6.5CM Range Data, help with next steps

[Reformedcitykid]

Hey all, was hoping you fine folks could help me take a look at some range data. To this point I've loaded a shot a whole bunch of rounds of different bullet/powder combos, and want to start fine-tuning what I have. For whatever reason, the next steps of load development eludes me, even after watching numerous videos and reading as much as I can on it. I've put too much emphasis on group size, but I know that velocity matters more, and groups can be adjusted based on seating depth. I'm a hands-on learner, and think that it'll click once I get some feedback on rounds that I've actually loaded and put downrange, as opposed to looking at numbers and charts of other people's data.

Below is the data for one of the reloads, based on your thoughts I'll extrapolate that to my other loads. Any guidance would be much appreciated, thanks in advance!

140gr Berger Hybrid Target
H4350
CCI BR2 primers
Hornady 1x fired brass
CBTO - 2.303"
Rifle - Tikka T3x CTR w/ 20" barrel

Grain Powder (gr)	37.8	38.1	38.4	38.7	39.0	39.3	39.6	39.9	40.2	40.5	40.8	41.1
Shot #
Group In	0.834"	0.514"	0.259"	0.444"	1.054"	0.628"	0.173"	0.630"	0.785"	0.738"	0.819"	0.895"
Group MOA	0.797	0.491	0.248	0.424	1.007	0.6	0.165	0.602	0.75	0.705	0.783	0.855
Shot 1	2364	2377	2397	2415	2446	2466	2484	2490	2528	2507	2569	2556
Shot 2	2335	2339	2415	2418	2476	2460	2465	2485	2513	2501	2559	2574
Shot 3	2328	2360	2411		2460	2458	2462	2492	2499	2548	2545
Sum	7027	7076	7223	4833	7382	7384	7411	7467	7540	7556	7673	5130
Mean:	2342.3	2358.7	2407.7	2416.5	2460.7	2461.3	2470.3	2489.0	2513.3	2518.7	2557.7	2565.0
Median:	2335.0	2360.0	2411.0	2416.5	2460.0	2460.0	2465.0	2490.0	2513.0	2507.0	2559.0	2565.0
Min:	2328.0	2339.0	2397.0	2415.0	2446.0	2458.0	2462.0	2485.0	2499.0	2501.0	2545.0	2556.0
Max:	2364.0	2377.0	2415.0	2418.0	2476.0	2466.0	2484.0	2492.0	2528.0	2548.0	2569.0	2574.0
Shot #	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A	#N/A
Standard Deviation (SD):	15.6	15.5	7.7	1.5	12.3	3.4	9.7	2.9	11.8	20.9	9.8	9.0
Extreme Spread (ES):	36.0	38.0	18.0	3.0	30.0	8.0	22.0	7.0	29.0	47.0	24.0	18.0

 

[piie]

What is it you’re aiming to do with this rifle? For anything sub 600m, especially hunting, you’ve already got a few good loads that you can do some seating depth variations on if you think you need better ES /SD. For longer ranges, your existing loads could also work, but you’re handicapped by the 20” bbl length there.

 

[Reformedcitykid]

What is it you’re aiming to do with this rifle? For anything sub 600m, especially hunting, you’ve already got a few good loads that you can do some seating depth variations on if you think you need better ES /SD. For longer ranges, your existing loads could also work, but you’re handicapped by the 20” bbl length there.

It is mostly going to be sub-600, with the occasional longer distances. Probably not going to be hunting with this one though. Which loads would you choose to further tune, if you had to? Seems to me that 39.6, 39.9, 40.8 & 41.1 all did pretty well based off velocity, ES & SD?

 

[piie]

Honestly - if you're going to stick to 99% sub 600, then your load is already there - 39.6 - what more do you want at 0.173" groups? Load more of them, shoot some 5 shot groups and see if it holds up. Then close the books, and shoot....

 

[Doom]

Where are the targets?

 

[dryhumor]

One thing to consider as you shoot. When the trigger broke, did you feel good about the shot. It’s just as easy to wiggle one in as it is to wiggle one out. I did a quick stop and shoot this morning of 3 shots while running errands. I felt one shot was off when the trigger broke- may have been me, maybe not. That shot was about 3/4 out from the cold bore and third shot.

Another thing to consider in looking at your velocity numbers is that there are some wide readings among the three of the three shot groups. Sometimes I weigh cases after they are prepped but before priming. The outliers in weight are sorted out, and have an F written on the case with a sharpie. They become foulers, and load them with a safe mid weight charge.

This morning’s shots, after FL sizing, I weighed the cases. 2 cases weighed the same the third varied a little bit. So, may have been me, maybe not on the one that was out. Was shooting brand new brass. Since it’s a 200 ish yard hunting rifle I’m not too concerned.

You did not indicate what chronograph you were using.