Akula69
Member
Now this may be a question that others have had (and I did do a cursory search but did not find a direct answer to the question) so here goes:
Is there any correlation between cartridge overall length (as shown in reloading recipes) and comparator length?
I recently reloaded some 300 AAC with a 147 grain tracer projectile (its a bit longer than normal 147 grain projectiles due to the phosphorus pocket at the end) using the comparator. The projectile seats with the cannelure just north of the case mouth.
The powder I'm using (CFE-BLK) does not create a compressed load and requests a COL of 2.235. Using the comparator on the projectile ogive, (after slugging the barrel) I have a caliper reading of 1.600 (+- .002). This comparator length results in an average COL of 2.18. Both cartridge lengths will fit in the magazine and feed reliably (although I suspected the 2.235 cartridge is touching the lands and confirmed it by 'coloring' a projectile with a sharpie to see the marks)
Now, I realize using the comparator is to get as close to a 'no bullet jump' situation as possible, but I have a concern about the .055 overall length difference. Should I consider a different powder (AA 1680) which allows for a shorter (edited, I originally posted "longer") COL? or just use the 2.235 regardless what the comparator indicates?
Is there any correlation between cartridge overall length (as shown in reloading recipes) and comparator length?
I recently reloaded some 300 AAC with a 147 grain tracer projectile (its a bit longer than normal 147 grain projectiles due to the phosphorus pocket at the end) using the comparator. The projectile seats with the cannelure just north of the case mouth.
The powder I'm using (CFE-BLK) does not create a compressed load and requests a COL of 2.235. Using the comparator on the projectile ogive, (after slugging the barrel) I have a caliper reading of 1.600 (+- .002). This comparator length results in an average COL of 2.18. Both cartridge lengths will fit in the magazine and feed reliably (although I suspected the 2.235 cartridge is touching the lands and confirmed it by 'coloring' a projectile with a sharpie to see the marks)
Now, I realize using the comparator is to get as close to a 'no bullet jump' situation as possible, but I have a concern about the .055 overall length difference. Should I consider a different powder (AA 1680) which allows for a shorter (edited, I originally posted "longer") COL? or just use the 2.235 regardless what the comparator indicates?
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