Here's my wildcat, .45 Cinderblock

Of all the active posts I see maybe 2 regarding actual wildcatting, you know experimentation based on experience but still off the reservation and lacking any real book data. I figured with savage's barrel nut making switching barrels easy that it'd be more popular.

Darn it all to heck. Heck I tell ya.

Anyway, here's some dirt on my own wildcat. It's called .45 Cinderblock for reasons which will become obvious shortly. I have it set up in a 1916 built Swedish Mauser M94 with a 18" tapered barrel (I also have a bull barrel 20" version on a spanish mauser action that I like less).

So wanna know what it looks like? Go grab a .45acp from your safe, I'll wait. <waits> That's exactly what it looks like. In fact the .45 Cinderblock chamber is dimensionally IDENTICAL to .45acp chamber. Yes that's dangerous in a lot of ways but only really to my .45acp pistols if you think about it.

I take .460 Rowland brass and cut it to .888". The rifle won't easily chamber anything beyond .891" as a snug headspace is important. Add in CCI magnum pistol primers and a LOT of Longshot powder (well above book limits for .460 Rowland) which forms a well compressed charge, top with 185gr JHP or 200gr JSWC or 200gr LSWC or 200gr HBLRN, do not crimp at all just roll the bell out of the case mouth. With my top loads I get 2000fps (well, 2010-ish) from jacketed bullets. Lead bullets I have gotten 1900FPS from but you can only do that with solid base bullets as the hollow base bullets turned into spin stabilized 3" long lead nails that would break up at 15yrds from the muzzle and spall 3 counties with frags at 90 degrees to the direction of bullet travel.

SWC bullets make a sound like a bull roarer when I drive them past 1600fps and it gets louder as the velocities increase. Scares the hell out of critters when you start whizzing those across the landscape. My 185gr load makes it through a big rig steel wheel, or 20" of gelatin (quad thickness batch, non-calibrated) or 2 propane tanks (empty).

Downsides: .452" bullets aren't designed for these kinds of velocities. They can and do come apart, especially cup-n-core bullets. Cast lead is great but leading gets terrific unless I use bear creek moly coated. Another downside, if you put one of my Cinderblock loads in a pistol and fire you'll be injured and destroy the pistol. Headstamp identification is mandatory and if you can't tell what the load is then it's a rifle only load.

Upsides: .452" bullets break things and leave BIG holes. At 2K FPS I'd take one of these up against any black bear, deer, hog etc... I wouldn't use it on an elk unless I was using FMJ but it'll sure kill one if I find myself needing to. I can put my .45acp bullets in it and it has no recoil and is pretty quiet while making steel ring well and holes in targets big enough to see without a scope. There's seemingly no amount of powder I can put in the case that's evil in my rifle (the most over-hot load to date had to be dropped in 2 stages and left the cases with very slightly loosened primer pockets after firing and I don't go that high any more). My mauser feeds from 7-15 round 1911 magazines. Beating .44magnum power with a .45acp size case is super neato. Full power loads have the same recoil as a .44mag rifle with muzzle blast that will curl your hair. It's nice to be able to shoot rabbits for food or shoot them for vaporization depending on which load I pick.

It took 15 years of reloading before I was comfortable doing this sort of stuff, please don't try to replicate my results as it is EXTREMELY dangerous. If you want my load data PM me and agree to never use it.

Thats AWSOME ive done similar and am now working a axis 45 acp +++ p . Single shot for now and just wanted to burn up some old reloads originally, now its plain fun . Its cool to see what you ve done .
Thanks Gary

Thanks, honestly that's not the usual reaction. And to think, I started today in kind of a funk. Hmmm... might just be a good day.

My goal was to get 230gr pills up that fast but I'd have to create a proper throat in the chamber and just barely stick the bullets in the case and they wouldn't feed from a magazine. I have a 29" bull barrel that's waiting in the wings but it makes for a 14 pound gun without sights and with a super-dee-duper light weight stock so it balances very badly. I also don't want to use that until I decide on the merits of the various base cases as I'd like to chamber it exactly 1 time. I've been contemplating a .45winmag chamber or doing another more outlandish wildcat like a .452-50ae or something similar. The .50 cal case would require opening up the bolt face on a mauser but I think I could get it to work. If I did that though I'd probably pick up a Savage WSM gun and use that as a base instead of a mauser.

A tip, AA #7 and Longshot are going to be your friends (460 rowland data powders are a match). Unique is dirty as hell and even magnum primers don't light it consistently when it's overloaded (overloaded by .45acp pistol load book standards) really far. I can't tell you how much unique I've blown out of the action and barrel that didn't burn. Green dot was nice in modest overcharges but peaky and surprisingly small load changes made for great differences in pressure signs. Magnum powders were suggested as being inappropriate and I have ignored them. I don't think I could get enough of 2400 or H110 in the case to be any fun anyway.

I've taken .45acp brass pretty far but you have to watch it as BIG overcharges work the brass really hard. I could get loosened primer pockets after 1 or 2 firings no problem. .460 Rowland brass is much stronger and just requires a bit of a tedious trim to .45acp length.

Another tip, watch your firing pin protrusion and primer choice. Others (not me) have had primer piercing and had to knock a couple thousandths off the firing pin. I checked mine during assembly and took action before it was a factor though I did take 1 pin too far, so beware that it's not hard to overdo even with 800grit wet-dry and just a few swipes.

I once cut a 30-06 case naer the shoulder ,resized and used 444 marlin data ,o ya ,i had a couple of old military reamers i ran DEEP into an undersized navy arms reject barrel ,that miked out at about .455 . It does make a strange sound when jacket and core seperate. Im too old now to do anything that foolish again.
Let me know whats been working for you.
Thanks ,Gary

I forgot to say green mountain has some 45 acp heavy blanks for $33 . They have been very good.
Gary

I started with top .460 data in .460 cases and have gone pretty far with a variety of .45acp cases. I tried small rifle primers in some .45acp cases that came with the small pocket, that really didn't do well with any of the powders at rifle-only load levels. Plain ol' .45acp cases will take a lot in a rifle barrel though. I've gone into double digit loads of longshot with them. Makes a fun hole poker. When I go to the range with my full power loads people tend to gather to look at the visible signs of big muzzle blast. Shakes dirt off the walls and ceiling of the shooting stall... a bit like a .50AE being touched off (actually a hell of a lot like it). Just a big thunderous boom that doesn't seem to kick as hard as it should have for all the racket.