nfg
04-18-2012, 04:12 PM
Got a few questions on bullet designs for large caliber, 60 - 73/20-12ga slugs/bullets for all you "sluggers" out there.
I ordered an Aluminum 2 cavity, 700 gr, 2 groove - 1 crimp groove, 0.500" long truncated cone nose, 50% meplat mold and my caster is having problems producing well filled out bullets...they are wrinkled, frosted, sprues pulling out instead of cutting smoothly, etc. His 45-50 cal bullets come out great but this one is causing a bit of a ruckus so I'm wondering if it is my bullet design. :violin: :confused:
The bullets are ~662gr to 668 gr as cast for 50 pieces with ~70% running 666-668gr and are running ~1200-1600fs out of my scoped NEF 20 ga USH with plastice cases, but the accuracy is also running 3-4" at 15 yds. That "could be/probaby is" from several reasons...I haven't tried any factory ammo yet to get a baseline...so...:oops:...I will try several brands now that the snow is leaving.
My questions as to design are...
Radiused or angled grooves and groove angle/widths?
Fewer wider bands vs more thinner bands?
Equal lenght/width bands vs wide grooves/narrower bands or opposite?
Nose profile...TC, SWC, RN, beer can and nose length?
Meplat ratio?...I've read somewhere that 65-75% makes for a more accurate, non tumbling bullet.
Mold material...brass, Iron, Al for WW plus Tin metal.
I've also been playing with 5/8" 360 brass with several designs that are totally labor intensive to produce on my manual lathe not to mention the cost of brass these days.
Thanks for any help/comments/advice. :awesome::cast_boolits:
I have a 600-750 gr SWC similar to 38 - 45 cal pistol target bullets and a couple of flying beer can designs similar to the old 730gr Dixie slug Terminator running 500-650 gr that look great on paper and I will be ordering a brass mold for one of them as soon as I get some feedback.
Thanks again for your help.
I ordered an Aluminum 2 cavity, 700 gr, 2 groove - 1 crimp groove, 0.500" long truncated cone nose, 50% meplat mold and my caster is having problems producing well filled out bullets...they are wrinkled, frosted, sprues pulling out instead of cutting smoothly, etc. His 45-50 cal bullets come out great but this one is causing a bit of a ruckus so I'm wondering if it is my bullet design. :violin: :confused:
The bullets are ~662gr to 668 gr as cast for 50 pieces with ~70% running 666-668gr and are running ~1200-1600fs out of my scoped NEF 20 ga USH with plastice cases, but the accuracy is also running 3-4" at 15 yds. That "could be/probaby is" from several reasons...I haven't tried any factory ammo yet to get a baseline...so...:oops:...I will try several brands now that the snow is leaving.
My questions as to design are...
Radiused or angled grooves and groove angle/widths?
Fewer wider bands vs more thinner bands?
Equal lenght/width bands vs wide grooves/narrower bands or opposite?
Nose profile...TC, SWC, RN, beer can and nose length?
Meplat ratio?...I've read somewhere that 65-75% makes for a more accurate, non tumbling bullet.
Mold material...brass, Iron, Al for WW plus Tin metal.
I've also been playing with 5/8" 360 brass with several designs that are totally labor intensive to produce on my manual lathe not to mention the cost of brass these days.
Thanks for any help/comments/advice. :awesome::cast_boolits:
I have a 600-750 gr SWC similar to 38 - 45 cal pistol target bullets and a couple of flying beer can designs similar to the old 730gr Dixie slug Terminator running 500-650 gr that look great on paper and I will be ordering a brass mold for one of them as soon as I get some feedback.
Thanks again for your help.