A question for you reloading buffs. Will I gain any benefit from using the Lee factory crimp dies, in fact what are the benefits of crimping your loads?

Are you referring to rifle or handgun rounds? (The Lee FCDs are quite different for each.)

Basically, crimping helps
(1) hold bullets in place during recoil,
(2) retard bullet release to improve igniton, especially helpful with slower powders under lighter bullets.

To prevent a rifle bullet from being pushed back into the case in:

1. A tubular magazine
2. A autoloader
3. A hard recoiling caliber such as a .375

I crimp these into a crimp groove in the bullet.
I also turn the belled case mouth in after it has been expanded for cast bullets if it helps feeding.

I have never tested the effect on accuracy. If a load does not perform well I would suspect something else. I would never crimp expecting to improve accuracy.

Jimc, for rifle rounds, sorry I always forget to say as handgun not an issue since they were banned in the UK. I reload 243 win, 30-06 sp and 375 H&H.

G M

I have done three tests of loaded-at-the-same-time / shot-at-the-same-time identical loads with crimped and uncrimped loads using the LFCD to crimp. All three times the velocities increased by an average of 10 fps and the accuracy was better by an 1/8".

I use a light to medium crimp where the collet gaps in the top are not completely closed.

I agree with Woods, very close to my limited results. I started using the FCD for my milsurps and continued for our range rifles when my wife was still shooting, still do for myself. Why change what works.

If you go to the Accurate reloading main page, click on the FAQS page, you will find about half way down an article.
"The Effects of Crimping on Accuracy and Velocity"
Great info about crimping. I used to poo poo crimping. Now I crimp. Well not all the time, but a lot more than I used to.

muck

Gerry, sorry about your situation. If/when our Democrats figger how to do it we will lose ours too.