Today was range day and it was not a good day lol. My local range has gone cheap and replaced the target stands with ropes thus allowing the target to move and sway in the wind. Add that with the fact that what seamed like every person in the county with an AR platform rifle and huge compensator that thought they were gonna rapid fire while bumping the bench was crammed next to me on the now only four 100 yard shooting lanes.
To the nitty gritty...I started with 37.0gr of IMR 4198 and worked my way to 44.0 grains in five shot groups. There are no pictures of groups in this post because someone tossed my target. At 37gr the group was about eight inches wide and at 38.0gr it dropped down to four inches. The rifle hated charges 39.0, 40.0gr, and 41gr throwing everything over five inches. I assumed that the groups were widening and I was off target by charge group 42.0 but in fact I later learned that the whole group was shifting to the left. I tried some kentucky windage and confirmed this but was out of ammo at this point. A charge of 43-44gr proved to be a lot tighter even when using kentucky windage so I will revisit this area as well as the 38.0 grouping.
Here is the hard data:
Barrel Length-18"
Barrel Twist-Approximately 1/14"
COAL:2.992"
Formed 30-06 Brass Trimmed To 2.484"
Powder: IMR 4198
Solid Crimp
Exterior Temp:79°F
Humidity:34%
Approximately 100' Above Sea Level
Primers: CCI NO.34 Large Rifle
Boolit: Mi-HEC clone of RCBS-35-200 (202gr) cast from 94-3-3 (BHN-11) with homemade aluminum .014" gas check
Charge/Average Velocity/Mean Spread/Comments On Remaining Shots In Group
37.0gr-2046fps 253fps spread/9 shots (six errors on chrony)
38.0gr-2105fps 178fps spread/4 shots (one error on chrony)
39.0gr- 2139fps 33fps spread-5 shots
40.0gr- 2252fps 115fps spread-5 shots
41.0gr- 2302fps 162fps spread-4 shots (one misfire/dud)
42.0gr- 2392fps 117fps spread-5 shots
43.0gr- 2400fps 110fps spread-5 shots
44.0gr- 2484fps 230fps spread-4 shots (last shot not recorded)
Notes- The mauser really dents a primer in a solid manner. One primer from the 42.0gr charges was punctured completely. There were two rounds that needed to be fired a second time including the dud that did no fire on the third try. This rifle does not like to extract Federal factory 35 Whelen brass from the chamber. Federal brass require a rod to lightly tap out after firing.