Blackmon .308 RBT dies.

[just bill]

On the core seating die, there is an adjustable punch. When I received the dies, I immediately proceeded to form some boolits, which all turned out great, 1.32" to 1.40" and 212 gr. to get 225 gr. I am curious as to this adjustable punch. Does adjusting it effect the boat tail in some way. Most of the dies I've seen don't have this type punch. It appears to Shorten the boat tail if adjusted. I just don't want to ruin a good thing by adjusting it, on the other hand I want to get the maximum performance since these dies are for long distance shooting out of a 300 win mag.

Thanks,
Bill

[Utah Shooter]

If they are like my dies the adjustment is to make sure you get the right amount of pressure to expand the jacket properly. But it seems to me perhaps I am not understanding the question. Photo?

[aaronraad]

Hi Bill

The adjustment is handy so you can match the length of your boat-tail out of the core seating die, to the boat-tail punch on your point form die. There is an optimum core seat boat-tail length that will give you the best finish once pointed. Otherwise you would need to have an ejection pin trimmed to the correct length to make a longer boat-tail. Highly difficult to modify the ejection pin to make a shorter boat-tail. ;)

Just don't forget to adjust the depth of your core seating punch and even punch diameter (jacket taper!) if you make an adjustment, to get your ideal seating depth and pressure (lead line). Consequently you might also have to adjust the depth of your boat-tail punch on the point form die, so you still get the ideal meplat diameter and appearance following reliable ejection.

Cheer
Aaron