15 February 2008, 19:33
kududeRegulation of 9.3x74R Merkel (Continued)
Well, the adventure continued today. I went to the range with 20 rds of 285gr Privi Partisan and 65.5gr of H414, and 20rds of the same bullet with 67.5gr of H414. I also took my 9.3x62 bolt gun as a comparison.
The following are the velocities of the 65.5gr H414 loads that were captured. Each shot was numbered and indicated on the targets;odds=right & evens=left barrel:
1-na
2-2154fps
3-na
4-2148
5-2290
6-2175
7-2177
8-2167
9-2180
10-2172
19-na
20-2189
21-2197
22-2183
23-na
24-2213
25-
2395 26-2161
27-na
28-2174
The following are the velocities of the 67.5 gr load. As you can see these were higher than expected and predicted according to the book. Therefore, only four rounds were fired at 50 and four at 100. The only indication of excessive pressure was a slight, barely discernible cratering of the primer. However, safe before sorry. Same comments as above apply:
11-2396
12-2399
13-2419
14-2423
15-2369
16-2406
17-2403
18-na
According to the Hodgdon info, 64gr starting load is 2206 (24" barrel) and 68gr max load is 2351. Pressure is 40,200CUP on max.
This is the 50 yd target; the 65.5gr shots are "connected."
This is the 100yd target; the 67.5gr shots are "connected." The point of aim was just above and right of shot 11 (11 was at 7 o'clock of the 10 ring). Note position of shot 25 & velocity (2395).
The following are the the 50 & 100yd 9.3x62 targets shot using the same technique as the Merkel:
My conclusions: The "load" for this bullet and powder should be about 66.6gr-67gr. The distance for regulation appears to be about 60yds (50 meters?). It is hard for these old eyes to see that front sight with my correction. I have got to do all test with shooting glasses w/o correction.
Questions: Are my conclusions on target?
Based upon the velocities and the indications, is the velocity too high for the 67.5gr load?
Are my results consistent with your experience with 9.3's?
What is the pull weight on your triggers for your doubles, particularly Merkels if there is a difference in the trigger mechanism between rifles?
You comments are requested. Thanks. Kudude
15 February 2008, 23:50
Tim CarneyAs I read your 50 yd target with 67.5 grains the barrels are crossing, evidence of too high velocity. Doesn't show at 100 'tho.
The composite group at 65.5 at 50 is not tight enough but barrels are properly printing on the left and right.
Believe you are right about a powder charge of 66.5 or so likely to give the best regulation.
Regards
16 February 2008, 11:51
N E 450 No2I would load 66 and 67 grains and repeat the test.
It looks like your double is following estabilished perimeters.