Update!
Finally got out for some load development with the new optic, a Vortex PST 2.5-10. I used 130gr Berger VLD and 123 Amax, both with IMR 4350. This is with once fired Federal brass.
Temps were almost 90 with high humidity. This rifle was built for hunting and with weight in mind as its for my 12 year old son. It has a Remington sporter contour barrel and heat, especially in these temps, will be a factor. This should improve in the colder temps of hunting season.
We prepped the brass and trimmed to 2.025, set seating depth to magazine length (2.83 COAL).
In this first pic, we started with 37.5 grains and the 130 VLD's. This is two groups shot on the same target. The outer holes are three shots with 37.5 grains (they make the outer most triangle). We let the barrel cool and shot three more with 37 gr. Those are the three inside the first three.
There is some room for improvement and will update with the next round of development.
This next photo is the 123 Amax. This is using 37.5 grains of IMR 4350 at a COAL of 2.83. The top hole are the first and second rounds of a three shot string. The one hole that is out is the third shot. After it came out we felt the barrel and could not keep our hands on it. We decided to stay where we were and let the barrel cool off. I loaded one more to check the load and put it in the same hole as the first two. That confirms the load is consistent and barrel heat was the factor in the third shot.
This is a pic of the same target as before measuring the spread if heat was not a factor. The third shot is after the barrel cooled, coming off the gun and light changed.
We did not use the chrony on any of these loads and know the loads are on the low end. As the weather cools off I will be looking for the higher node and will update then.
