Fine tuning loads lee factory crimp die
- Thread starter JDD
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waveslayer
Well-Known Member
Crimping does not improve any accuracies whatsoever. It's for revolver rounds. Don't waste your time. Besides Lee is not a well-known brand for performance nor for top-quality Stuff. Lee's the equivalent to Harbor Freight
Thank you for the kinda data I am looking far. I don t wear pink panties and can give back what I get and a lot more if need be. Thanks for the concern.
Marc Gauthier
Well-Known Member
false
Not true , roll crimp and taper crimp are different animals than a collet applied crimp. Do a little research.
Dell
Well-Known Member
Never have and never will add a "crimp" to precision rifle ammo. When I find a load I like, I neck size .002 (bushing bump die) less than measurement of a loaded round and bump the shoulder back .003. I've found over the years that consistent neck tension is important for the best accuracy. Helps get rid of those nasty flyers as well
Some people just have really big egos, especially on the internet. I just ignore it and truck on.
I don't crimp..not even on my ARs. Haven't really found any reason too as my loads for them are accurate. Some people crimp and say it's great and some say there is no need to. When you get observations like that, they only real way to set your mind at rest is to test it out yourself if you are so inclined to.
I seriously think that if you just play with the seating depth and fine tune with powder charge that your ES will shrink.
Canadian Bushman
Well-Known Member
The problem with crimping is that it can be very dependent on case OAL as well as ID and OD chamfer angle and depth. All these variations can affect the severity of the crimp.
On top of this, crimps will typically deform the bearing surface of the projectile. This bothers long range shooters because it can be very difficult to quantify.
To avoid this a lot of long range shooters simply avoid crimping and tune with the other more quantifiable means like seating depth or neck tension.
Ammo can be accurate with or without a crimp. Most longe range guys just avoid it for the sake of simplicity or because they have been advised to do so.
On top of this, crimps will typically deform the bearing surface of the projectile. This bothers long range shooters because it can be very difficult to quantify.
To avoid this a lot of long range shooters simply avoid crimping and tune with the other more quantifiable means like seating depth or neck tension.
Ammo can be accurate with or without a crimp. Most longe range guys just avoid it for the sake of simplicity or because they have been advised to do so.
I'v used mine and can't say it works or doesn't, improves or worsens, and my conclusion was that it's a wasted operation, even for AR's.
therifleman556
Well-Known Member
How much Lee stuff have you used?
Warbird2006
Well-Known Member
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- Apr 15, 2012
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- 412
I actually know a shooter who crimps all his 6.5 CM. He shoots Precision Rifle Matches and is quite succesful.
Agreed the dies are cheap. I will test and observe. Just looking for observation of other serious reloaded. I can tell by a poster response and attitude if they really know and can perform or if a limited amount of success leads them to think to much of them selves. Living in South Louisiana I been lucky to be exposed to some of the best shooters in the world. One is a "world champion " Benchrest shooter and gunsmith. He has dozens of targets shot at 200 yards shot during competition that look like single bullet holes. Others shoot different discipline. To the man they all have one thing in common. A scientific process of testing !!!!. They determine critical attributes , discount frivolous measures and build a tool chest that offer solutions to problems as they come up.
Collet crimping (FCD) and increased neck tension TYPICALLY reduces velocity due to more energy being spent releasing the bullet from the case. A collet crimp, or increased neck tension, will also reduce ES because it makes a more consistent contact with the bullet, resulting in a more consistent release.
I use a Lee FL die for several cartridges. I remove the expander ball from it, using it FL size the outside dimensions of the case. Then, I use a mandrel in a separate step to set final neck/bullet tension. My tension is right at .003" and is extremely consistent throughout the length of the neck thanks to the mandrel.
I also turn my necks too, but that's not really necessary when using a mandrel. It's just something I do out of anal retentiveness.
You can get a mandrel setup from somewhere like K&M. You can get one machined to the exact size you want to give you your desired amount of tension. A mandrel and the press adapter are $30 or less.
Use that along with your Lee FL die and a quality seating die, and you can make very consistent and accurate ammo for pretty cheap.
At .003" of tension, you don't need a crimp. I don't crimp any of my bottle neck cases and I run semi-autos as well bolt action. They run very consistent, cycle smooth, and I get no bullet setback. My SDs are under 5fps and my ES is below 10fps.
While increasing uniform neck tension can increase your accuracy and decrease your SD/ES, so can utilizing a FCD. It's not as superior of a method though. Collet crimping puts peak case neck contact with the bullet only on the point of the crimp. If the bullet gets bumped, it's compromised. It may no longer be consistent with your other rounds. Mishandling of the rounds, rough cycling/feeding, etc is all it takes.
By setting your entire neck to a consistent amount of tension, you don't need to crimp and it makes the point if contact with the bullet uniform throughout the length of the neck and bullet's bearing surface. That means it's not easily bumped out of round
I use a Lee FL die for several cartridges. I remove the expander ball from it, using it FL size the outside dimensions of the case. Then, I use a mandrel in a separate step to set final neck/bullet tension. My tension is right at .003" and is extremely consistent throughout the length of the neck thanks to the mandrel.
I also turn my necks too, but that's not really necessary when using a mandrel. It's just something I do out of anal retentiveness.
You can get a mandrel setup from somewhere like K&M. You can get one machined to the exact size you want to give you your desired amount of tension. A mandrel and the press adapter are $30 or less.
Use that along with your Lee FL die and a quality seating die, and you can make very consistent and accurate ammo for pretty cheap.
At .003" of tension, you don't need a crimp. I don't crimp any of my bottle neck cases and I run semi-autos as well bolt action. They run very consistent, cycle smooth, and I get no bullet setback. My SDs are under 5fps and my ES is below 10fps.
While increasing uniform neck tension can increase your accuracy and decrease your SD/ES, so can utilizing a FCD. It's not as superior of a method though. Collet crimping puts peak case neck contact with the bullet only on the point of the crimp. If the bullet gets bumped, it's compromised. It may no longer be consistent with your other rounds. Mishandling of the rounds, rough cycling/feeding, etc is all it takes.
By setting your entire neck to a consistent amount of tension, you don't need to crimp and it makes the point if contact with the bullet uniform throughout the length of the neck and bullet's bearing surface. That means it's not easily bumped out of round
Well keep me posted. I'm always interested tests people try.
