6.5 x 53 US Military cartridge

I have this listed as a 6.5x53 US Military cartridge, but no other info available. Any help appreciated.


I have an idea, but I am not able to see the second picture,only the head picture. Can I get a exact case length in inches or MM’s and also description on any projectile and mouth crimps?


Edit; Ok, now I can see the second picture, but could still use the exact case length in inches or millimeters and also description on any mouth crimps.

Looks kinda like a .25 Remington to me. The military did use that caliber in trials.

I seem to recall seeing something about this in HWS volume 3, but don;t have a copy with me right now.

That the primer looks to not be centered in the head, would make me think it would be a very early product, but of whose?

Perhaps it is centered?

I have 6.5 Dutch by Birmingham Metals & Munitions with a very similar looking head but it is a rimmed case, also the use of a copper primer dates it.

I think it’s the .25 Remington Hi-Power Auto experimental & not at all used by the military as far as I know, but part of the Remington Auto development along with the .35 and .38 experimental rounds. These last two are found loaded but I’ve not seen a loaded 25, just primed empty cases by UMC.

Edited to remove a wrong reference

It could be an experimental predecessor to the .25 Remington, but I’m fairly certain this one has a larger case body diameter than the .25 Remington. I think the oblique light is making the primer pocket look off-center. Jack

I have a feeling it is a Royal Laboratories product, but I need some dimensions before I commit my thoughts any further.


No it’s the 25 Remington experimental /developmental.

Also look in Tillinghast list 18 page 4.

I see Huon has a standard 25 Remington Auto with the pointed bullet at the reference I noted above. That is not the same as this, Sorry for the incorrect reference, and I’m deleting it from the above post.

Bet it has a Boxer primer. Daan?

Here are the 2 together, with the bottom one the 25 REM as per HWS1. The measurements of the 6.5x53 are as follows:
Neck: 6.39mm (0.251”)
Case Length: 52.97mm (2.085”)
Rim: 11.6mm (0.456”)
Boxer primed, as well as slightly off-centre.

My HWS3 is still on the way, so I could not check.

PS - Pete do you have a copy of Tillinghast p4?

Thanks for all the input

The 6.5x53 is listed on page 49 of “Cartridge Cases”, with Buttweiler’s catalog IX/1, item 439, as a reference. The cartridge shown by Buttweiler is called the .257 Remington Experimental No.8. Dimensions are: rim .456, head .472, case mouth .288, bullet .256 and case length 2.085. According to Buttweiler this cartridge seems to be a development round for the Remington Model 8 semi-auto rifle, which lead to the .257 Roberts. The case is unheadstamped with a copper primer. Buttweiler also says he can find no hard evidence on this cartridge.

A bit further on the 25. From the U.M.C.Co. ledger titled “HISTORY CARTRIDGES AND SHELLS” which UMC used to keep track of production changes. On a page dated July 1912 it shows:
"25 Cal. Remington High Powder
Commenced experimenting July 1912,
Shell made from the 38 Remington headless"
All it says.

In the photo below (top to bottom) of the .25, .35 and .38 (although this is some times called a .37) the head on the .25 is 11.91mm, the .35 is 11.86mm, and the .38 is 11.88mm.
The primer on the .35 and the .38 are flat copper with an underlined U stamp. None of the three are headstamped.

In the photo of part of the catalog page Jim has circled the price. Not much more information! (I must have been feeing rich that day)
For what it’s worth I haven’t see one of these .25’s loaded, not to say that none survived as loaded examples.

vidar made his post while I was writing this one and I have to disagree with RTB as the .257 Roberts was developed as a wildcat by Ned Roberts, although I don’t know where Mr. Roberts started I doubt he had a bunch of these to play with. A cartridge I have labeled & consider as an original .25 Roberts used a 7x57 Mauser parent case. See Wildcat Cartridges by Richard Simmons pg 146. RTB’s case measurements do very closely agree with my case give or take a couple .001’s

As an additional note I think sometime ago Ray Meteka contributed to a post, or started one, concerning the .25 Roberts parentage. Perhaps someone who knows how to search can find it?


Here is a post by Ray on the subject: viewtopic.php?f=8&t=7464


I think that this case was made by reforming a .30-06 or another member of that large family to approximate the dimensions of the .25 Remington, and reducing the rim to the size (or thereabouts) of the .25. In the process the rim ended up non-concentric with the case body, hence the offset primer. If you look at the photo above the rim is much lower than the case body at the top but just about even with it at the bottom. Jack