Greener GP in 40-82

[andym79]

Hi guys, I am looking to have a Greener GP shotgun barreled in 40-82, and loading it with BP, or smokeless softly, but am unsure if its will make the turn, has anyone do this on a GP action or with a cartridge of the same length e.e. 50-90?

If not how about on a large frame Henry Martini, if it works on that it will on a GP.

 

[Gordon]

The GP action is huge and strong . I had a 12 ga with an extra barrel somebody made up in .470 Nitro for African use. My son on east coast has it now.
I just remembered about reading the Take down feature of the Mark 2 Greener GP action being weaker than the non take down because the ring is split on bottom and barrel clamped in place by screw. But the big heavy threads that go into the 12ga gauge receiver are huge around the chamber of even the .470 Nitro chamber and with a modern barrel steel I can see little problem with strength and the head size is reduced for back thrust (compared to 12 ga.) even tho the .470 Nitro works at double a 12ga. Magnum load does. Any way for the dozen .470s I fired thru it to regulate the sights at 100 yards the cases looked and ejected perfectly. The 40-82 being longer is also thinner so I doubt it will have a problem with the martini feed ramp angle , other than grinding slight grooving toward the front for bullet alignment possibly like mine had .

 

[andym79]

I believe the GP was chambered in 12G 2 3/4" (70mm) so in theory anything with an COL of 2.75" should fit!

 

[andym79]

The 470 nitro is a serious case, its 3 1/4" long isn't it? I f a gp action can take that a 40-82 should be alright

 

[Gordon]

It's all about being able to make the turn into the chamber, but the action is big. Not .50 BMG big but good for most lower pressure rimmed cartridges