Re: Measuring Base-to-Ogive and Base-to-Datum for Sizing
Posted: Mon Jul 11, 2016 12:52 pm
Interesting results, what is the rifle and is it a standard or custom build?
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Measuring Base-to-Ogive and Base-to-Datum for Sizing
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Re: Measuring Base-to-Ogive and Base-to-Datum for Sizing
Posted: Tue Jul 12, 2016 8:36 am
It's a Remington 700 with a border barrel. It was made by Dave at Valkyrie firearms. For what it's worth it has a small amount of freebore as it was reamed for 123gr projectiles.
Re: Measuring Base-to-Ogive and Base-to-Datum for Sizing
Posted: Tue Jul 12, 2016 3:58 pm
Doing a little statistics on your velocity data (unpaired T test), the three Hornady loads are not significantly different, but the Lapua pair are.
http://www.graphpad.com/quickcalcs/ttest2/
Triffid
http://www.graphpad.com/quickcalcs/ttest2/
Triffid
Re: Measuring Base-to-Ogive and Base-to-Datum for Sizing
Posted: Tue Jul 12, 2016 5:49 pm
Thanks Triffid, did you check my data for normality first 
If non-Roman then it makes sense to compare the non-parametric medians via the Mann Whitney test.
Nerds stuff aside, it's a surprise to me that the velocities aren't different. Would it be too much of an assumption to assume that there's no nett change in pressure? I have no way to measure this without directly involving the velocity so wondered what people's thoughts are.
If non-Roman then it makes sense to compare the non-parametric medians via the Mann Whitney test.
Nerds stuff aside, it's a surprise to me that the velocities aren't different. Would it be too much of an assumption to assume that there's no nett change in pressure? I have no way to measure this without directly involving the velocity so wondered what people's thoughts are.