Lee Factory Crimp
- Thread starter FullDraw
- Start date
Used one for a 7mm Rem Mag for a decade. Excellent results with both 150 grain Ballistic Tips and 139 grain Hornady BTSP's.
I have used them on a few different occasions. Quite some time ago I did the usual load work up with un-crimped bullets to find the top 3 load for several rifles. Then I took these top 3 loads and tried them with crimped bullets.
The only time my groups got worse was with a load for a CIL 830 in .222rem. That rifle just didnt like the crimps. In most other cases the uncrimped vs crimped loads stayed right around the same accuracy. (Hard to tell 1/10th inch changes in accuracy with my ####ty scopes and average shooting abilities)
My 7mm08 groups actually got quite a bit better with the 154g RN loads. But stayed the same with the 139gSST's.
Try it and see. Thats about all I can say.
I havent used the crimp since I started neck-sizing only. I'm relatively new to reloading (3 years) and I have found that neck sizing and playing with seating depth has provided much bigger improvements in my groupings than anything.
The only time my groups got worse was with a load for a CIL 830 in .222rem. That rifle just didnt like the crimps. In most other cases the uncrimped vs crimped loads stayed right around the same accuracy. (Hard to tell 1/10th inch changes in accuracy with my ####ty scopes and average shooting abilities)
My 7mm08 groups actually got quite a bit better with the 154g RN loads. But stayed the same with the 139gSST's.
Try it and see. Thats about all I can say.
I havent used the crimp since I started neck-sizing only. I'm relatively new to reloading (3 years) and I have found that neck sizing and playing with seating depth has provided much bigger improvements in my groupings than anything.
crimp vs no crimp is a recurring argument. It does not increase pressure significantly, however it tends to have a more uniform bullet release pressure. Some people say it is more accurate that way, some say it is more accurate without crimping.
The best way to find out is to crimp and not crimp your pet load.
And if you are going to use an autoloader or handle them in a non-bench shooting manner, it is probably best to crimp them.
The best way to find out is to crimp and not crimp your pet load.
And if you are going to use an autoloader or handle them in a non-bench shooting manner, it is probably best to crimp them.
- Location
- The Conservative part of Ontario
I think there is a difference in the powder you are using, and the cartridge as well.
My wife's 44Mag gets much more uniform velocities if I use a factory crimp with H110. But if I load 4227, it doesn't seem to make much difference.
It's most noticable when she's shooting cast bullets. H110 is hard to ignite, so I'm thinking that's where the crimp helps out.
I use the Factory crimp on 30-30 too, really helps to get a uniform crimp on a cartridge for a tube mag firearm.
I also use it for the BLR. it helps feed more smoothly. Although in this case, a good outside chamfer would do as well.
My wife's 44Mag gets much more uniform velocities if I use a factory crimp with H110. But if I load 4227, it doesn't seem to make much difference.
It's most noticable when she's shooting cast bullets. H110 is hard to ignite, so I'm thinking that's where the crimp helps out.
I use the Factory crimp on 30-30 too, really helps to get a uniform crimp on a cartridge for a tube mag firearm.
I also use it for the BLR. it helps feed more smoothly. Although in this case, a good outside chamfer would do as well.
- Location
- The Conservative part of Ontario
Seat bullets to normal OAL, but don't crimp.FullDraw said:
Run them into the factory crimp die, and just bump the press handle lightly when the ram hits the top of the stroke, (as limited by the Factory crimp die) presto, crimped. Does NOT matter if the bullet has a cannelure or not. It will crimp them anyway.
It's very fast, but it is a separate operation.
I see no need for any crimp on a bolt gun or single shot, the interferance fit between bullet and case neck is more than adequate for most guns. The times you do need it is for pumps, lever guns or semi autos with tube feed magazines when the mass of the cartridges in front can push back the bullet behind them when the rifle recoils. The other time you need to crimp is with hot loads in magnum handguns where the recoil of the revolver itself is enough to shift a bullet due to inertia of the heavy bullet and the force of recoil.
Trying to crimp any case on to a bullet with no cannelure is doing nothing except unnecessarily working your brass, it accomplishes nothing in terms of securing your bullet.
The advantage of the Lee Factory Crimp die is that it crimps with a primarily inward force on the case mouth. Most other seating dies will "taper crimp" but the force is more downwards at about a 45 degree angle. This downward force can deform the case shoulder if a bit too much crimp is applied. The other problem with taper crimp dies is that getting a consistent crimp is much more dependant on consistent overall length than a Lee factory crimp die is.
Trying to crimp any case on to a bullet with no cannelure is doing nothing except unnecessarily working your brass, it accomplishes nothing in terms of securing your bullet.
The advantage of the Lee Factory Crimp die is that it crimps with a primarily inward force on the case mouth. Most other seating dies will "taper crimp" but the force is more downwards at about a 45 degree angle. This downward force can deform the case shoulder if a bit too much crimp is applied. The other problem with taper crimp dies is that getting a consistent crimp is much more dependant on consistent overall length than a Lee factory crimp die is.
- Location
- The Conservative part of Ontario
762shooter said:
The Lee Factory crimp die will actually crimp a non canellured bullet. It puts a "canelure" in the bullet during the operation. I pulled one to see for myself. It's nothing huge, but it's there.
There are a lot of advantages to this form of crimp. If you don't think you need 'em, your loss!
- Location
- big sky country
I use the Lee Factory Crimp dye with my AR-15 loads. With my bolt guns I don't.
The nice thing about the Lee Factory Crimp is you can put as light or heavy a crimp as you want.
The nice thing about the Lee Factory Crimp is you can put as light or heavy a crimp as you want.
I crimp all my loads for my ARs even the sierra matchkings and Hornady match bullets (with no canalure) The lee crimp die makes a slight canalure, which does hold the bullet more secure. I do it for peace of mind, and it does not affect accuracy.
