Just loaded up a few rounds for my 700 sps in 308. I usually load 175 smks with 42.4gr of 4064 at 2.8 OAL. I have been wondering if I can shrink my groups if I load off the lands. Here is how I determined my headspace.
Took a fresh piece of brass that had been necksized. Seated a 175smk barely in the case, then chambered that round. Noted the OAL (I dont have a gauge). 2.950 is the number I came up with.
I repeated this several times and only got smaller numbers, I assume the largest number was the most accurate and the smaller numbers came from me either repeatedly chambering the same cartridge or chambering the test cartridge too hard.
2.950 was my largest number, I came up with numbers around 2.940 to 2.935 after repeatedly chambering the same round.
Next I tweaked my bullet seating die until it would consistently seat at 2.935. So now my handloads should be .015 off the lands correct?
I used the same charge, 42.4gr. I assume I shouldnt have an increase in pressure by increasing my OAL, correct?
Just checking to make sure I did this right. I can always pull em and change the OAL.
Took a fresh piece of brass that had been necksized. Seated a 175smk barely in the case, then chambered that round. Noted the OAL (I dont have a gauge). 2.950 is the number I came up with.
I repeated this several times and only got smaller numbers, I assume the largest number was the most accurate and the smaller numbers came from me either repeatedly chambering the same cartridge or chambering the test cartridge too hard.
2.950 was my largest number, I came up with numbers around 2.940 to 2.935 after repeatedly chambering the same round.
Next I tweaked my bullet seating die until it would consistently seat at 2.935. So now my handloads should be .015 off the lands correct?
I used the same charge, 42.4gr. I assume I shouldnt have an increase in pressure by increasing my OAL, correct?
Just checking to make sure I did this right. I can always pull em and change the OAL.