hankousmc
hankousmc
9 posts
Joined October 2013

Bullet seater problem

I have an RL 550B. I have used the same set of Dillon dies to crank out thousands of 223 rounds. I have used Sierra and Hornady 52 and 69 gr boat tail bullets exclusively. No issues. That is, until I bought a box of Sierra 69 gr TMK bullets. The seating die leaves a pronounced dent in the bullet in the form of a ring about a third of the way down the bullet from the tip. We're not talking about a dent only I can see. It's a very deep dent. I can use another bullet (Sierra Match King 69 gr) on the same run, and there is no dent. Some people have said I need to "turn the seater cup around, as it is not matching the shape of the bullet". I have taken the die apart several times for cleaning, and saw no "cup". I do not notice having to use any more force to seat this new bullet. This ring dent dramatically affects precision, as my groups have opened up from 1 inch to about 8 inches at 100 yards.
dillon
Administrator
dillon
3,222 posts
Joined July 2007

RE: Bullet seater problem

It sounds like the TMK bullet has a different angle to the ogive of the bullet, more like a VLD bullet. The seat stem has an angle machined into it. It sounds like a different angle is needed. I have some of those bullets at home, so I will have our engineer measure the angle of the ogive. Give me at least a few days to get some results.
Roosternew24
Roosternew24
1 post
Joined July 2013

RE: Bullet seater problem

I'm having the same problem. Is there a fix to this issue?
Rhed
Rhed
3 posts
Joined January 2017

RE: Bullet seater problem

Don't know if this would answer your question. And I know this is my first post. Just ordered my first press too yesterday. But been reading a lot in forums and the net before taking the plunge. And I did come across this. Hope this helps..

https://www.google.com/amp/s/sierrabulletsblog.com/2016/04/20/seating-concerns-with-sierra-tipped-matchking-tmk-bullets/amp/
dillon
Administrator
dillon
3,222 posts
Joined July 2007

RE: Bullet seater problem

We didn't find any appreciable difference in the ogive on the 69 grain TMK, and CFE223 powder. I had no marking on the projectile from the seat stem.
The heavier TMK .224" bullets do have a different ogive. They are much like VLD projectile. The Dillon seat stem will leave a visual mark around the ogive. No effect on runout or accuracy that we could determine.