Federal cases in some calibers are soft, such as the Win 308. The 270 has about as high a pressure rating as there is in ammo so, maybe that could be the reason. But, I would inspect it or have a good gunsmith inspect it, for anything that might cause sticking. Shoot some Federal ammo and the ammo may tell you whats going on.

One of the reasons that cases stick, is the action "springing". The rear locking lug, 788 Remington's were famous for that. After firing, the action, springs back, increasing the headspace, when the preasure has subsided, and the chamber, goes back to normal, the case has increased in length and locks up the action, because there is a lot of pressure on the breech block (blot the case of the 788). The cases, usually stick in the chamber, too. But, if the BB opens normally, that won't be what is happening.

The 270 has a lot of taper so, it kind of hard to imagine why it stick. The other option would be a bulged chamber.

Look for a shiny mark, somewhere on the neck or behind the shoulder. Chamber and extract, a few times and/or mark the case with Dykem or a magic marker to see it better.

Frank



Frank

     Some of the Swiss Martini 7.5's were chambered in the old 7.5x53.5 ctg, the so-called GP-90.    Others have been made for the modern 7.5x55, the GP-11.  I bought one of the former a while back, partly to see how they made the extractor work for a rimless ctg in a Martini.  Ingenious.
      I agree with the poster who suggests examining the fired cases, as failure to extract can come from many causes, some harmless, others worrisome, but all undesirable.  The Martini action doesn't have a lot of extraction leverage, so even a little rust in the chamber might make a case stick.   

CHRIS
RGChristensen

Gowanus wrote on Feb 19^th, 2019 at 7:01am:


        If the problem is the extractor slipping past the cartridge, it is probably because the extractor is the original one for one of the 7.5 Swiss cartridges, the bases of which are LARGER than that of the 30-06 case.   
     This is probably fixable, but could be expensive, as the Swiss design of a rimless extractor for a Martini is a finely-tuned device. On the other hand, it could be as simple as installing a thicker actuating "feather". If you are going to use it as a hunting rifle, an un-reliable extractor would be a real PITA.

CHRIS
RGChristensen

Hmm... would an original extractor for one of the Swiss 7.5 service rounds be close enough in size to eject certain brands .270 but a touch too large for others?

Aside from this, would the action itself be strong enough for the high pressure .270?
I’m guessing it should be since I can’t imagine a Swiss gunsmith would convert it in the 1960s if it was dangerous. 
Since it’s set up as a hunting rifle, it should be safe for hunting loads right?

The extractor can be fixed, or maybe I just stick to cases that work reliably... The fact that everything located behind the chamber may have been forged and fit in the 1800s with a much less powerful loading in mind has me a wondering about safety.
I don’t want the thought of a catastrophic failure in the back of my mind when I pull the trigger, but I’m not sure how strong these target rifles were built to be.

Is it common for martini rifles chambered in something like 7.5x53.5 to be simply converted for use with 7.5x55 or more exotic rounds like 30-06, 8mm Mauser or 270?

Thanks for taking the time to answer my questions!
I still can’t decide if it’s worth buying this rifle, I don’t trust myself to rework the extractor on a gun like this where it’s nearly irreplaceable, and have no idea the cost to have a trustworthy gunsmith work on it.

What would you think would be a fair price to pay for an altered rifle like this? With so few out there that are similar, it’s hard to tell.