Variations in OAL

[chuckshoots]

I've seen it before. They'll still go bang. Not that you should tolerate it, but you dont need to go pulling down everything.

The bigger problem is the opposite one, where you dont have ENOUGH neck tension. Sounds like you have more than enough.

Awesome thanks. I went and cleaned the inside of the necks after noticing it and it is pretty sufficiently dealt with.

[Bill Steele]

...Is it odd when you seat the bullet to see some copper from the jacket scratched up off the bullet? I am thinking it is from grime on the inside of the case neck, as it only happened on a few.

Two things that may or may not have been covered. Use a chamfer tool and chamfer the mouth of each case. I chamfer each case, even when using boattailed bullets. It doesn't take a lot, can be easily done by hand. After everything is done and you are just about to start seating primers, etc., use a bore brush to clean the inside of each case neck (like you learned).

Sounds like you are well on your way.

[CobraRed]

I actually "jam" or use an OAL that seats on lands (2.866 Amax .308). I do find a rather consistent measures off the meplat after some seating tinkering, but a ogive measure is best.

[gemini1]

aaaaaaand you might want to know your gun max OAL, the point where the ogive does start to contact the lands. Easy to measure. make a dummy round, chamber it, and push a cleaning rod against the tip and mark the muzzle on the rod. Then put JUST a bullet into the chamber and use something like a dowel or pencil to push the bullet into the lands, and measure again with the rod. Add the difference at the muzzle with the OAL (from the ogive) of the dummy and you have your max OAL (measuring the ogive) before the bullet contacts the lands.

Good info to know.

I tried doing this, and I got 0.118 5/100. The dummy round measures 1.954 5/100 from ogive to base, so adding it gives me 2.073. Does this sounds right for a 5.56? The dummy round tip to case is 2.252 5/100

Also, what about the case length? isn't this another issue to consider? (whether the sizing die was screwed in to proper depth?).

Another method I read at THR was to use/insert a rod in the barrel and get the measurement with the bolt close, then remove the bolt and insert a bullet in the chamber and measure again. Trying this method, I got a COAL of 2.367 5/100. Again, does this sound right for a 5.56 cal?