WinchesterAA
Member
- Joined
- Mar 9, 2006
- Messages
- 870
So I finally got around to making a comparator and modifying a case to act as a COAL gauge for my future 308 loading. (No press or powder yet)
RIFLE SPECS:
Remington 700 AAC-SD 20" barrel, 1/10" twist rate
Minimum seating depth for fitting in the magazine: 2.820" head to tip
Since my barrel's twist rate is on the faster side, I thought I'd start with 180 grain and 200 grain bullets just to see what I could do with them.
MEASURING TO TOUCH THE LANDS
180 grain COAL measurements from the head to ogive:
Min: 2.358"
Max: 2.361"
Avg over ten measurements: 2.359"
200 grain COAL measurements from the head to ogive:
Min: 2.378"
Max: 2.384"
Avg over ten measurements: 2.381"
My questions are:
With the 180 grain bullet seated such that the OAL from head to ogive is approximately at the lands, the actual seating depth is less than 1/10th of an inch (not counting the boat tail portion which doesn't contact the case neck). That's much too little, right?
With the 200 grain bullet seated such that the OAL from head to ogive is approximately at the lands, the actual seating depth is approximately .22", which is less than the occasionally recommended "caliber depth" minimum, but should still be OK, right?
With the 200 grain bullet seated at the minimum COAL from head to tip to fit in the magazine (2.820"), the actual seating depth is about .360" which puts the base of the boat tail about 1/10" below the shoulder of the case. Is that bad? How far past the shoulder can you go before causing a problem?
RIFLE SPECS:
Remington 700 AAC-SD 20" barrel, 1/10" twist rate
Minimum seating depth for fitting in the magazine: 2.820" head to tip
Since my barrel's twist rate is on the faster side, I thought I'd start with 180 grain and 200 grain bullets just to see what I could do with them.
MEASURING TO TOUCH THE LANDS
180 grain COAL measurements from the head to ogive:
Min: 2.358"
Max: 2.361"
Avg over ten measurements: 2.359"
200 grain COAL measurements from the head to ogive:
Min: 2.378"
Max: 2.384"
Avg over ten measurements: 2.381"
My questions are:
With the 180 grain bullet seated such that the OAL from head to ogive is approximately at the lands, the actual seating depth is less than 1/10th of an inch (not counting the boat tail portion which doesn't contact the case neck). That's much too little, right?
With the 200 grain bullet seated such that the OAL from head to ogive is approximately at the lands, the actual seating depth is approximately .22", which is less than the occasionally recommended "caliber depth" minimum, but should still be OK, right?
With the 200 grain bullet seated at the minimum COAL from head to tip to fit in the magazine (2.820"), the actual seating depth is about .360" which puts the base of the boat tail about 1/10" below the shoulder of the case. Is that bad? How far past the shoulder can you go before causing a problem?
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