doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com 9,0 x 72R Regulation info

Sometime ago I had posted regarding a double rifle wherein some loads were being worked up for regulation. Turns out the rifle is chambered in 9.0 x 72R....and is proof marked 118/35. Long story short....the bores are .358. A set of proper dies was obtined from C&H dies as well as several varieties of .35 cal bullets from Speer (180GR) and Remington (200 Gr)and Cast (165Gr) for .38 special.

With 40 Gr of Reloader 15, 1.5 Gr Dacron filler and standard large rifle primer and the overall cartridge length set at 3.385 inches (85.98mm) some very fine 50 yard composite groups were obtained. Using the above components and 180 Gr Speer bullets a three shot group of 1/2 x 3/4 inch (12.7mm x 19.05mm) and a four shot group of 1/2 x 1 3/8 (12.7mm x 34.95mm)was produced. The average velocity was 1720fps.

As a warning, .365 cast bullets were shot in this rifle with a similar 40 Gr of R15 as noted above resulting in evident signs of pressure. A check of the neck after this test load revealed that the neck was .363 diameter or .002 smaller than the bullet that was fired. A four shot test group with this load was all over the target (6.0 inch horizontal x 11.0 inch vertical spread)due to the oversized bullets (for the .358 bore) It was a very good thing the bullets were cast lead and not jacketed bullets!

The point of this post is to make note that if you are shooting and fooling around with the older European double guns and drillings to be sure and do a chamber cast to determine exact chamber and bore measurements. In this case, even though the proof markings indicated what is normally and expected to be seen for 9,3 x 72R chambered rifle (118/35) one should not presume that the mark is definitive. In all of my past research I had never read or heard mention of the 9,0 x 72R cartridge but the fact that C&H (and RCBS) have dies in this caliber illustrates that it is "out there" and was used in at least a few double guns. It is noteworthy that there is no mention of the 9,0 x 72R in Dixon's European Sporting guns, COW or other books that had European cartridges that I had made inquires about.

Best of luck this season to one and all,

Jeff

Jeff;
As I understand it when these rifles were marked by the gauge system they used plug gages made up in .010" increments. A 118/35 gage was .340" in diameter while the next one up 108/49 was .350". The bbl was marked according to the largest plug which would enter the bore to specified depth. The reason both bore sizes sometimes wer marked with the same gauge was that the 9mm one just barely accepted that size while the 9.3 bore just barely missed accepting the next larger.
You are certainly "Absolutely Correct" in the need to adequately determine actual dimensions of both bore & chamber on these older guns. Excellant & informative post.