I observed something this evening that I've never seen before, but assume it due to variations across bullet lots from the same vendor.

Fully understand variations on bullets with lead tips. On ballistic tips my experience has always been that they are very uniform and I've always achieved a +/- .0005 variance on my average seating depth.

Well, this evening was plugging along on my 280AI loads (separate thread here) and had it dialed in a 3.330". No issues. It was consistent.

Well, I switched to a newer lot of Nosler 160 gr ABs and kept going. I came back and the cartridges were 3.325" with the new lot. Nothing else changed.

Have other folks seen this?

you do know they set up the machines by hand for each run of bullets.

sometimes the blems you get are the bullets made during the setup process.

they can vary a touch here and there as they work towards the final settings.
[and operating temp of the dies themselves]

or they can be pretty darn good from the check and move process right before the machines get going 100% up to speed.

I had a similar issue with 2 diff. lots of 168g TTSX Barnes.

..308

So, AH, is the issue in your opinion that Nosler changed the ogive, whereby the bullet seater engages it closer to the tip, thus pushing it farther into the case?

I had that problem with Hornady 139 gr 7mm bullets and the canelure was also in a different location.

quote:

Originally posted by sambarman338:
So, AH, is the issue in your opinion that Nosler changed the ogive, whereby the bullet seater engages it closer to the tip, thus pushing it farther into the case?

I wouldn't say they changed it, I'd say there might be a manufacturing variation.

slight anomalies such as die temperature, lube viscosity, air temp changes, and machine speed will make slight tolerances unavoidable.

the only way to have 100% consistency is to run the machine at the same speed at the same air temp and not have any wear on any of the dies or machinery.

so even doing that will only produce same-same for a short period of time.

quote:

Originally posted by Lamar:
slight anomalies such as die temperature, lube viscosity, air temp changes, and machine speed will make slight tolerances unavoidable.

the only way to have 100% consistency is to run the machine at the same speed at the same air temp and not have any wear on any of the dies or machinery.

so even doing that will only produce same-same for a short period of time.

I'm going to check to see if the seating depth vs the lands are different for these bullets.

Everything you change in reloading a case, can effect many things, for the most part and for hunting purposes none of it has any real effect on the accuracy or killing effect of the bullet, bullets, primers, cases, powder have a degree of difference, in severe cases it can create havoc..fortunately its usually not even noticeable...A group shooter, target shooter, all these things create anything from havoc to over reactionary problems..Only the shooter can make proper decisions on its effect..and normally he is the only one that can fix it or even figure it out..takes gun in hand to determine the problem..

You need to measure using a comparator. I have started measuring OAL using a comparator and a shell holder because sometimes primers are not fully seated (even if you use a uniforming tool).

Anything else is a waste of time unless you are loading for a rifle to be used at close range only (less than 300 yards)

What AZWriter said.

Remington core lokts bullets are never the same length you got to check the length on every bullet you seat., But I love those bullets.