Gentlemen:

What would be the difficulty of modifying a Montana Arms Mini action from the .378 bolt face to .422. I am trying to get a proper action for either the new 6.8 SPC or the .30 Remington. I am trying to buld a cast bullet gun using either of those two cases.

the biggest problem would actually obtaining the action.

standard work to do that. though I don't know if it's long enough.

quote:

Originally posted by lind3006:
...a Montana Arms Mini action

MRC does not actually produce that action. It only exists on the drawing board. MRC estimates start of production in 2008, but until such time when the first production specimens appear, I would not hold my breath.
- mike

Yea, I do realize that the action is currently unavailable, so I should have titled it "Theoretically Modifying a Montana Mini Action."

I still think the .30 Rem "Theoretically" can be an excellent cast bullet round, but I find I am leaning more toward a single shot than I care to admit, if only to be able to get the project moving foreward.

Thanks for the replies, guys.

lind

How about a Daly or soon to be Remington Mini-mauser. in .223 or 22-250 boltface.

Or a CZ 527.

Rich

We built one of our first two TigerCats on the MiniMauser in 6.8rem. Sweet little rifle at 5.5 pounds before scope. Made some believers on the prairie against antelope this year. The rifleman included.

The work to make the action feed is significant but not overwhelming. Widening of box and mag well, slight mods to the follower and feed ramp. And a bit of grinding in the bottom metal to get the wider box to fit. Opening the bolt face of course. We had to go a little further to fit our stock design but most folks could stop right here. Main thing is the 6.8rem case is fat enough to make things tight in the magazine until you open it up in there. Max feeding length for cartridges is 2.26", which a little shorter than optimum. One last thing. The antibind bar on the Mini is misnamed. It is a PRO-bind bar. Get rid of that infernal part. It will break off soon enough anyway. As it comes from the factory, it is very soft and galls up on the receiver sho-nuff. Case harden it and 'pop', thar she goes. Instead, pitch it. Make up two little sleeve halves to fill the ring retainer groove, silver solder them in and jewel the bolt. Like the invisible man. And now that thing will feed slicker than a gut pile going down an ice hole. (yes, I stole that.)

We barreled the action with a 22" M70 style FWT contour tube. Loaded with Hornady 100gr SP zipping (well, not quite) at 2700fps. Took speedgoats down like lighting bolts 200yds and under. At 250 to 325 bullet placement becomes crucial. But no antelope hit with this this rifle lived more than 4-5 seconds. Five one-shot kills, 120 to 330yd, make a pretty good case for this cartridge. Also three rattlesnakes, two badgers and a coyoteeee.

FWIW... A Kimber 84M has the same ring size as the MiniMauser. And it is only 1/2 longer overall -- all of that in the magazine. I think it might be interesting to start with a Kimber in .223 or .204 Ruger, open up the bolt face and see where you can go from there. With this magazine one could seat bullets out of the case a little bit and this cartridge would certainly benefit from a little more powder in the engine room. The Kimber bolt is .585dia compared to the MiniMauser's .550. A little more beef where it counts. (support of case head).

lind3006, if you have the lathe, just rebate the cases. I do this quite a lot and it in no way compromises the integrity of the case. I had a form tool ground.
Butch

Rod@Serengeti:

I thank you for your answer. I think you have opened my eyes to a solution to my problem about finding the right action. I plumb forgot about the new Kimber action, mainly because I did not recall it was made in .223. Now, should I toss the barrel and install a new one or re-bore and rifle the old one? Does anyone remember what the magazine length is for the 84M? I am still trying for the .30 Remington as my cartridge of choice. And, I am hoping it will fit into the 84M magazine. Geez, if it can take a .308 then it should be a shoo-in.

Thanks, guys