Recently I sent away some once-fired brass to Hornady so they could make me a case for their OAL tool.
Now I've finally been able to measure the distance to the lands in my rifle's barrel for any given bullet. (Proof Research AR-10 22")
When I use a 140gr Hornady ELD Match bullet, the distance to the lands, from base to ojive is 2.262"
Subtract .030" from that for a little jump, 2.232", the OAL of the 140gr cartridge is 2.85" and fits just under the limit of an ASC magazine, but won't fit in MagPul.
When I use a 147gr Hornady ELD Match bullet, the distance to the lands, from base to ojive is 2.29"
Subtract .030" from that for a little jump, 2.26", the OAL of the 147gr cartridge is 2.904 and that is too big for any magazine.
So, even though the G1 ballistic coefficient of the 147gr projectile is superior to the 140gr (.697 vs .646) , I am thinking that I will have better accuracy from the 140gr projectile in an ASC mag which allows an OAL to 2.864" because the 140gr can be loaded closer to the lands in my rifle than the 147gr can and still feed properly.
That being said, I made 50 rounds of 147gr @ 2.8" with powder charges for 5 velocities and 50 rounds of 140gr at 2.85" with powder charges for the same velocities.
I've got a chronograph on order and when that arrives I'll be able to collect some data and have target results.
Obviously a bolt action rifle / magazine will probably have more space and in that case the 147gr is probably the better choice.
I have not measured any of the 143gr bullets or the -X hunting loads yet.
Thoughts?
Now I've finally been able to measure the distance to the lands in my rifle's barrel for any given bullet. (Proof Research AR-10 22")
When I use a 140gr Hornady ELD Match bullet, the distance to the lands, from base to ojive is 2.262"
Subtract .030" from that for a little jump, 2.232", the OAL of the 140gr cartridge is 2.85" and fits just under the limit of an ASC magazine, but won't fit in MagPul.
When I use a 147gr Hornady ELD Match bullet, the distance to the lands, from base to ojive is 2.29"
Subtract .030" from that for a little jump, 2.26", the OAL of the 147gr cartridge is 2.904 and that is too big for any magazine.
So, even though the G1 ballistic coefficient of the 147gr projectile is superior to the 140gr (.697 vs .646) , I am thinking that I will have better accuracy from the 140gr projectile in an ASC mag which allows an OAL to 2.864" because the 140gr can be loaded closer to the lands in my rifle than the 147gr can and still feed properly.
That being said, I made 50 rounds of 147gr @ 2.8" with powder charges for 5 velocities and 50 rounds of 140gr at 2.85" with powder charges for the same velocities.
I've got a chronograph on order and when that arrives I'll be able to collect some data and have target results.
Obviously a bolt action rifle / magazine will probably have more space and in that case the 147gr is probably the better choice.
I have not measured any of the 143gr bullets or the -X hunting loads yet.
Thoughts?