some range data and questions


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mnhntr
April 4, 2012, 10:15 PM
Ok so I went out on a really nice day to get some time behind my LRP. I got it in the fall, and did not get a lot of range time with it over the winter. Working up loads in the fall I got less than good groups with H4350 and 140gr Berger VLDs. I tried different seating depths and charges. I ordered some SMKs 142gr, and set out to the range today.
This is the load particulars: 142gr SMK, H4350 powder, Winchester 7mm-08 brass necked down, Federal Match primers. The SMK's all got seated at 3.280 in. The best was the second group then it seemed to open on the third and start to tighten on the fourth. The fourth is max but there were no pressure signs so I am going back tomorrow with 44.7gr and 44.9gr to try them.


1) 41.5gr H4350
Avg 2730 fps
33 ES
14 SD

2) 42.5gr H4350 (Best group)
Avg 2775 fps
41 ES
15 SD

3) 43.5gr H4350
Avg 2863 fps
30 ES
11 SD

4) 44.5gr H4350
Avg 2918 fps
26 ES
10 SD

Now the questions. Do you clean and foul before each group when working up a load?
How many rounds before cleaning when working up a load?
How do you know if the load is inaccurate or the barrels needs cleaning?
I have about 75 rds through this rifle and I know it is better than I am. I just do not want to waste my time and reloading supplies doing everything wrong.

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ArchAngelCD
April 5, 2012, 01:34 AM
I don't understand your data. There is no accuracy notes with the data. Accuracy is the most important stat, not ES and SD. While it's good to get low numbers especially SD it's not always important because I've seen triple digit SD numbers yield sub MOA groups many times. Also, I might have missed something but what caliber is this?

When I'm working up a load I will clean the barrel between each load and fire 1 fouling round before checking accuracy. I also like to fire 4 or 5 rounds in each group instead of 3. I feel it tells you more about the load than only 3 rounds. I try to fire 5 rounds per group unless the barrel is very hot after 5 and then I will shoot only 4 per group.

I would NOT go over the Max recommended charge weights. You are increasing your load 1 full grain for each group. Take your best 5 round group charge weight and go .5gr above and below that number and work from there. (42.0gr and 43.0gr) Then work in .2gr increments and finally .1gr changes until you fine the sweet spot. Remember to let the barrel cool completely between groups. This is how I would do it but it's not the only way...

Good luck.

mnhntr
April 5, 2012, 10:33 AM
Thanks, the second group was the best accuracy wise and I did shoot 5 shot groups.

GW Staar
April 5, 2012, 12:49 PM
Sorry wrong Thread.

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