I have a drilling by Muchler, circa 1928-30, chambered for 8x57JR. (I've already slugged the barrel and checked the chamber). I'm seeking reloading data for this round.
I understand that GGCA is reluctant to give reloading guidance - understandably; however, can anyone point me to a source of reliable data? I have found a plethora of data for the 8x57JS or JRS, but other than some vague suggestions nothing for J or JR.
I have found .318 bullets in 170, 196 and 200 grains. All I need to get started are some reliable powder recipes. The only powder company that replied to my request for data was Alliant, but the data they gave me all had higher velocities than I am comfortable shooting in my gun (2300fps). As I understand, 1800fps was typical for the 8x57JR pushing a 196gr bullet.
My drilling is in excellent condition, tight on face and with excellet bores.
If anyone can assist me with some published data for the 8x57JR, I would be most grateful.
I believe the 2300 fps is closer to the original velocity than the 1800 fps. The 1800 fps is closer to the velocity expected for the same weight bullet in the 8x57R/360, which is often confused with 8x57IRS (in print,not use). I believe you can use the Alliant data with 196 or 200 gr bullets, by using 10% less powder and working up until it shoots to the sights. This is a pretty common way to approximate the original load. The RWS load for 196 gr bullet in 8x57IR shows 2310 fps. In 8x57IRS the 196 gr bullet shows 2390 fps. The difference in chamber pressure between the two is not too much, so I believe you could use the data for 8X57IRS( different powders) by using the same procedures as the Alliant. A chronograph would be very helpful, and they are pretty cheap considering ones usefullness. When working the load up, be sure to let the barrel cool. A warm barrel bound to two cool shotgun barrels will not shoot to the same point of impact as it would if cool. Once you find your best load, you won't have to worry about this in regular hunting use.