Originally Posted by 10 Spot Terminator
This is the first I have heard of a roll crimp in rifle dies . As it is not adjustable as in pistol dies I am not understanding how this works. A slight bevel in a pistol die has to be adjusted to contact the rim of the case during the last couple thosandths ot the total travel on the bullet seating operation to work. As rifle bullet seating is all over the place due to the bullets being seated by the ogive rather than the bullet nose in a pistol , at what point does it roll the neck ? All I have read states rifle cartridges have no crimp but tension is controlled by the inside diameter of the necks when sized and that to alter this requires changing of the expander ball diameter in the sizing die. You can add a crimp such as Lee offers in its factory crimp die but it is not a true roll crimp design either but a multi point adjustable pinch style on the case neck done in a seperate operation after bullet seating. As for taper crimp dies they are available although not common for several rifle cartriges designed to feed in semi and full auto rifles with detachable box magazines and lever guns with tube magazines as well to promote mininimal bullet runout and better ammo feeding to the firearm. If there is a resource to get info as to the rifle roll crimp I would be grateful if you would point me in the right direction as I am always looking for more food for thought when it comes to reloading. I strive to build the best loads I can with the help of those like yourselves who can teach me how .
Pull out any of your reloading manuals and double-check the bullet seating instructions for bottleneck rifle cartridges. Or check the instruction sheets for any set of dies that you've got on the shelf.
Here's a PDF of the RCBS instructions. http://www.rcbs.com/downloads/instru...structions.pdf
Every brand of bottleneck cartridge seating dies that I've dealt with have a built in roll-crimper shoulder at the top of the seater die. The adjustment procedure is basically the same as it is for a roll crimp on a straight-walled case or the taper crimp on a straight-wall case.
If you're not crimping, you don't thread the die down fully touching the case and then adjust your bullet seating depth using the seater plug screw.
If you want a roll crimp, thread the die into the press just as you would for no crimp and seat a bullet to your desired COAL. next step, back off the seater plug a couple turns and run the cartridge back into the die and thread the die down until you feel the case mouth contacting the inside of the die. Thread the die in just a bit further and appl your crimp...adjust a bit as needed to get however heavy of a crimp that you need. Tighten the lock ring. Run the seated and crimped cartridge up into the die again and adjust your bullet seater plug down until it's touching the bullet. That is the basic setup procedure...make minor tweaks to either the die position or the seater plug position as needed to get the bullet seated and crimped in one pass.