Ian
Notorious member
I've had it with crooked rifle case necks. It seems the one process for loading cast bullets that has no straight-line die option is expanding case necks, and I'd like to fix that.
Using bushing neck sizing dies or modified full-length dies minimizes the over-sizing typical of standard rifle dies intended for jacketed bullet use, but still I prefer to expand up at least a thousandth or two before seating because tests have proven to me it gives more uniform neck tension compared to simply turning the necks uniform and relying on the neck bushing to final-size the inside diameter to achieve the correct neck tension. Time for a better mousetrap.
What I had in mind is to use off-the-shelf, standard, inexpensive die bodies and make a sliding-sleeve insert similar to Forster's in-line seating dies, except instead of a bullet seating punch, have an expanding spud that aligns inside the sleeve at the top and has the necessary shape to do the job and put a minimal flare on the case mouth.
A Forster seating die itself would be a great place to start, but expensive. The sliding sleeve could be bored out slightly at the top for a larger-diameter spud than the seating stem, in order to make room for the slight bellmouth. The neck would be essentially un-supported, but the spud would be held snugly on-center by the sliding sleeve and thus the neck forced to be in the center of the case body.
The other option that springs to mind is the Lee Rifle Charging die, which costs $10-12 and has a step at the bottom that would keep the sleeve from falling out. A sliding sleeve, reamed with a chamber reamer, then bored at the top to slide over a precisely-fitted expanding plug, plus a spring, would be all that's necessary to add to the die. The aluminum cap could even be used to adjust the expansion depth.
I know, make one and show us Well, I thought I'd better check with the hive mind to see if there are any better ideas first. The biggest problem for me is boring a straight hole through a 2" steel rod and turning the OD exactly concentric. I guess I could just drill it through and then turn between centers with a faceplate and dog, just do half and swap ends. Ideas?
Using bushing neck sizing dies or modified full-length dies minimizes the over-sizing typical of standard rifle dies intended for jacketed bullet use, but still I prefer to expand up at least a thousandth or two before seating because tests have proven to me it gives more uniform neck tension compared to simply turning the necks uniform and relying on the neck bushing to final-size the inside diameter to achieve the correct neck tension. Time for a better mousetrap.
What I had in mind is to use off-the-shelf, standard, inexpensive die bodies and make a sliding-sleeve insert similar to Forster's in-line seating dies, except instead of a bullet seating punch, have an expanding spud that aligns inside the sleeve at the top and has the necessary shape to do the job and put a minimal flare on the case mouth.
A Forster seating die itself would be a great place to start, but expensive. The sliding sleeve could be bored out slightly at the top for a larger-diameter spud than the seating stem, in order to make room for the slight bellmouth. The neck would be essentially un-supported, but the spud would be held snugly on-center by the sliding sleeve and thus the neck forced to be in the center of the case body.
The other option that springs to mind is the Lee Rifle Charging die, which costs $10-12 and has a step at the bottom that would keep the sleeve from falling out. A sliding sleeve, reamed with a chamber reamer, then bored at the top to slide over a precisely-fitted expanding plug, plus a spring, would be all that's necessary to add to the die. The aluminum cap could even be used to adjust the expansion depth.
I know, make one and show us Well, I thought I'd better check with the hive mind to see if there are any better ideas first. The biggest problem for me is boring a straight hole through a 2" steel rod and turning the OD exactly concentric. I guess I could just drill it through and then turn between centers with a faceplate and dog, just do half and swap ends. Ideas?