30-06 Variances

RCrosby

Should probably just honor the "lock" on the previous thread, but I'm curious that no one (or did I miss it?) mentioned the role that seating depth could play. I'm betting that, like most assumed, variation in ogives accounted for the pictured differences, but you could use the same bullet and show the same "results" by just varying the seating depth. No?

MG1890

Yes. It was showing ogive contact point versus case mouth. As I mentioned in my response, it was also showing "jump" to the throat.

nononsense

RCrosby,

There is nothing wrong with continuing a topic is there is more pertinent information or another related question. It's encouraged when the OP has more to add or a similar related question.

No one mentioned seating depth because most overall lengths of '06 cartridges is limited to magazine length or 3.340" per SAAMI. The part of the barrel stopping the bullet is the top of the lands or bore, which measures 0.300" in diameter. The bottom of the grooves diameter measures 0.308" or the major diameter of the bullet.

In the photos of the cartridges in the first topic, you are more than likely demonstrating the form factor of the ogive of the bullets since that is the minor diameter of the bullet's ogive and the length of the bullet showing is from 0.300 to the case mouth or 0.308".

Best.

tsr1965

Basically, the procedure for measuring bore or muzzle wear, of the 03A3', or Garand was meant to use one cartridge specification. The M2 Ball. By using just the specified cartridge, and assuming they were all the same, one could gauge how "shot out", their barrel of their battle rifle was. In no way was it meant to use 3 different loadings from 3 different manufacturers.

Best

EDIT 1

quote:The USA Breech Bore Gage was the only gage used to determine degree of bore erosion at the breech during service life of the M1 Garand.
There were no gages to assess bore condition at the muzzle.
Another important gage I never see mentioned here is a ring gage used to gage fit of the gas cylinder.

V35,

I do understand that there was no other actual gauge, to test bore wear, than the USA Breech Bore Gage. The system I described above was used in the field back then, and is still in use today by veterans and collectors. I have seen it many times ovewr being used at gunshops and shows.

v35

The USA Breech Bore Gage was the only gage used to determine degree of bore erosion at the breech during service life of the M1 Garand.
There were no gages to assess bore condition at the muzzle.
Another important gage I never see mentioned here is a ring gage used to gage fit of the gas cylinder.

sandwarrior

I don't know about "officially" but I've seen gauges that resemble a case with depth metric inscribed on the side of the "bullet".

I've also seen an M2 loaded cartridge being used and measured how far from muzzle to case neck. That's nothing more really than a rough gauge. And, all it really tells you is if you have to cut/re-crown the muzzle.