Just how strong is a Martini Cadet action?

[pertnear]

I have a really nice Martini Cadet that has been customized with a straight 1" diameter barrel chambered in .256 Win Mag (1:10 twist). Great little rifle & it shoots great. I'm worried about over pressuring the action so I have restricted my handloading to hawkeye pistol loads & even then not too near the book max. There are no pressure signs but I'd like to proceed a bit hotter. I have some experience reading primers & cases near max in bolt rifles. I heard folks declare that the Martini is a very strong actions while others say beware. I don't want to shoot SCREAMING hot loads just max safe loads in this rifle. Your thoughts & suggestions are most appreciated.

[M-Tecs]

Some info here. Mine is still in the 310 Cadet. The large firing pin hole might cause issues if loaded to the higher side.

https://www.24hourcampfire.com/ubbth...ns#Post4886900

https://forums.accuratereloading.com...sl/print_topic

[beshears]

The weak part is the .750 dia barrel shank. If firing pin is bushed it will handle 50,000 psi in a small dia cse. I would not go above a 222 dia case. I am building a 222 Rem right now. I was told by Robert Snapp a .225 Winchester will swell the barrel shank and destroy the receiver. He built a lot of them in 30-30 size cases.

[Jedman]

I own quite a few of them and believe what beshears has posted is all good facts. I do own a cadet that is chambered in 219 Zipper which is a 30-30 case with a head diameter of .418 and I keep my handloads on the mild side and have no troubles. It gives 223 Rem performance with a larger case with a rim. I have never owned a cadet action that has been converted to a rimless ejector but have heard of Bob Snapp and his conversions. The action is very strong but having the 3/4” dia. barrel shank is the weak link.
Jedman

[pertnear]

Thanks M-Tecs for the links - they are very helpful. The .256 WM is based on .357 Mag case necked down. The case body is just a smidge smaller than a .30-30's. You guys that have Martini's in .357M do you load to keep pressures down? Isn't factory .357 ammo a bit too much for the Cadet?

Supposedly mfg'd in 1906 per original owner(?) Serial numbers match on action & butt stock.

Martini_Scoped_&_cartridge.jpg Martini_Scoped_&_cartridge-Rside.jpg

[stubshaft]

I have shot thousands of full bore 357M loads out of my 310 Cadet and have observed no ill effects from doing so.