OAL and consistent velocity


PDA






gamestalker
September 17, 2011, 10:43 PM
I did up a batch of some 7mm RM and as always I use my RCBS scale that is older than dirt, and also as usual I seat my rounds up close and personal to the lands. Using some necked mixed head stamp brass that is probably on it's 12 or 13 th session and a hefty charge of RL22 to push the 139 gr. Hornady BT's, I was astonished at the consistent velocities I was getting. In the past I've usually maintained a 20-30 fps +/- velocities, which isn't outside the norm nor an issue, in my experience. But these rounds were within 3 fps of each other of 10 rounds fired.
The only thing I did any different was I got maticulous about my seating depth. Normally I'll get them touching and then back off .010" and groups are tight. But this batch I actually put them on the lands, so I'm assuming this was the factor that brought the fps spread together and increased the average velocity a tad bit. Nothing else changed, all the brass was looking great, no resistent extractions, but my average veloctiy went up by about 30 fps, average was 3450 fps - 3453 fps. I honestly didn't think it was possible to achieve consistency to that degree.

If you enjoyed reading about "OAL and consistent velocity" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
If you enjoyed reading about "OAL and consistent velocity" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!