I've never liked relying on case weight. You don't know where that extra weight is, whether it's in the wall thickness or in the case head.
I prefer to go off the wet/water capacity of the case. Ideally, I like to measure it once the case has been fire formed to your chamber and trimmed to...
I need a few pairs of 34mm rings.
I'd normally use NF Ultralight rings, but I'm entertaining ARC rings, the new M-Brace/M10 rings. I've seen some posts (elsewhere) about the pins in the M10s backing out. Is this an ongoing problem? Something that's been worked out?
If you go Magpul, watch out for counterfeit ones.
I found these ones interesting:
https://www.impactweaponscomponents.com/product/bipod-mount-v2
and
https://kineticdg.com/product/kinectmlok-harris-bipod-mount
I've not had that problem with S&B primers. I use them exclusively.
Is there a chance that primer wasn't fully seated, and the impact from the pin finished it?
A change in temperature could cause a change is muzzle velocity.
What your experiencing is most likely air density changes. I generally track that with my Brunton (you can use some Kestrels), using a calculation called Density Altitude. If you just use the elevation and temperature, you're...
I use the Brunton ADC Pro. The most important feature, for me, is Density Altitude calculations. The closest Kestrel that does that is more than 2X the price. The Brunton cost me about $110.
I only did some very basic load development, but a 3 shot group was .25". The ES/SD numbers also looked promising, but needs further chrono work.
FGMM Brass
168 SMK
42.0 IMR-4895
210 primer
2.850" COAL / 2.265" OGive
2650 FPS
(2) Stainless Remington 700 Triggers
Old Style - NOT XMark
$60 Shipped (Per Trigger)
$105 Shipped (Both)
Installer is responsible for properly adjusting the trigger to their rifle, to ensure safe operation.