I recently acquired a drilling that had been rechambered. I don't know that I would call it a dedicated wild cat in the sense of seeking higher performance but rather a rechambering to make a firearm usable by someone who might have been less than familiar with cartridge conversion.

The drilling was originally chambered in the old 360 express/9 X 57D cartridge. When I cast the chamber it was immediately evident this was not the cartridge the barrel was now chambered for. Measurements of the cast showed the 30-40 Krag case could be made to work if a tad short. The shoulder is a lot farther forward and sharper than the Krag case and the body taper considerably blown out. The cases were easy to make thanks to the generosity of 3 members of this board who supplied me with Krag cases. Once cases were made load development commenced. I settled on two loads. The hunting load of 15 grs. of Unique and a 250 gr. cast, gas checked bullet with an open cell foam filler. This load gave 1480 fps. and a bit over 1200 fpe. The play load is 15 grs. of Trail boss under the same bullet for a bit over 1200 fps. Both shoot to the same POA. Today I am going to try the same powder charges beneath a 200 gr. RCBS 35 cal., gas checked bullet just for grins and giggles and to reduce the pressure. The old drilling is not Nitro proofed so I need to keep pressures low. Interesting work...to have a black powder proofed firearm chambered to what is obviously some kind of smokleless powder case. The strange things we run into.

Glad to see you finally got your rifle up and shooting. Hope all is well with you.

I did Steve!! I ended up with the 200 gr. bullet as the play load. With the 50 gr. lighter bullet and same load the pressure seems considerably reduced. Accuracy with the old piece is amazing...to me and my old eyes. Here's a couple targets fired at 50 yards and 100 yards. The 50 yard target:



1st shot took out the 9 and the second shot is on the line between the 8 & 9 ring. I tapped the rear sight over just a tad and shots 3 & 4 are in the 10 ring. Then I moved to 100 yards.



1st shot cut the 10 ring. I didn't let the barrel cool as long as I should have and this drilling has always had a propensity to drift high and left. 2nd shot is on the line between the 7 & 8 ring and 3rd is on the 6 & 7 ring. Still, it's a 2 3/8 group at 100 yards, benched with open sights. I don't believe I can ask any more of the drilling or me!!!

And I hope you and yours had a very Merry Christmas with good wishes for a New Year!

You know you have my heartfelt congratulations for accomplishing your loads. I toast my glass of Geritol to you!

Thank you sir! That particular drilling was the most...overall challenging rifle cartridge, datawise, that I've worked with to date. After much experimenting and some exacting advice from guys on a 16 gauge forum I even have the shotgun bores shooting very good patterns. Do you by chance have an overabundance of pheasant out there in central Kansas?...lol!

quote:

Originally posted by 9.3 X 75R: an open cell foam filler.

What material did you use?

Open cell foam, like the packing foam. Not the denser closed cell.