This morning I had the opportunity to shoot some velocities with Gamin and Oehler 33 reading the same shots. For the Oehler the screens were at 10' and 15'. The Gamin was on the bench beside the rifle. This testing was incidental to checking some LAS zeros
Rifle in the first instance was my Marlin 336A Rippletop. Load was #311008 (117 gns), BAC lube, 4.3 gns Red Dot, and Winchester LP primer. The shooting started from a cold clean barrel and comprised fouler plus two five shot groups. Rifle cooled between first and second group.
Results herewith:
Oehler 33 Gamin
Fouler 1106 1110 (not in averages)
Group 1: 1070 1075
1066 1066
1064 1068
1064 1065
1064 1067
Mean 1065 1068
SD 3
Group 2: 1085 1087
1075 1078
1061 1068
1053 1058
1062 1066
Mean 1067 1071
SD 12
Later I ran five shots each with .22 CCI Standard and .22 Federal American Eagle HV from my Marlin 39A. Average velocities for the Standard were 1047 (Oehler) and 1050 (Gamin). Averages for HV Federals were 1222 (Oehler) and 1234 (Gamin).
The slightly higher velocities from the Gamin are as expected, since the Oehler readings are at, effectively , 12.5' while the Gamin readings are supposedly at muzzle.
You are only as good as your library.
