Lee Factory Crimp Die = Pressure Changes ?

Hidalgo

Hidalgo

Well-known member
I have decided to use the Lee factory crimp die on my .223 handloads that I'm feeding the ARs. I have 100 loads completed and not crimped that are about 1-to-2 grains away from a MAX loading (depends on which book you look at), and I have ZERO pressure signs. I would like to crimp and use these loads if I can do it safely.

When I crimp these loads, I know this process is going to increase my pressures. Has anyone using this particular die noticed if the change is dramatic?
 
Richard has stated in his book that crimping will increase pressure minimally (I think he says as little as 100 PSI). I don't think you will see any noticeable difference.
 
From my understanding crimping the case will not have a dramatic effect on overall pressure, but will cause the pressure to peak earlier. Let us know if it affects the point of impact or accuracy.
 
I've used the Lee crimp die for several years for my AR and have not noticed any pressure signs, even at max loads. IMO you only have to do a light crimp, just enough to keep the bullet from being pushed back into the case when the round is chambered. With a bullet like the NBT or fmj which have a very pointed bullet, the round will chamber more easily as it will not usually hit on the feed ramps. I've found that if I load a soft point (that is usually more rounded) I usually use a little heavier crimp as they can stub their nose and compress while chambering. I've not noticed any change in accuracy with a crimp but I'm not a benchrest shooter.

Jeff
 
While I was experimenting with finding an accurate load for my predator pursuit, I loaded 10 rounds each of different bullets crimping 5 rounds and not the others. No pressure signs were noticed on any, but I also was lower than max load.
I did notice a tighter group with the crimped loads. The load that impressed me most was a 60gr vmax with 23.5 grs H335 at 2.25oal. The crimped load did 3 shots into two holes but off the point of aim by an inch left. The uncrimped shots were dead on but spaced on the one inch sticky target.
I chose to forego the extra crimp step in my process as there is enough neck tension to hold the bullet and the accuracy is more than acceptable no matter what bullet is used.
 
I don't shoot an AR, but havn't crimped rifle rounds since I started loading near 50 years ago. If your dies are sizing correctly there is plenty of neck tension to hold the bullet and a bullet should not be able to be pushed back into a case.

I've heard nothing but good about the Lee factory crimp dies though. Most of my dies are Lee dies.
 
Don't over crimp, you want a slight taper crimp is all. Just enough so you cannot push the bullet further into the case with hand pressure.
 
Back
Top