Well, that's annoying. 257 Roberts and Barnes TSX.

[35WhelenAI]

VLD chamfer tool is what I use, but a standard chamfer tool has been fine as well when I used it. Main thing is the angle of the VLD tool is more shallow so it's as easy of a transition as possible for the bullet to ease into the case. Personally, I wouldn't lube anything with respect make seating easier.

From experience, I haven't seen any difference in field accuracy (or on paper with a hunting gun) when there was a "shaving" from seating the Barnes bullets early on (mid -late 1990's) before I started paying more attention to it. The bullet is engraved by the rifling and that causes far more change in the bullet than the small shavings that become (IMO) immaterial as the bullet is under tremendous pressure and smoothes any of those imperfections out by the time it leaves the bbl.

 

[SDHNTR]

Ive loaded tons of ammo with the case mouth over a cannelure ring. No crimp. No big deal, no ill effect. I seriously don’t even give it a second thought. Again, you have a neck tension issue, nothing more.

 

[A382DWDZQ]

Was also going to say that it might not be a bad idea to back the charge off a few grains once the neck tension is fixed.

 

[SloppyJ]

1000% a neck tension issue. You need to go with a smaller bushing, anneal it and resize, or do something else. Like above, I've never given a second thought to where the case mouth fell on a cannelure and it's never made a difference.

Think about how long the neck is, that entire neck should be around the same diameter so the leading edge of the case mouth is not the only location it has to "grab" the bullet.

What's the OD of the neck without a bullet seated compared to with a bullet seated? That's your neck tension. I have stuff i run very little neck tension on and have no problems. Like 1.5thou so you've gotta be damn near 0.

Since you necked it down from a different cartridge, I'm betting it's just not small enough.