.20 TAC BULLET SEATER QUESTION

[PMA3]

I have a Wilson seater die that leaves a circular ring about 1/4" down from the tip of 40 gr Vmax bullets. I can't feel any indent with my finger nail but I'm not sure whether this marring will effect the accuracy. Any other .20 cal users run into this problem with the Wilson seater and the 40gr. Vmax bullets?

 

[Tim s]

Generally, no problem. Depending on your brass this is a nice opportunity to consider a bushing die for slightly less resizing.

 

[mac86951]

I have a Wilson seater die that leaves a circular ring about 1/4" down from the tip of 40 gr Vmax bullets. I can't feel any indent with my finger nail but I'm not sure whether this marring will effect the accuracy. Any other .20 cal users run into this problem with the Wilson seater and the 40gr. Vmax bullets?

Bullet seating stem is the culprit. If it becomes a concern, polish seating stem.

I have a bullet in different caliber that is worse and I had to polish. Check your run-out, occasionally a poor bullet to seating stem fit can increase cause crokked bullet seating

-Mac

 

[lpreddick]

I have a Wilson seater die that leaves a circular ring about 1/4" down from the tip of 40 gr Vmax bullets. I can't feel any indent with my finger nail but I'm not sure whether this marring will effect the accuracy. Any other .20 cal users run into this problem with the Wilson seater and the 40gr. Vmax bullets?

i get this ring when neck resistance to bullet seating is excessive. if you look, there is a very faint ring on most all bullets. a ring that you can feel is WAY too much neck resistance and annealing is due. the ring area is not on the bearing surface, so it does not affect bullet engraving or performance. a really deep ring has deformed the bullet...bad.

 

[mac86951]

Good point, also valid.

 

[RockyMtnMan]

Seen that before with V-Max bullets. They do that sometimes because they have soft ogives that don't like a lot of extra seating pressure.

You can help this by:
1) Running a few strokes with a cleaning brush inside the neck of each piece of brass before charging with powder and seating bullet. This removes/smoothes out the carbon deposits in the necks of fired cases.
2) Annealing brass
3) Reducing neck tension.
4) Making sure case necks are chamfered and deburred correctly.

All in all, accuracy should not be overly effected by the indentation. But shoot the rounds on targets to be sure.

 

[PMA3]

The brass is NEW Lapua with the Dakota head stamp. It seems all new Lapua brass has tight necks and produce more neck tension than you want. After I shoot 50, I'll size them with my Redding bushing die and see if it's still a problem. I may also try a VLD seater stem from Wilson...I believe it will contact the bullet farther down the ogive and maybe not require as much pressure to seat, thus eliminating the circle.

 

[RockyMtnMan]

Well if you post all the necessary information in the first place, it's a lot easier to narrow down a problem now isn't it?

 

[lpreddick]

i get this ring when neck resistance to bullet seating is excessive. if you look, there is a very faint ring on most all bullets. a ring that you can feel is WAY too much neck resistance and annealing is due. the ring area is not on the bearing surface, so it does not affect bullet engraving or performance. a really deep ring has deformed the bullet...bad.

I now recall when I shot my 20 TAC a year ago, I too had quite a bit of resistance seating into new brass even though neck tension was not excessive(.002 neck expansion) . I put a tiney bit of case lube and the ring was barely noticeable. Once fired seated nicely.