11-21-2023, 05:07 AM
scott>' Wrote:My loaded rounds are getting longer when the action slams closed on my gun. Im using Lee dies, new starline brass, 105 mkz bullets, and 8208 powder. Ive sized the new brass to get any dents out of the necks. The loaded rounds are 29gr and maybe slightly compressed. Do I need more neck tension, or should I think about different dies? Are compressed loads more likely for this to happen? Thanks for any help
I had to overcome this same problem. There are several variables I found added up I had to...
- clean the neck ID from any case lube from the sizing process before seating, I used ISO alcholol on a qtip, frustrating slow...
- I was only getting .001" neck tension.... Ordered another expander mandrel and turned it down .002 to give me .003" neck tension.
- Crimp with Lee Factory Crimp die
- Compressed loads.... Fill case with powder then vibrate it before seating to settle powder and prevent compression. Im using 32.2gn of A2520 so I'm not certain yours is compressed mine I think is 100% case fill (after vibration) though but measuring that is not an exact science but its surprising how much vibration will settle powder.
My litmus test was to chamber the round 5 times without any inertia drift over .003", after those steps they passed.
What I do to assure it wont happen after 5 times is slowly close the bolt and use the forward assist to chamber the round, doing that I had zero inertia drift after dozens of chamberings over 10 days of hunting. No need to slam it home to load it for a hunt.