Y'all notice in Ben's second photo above, that he has gently deburred the inside of his case neck (before expanding), just knocked off the sharp edge. That allows a minimum of neck expanding to be effective.
I use custom M-die type expanders after deburring, and can start a bullet in the neck without being able to discern any space between the bullet and case mouth, yet there is no scraping.
I load 0.452 bullets for cowboy shooting and use a Buffalo Arms expander with diameters 0.450/0.454. In new or recently annealed cases, a bullet base just snaps into the mouth of the neck and can be seated cleanly. Case necks need annealing when it gets fussy to hand start a bullet.
NOE makes a great expander and flare tool. These fit into a Lee expander body.
http://noebulletmolds.com/NV/index.p...l8fl54o9p1aft3
".313 x .309 Exp. Plug To use with Lee Universal Neck Expanding Die Turns it in to a true neck expander like a Lyman M-die. Use a expander that is .001" over your bullet size for best fit."
You can buy what ever size you want to expand the neck, it also puts a flare on the case mouth.
I use it for my 30-06 XCB (14 twist) and have pushed it to 2850fps with no leading.
I know I am late to this party but find the topic interesting. I also own a Marlin 336. I was of the impression that cast boolits were to be avoided in micro groove barrels. Are folks here having success shooting cast from micro groove barrels? Will down loading into subsonic velocities help?
Thanks. Any help is appreciated
Ben, are you sure that's American Walnut for the "grip" on your tool? Looks suspiciously like American Sycamore to me.
Ahh, the Marlin 30/30 MG again. Need 310-311 boolits, proper expander, flare the mouth a tad, 2 coats (thinned) LLA. GC boolit above ~1500 fps with COWW. PC will add a couple thou. to dia. if needed.
results like this.
Attachment 196541
Whatever!
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |