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View Full Version : Which Chambering for a Straight-Pull Guide Gun?


barnbwt
November 9, 2012, 09:51 PM
I'm trying to decide on which cartridge I'd like to try rechambering a Steyr M95 to, but I'm a bit at a loss as to which direction I should take.

I got a somewhat lukewarm response to this question at THR, thought I'd give it a go at the dedicated Bolt Action forum here :D

I wish to end up with a straight-pull bolt-action guide-type gun. The actions of these rifles have been successfully chambered in 8x57 Mauser, and the 8x56R Nazi surplus mine shot was over 51000psi IIRC--so the action appears stout enough for anything up to (but not including) full-on 458 Win magnum.

I've done some research on the various offerings out there that may suit my needs, but I don't have the experience to know how they stack up against eachother. Hopefully, some of ya'll will weigh in on which round you like (and why). Belted vs. rimmed, etc.

My only requirement is that the cases be straight-wall, or very near it, with no neck. I've come to realize I shoot quickly reloadable cases a lot more often, so I greatly prefer no shoulder-bumping (I only gots a single stage :(). I'd also prefer something commonly available, or simple to form from another common case. I came up with several candidates below vying for the nomination; please suggest others you feel have similar attributes, as well.

My size envelope limits are:
-.608" Rim/base diameter same as 45/70 or smaller (and that's pushing it)
-Overall length 3.228 (8mm Mauser fits) and perhaps a tad longer

In ascending order (I think) of power level:
.444 Marlin** (I'm aiming for power well above most pistol rounds)
.454 Casull (probably too short to feed right)
.460 S&W
.450 Marlin*
.45-70 (the .602" rim of this is probably as big as can possibly fit on the bolt face)
.458 Win Mag* (Loaded-down to sub-SAAMI specs to stay below present bolt-loads. This guy may also be too long to fit with heavy rounds)

*the M95 is designed to feed rimmed cases from an en-bloc clip (for now). I will likely need to replace the magazine system and modify the extractor quite a bit. Since I'm starting from scratch, rimmed/non-rimmed is probably a non-issue, unless one is more reliable than the other (in both feeding and chambering)
**I've seen firsthand accounts of folks successfully doing this in 444, & heard of it being done in 45-70. 444 requires little other work than a new barrel, supposedly, but is the least "fun" of the candidates :p

SO, which do ya'll prefer?
Removing metal's easier than adding it, so maybe I should just work my way up the list?;) I'll have enough pennies in the jar in ~2 weeks to buy a barrel, so I need to get my ducks in a row now.

TCB

alex0535
November 9, 2012, 10:09 PM
Thought about .500 S&W Magnum?

Seems to fit your size constraints, falls in your operating pressures, straight walled, big heavy bullets that hit hard out of a 8.5 inch barrel. Out of a rifle they would probably be traveling a good bit faster.

And you would have a .50 bolt action. Which I think is pretty awesome.

taylorce1
November 9, 2012, 10:28 PM
You might want to go to Garry Reeder's web site and check out some of his GNR cartridges based on the .348 cartridge. Then you can look as well at SSK industries JDJ cartridges based on the .444 case. I'd probably look at the JDJ's first because most of them can be shot in a Contender which would be about right for your pressure range.

You might try a wildcat version of the 56R case. You could have a rimmed .257 Roberts or a 9.3X56R. Actually as I typed it a 9.3 caliber rifle would be a pretty awesome little thumper of all animals. The 9.3X57 was a pretty popular conversion as well on a lot of old Mil Surplus rifles.

barnbwt
November 10, 2012, 12:11 AM
500 S&W, well now, that's simply too big for the...--well I'll be damned, it's only .526"!:D I really hadn't thought that round would fit (ya'know being a 50 and all). Something a bit longer would likely feed better, though. Where does that round typically fall in with others? Between the 460 and 450 Marlin?

The .50 mention got me looking into other rounds in that caliber :eek:. Turns out 50-90 is almost narrow enough at the rim to fit (.662), and is a hair shorter than the 8mm Mauser. Not sure a rimmed cartridge with the rim trimmed to .007 would extract very well, though ;). Is there a rimless equivalent? Nevermind. My shoulder and wallet will thank me. A lightweight portable buffalo cannon could only end badly.

cartridges based on the .348 cartridge
You mean like the 500 Alaskan? Thanks for the tip, hadn't heard of that one before, sounds pretty cool. Sounds like I'd need a sling :o

I'm thinking 45-70 for now. It seems to have the greatest breadth of versatility (light to awesome, but not quite godlike ;)) of the calibers I've seen so far, and it's far more commonly available. If a similiar-power contender, the 500 S&W may get the job, though, cuz 50 is 5 better than 45 :p

TCB

alex0535
November 10, 2012, 01:01 AM
You seemed to want something pretty big. .45-70 is plenty for anything you want to take down, as are most of the calibers you list.

I think the .50 S&W will hit as hard or harder than the .50-90 and ammo/brass will probably be easier to find. It would a unique rifle, and a powerful one as well.

Its a handgun cartridge, so in a 8+ pound rifle the recoil is going to be stout, and its going to be loud but I don't think it would be unmanageable.

Pond, James Pond
November 10, 2012, 04:16 AM
Its a handgun cartridge, so in a 8+ pound rifle the recoil is going to be stout, and its going to be loud but I don't think it would be unmanageable.

Without wishing to hijack, could someone explain this to me?

I'm still learning so some things don't make immediate sense.

I'd have thought that a handgun cartridge out of a rifle would be more manageable than the same cartridge out of a handgun.

Is this not the case? If not, why not?

Husqvarna
November 10, 2012, 05:05 AM
choose one you can share a revolver with to

or 45-70, you can reload that out in the field, ;)

barnbwt
November 10, 2012, 09:44 AM
You can get a revolver in 45-70 :D

TCB

taylorce1
November 10, 2012, 10:11 AM
You mean like the 500 Alaskan? Thanks for the tip, hadn't heard of that one before, sounds pretty cool. Sounds like I'd need a sling


You really need to go check out Gary Reeder's Wildcat page (http://www.reedercustomguns.com/information/GNR_cartridges.htm) and then check SSK industries JDJ cartridges. (http://sskindustries.com/cartridges) The more I think about it, I think the Reeder cartridges will be too high pressure for your application but it is still nice to see what can be done. The JDJ cartridges will be right up your alley if you use the ones based on the .444 case, I had a .375 JDJ that would push a 260 grain bullet 2400 fps from a 26" Encore barrel, 235 grain bullets were just over 2600 fps. To me the JDJ's are pretty impressive and they do it with less pressure than the GNR's.


Its a handgun cartridge, so in a 8+ pound rifle the recoil is going to be stout, and its going to be loud but I don't think it would be unmanageable.

Without wishing to hijack, could someone explain this to me?

I'm still learning so some things don't make immediate sense.

I'd have thought that a handgun cartridge out of a rifle would be more manageable than the same cartridge out of a handgun.

Is this not the case? If not, why not?


Here you can read this on the .500 S&W (http://en.wikipedia.org/wiki/.500_S%26W_Magnum). I know your thinking pistol, what gives? We as Americans like to be bigger and badder than everyone else especially with modern firearms, just search for the 12ga from Hell thread. However since the .500 S&W operates at 60,000 PSI it probably isn't safe to chamber in the rifle we are talking about.

Just to put it in perspective in an 8lb rifle a .500 S&W shooting a 500 grain bullet @ 1400 fps will recoil with just over 27 ft-lbs of energy, the .308 with a 150 grain bullet @ 2900 fps will recoil with 15.5 ft-lbs of energy in the same weight rifle. I used data from Hogdon's Reloading (http://data.hodgdon.com/cartridge_load.asp)page and this is the Recoil Calculator (http://www.handloads.com/calc/recoil.asp)I used to come up with these figures. I compared the .308 to the .500 because I know you just recently purchased the .308 and its recoil surprised you when you first shot it. Here is a good article on recoil and its effects (http://www.chuckhawks.com/rifle_recoil.htm), the author states that anything over 20 ft-lbs of recoil will more than likely cause a shooter to develop a flinch.


To answer your question it is more manageable to shoot a .500 S&W out of a rifle, but it doesn't mean it is going to be any more fun to do so. I hope that answers some of your questions.

Cary
November 10, 2012, 10:15 AM
You sure can. I have a Marlin 1895 in 45-70 and cringe at the idea of shooting the same round from a revolver.:eek:
http://www.magnumresearch.com/Firearms/Magnum-Research-4570-Revolver-75-inch-Barrel.asp
I would vote for you going with 45-70 as well. Ammo, brass, bullets, and a large selection of powders to choose from.
Cary

barnbwt
November 10, 2012, 11:36 AM
Yeah, I'll just bet that stands for Big "Frame" Revolver ;)

Taylor, I've always enjoyed .308 from my 700 over the last 2 years :). What surprised me was the K31 which fires a similar load, but has way worse felt kick due to the crappy steel butt plate with sharp corners. The Rem is a pussycat by comparison. I'll be replacing the steel plate on the Steyr soon, since it looks even worse, and has a large head-shaped dent in the middle:eek:. With a better butt and better stock fit, I'm able to go a bit beyond 30-06 recoil.

Good call on foregoing the 500S&W. I had a feeling that anything with "magum" in the name is in the high pressure range I'm trying to stay away from. Still, it's pretty scary to think something as stout as the 500 AK could fit in the action; it's crazy how much energy density we've gotten to these days. That cartridge is usually loaded to ~40000psi and has a bolt diameter .03" larger (~25% increase in thrust area, ~23% less pressure; so it is probably still safe for the gun, at least)

EDIT: Thanks for the replies everyone, I've learned a lot about cartridges I've never even dreamed of shooting before :)

I've decided to go with the 45-70. Its pressures and bolt thrust are well within established limits, and it's a fairly common, highly vaunted cartridge. It's also capable of dealing with anything I'd want to shoot at without destroying my shoulder, and can be downloaded for cheap practice plinking. One more set of dies (I think I'd just need a case sizer [maybe] and a bullet seater/crimper, right?) and a bullet mould and I should be set for cheap shooting.

Now I just need to pick a barrel, and find a smith and determine how I want to go about the ream work. Anyone have a particular barrel maker they like? I'm looking for something medium-light profile 16-18". Being a bolt action, the rifle, with a good barrel would be capable of excellent accuracy; but I'm not sure if a match grade barrel would be worth the cost in this application. It would be neat to have a lightweight trapper gun that also shoots MOA out to however far I can range effectively:cool:. The M95 even comes with a 2" tall ladder sight :p

TCB