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Wierd Martini 32-40 with .312 grove diameter (Read 709 times)

DHB Participating Member Offline Posts: 30 Location: Houston Joined: Apr 25^th, 2011	Wierd Martini 32-40 with .312 grove diameter Sep 27^th, 2022 at 12:12am	Print Post
	I picked up a Martini with a Marlin 32-20 octagon barrel already on it. The barrel is chambered in 32-40 but the grove diameter is .312. Any ideas for a load for this rifle? I have taken 32-40 168 grain cast bullets and sized them down to .314. I have a Herter's Universal sizing die to neck the cases down. I can use 115 grain 32-20 bullets which are much lighter than 168 grain 32-40 bullets. Any ideas will be appreciated. Thanks, DHB

	DHB
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Dellet Frequent Elocutionist Offline Posts: 1035 Joined: May 19^th, 2017	Re: Wierd Martini 32-40 with .312 grove diameter Reply #1 - Sep 27^th, 2022 at 6:15am	Print Post
	Twist rate will be the limiting factor for bullet choice. Probably will be 1/20 and that will limit your choices to the lower weight bullets.


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beltfed Frequent Elocutionist Offline Posts: 1725 Location: Central Wi Joined: Dec 20^th, 2007	Re: Wierd Martini 32-40 with .312 grove diameter Reply #2 - Sep 27^th, 2022 at 9:18am	Print Post
	as said, check twist rate. It may be too slow for longer bullets. Otherwise, there is the Lyman 314299 , 200 grain bullet or similar NOE clones that would be about the right diameter to start with. beltfed/arnie


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DHB Participating Member Offline Posts: 30 Location: Houston Joined: Apr 25^th, 2011	Re: Wierd Martini 32-40 with .312 grove diameter Reply #3 - Sep 27^th, 2022 at 11:52am	Print Post
	The diameter is not the problem since I have a .314 bullet sizing die. My question is what starting load with a 32-20 115 grain bullet. If I size a .321 bullet to .314 I can use 34-40 load data. The heaver bullet might not group in the .312 barrel. I will check twist. Thanks DHB

	DHB
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waterman Frequent Elocutionist Offline Posts: 2802 Location: Behind the Redwood Curtain Joined: Jun 9^th, 2004	Re: Wierd Martini 32-40 with .312 grove diameter Reply #4 - Sep 27^th, 2022 at 12:38pm	Print Post
	My .32-20 Low Wall shoots pretty well at 50 yards with 9.0 grains of SR 4759. Old loads, before 4759 disappeared. With a bigger case, maybe 10 grains of 4227 for starters. I expect twist will limit accuracy with longer, heavier bullets.


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oneatatime Frequent Elocutionist Offline Posts: 3758 Location: Rocky Mountains Joined: Oct 30^th, 2011	Re: Wierd Martini 32-40 with .312 grove diameter Reply #5 - Sep 27^th, 2022 at 3:29pm	Print Post
	So is this just a 310 Cadet barrel rechambered to 32-40?


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DHB Participating Member Offline Posts: 30 Location: Houston Joined: Apr 25^th, 2011	Re: Wierd Martini 32-40 with .312 grove diameter Reply #6 - Sep 27^th, 2022 at 4:09pm	Print Post
	No this is a Cadet that has been re-barrelled with a Marlin lever action or pump barrel apparently from a 32-20. The guy it came from was the original NRA board member on Black Powder Cartridge Rifles. I would have asked him but he stepped on a rainbow about 2 years ago. I have NO IDEA why he would have chambered a 32-20 barrel for 32-40.

	DHB
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Cbashooter Frequent Elocutionist Offline Posts: 1586 Location: Eastern Wa. Joined: Mar 31^st, 2018	Re: Wierd Martini 32-40 with .312 grove diameter Reply #7 - Sep 27^th, 2022 at 5:50pm	Print Post
	your 31-40 sounds fun! I'd bet short bullets like the Lyman 3118 would shoot very well with 2400 or 4227. The RCBS 115g is similar and always a good one for me in large case " fat " bore 30 calibers.


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oneatatime Frequent Elocutionist Offline Posts: 3758 Location: Rocky Mountains Joined: Oct 30^th, 2011	Re: Wierd Martini 32-40 with .312 grove diameter Reply #8 - Sep 27^th, 2022 at 6:37pm	Print Post
	Sorry, I missed the Marlin first time through. Looks like you will be stuck with the lighter bullets. That said, the 32-20 may have been handicapped in bullet weight because of the repeating actions that chambered it. It's possible that you can stretch it out a bit with 125-130 grain bullets. I can send you some bullets that I shoot in my 32-20 that weigh 127 grains with a GC before lubing. They shoot pretty good with 7.5 grains of 2400 and in a 32-40 case could probably use 1 or 2 grains more.


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DHB Participating Member Offline Posts: 30 Location: Houston Joined: Apr 25^th, 2011	Re: Wierd Martini 32-40 with .312 grove diameter Reply #9 - Sep 28^th, 2022 at 12:07am	Print Post
	oneatatime wrote on Sep 27^th, 2022 at 6:37pm: Sorry, I missed the Marlin first time through. Looks like you will be stuck with the lighter bullets. That said, the 32-20 may have been handicapped in bullet weight because of the repeating actions that chambered it. It's possible that you can stretch it out a bit with 125-130 grain bullets. I can send you some bullets that I shoot in my 32-20 that weigh 127 grains with a GC before lubing. They shoot pretty good with 7.5 grains of 2400 and in a 32-40 case could probably use 1 or 2 grains more. Do you think it would be safe with all that extra room in the case? I don't want an explosion. I forget the proper term. I am more after accuracy than speed.

	DHB
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DHB Participating Member Offline Posts: 30 Location: Houston Joined: Apr 25^th, 2011	Re: Wierd Martini 32-40 with .312 grove diameter Reply #10 - Sep 28^th, 2022 at 12:09am	Print Post
	Oneatatime, what do you use for lube?

	DHB
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oneatatime Frequent Elocutionist Offline Posts: 3758 Location: Rocky Mountains Joined: Oct 30^th, 2011	Re: Wierd Martini 32-40 with .312 grove diameter Reply #11 - Sep 28^th, 2022 at 12:58am	Print Post
	DHB, I ran across this link: (You need to *Login* or *Register* to view media files and links) If you use the calculator referenced, it comes up with a .69 inch bullet (my 127 grain) at 1650 fps will be fine in a 20 inch twist barrel which I believe may have been the standard twist rate for the Marlin 32-20. So a longer bullet would have to be driven faster and a shorter bullet could be driven slower. Check your twist and play with it. If you go to Accurate Molds catalog you can see the lengths of the various weight 31 caliber bullets and you can use that and the velocity you desire to see what will theoretically work. I use Javelina lube. 4227 is a standard powder (and it is available today) for the 32-40 and is entirely usable in the 32-20.


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DHB Participating Member Offline Posts: 30 Location: Houston Joined: Apr 25^th, 2011	Re: Wierd Martini 32-40 with .312 grove diameter Reply #12 - Sep 28^th, 2022 at 12:32pm	Print Post
	I have "plenty" of 4227 on hand. Thanks for the info. DHB

	DHB
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