How close is the .56-50 Spencer (centerfire) to the .510 GNR
It looks more tapered, but several cite making them from .348 or .50-70 cases. Starline is making the brass in limited numbers. I just wondered if anyone knew about the dimensions.
It looks real close. Same .51 bullet.
![[image]](images/uploaded/20260206225514698671521746b.jpg)
The original for the rifle probably was the
round on the left but if they are running some brass I would bet it was the round on the right due to the strong rim and the sides of the brass.
Yeah the one far right is centerfire, rest rimfire.
It might be interesting as a potential source for .510 GNR brass. Not sure if it’s a little shorter or longer. If it’s more tapered it would probably size down. One of my favorite historical items is an old board with seven .50 holes in it. Abe Lincoln stood that board up against a tree behind the White House and tried out this new fangled repeating Spencer carbine for himself before allowing any military orders. They still have his shot target.
My .510 GNR bullet mods came from ideas these civil war buffs were using to shoot Spencer’s converted to centerfire. They needed a .512” bullet less than 450-500 grs. so they were cutting tops out of cheap Lee molds. This shortened and lightened the bullets. I caught on to the idea of using a lube groove opened up as a gas check shank.
I wonder if the old Spenser brass would
handle the pressures of the 510 GNR.
This is brand new Starline. It's running $1.25-$1.35 ea.
I'm researching to see the actual dimensions. The old Spencer rimfire rounds I think were copper. Some folks made cases to accept .22 blanks to fire in rimfire guns. They served as primers. VERY expensive cases. But it let you shoot a 160 yr. old rifle. I've examines real Spencers that were almost new condition for about $3500.
Shoot, my calipers are at work. Crudely
I'm showing the Spencer brass 1.5mm or so shorter. I get about 31mm for my loaded .510 GNR ammo and the Spencer says 29.5mm. Not a problem. The rim diameter is a little more difficult to measure with a ruler but it looks like the .510 GNR is 15mm or so and the Spencer specs. say 16.1mm, again about a hair.
There are other dimensions in play but it's close enough to get some and just see. I have made .510 GNR brass from the Linebaugh, Max., .348 WIN., .50 AK. all work fine.
![[image]](images/uploaded/202602080245126987f8b86038e.jpg)
centre fire brech block
S&S firearms makes a center fire breech block for thee rim fire spencers.lets you get the old ones firing again
Wow! Never knew someone made those!
Bannerman sold a bunch in the 20’-30’s surplus and Gremmer sporterized some into Buffalo guns!
when spencer went under and was
acquired by winchester, the tooling etc was sold to belgium they made spencers for a while and they were center fire. i have one of those, otherwise i would go for one of these breech blocks.
![[image]](https://i.imgur.com/a3w3tMJ.jpg)
it looks rough but the bore is quite good
That is really interesting...
I researched J.P. Gemmer a bit. I have a Sharps done in his pattern. It intrigues me so I looked into it some. It seems odd for a "Spencer" to be considered a Buffalo gun but a 350 gr. bullet at 1200 fps would shoot right through about anything. Rimfire or not.
https://www.rockislandauction.com/detail/70/226/sporting-rifle-conversion-of-a-spencer-...
very true, but native american hunters
were not pleased with the spencers for buffalo, according to early frontier traders like Andreew Garcia. but it sure would have out-preformed the 44 henry and such. the 44 Evans short wasnt much better but the 44 Evans long was probably a bit better.
44 Evans long , a 28 shot repeater
![[image]](https://i.imgur.com/rthUwDd.jpg)