@ 08:08 pm (GMT)
Nathan FosterHi Thomas, Marty who sized from 9.3 down to .375 is staying with us at the moment, enjoying some long range shooting.
This is a very good idea because you can swage the 162gr SST or A-Max from .284 down to .277.
Marty found a whack a mole set up better than using a home press. So no need for a threaded die- though marty is using a .222 sizing die reamed to suit.
The ideal die needs to start out at say .285. the entire projectile sits in (base of the bullet below, not flush with the top of the die). The die then tapers down to .284, then down to .277" Length of the .277" section only needs to be 10mm at the most (.400"). The die then needs an open section at the bottom so that after you knock the projectile through the .277" section, the projectile can pass down into a collection section (if that makes sense- like an hour glass).
The punch used to drive the bullet needs to be a relatively close fit with a wide head that stops the punch following the projectile right through and driving it into your work bench.
I think this is something Dave Manson (Manson reamers) could play with successfully if he has the time at some stage. So if you are dead serious, he may be a person to contact. He could make either a reamer or a completed tool. You can use me as a reference if you like- Dave will contact me directly to bounce around ideas if you want to proceed.
The next question is twist rate. A 1:9 twist is more ideal for these projectiles. Velocity can be a major factor- the faster you can drive the bullet, the less need there is for a fast twist (occasionally the opposite occurs depending upon individual bores). I have run 162gr bullets in 1:10 twist 7mm rifles of old. Some work some don't. Would be the same for the .270.
Win or lose, it will be a good project if you wish to pursue it Thomas.