OAL in a .45-70 Marlin...help !

[konaaahbend]

I'm shooting a Marlin 1875 XLR in .45-70, I'm trying to find an optimum oal to increase accuracy (as best as to be expected since it's a .45-70, lol) . So, I've taken a sized case with four splits in the neck, inserted the 485 g lyman I'm trying to fine tune and I come up with a round that measures 2.757. If I subtract .002 for the jump to the rifling and use that (2.755), I'm still waaaay over the 2.550 round length used in all the reloading manuals. As long as the rounds chamber and eject and my pressure isn't exceeding recommended rates, can this length work ? Now, I know that 2.55 is the standard because it's what works in all guns of this caliber, but can I really go over the measurment ? Does anyone else know how much jump to the rifling works for this gun ? I'm just a meat hunter trying to improve my odds and justify an expensive gun to my wife !

[Ricochet]

The problem in mine is feeding out of the magazine if it's longer than the standard 2.550". Nose of the bullet jams when the elevator lifts the cartridge. I have the same problem using long nosed Keith boolits in my 1894.

[konaaahbend]

Oops, I meant 1895 XLR, not 1875. Thanks Rico, thinking I might need to stick with the 2.55 unless I want to single shot it !

[JRW]

The original 1895 frame was a bit longer than the current model. The current model must have the boolits seated to feed from the magazine, and as Ricochet stated. that is 2.55.

[pdawg_shooter]

I load a 430gr paper patch bullet to 2.580 for my 1895G. Feeds and chambers fine.

[35remington]

The problem is also ejection of a live round from the gun. When OAL exceeds about 2.57", the rounds may hang up on the front edge of the ejection port. Then you've either got to shoot the round or remove the lever to get the round out.

[BarryinIN]

There was an article in one of the Precision Shooting magazines by M.L. McPherson on modifying the (current) 1895 action to handle longer OALs. I don't recall what issue it was, or what length he was striving for, but it was to feed the Speer 350 grain with it's long tapered nose (as 45-70 bullets go).
It wasn't a very complicated procedure. Most of it was cutting back the portion of the carrier that acts as a stop for the fresh cartridge being fed, and beveling the lower side of the ejector body so the round could pass by.

I take it that individual guns vary, with some taking longer rounds than others. Mine will handle them to at least 2.560, which has been enough for me so far and I have not done the mod.