I have been working up a load for my 6.5mm M91 Carcano using the 170gn, .270 diameter `Cruise Missle`mould from Midsouth Shooters Supply.
My initial attempts to get accuracy were to say the least, not encouraging.
The bullet gas checked to .268 and various charges of 5744 were totally inaccurate with every bullet key-holing.
I reduced the bullet weight to 150gns by removing the lower driving band with no better results.
I then switched to GM3 powder and the load was transformed (see pics). The cut down bullet gas checked as cast, has proved to work better than the full sized bullet.
Still some fine tuning to do, but the latest 150gn load looks very promising.
The load with the 170gn bullet still has some way to go, but judging by todays results at the range, there is every reason to suppose that it can be considerably improved.
ukrifleman