OK guys,..in the spirit of the "top secret accuracy tricks" thread,..here is another one.

What do you all do, use, or apply to control velocity deviations and extreme spread??

Just mentioned this in another thread. The Lee Factory Crimp Die reduces the velocity spread considerably.

NotRicochet
How would this work with bullets that have no canelure? Is it simply a crimping of the case mouth enough to increase tension or do I need the cannelure?

What about neck turning to a concentric wall thickness and using my bushing dies to get a .002" neck tension?

not ricochet is right about the lee die i use it too i also use a lee taper crimp die sometimes.

JustC, it crimps the case right into the bullet jacket, making a cannelure where the crimp goes. A smaller, shallower one than the pre-made cannelures, just custom-made to accommodate the crimp. Works great!

What I was referring to indirectly is a statement by Speer that their bullets should not be used with the Lee Factory Crimp Die, because it would "damage" their bullets. The cannelure produced by this crimp is very symmetrical and of similar depth to the engraving of the rifling in the jacket. If the Factory Crimp Die "damages" bullets, so does shooting them through a rifled bore. Other bullet makers haven't seen the need to issue such a warning. It seems that there is some personal bad feeling between Vernon Speer and Richard Lee. I've shot quite a few sub-1" groups with Lee-crimped Speer 200 gr. PSPs in my Weatherby Vanguard .300 Weatherby Mag.

How would this affect my "match" chambers and match prepped brass? Is there any downside with the tight chamber on my bench guns? Can the die be used in a 280 caliber designation to crimp bullets in a 280AI or would a custom die have to be ordered?

also,..does it affect case life? will the mouth need trimming more often?

Thanks

Don't know about how it'd work in a tight benchrest chamber. There you have no concerns about cartridge OAL or bullet security in the case, and can easily seat it out so it jams right into the lands. I think I'd do that and forget about the crimp, as is usual in benchrest shooting. Crimping doesn't seem to me to increase the need for case trimming much, but the extra working of the case mouth is bound to eventually result in neck cracking, perhaps prevented by periodic re-annealing of the neck.

My shooting may be mostly off of a benchrest these days, but it's all with hunting rifles. Benchrest shooting is a whole new ball game!

I have been thinking about the LFC and the pressure applied to produce the crimp. I am wondering if I should control the force better than the "muscle memory" method I have been using, like maybe hanging a weight off of the press handle? worth a try, or too anal?