of these make a V-block with a stop been using on for years for 300 BO, 7.62x40 WT and B&M cartridges....put a little Door-Ease wax every couple cuts...only need to cut .005" longer with very little burr.....

https://www.harborfreight.com/2-in-mini-bench-top-cut-off-saw-62136.html

I have the mini and the 6"... belted brass is a lot tougher than .223... switched to the stepped drill bit method and LOVE IT (super easy and fast)... but thank you for offering your thoughts... the HF stuff is great on .223 (I have done thousands of .300 B/O that way.

It is the rim end that I am having fits with... other that "one at a time on the lathe". My hope is to chuck the brass in a 1/2" drill and have some type of modified tailstock tool/World's Finest Trimmer to rebate the rim... with a positive stop on the base of the rim.

I'm just not smart enough to solve.

Sounds pretty laborious to me.

Barrel is due back from my Smith in the next few days, so loaded up some dummy rounds to to check mag/action function.





Five stuffed in a SR-25 type HexMag...

There really is no point unless you have a case length limit like some stated do for deer hunting.
I have done it with 7mm Rem cases shortened to 1.8" but sanity prevailed and the bow hunters control over the state gun laws was sanitized.
John

A few $$$ hick-ups caused the delay, but all is good now.

Parts came in and built her tonight.

A little mag work... glass her... and shoot!

Blood red in case there are any oops.

Knew there would be some tweeking...

Chamber is good and rounds (dummy) case check fine.

Dramas:

1) Guntec upper is compatible with CMMG lower, but not PSA... everything works fine except the bolt catch... tried multiple BCGs.

2) Need to blend the barrel extension... 80% of the test chamberings do not chamber smoothly...





... and damage the brass (top of chamber impact)





3) Tried three different mags... all will need some mods...



Need to remove material as show in red... and try again.



Not deterred

Proofing load will be a full power/performance 500 gr. Dangerous Game .458 Winchester Magnum load with rifle strapped to a tree/bench... and a long string.

+P 450 Marlin load data after that...

Over the past few years... I have received "expert" advise from many people that state a .458WM is just too much gun for... this or that.

I listen patiently for a while... and when they allow me the chance to speak... I ask if they have ever shot one?

95% never have.

Mr. Cash A long life may depend on becoming good at all hazard avoidance, but would be boring as Chit.
Buy bandaids, go slow ( in aircraft, slow crashes are always better than fast ones) and enjoy your inventive nature
Good hunting
Lj

Cool project. What are you using for bolt and barrel extension, it looks a little different than standard 308 parts?

Just a thought on that barrel, looks like a pretty sharp edge on the "feed ramp" or lack thereof. In my AR wildcats I've found radiusing that edge a little helps a lot with feeding, and that might solve your brass damage issue. Of course proper working/blending of the feed ramp is the other part of that too.

Lilja barrel extensions...

I have multiple BCGs... trying several.

You are correct in much of what you say.

1) I blended the B/E last night.

2) I took a inside chamfer tool to the chamber mouth... TINY debur... maybe 0.0005" basically just dulled the edge to "less sharp".

3) I am trying a roll crimp on cases...

4) I dropped COL from 2.795" to 2.700"

Made a couple of mag mods...

Doing much better on feeding now.

Trigger time next week...

Keeping loads on the mild side... ladders only to 2,100 (325 FTXs). Will push harder after the barrel is broken in.

I will pop a full performance .458WM load as a proof, before I go beyond 2,100.

Another 30 Herrett shooter here. I use a Dremel tool with a fiber reinforced cutting wheel to make the first rough cut on 30/30 brass. Works great. Just make sure your cut is a little on the long side so you can square up the mouth when you finish with your case trimmer.