Loading Sierra 69 MK in 223, OAL variations..

[HSMITH]

I just got done loading some Sierra 69 grain Matchkings in 223. Setup is a Rockchucker, FL sized and trimmed brass, Hornady New Dimension seating die. 4 out of 5 or so would seat to the desired OAL while one would be short or long by as much as 8 thousandths. I loaded some 55 grain Gamekings and the most variation was a thou and a half over 100 rounds with the same setup. I had the same problem with Hornady 68 Match HP bullets also, but with them only 2 of 5 hit the right OAL with up to 12 thousandths of variation each way.

Am I overlooking something simple? Press is clean, dies are clean and tight, etc.

Thanks for any help you might be able to gve.

 

[Sheldon]

Those match hollowpoint bullets will give a lot of variation in length due to the way they're made. If you used a measuring device that measured off the oglive of the bullet instead of the tip you would see a much more stable measurement. Stoney Point makes such a tool as does Sinclair.

Here's a link to the Stoney Point site with the tool.
http://www.stoneypoint.com/comparator_index.html

 

[Steve Smith]

HSmith, I am kinda surprised that you have been around as long as you have here and didn't read this. Oh well, that's fine. Match hollowpoint bullets are quite inconsistent in total length. The base to ogive is much more consistent, and you should be using an ogive measurement for loading them. If loading for an AR, you first find one of the most LONG bullets in your lot, load that to less than 2.260" OAL (base to tip) so that it fits in the magazine (I usually go 2.250"). Then take an ogive reading from that with a Stoney Point OAL gauge (or equivalent) and then measure the rest of your ammo with that. Your readings should be MUCH more consistent.

If you plan to shoot 80 grainers, let me know, you need to do more work.

 

[HSMITH]

AHA!!!!! Thanks guys, I was overlooking something simple. I know this but for some reason it never dawned on me, DUHHH!!!!!

Steve, no 80's in this gun as it is a 1 in 9 barrel. I think 69's are about as heavy as I will try, especially if I can get it shooting well. The next one though will be a service rifle type with a 1 in 7. I have been eyeballing the 'service rifle' upper from White Oak.......