The 308x45 Project - 30cal Hunting Round for the Recoil Shy, Kids or the Elderly
Wildcatting is a mental disease. A while back 223 Short/22 Mamba/24 Mamba team member George found a 308 Winchester take-off SS barrel locally for me. While not knowing what to do with it, I mulled over a few ideas, and came up with a 308x45 <--- I know that is a mixture of American and Metric measurements, but considering all other short 308 cartridge names in use, it is the only one that fit.
I hate recoil, and wondered if we shortened the 308 to the same length as the 223 Remington, resulting in the powder capacity to match the 22-250, could I have a decent hunting rifle.
George took 0.255" off the 308 chamber. George took 0.255" off a Lee FL Sizer die, and beveled the opening 60º. The Lee Collet Neck Sizer can be trimmed the same amount without interfering with its mechanics. I calculated that the new max body taper would be 0.003" less than the standard 308. Actually the same diameter made by a small-base FL sizer die. No change to shoulder angle, no change to neck length.
George removed the guts from the FL Sizer and ran a case thru, and trimmed the excess 0.255" off the neck. He added some threads to the barrel to bring it back to standard number of threads.
As the new neck is made from thicker bras than standard 308 necks, we had to make a fool-proof hand reamer to take a few thou out of the chamber neck, unless you want to internally ream every case after forming. Discussion later.
And there you have it.
My prediction is that it will make a really nice deer rifle with light bullets for the recoil shy, kids or the elderly, that will punch a decent size hole in the game.
Final Spec Drawing. Nice to have a wildcat that does not require a finish chamber reamer, an optional finish neck reamer, no custom dies just minor mods to off-the-shelf dies and only a small case forming and trim of about 1/4", and an existing barrel setback without a rechamber. The finished case and trimmed FL Sizer with beveled opening shown, next to a yet to be fire formed 24 Mamba.
Of course, if the wildcat sickness befalls us after we have produced this one, I see a 358 version in my future, especially as George pointed out the vast array of cheap bullets available along with the full range of regular 358 hunting bullets. Then of course there is the potential for a 264x45 using a 6.5 Creedmoor barrel with its less case taper, longer neck and 30º shoulder, if I did not want to go straight 260 Remington.
Last edited by briannmilewis; 02-02-2019 at 11:10 PM.
Reason: Image update