Fairly new to reloading and working up accurate loads - just wanting some confirmation on this load work up...
Got a new 6.5 Creedmoor pre-fit for my origin action (24" Proof SS medium sporter barrel) and was starting load development. First, I found the lands at CBTO of 2.232" (which was a COAL of 2.862" for 140 ELD-M). Then, I looked around SH and found that most were finding their nodes between 40-43 gr of H4350 (using 140 ELD-M and Lapua SRP brass) - this was corroborated with Gordon's Reloading Tool (43.0 gr for 99.4% of max pressure) and the Hornady book (max shows 41.5 gr at 2700 fps with 2.8 COAL). Primed them all with CCI-450, then loaded up a ladder with 2 rounds each ranging from 40-43 in 0.3 gr increments (used 0.020" jump as I saw this was pretty common). I loaded an extra 2 rounds at the lowest charge so I could get the optics crudely zeroed. Here were my results (magnetospeed sporter):
gr - velocity
40.0 - 2674, 2685, 2677, 2673
40.3 - 2691, 2693
40.6 - 2725, 2731
40.9 - 2730, 2727
41.2 - 2750, 2762
41.5 - 2762, 2752
41.8 - 2781, 2772
42.1 - 2786, 2800
42.4 - 2823, 2817
42.7 - 2832, 2794 (not sure why this last one was way out of line)
43.0 - 2845, 2845
These were not fast fired and barrel was warm but not hot throughout test. The graph below is a screenshot from Gordon's reloading tool (similar to QL). And for what its worth, after inputting these charges and speeds, GRT calibrated the burn rate for my batch of H4350 and told me the low/med/high nodes were supposed to be at 40.7 gr ( 2692 fps, 52335 psi), 41.8 gr ( 2769 fps, 57202 psi), and 43.6 gr (2883 fps, 65672 psi) - so the speed on the middle node correlates to my speed, but not for the lower node and not data for the high one. Also max pressure was defined as 63091 psi so high node should be out.
My goal is to not have a hot load, but get the most appropriate velocity that a 6.5 CM can offer. My questions are:
1.) Did I do this ladder correctly? My goal was to hone in on a charge, then play with seating to get the accuracy.
2.) Can you really do load development on a brand new barrel? My understanding is the node shouldn't move, but as the barrel speeds up, the amount of powder to stay in node will decrease. If so...
2.) Are there 2 nodes near the bottom side (40.6-40.9 and 41.2-41.5) or is that 1 wide node?
3.) Should I concentrate down here or is there another one up near 2820ish? Is 2820 too hot?
Here is a picture of the primers for the highest 4 charges if that helps anyone (I dont see a problem but interested in others opinions). From left to right: 42.1, 42.4, 42.7, 43.0.
There is slight ejector slot flow, but that is seen even on the lowest 40 gr charges (a little more pronounced I guess on the high charges). Same for the craters - I can feel a slight crater with my fingernail on the 40 gr but more pronounced on the 43 gr. Other thing I noticed is that at 42.1 (far left in this picture), the primers started to have a flatten top with being the most flat at 43gr. They still look to me like there is plenty of roundness on the edges of the primers though.
Anyway - constructive criticisms or next steps are appreciated. Thanks SH!
Got a new 6.5 Creedmoor pre-fit for my origin action (24" Proof SS medium sporter barrel) and was starting load development. First, I found the lands at CBTO of 2.232" (which was a COAL of 2.862" for 140 ELD-M). Then, I looked around SH and found that most were finding their nodes between 40-43 gr of H4350 (using 140 ELD-M and Lapua SRP brass) - this was corroborated with Gordon's Reloading Tool (43.0 gr for 99.4% of max pressure) and the Hornady book (max shows 41.5 gr at 2700 fps with 2.8 COAL). Primed them all with CCI-450, then loaded up a ladder with 2 rounds each ranging from 40-43 in 0.3 gr increments (used 0.020" jump as I saw this was pretty common). I loaded an extra 2 rounds at the lowest charge so I could get the optics crudely zeroed. Here were my results (magnetospeed sporter):
gr - velocity
40.0 - 2674, 2685, 2677, 2673
40.3 - 2691, 2693
40.6 - 2725, 2731
40.9 - 2730, 2727
41.2 - 2750, 2762
41.5 - 2762, 2752
41.8 - 2781, 2772
42.1 - 2786, 2800
42.4 - 2823, 2817
42.7 - 2832, 2794 (not sure why this last one was way out of line)
43.0 - 2845, 2845
These were not fast fired and barrel was warm but not hot throughout test. The graph below is a screenshot from Gordon's reloading tool (similar to QL). And for what its worth, after inputting these charges and speeds, GRT calibrated the burn rate for my batch of H4350 and told me the low/med/high nodes were supposed to be at 40.7 gr ( 2692 fps, 52335 psi), 41.8 gr ( 2769 fps, 57202 psi), and 43.6 gr (2883 fps, 65672 psi) - so the speed on the middle node correlates to my speed, but not for the lower node and not data for the high one. Also max pressure was defined as 63091 psi so high node should be out.
My goal is to not have a hot load, but get the most appropriate velocity that a 6.5 CM can offer. My questions are:
1.) Did I do this ladder correctly? My goal was to hone in on a charge, then play with seating to get the accuracy.
2.) Can you really do load development on a brand new barrel? My understanding is the node shouldn't move, but as the barrel speeds up, the amount of powder to stay in node will decrease. If so...
2.) Are there 2 nodes near the bottom side (40.6-40.9 and 41.2-41.5) or is that 1 wide node?
3.) Should I concentrate down here or is there another one up near 2820ish? Is 2820 too hot?
Here is a picture of the primers for the highest 4 charges if that helps anyone (I dont see a problem but interested in others opinions). From left to right: 42.1, 42.4, 42.7, 43.0.
There is slight ejector slot flow, but that is seen even on the lowest 40 gr charges (a little more pronounced I guess on the high charges). Same for the craters - I can feel a slight crater with my fingernail on the 40 gr but more pronounced on the 43 gr. Other thing I noticed is that at 42.1 (far left in this picture), the primers started to have a flatten top with being the most flat at 43gr. They still look to me like there is plenty of roundness on the edges of the primers though.
Anyway - constructive criticisms or next steps are appreciated. Thanks SH!
