in2anity wrote:I still would like to know what the published velocity is relative to however...
I can only surmise that the majority of the brands don't published actual tested data, they just use a sensible average.
Look at the MV numbers from Federal, SK, CCI and plenty of others. Across the rate you'll see certain numbers repeated in all the brands 1250, 1200, 1080, 1050, 1040.
No velocities like 1252, 1204, 1086... You're telling me everyone's making a dozen types of different ammo, testing them on different platforms, and all are getting velocities to a neat 10 fps on everything? I think not.
They're just indicative figures to get you in the ball park you want to be in. Sub-sonic or super-sonic, and how slow or fast you want on either side of the fence. Understandable considering that unless you're using their testing platform (which we're not) the numbers won't be correct anyway.
Sellier & Bellot and RWS are the only 2 brands I can think of that state velocities with the variance you'd expect. As examples RWS states 1082 fps for their club ammo, S&B say 1066 fps for theirs. But again, once it goes through your or mine or anyone else's rifle those numbers aren't going to be spot on.
If you want truly accurate numbers you need to run the loads through your own setup work it out yourself. You should still be able to get a somewhat accurate figure without a chrono though.
Try this... Zero for 50 metres, shoot a 10-shot group at 25m, 50m, 75m, 100m and 150m
without change the zero and record the average rise/drop.
Put the projectile weight, BC and claimed MV of the ammo into a trajectory calculator and see what the calculated arc looks like compared to the results you've recorded.
From there increase or decrease the MV figure entered in the calculator as required incrementally and refresh the results, comparing the calculated arc to your recorded results.
When they match you've got you've got your actual (close enough) MV.