I want to start by saying it really sucks to hear that this is the kind of experience that guys are having with LAW and I'm not writing this to rub it in anyone's face, just writing a follow up like I said I would after I got back to the range. I appreciate that you all shared your experience because I was ready to send mine back too but after hearing about the long turn around and lack of results when guys finally got them back I decided to address the issues myself. I bedded the action and relieved the barrel channel and tweaked the mag spring which fixed the other issues. That being said I made it to the range today and shot a OCW test using Berger 210 Hunting VLD's seated .005" off the lands and retumbo from 75.5 gr. to 79.5 gr. in .5 gr. increments. Retumbo wasn't my first choice as its a bit slow but I have a ton of it that I bought for my 338 Lapua but the Lapua took a liking to Reloader 33 so I figured I'd give it a go in the LAW 300 win mag. I wasn't using the magnetospeed as I didn't want to make a decision based on velocity which I've done in the past, I wanted to develop a true OCW load and figure out velocity for it later. I ended up with a nice node from 77.5-79.0 grains where groups were all right at 1/2" inch and there was only a 3/8" vertical between the 4 charges with the 77.5 and 78 having nearly zero vertical dispersion to group centers and 78.5 and 79 also having nearly zero vertical dispersion. These were shot round robin as a OCW test should be to avoid favoring a load due to the amount of barrel fouling being higher or lower from one charge to the next. I'm going to be loading up some more of these four charges and head back to the range as soon as I get the opportunity to see which I'll be going with as long as I have similar results and I'll be using the chrono next go. I'm also hoping things may tighten up group wise as not having to put 27 rounds through the rifle it won't be nearly as fouled for the last round which is where the groups opened up to the 1/2" range.
On the reloading side:
My finished cartidges are about .250" longer than SAAMI spec so I'm increasing usable case capacity by a noticeable amount. There were no pressure signs on the cases with the 79.5 gr. charges so if I do see the velocity is much lower than I'm looking for I won't hesitate to go up, as Quickload and the Berger manual give pretty similar velocities with SAAMI numbers and comparable charges. When I adjust Quickload for my seat depth then the velocity and pressure drops (obviously) from the increase in usable case capacity. When I shoot with the chrono if the velocity isn't in the ballpark of what I'm seeing on Quickload I will be ordering more strain gauges so I can set up the 300 win mag on my Pressure Trace unit so I can get a better idea what is going on pressure wise.
-Joel
