Martini Cadet action barrelled with 9mm barrel

[ohland]

Today, I found out that a Matini Cadet action was rebarreled with a 9mm barrel. My Dad was having troubles with cast boolits in the gun, and he mentioned that the other .357s would chamber some loads. Some of this has to do with the reamer used on the Martini (no lead ahead of case), and some has to do with the bore size (.355 vs .357).

Wondered about getting .356 and .357 H&I dies, I guess I will. Barrel shoots good, but it gave Dad some trouble with .357 dia 180gr jacketed, with high pressure signs. Darn, whoda thunk it?

:coffeecom

[curator]

Have you made a chamber cast? Martini's generally don't work well with rimless cases like 9mm Luger. .355 groove diameter is no problem with cast boolits. I normally shoot .325" diameter heeled boolits in my .32-20 chambered Cadet Martini with .322 groove diameter. Great accuracy, no leading and no pressure signs.

[badgeredd]

I'm wondering if the 180 ghrain jacketed bullet might be too long for the chamber. With cast bullets, you'll want to be a little oversize the bore diameter if at all possible to insure a good fit. I suggest you slug the bore and do an impact slug of the chamber throat before proceeding to save youself time and money.

Edd

[Tatume]

Have you made a chamber cast? Martini's generally don't work well with rimless cases like 9mm Luger.

From my reading of the OP, I don't get the impression that the gun is chambered for 9mm Luger, only that it has a 0.355" barrel. The cartridge appears to be 357 Magnum.

Take care, Tom

[cwheel]

Mine BSA was rebored at some point after import. SN of the gun is under 200. Barrel is still marked as a 310, but was bored and re-rifled to .357 mag. with what looks like a micro-grove rifling. Slugs exactly .357. Think in the 50's, this was a very common thing. Would expect it is unlikely that the rifle of the OP is 9mm @ .355, slug the barrel, do a chamber cast, check and see if it isn't indeed set up as .357mag. Top of the barrel is stamped .357 as well, look for it above the .310 stamp. Lots of these done in other cals as well, but .357 and 32-20 are some of the most common.
Chris

[ohland]

From my reading of the OP, I don't get the impression that the gun is chambered for 9mm Luger, only that it has a 0.355" barrel. The cartridge appears to be 357 Magnum.
Take care, Tom

Barrel is chambered to 357 Mag.

[badgeredd]

Mine BSA was rebored at some point after import. SN of the gun is under 200. Barrel is still marked as a 310, but was bored and re-rifled to .357 mag. with what looks like a micro-grove rifling. Slugs exactly .357. Think in the 50's, this was a very common thing. Would expect it is unlikely that the rifle of the OP is 9mm @ .355, slug the barrel, do a chamber cast, check and see if it isn't indeed set up as .357mag. Top of the barrel is stamped .357 as well, look for it above the .310 stamp. Lots of these done in other cals as well, but .357 and 32-20 are some of the most common.
Chris

Mine is the same as yours...ohland said it is barreled with a 9mm barrel with no lead ahead of the chamber...therefore the reason I am thinking the 180 grain bullet is too long for the chamber. I'd try a 150 grain semi-wadcutter dummy cartridge to see if it would chamber ok.

Edd

[cwheel]

That is a big miss on the bore size, but I've sure seen worse. Does the barrel rifling resemble Marlin Micro grove ?? mine does and looks almost lapped it is so smooth and mirror like. Wonder how it would shoot with boolits sized to .356 and loaded into a .357 case ?? Think to do that and not have a loose boolit you would have to use a 9mm expander to get the right fit. Is it a original Martini barrel re-bored or a replacement barrel ??
Chris

[Outpost75]

The .355 groove diameter is not an issue. Colt ran .354 barrels in. 357s and. 38s for years.

The chamber with no leade or ball seat is the problem. Find a .358 rifle throater and just "kiss" the rifling origin ahead of the chamber to cut a short ball seat of 1/16" or so, with a normal throat angle and it should shoot wonderfully. You want enough. 358-.359 diameter cylindrical ball seat to enable crimping a Keith bullet in the normal crimp groove and to chamber it without excessive effort, but light resistance with slight marking of the driving band is OK.

[leadman]

I had a friend that has passed on and he had a Martini chambered for a 9mm shotshell. Don't recall if it was rimmed or rimless.
If the 180gr bullets are hitting the rifling load them is 39 spl cases, with a reduction in powder charge. Or since it is a single shot ignore the crimp groove and load it shorter.

[ohland]

The chamber with no leade or ball seat is the problem. Find a .358 rifle throater and just "kiss" the rifling origin ahead of the chamber to cut a short ball seat of 1/16" or so, with a normal throat angle and it should shoot wonderfully.

After the mini ice age is over, there are plans to pull the barrel (unless you have a flexible reamer that will fit through the Martini action!) and use a 357 Max reamer (bought years ago) to correct the chamber. The other 357s that were chambered with the Max reamer have NO problem at all.

Oh. Is the rifle throater short enough to fit in through a Martini action? That would make things so much easier....

No holy joy, the 358 throaters (so far) are all normal design, not pull-through...