Hello

Sorry if this information has been posted before (I did try a search!). I'm trying to work up some loads for my M1910, using brass formed from various other calibres (mainly 30-06, but some others as well). I have a problem with neck tension - some rounds I can just push the bullet back into the case (this happens in some rounds with most makes of brass, including some once-fired original Kynoch brass). So...

Do I crimp the cases?

If so, what is the recommended "trim-to" length?

Bit off-topic but does anyone know of a source of the Hornady 270gr RN bullets? Or another make?

Many thanks.