Ok all I've got the chamber casts! I'm not 100% what to make of them yet; at this point picking from only the cartridges I know, I'm leaning towards 9.3x74r based on the shoulder diameter and the OAL. However, here are some pics and the results posted below.
Right Chamber
OAL - 2.9425 (closer to x74)
Base Diameter - .4775 (closer to x72 Sauer)
Shoulder - .412 (closer to x74)
Neck - .3905 (closer to x72 Sauer)
2nd Neck - .392
Groove Diameter - .3625
Neck taper is very slight, looking at picture is looks closer to x74
Measured 1hr 20min after cast.
Left Chamber
OAL - 2.960 (closer to x74)
Base Diameter - .4725 (closer to x72 Sauer)
Shoulder - .411 (closer to x74)
Neck - .390 (closer to x72 Sauer)
2nd Neck - .393
Groove Diameter - .362
Neck taper is very slight, looking at picture is looks closer to x74
Measured 1hr 2min after cast.
1st pic shows a visual comparison of 9.3x72r Sauer & 9.3x74r
It is from Cartridges of the World 4th Edition 1980. My Purpose here is to compare the shoulder angles.
2nd pic shows the cast of the left chamber & beginning of bore. I am only posting the left cast as the pics came out better but I do have pics of the right chamber cast.
3rd pic shows a visual comparison of a 9.3x74r snap cap from A-Zoom with the chamber cast. Comparing the shoulder angle to the snap cap and the the first picture it seems to more closely match x74.
4th pic is a close up to attempt to show the similarity of the neck between the snap cap and the cast.
5th pic shows my measurements and sketches to show where I took the measurements. The numbers in the bottom corner are when an hour was up after casting and when I measured. The x72 or x74 are the cartridges those dimensions were closer to.
6th pics shows the case measurement data I used, it is taken from Cartridges of the World 4th Edition 1980.
Additional Info.
The rifle closes easily on 9.3x74r snap caps manufactured by A-Zoom without issue. There are no marks on them to indicate they are being crushed.
I have one live 9.3x74r cartridge manufactured by Norma, date unknown; it looks older though. The rifle closes easily over that cartridge in either chamber.
Now to quote advice on another thread.
Thread:
http://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=402766&page=1bls,
You can tell which 9.3 it is, pretty easily.The 72R is close to 30-30 head size, although rim dia of 30-30 is a little larger. The 74R is close to the 30-06 headsize( just a little smaller, but a 06 case will usually go in( try it head first). With a 30-30 and 30-06 case, you can figure it out.BTW Buchsemann is correct that you can use the Brenneke in any choke avaliable.The 9,3x72R is about like 38-55 to 35 Rem. A lot of deer have fallen to both of them.
Mike
Using this info the rifle closes on a 30-30 case no problem; the rim skips the extractors easily. A 30-06 does not fit all the way into the chamber but will slip in without issue case turned around.
Thanks again for any and all help!
Matt
