Ok. This just rang a bell in my head, but I just got a Stoney Point OAL gauge and a bullet comparator. I measured the OAL with the gauge, and then used the comparator to measure the "OAL". 2.400 inches with the comparator. Then, I measured the "OAL" without the comparator, just on my caliper blades, and got 3.042 (.308 WIN 165gr Nosler BT in a Rem 700SPS). Now, correct me if I'm wrong, because I am a fairly new reloader, and often need things spelled out for me.

That is because the comparator measured the distance to the orgive of the bullet, and using the blade actually measures to the tip. This is safe to do, because the tip may protrude past the lands, but there is no danger until the orgive reaches the lands.

If I'm right on, then this is a dumb question, but if I'm wrong, I am not using the comparator properly.

Thanks guys

Hey dogs

Just loaded some myself, and if I understand you correctly you are on the right track. The overall length from case head to bullet tip on my 338 win mag 225 gr TSX bullet was 3.360". Since I want to seat the bullet .05", the OAL length I am looking for is 3.31". I seat the first bullet to that OAL then install the comparator onto the blade and rezero (the comparator should be exactly 1") and took the measurement to the ogive and it measured 3.70". Then I seat all the other bullets to that 3.70" comparator length because measuring to the ogive is more meaningful than measuring to the tip of the bullet which could be off.

Hope this helps

You`ve got it right with a cavet, if the OAL from base to tip is longer then the mag you will need to seat deeper or use your rifle as a single shot. The 308 has a SAMI max OAL of 2.80" but some mags are longer if yours is you are OK, if not you may want to seat to max OAL lenght or deeper.

quote:

Originally posted by devldogs:
...I just got a Stoney Point OAL gauge and a bullet comparator. ..

The very best of "luck" to you.

quote:

Originally posted by devldogs:
...the tip may protrude past the lands, but there is no danger until the orgive reaches the lands.

I'd say the tip ALWAYs (or almost always) protrudes past the lands. But there could certainly be "danger" before the ogive reaches the lands.

You are right though in what you are doing. The only reason I ever check the OAL to the tip is just to make sure it fits in the magazine. The "useful" OAL is base to Ogive. And that is the ONLY measurement you should use when looking at seating depth, and each loaded round needs to be checked since not all bullets are identical. I either sort the bullets before I load them, or when I start the seating process, I always back out the competition mic about 7-10 thousandths before seating the next bullet, then check each one in the RCBS Precision Mic.