Savage bolt gun, clip magazine? You may be fine without the roll crimp.
I use to load for a Martini action 32-20, currently loading for a Winnie 92 25-20 and both cases only give the slightest taper crimp. Mostly in the interest of case life, and both do group a little better.

If you want to stay at high end loads best stay with "J words", be ready for your cases to streach real fast.
Hope yah got a trimmer.

But I reckon the 32-20 and 25-20 show there true magic when allowed to relax and throw cast bullet with a good meplat out at around the 1400fps range.
Will kill small game just as dead, without spreading the animal accross the pasture.
Moderate loads, kind on cases, kind on old guns kind on hearing and don't clear the whole area out.

If you need flat shooting, another caliber may be in order. JMO.