Lee Crimp Die & accuracy

[SD Shooter]

I have read that the Lee Crimp Die inproves accuracy because it produces uniform tension of the case mouth on the bullet. I purchased two crimp dies, one in 300 Win Mag and the other in 375 H&H. The 300 Win Mag shoots under an inch consistently. The 375 H&H has not settled down to any better than 3" at 100 yards with 220 gr. bullets. With 270 gr. bullets, the 375 H&H is more like 5 inches at 100 yards. Same with 300 gr. bullets.

I know that I still have a lot of work to do on the 375 trying to work out the best loads.
Just interested in other opinions about the crimp die.

Thanks in advance,

SD Shooter

[rost495]

For it to do its work correctly you'd have to have perfect brass. IE all same neck thickness, coencentric thickness, all exact same case length and so on. FWIW IMHO its a crock. I've loaded so many rounds and never crimped(excepting revolver rounds) and never had an accuracy problem. I suspect the issue on the 375 is you have not found its sweet load yet. And with the 300 you have that load, it has nothing to do with the crimp.

Jeff

[handloader1]

I don't crimp anything I do not have to. Good luck.

[tula9130]

I agree with rost495 on the .375 H+H issue.However have to disagree about the crimp die.Cases don`t have to be perfect for it to do it`s job especially on case length.It does not rollcrimp on the case mouth.It also won`t crush a case as with the crimper built into most seating dies.

Opinions will vary.But with every caliber I load for I have the FC die.It is worthy of a test with crimped vs uncrimped at the range under good conditions as a controlled experiment to find out yourself.

[johnch]

I load lots of 223 ammo for my AR 15 . I have found that the Lee crimp die dosn't affect accuray but changes POI slightly.
In my revolver loading I only crimp with the lee crimp die.
The crimped rnds will have less chance of bullet setback in your 375.

[1mile50]

I know a guy, named Matt. Matt shoots a .375 H&H Ruger #1, trigger work, barrel cryro, integral muzzle brake machined in, otherwise as came from factory. Matt shoots 1/4 moa at 100 yards w/this rifle. Matt carries a 3 shot .050" group around in his pocket. Mat works on his loads for a year or two, before he is satisfied. Matt said on this very subject "Crimping a rifle round destroys accuracy."

[James B]

I have been very happy with the FC dies. In all the calibers that Ihave tried it in, (quite a few), It always increases consistancy over the chronograph. I use a very light crimp but it works for me. One thing is for darn sure, it has never made a round less accurate in my testing.

[tula9130]

Here`s an interesting link.
[link]http://www.accuratereloading.com/crimping.html[/link]

[1mile50]

Saeed is a hunter and shooter of vast experience. I read Saeed's page on crimping some time ago. I can agree with it, up to a point. Point is, accuracy and expectations of accuracy are both relative. I have a Lee Factory Crimp in .223 that I have used with good results in a semi-auto rifle. This rifle bangs the round pretty hard while loading and the Lee die prevents the bullet from setting back. The crimped rounds group well, also.

Matt shoots 1/4 moa at 100 yards w/this rifle.

I didn't mean Matt shoots 1/4 MOA with his .375 H&H on a good day. I meant any day.

"Crimping a rifle round destroys accuracy."

Matt meant, if he were to crimp, he would not be getting 1/4 MOA. Matt might very well get 1/2 MOA with a crimp. But that's still destroying his accuracy. Matt's expectations are higher than most.

Crimping can for sure narrow your extreme velocity spread. The crimp keeps a momentary grip on the projectile, ensuring the projectile's release happens farther along the pressure curve, meaning the powder burns more evenly. Also, the crimp keeps a more consistent grip on the bullet than just a sized brass neck. A key to accuracy is consistency.

But, there is more than one way to skin a cat. Better ways too. Ask a 200 yard benchrest shooter if he crimps. Or, go to a Benchrest message board and bring it up. These guys are infamous for trying anything or doing anything, just to shrink groups down a few thousanths or so. They spend more time on the details than you would believe. Go ahead, ask them. Depending on the type of projectile and the rifle's chamber they will get their consistency by annealing and using bushing neck sizers on neck turned brass or loading the projectile to the lands, or loading the projectile measurably jammed into the lands.

If they are crimping, they aren't winning. You can't squeeze a Berger VLD or similiar, and make a more accurate round.

[tula9130]

Good point 1mile50 and one that should have been brought up,which you did.I do not shoot competition matches.Just an average hunter,shooter,reloader.Ammo for field rifle use and bench rifle use are two different things altogether I know.Point taken.

I have a stock Ruger#1 in 243Win.I cant reach the rifling with a 70gr NosBT and keep a raesonable amount of bullet in the case neck IMO.That is one reason I use the die.