In general terms, how much does crimping effect case pressure, specifically with the Lott?

For background, I have been using a light crimp, enough to take out the bell in the case mouth at least, but honestly have a hard time with the bullets I'm using (which have a small cannelure/grove), telling a light crimp one from a heavier one. A few of the rounds I loaded at the top end of the limits are showing signs of case separation towards the top of the case. Head space seems okay (I'll have it checked when at the smith), primers not leaking or crushed, bolt a bit sticky. I'm backing off the load, but curious if I should also lighten up on the crimp on the lesser load. Thanks!

I seriously doubt it effects PEAK pressure at all. Since peak pressure occurs after the bullet has left the case.

There have been "studies" done that suggest crimping supports more consistent powder ignition and burn, therefore is more accuracy friendly.

ASS_CLOWN

I would approach the crimp carefully if I was at a real sho nuff max, otherwise I'd pretty much ignore it.

I have never experienced a noticeable pressure increase due to a crimp but I cannot rule it out.

I think the whole point of the crimp is to keep the bullet from getting battered deeper into the case which could really boost the pressures. It also can help keep a bullet from getting spit out of the case from rolling/bouncing around in the pickup truck/land cruiser in the heat. So long as the case isn't so long that it is getting pinched into the bullet by the chamber/neck the crimp shouldn't cause any trouble. Daddy Ray is so right about not going for max loads; they are hard on you, hard on the gun, and hard on the cases.
JCN