Originally Posted by Mikecr
Alright, I'm pretty sure you're both stoned...
Have either of you developed a load in your lives?
OAL can very important to accuracy. Certainly you must know this.
If you aren't setting it carefully, then it really doesn't surprise me that 1/2moa seems like a big deal..
YZM19 you're on the right path. When you find the sweetest performing OAL based on your gauge readings, you can set your seating to reproduce it for most of the barrel's life.
I handload for 19 Badger .222, .223, 22-250 .243, 25acp, 6mmBR,.243Win, 25/35, .250/3000, 257 Roberts AI, 260Rem, 6.5x55, 270, 7x57mm, 7mm Rem mag, 32acp, 32sw, 32S&WLong, 32-20, 30 Mauser, 7.62x25mm, 30-30, 303Sav, 300Sav,.308, 30-06, 300 Win Mag, 7.5 Swiss,7.62x39mm, 303Brit, 7.62x54R, 8x57mm, 338WM, .380, 9x19mm, 9x23mm, 357Sig,38special, 357 mag, 38sw, 40sw, 10mm, 10.4mm, 44 mag, 45acp, 45Super, 460 Rowland, 45acpRifle 45Colt, .410, 45/70, and 12 ga.
I own reamers in 17M2, 22LR, 223 .250" neck, 6MMBR .272" neck, 243, 257RAI, 7mmRM, 30 Mauser, 308, 300WM, 7.62x54R, 338WM, 9x23mm, 357Mag .380 neck, 45acp .471" neck, and 12 ga Remchoke.
I own ~50 load books, but don't use them anymore, I make up my own loads.
I have gone to the range 70 times over the last 6 years, and written up a detailed range report each time. I just counted the range reports
I can imagine that precise OAL has been found by someone else, sometime, to affect accuracy to the point a difference can be detected, but I can't.
All my experiments show that jammed into the lands is more accurate, and how far jammed in does not matter enough to measure.
I have s***canned precise OAL, along with weighing brass and turning necks.
There was just no pay off for the trouble in my experiments.
I find where the bullet first gets marks from being jammed into the lands.
I find where the bullet gets stuck in the lands and the case extracts with the bullet left behind.
I then pick some OAL in between.
No great seating accuracy needed to find such a spot.