Crimp in the lube groove?

[tsubaki]

I’m testing for use in a couple of 300AAC firearms a powder coated Lee C309-160-R.
Using the crimp groove places the OAL at about 1.855”.
Measuring the chambers I’m getting a max OAL of 1.955” which is right in the upper lube groove.
Is there any reason I shouldn’t crimp in the lube groove?

[Dusty Bannister]

If that is a shingle shot firearm you are testing, why crimp at all? Neck tension should do all you need.

[davidheart]

I'd imagine your crimp won't have the same sort of strength in the lube groove as it would in the driving band. However, as Dusty mentioned, if you're using a single shot or bolt-action, you generally don't need to crimp at all. If you're using a semi-auto then you certainly should crimp at the location of the boolit you'll have the greatest strength and repeat-ability.

[Rcmaveric]

I crimp my .270 win and 30-30 bullets both in the first lube groove. As long as the round chambers and the action cycles it will be fine in my experience. I like to seat the bullets .002 of the lands so makes them long.

As noted previously semi autos, tube fed and revolvers are about the only guns that really need a crimp. I have since stopped crimping for my bolt actions that includes the .270 win. Neck tensions are good enough to hold the pills in place.

Sent from my SM-G925T using Tapatalk

[tsubaki]

It’s intended to be for both a single shot pistol and an AR platform IF it will cycle in the AR.
Some AR platforms are reputed to have a problem with short/round nose projectiles. Reason for wanting to utilize as much length as possible.

[popper]

I don't crimp (in a groove - just FCD to remove the 'bell') for 308, 30/30 or BO, ARs or levergun. None of my moulds have a crimp groove. I don't shoot revolvers, all my rifle moulds are FP..

[Lloyd Smale]

did it all the time with cast bullets designed for 4570s using my #1 458. It had such a long throat no matter how far you seated bullets out you seldom reached the lands.