Tree analysis

[ronstone09]

I am starting to build a load for my 7mm-08 that I plan to shoot in local 600 yard competitions. I am using Lapua brass necked using a Redding S die to 0.310 inches, CCI BR2 primers and Cutting Edge MTH 130 bullet. COAL to start was just fitting into the magazine at 2.808 inches. Cutting Edge sent some initial load data and Alliant RL 17 looked promising.

I have attached pictures of my recent tree analysis. At 44.0 grains an equilateral triangle is produced Fig shown for 44.0 grains and showed the same result for 45.0 grains and 45.5 grains (pictures not shown). At 44.5 grains a tightened group is produced (Fig shown). At 46.0 grains a tightened group is produced but different shape (Fig shown). At 46.5 my last test the group opened up to 3 inches.

Should I concentrate on the 44.5 group or the 46.0 group. Keep in mind the 600 yard distance. Also are these results suggesting I should vary the seating depth.

Thanks
Robert

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i would suggest you buy "precision long range shooting and hunting " darrell holland goes into depth on ladder testing and what to look for in your results !

 

[merbeau]

Ok nice, what's your opinion on bbl brake in , personally i believe in it ,and it's more relaxed from a stand point of reloading , and it lets your barrel tell you what it likes . Granted your excited ,and that's normal. I'd suggest trying some Sierra tipped match kings in 130s & 160s , a great friend of mine ran the 130 sierras threw his target 708 rifle and he almost won his first 600 yard match . He traded me a leftover box of 20 count 160 tipped match kings my 708 loved them ,best 3/shot group was 1&1/16 at 300 yds ,followed up at625 with a 3 shot 2.75 group measured with a tape bullet holes not subtracted , have picture also . Tmv tested muzzle velocity 2780 fps powder h4350 ,cci/200 ,col 2800 ish . Never shot the tipped Sierra 130's but their on my to do list . H414 is very good powder , don't forget to try Sierras normal 150 match king it likes the 1/9 twist , happy testing , happy loading , your Rifle was made for these components ,gd on you !!!.

Typical for most of many forum discussions. The original question branches out into many different limbs from the original tree. I say to each his own. I started out with the Cutting Edge 120 Extended range bullet and it was unstable. Barrel break in typically
5 shots - cleanup after each individual shot.
3 shots - cleanup after the 3rd shot.
5 shots - cleanup after the 5th shot.

According to the latest Sierra website they do not make a 130 grain Match King. They have a 120 pro hunter then a 140 grain game king. The first SMK is 150 grain which I do not want to shoot. I have had good luck using these bullets both for 300 and 338 Win Mag. I shoot Lapua in my 6.5 with great success. I sure hope that 'gd' does stand for G*D **** because if it does totally unacceptable on a public forum.

 

[merbeau]

i would suggest you buy "precision long range shooting and hunting " darrell holland goes into depth on ladder testing and what to look for in your results !

Good suggestion

 

[jjmp]

Sierra never made a tipped match king 130 but they did make it in old style hp match king which they have dropped . gd stands for good. Your bbl brake in is better then none .