Probably a dumb question, but can I use a 308 case gauge to determine correct shoulder setback for a 7mm-08? After checking the design specs for both 308 and 7mm-08, I believe the answer is "yes", but to relieve any nagging doubts I'd like to hear the answer from the pros. Can I assume that the answer would be the same for other cartridges based on the 308 Remington cartridge such as the 243, 260 and 280? Thanks.
Using a 308 case gauge for 7mm-08?
- Thread starter oldfudd
- Start date
Yep, will work fine as body and headspace dimensions of 243/260/7mm08/308/338Fed/358Win are all the same.
Be aware case overall length varies amongst these, however.
Also, the 280 cartridge is not in this same family. It is in the 30-06 family.
Be aware case overall length varies amongst these, however.
Also, the 280 cartridge is not in this same family. It is in the 30-06 family.
Thanks for confirming what I assumed. Yep, I agree that 280 belongs to the 30-06 family along with 270 and others (for which I can use a 30-06 case gauge).
if you don't have a specific case gauge, slowly back away from the reloading bench and go get one.
cheers.
cheers.
Actually 270/280/3006 isn't as straight forward as the 308 family...mainly because there was never a SAAMI recognized 270-08 chambering.
See, a 308 cartridge simply won't fit in a 7mm08 chamber, so there's no danger in a mixup. A 7mm08 cartridge fired in a 308 chamber isn't dangerous either.
However, 270 (.277") and 7mm (.284") are close enough you COULD jam a 280 cartridge into a 270 chamber and fire it (with devastating results)- IF the 280 didn't have ~.050" longer headspace dimension, which it does.
This is a common phenomenon in cartridge families that include both a 270 and 7mm variant. (And maybe ones with both .257" and .264" variants also....not sure)
...just FYI
Last edited:
HodgdonExtreme -- thank you for your words of caution. I'm approaching this kind of like when using my Giraud trimmer (recent topic on using the trimmer cartridge/shoulder fixture for similar cartridges with the same shoulder angle). I agree, the 308 family is pretty similar. For 30-06, I'd always check the cartridge design specs, including shoulder angle, before relying on the 30-06 case gauge. All -- I appreciate the feedback. Thanks again.
