Hi guys, I need some advice here.
I went out last week to load test my Weatherby Vanguard in .243 with a batch of new Lapua brass (first time using it).
My load was as follows: Full length resized Lapua brass, Win LR primer, Hornady 87gr V-Max 5 thou off and Reloder 15 starting at 35gr working up to 37.5gr in .5gr increments. 3 shots fired at each charge.
Not exactly bench rest class load testing I'll agree but this is a sporter barreled hunting rifle I use for informal target shooting, varminting and deer hunting.
Now my problem is that I went out yesterday to test my chosen load for accuracy again and chrono the results, I was alarmed to find my load was shooting 2+'' 5-shot groups! mostly vertical I might add
Now I might be an idiot for doing this but I nearly always anneal brass after each firing as I find brass life is seriously increased, so as usual I turn my brass on a modified power screwdriver over a flame for a set amount of time (looking for cherry red) then size as usual.
I'm thinking that my annealing routine is nowhere near as uniform as Lapua's (duh!) and as such I am loosing accuracy due to inconsistent neck tension (pressure from seating bullets in virgin Lapua brass did seem a 'tad' more consistent).
Possible theories include:
1) The 'accurate' 37gr load I chose was a fluke good 3 shot group, successive shots would have shown poor grouping?
2) My annealing routine is in-precise and changes in neck tension from round to round is ruining accuracy.
3) Accuracy testing needs to be done on once fired brass vs virgin brass
4) The 2nd test day was 10-15°C higher leading to pressure changes pushing me out of the 'node'.
Original load test (yesterdays bad groups NOT shown):
note: shooting position, setup and distance (100yds) were exactly the same on both days. The rifle had been thoroughly cleaned and foulers taken both separate days.
Thank you in advance for any advice guys!
Phil
I went out last week to load test my Weatherby Vanguard in .243 with a batch of new Lapua brass (first time using it).
My load was as follows: Full length resized Lapua brass, Win LR primer, Hornady 87gr V-Max 5 thou off and Reloder 15 starting at 35gr working up to 37.5gr in .5gr increments. 3 shots fired at each charge.
Not exactly bench rest class load testing I'll agree but this is a sporter barreled hunting rifle I use for informal target shooting, varminting and deer hunting.
Now my problem is that I went out yesterday to test my chosen load for accuracy again and chrono the results, I was alarmed to find my load was shooting 2+'' 5-shot groups! mostly vertical I might add

Now I might be an idiot for doing this but I nearly always anneal brass after each firing as I find brass life is seriously increased, so as usual I turn my brass on a modified power screwdriver over a flame for a set amount of time (looking for cherry red) then size as usual.
I'm thinking that my annealing routine is nowhere near as uniform as Lapua's (duh!) and as such I am loosing accuracy due to inconsistent neck tension (pressure from seating bullets in virgin Lapua brass did seem a 'tad' more consistent).
Possible theories include:
1) The 'accurate' 37gr load I chose was a fluke good 3 shot group, successive shots would have shown poor grouping?
2) My annealing routine is in-precise and changes in neck tension from round to round is ruining accuracy.
3) Accuracy testing needs to be done on once fired brass vs virgin brass
4) The 2nd test day was 10-15°C higher leading to pressure changes pushing me out of the 'node'.
Original load test (yesterdays bad groups NOT shown):

note: shooting position, setup and distance (100yds) were exactly the same on both days. The rifle had been thoroughly cleaned and foulers taken both separate days.
Thank you in advance for any advice guys!
Phil