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for my single shot I decided to neck size the brass fired in my gun.Things seem to be going along smoothely,until...

I took the seater plug out of my ol fl die to use it as a crimp die.The rounds I loaded were just fat enough near the bottom to not enter the old seater die...so, no crimp.:huh:

Now I'm almost afraid to see if they will chamber in the rifle.they should,but......

A lot ot folks say they never crimp rounds shot in a single shot,so I guess I'll find out how they work Sure glad I stopped at 40 rounds !!!

ps anyone have a crimp-only die for a .223 to sell,like maybe Lee?

I know they make them.I'll order one if the accuracy isn't what I think it should be.Expectations are low to medium,we';ll see.
 
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Do you have a Case Gauge? I found that one of these answers lots of questions about "will it fit". If your cases won't enter the seater die that sounds to me like there might be a problem with either a real large chamber on your rifle or the case itself.

As for crimping, it's a procedure that often generates threads of many pages. The forces that make crimping necessary usually don't exist in Bolt Action Rifles unless fed from a tubular magazine. It is even arguable for Auto-Loaders like the AR and variants.

I don't use the seater die to crimp my rounds as it is often designed to perform a "Roll Crimp". I've found that this can distort .223 cases . Instead I use a Lee Factory Crimp die for crimping. A collet type die that does a fantastic job. I've even found that it can "straighten out" some rounds that have a little extra run-out. I check all my finished ammo (100% for .308 and spot check on .223) for runout. I have found that rounds with excessive runout (.002" for me is excessive) actually straighten out when run through the Lee FCD. Many that were excessive before are now well within the limits I have established for my ammo.

One argument FOR crimping is that the crimp tends to hold the bullet in place until more of the powder has ignited thus contributing to more uniform performance of the round. In reading Richard Lee's view on the topic he has had crimped rounds tested for increased pressures and found that it only adds a couple hundred pounds more pressure. Unless loading at the absolute upper limits of the rifle this is not significant. Some say it adds to the accuracy and others not. Of course the proof will be in the results YOU get.

An argument against is that the case mouth is being worked more and the brass will harden leading to premature cracking, splitting, etc. Many who want the max loading cycles out of their cases (often carefully selected for matched volumes) refuse to do anything more to the case than is absolutely necessary to make it fit the chamber and provide sufficient neck tension on the bullet.

Rather than looking for a 'Seat Only' die, I'd consider a Crimp Only Die like the Lee FCD. I have one for every caliber I load and couldn't be more pleased with the results.

Also consider obtaining a Case Gauge if you don't have one. Not only for a final check on loaded rounds, but they are a great asset when setting a FL sizing die.
 
you're right,I edited the post to say crimp only die.thanks.
I will try them out and if bad,save most of them until I get a crimp die,they ship fast,a day or 3 won'tmatter.
thanks for the input,deadshot.
 
Ask yourself, why do you crimp? Not all rounds are crimped, even in factory loads.

The OP was specifically discussing .223 rounds and there one really only needs to consider crimping if shooting in an Auto-Loader. Then again, some do and some don't. It doesn't hurt when a round is being jammed over a feed ramp to secure the bullet with a crimp.

There is another reason to crimp and that's with any case that has been "belled" in order to seat a bullet. That covers pretty much all pistol rounds. The "crimp" is employed to squeeze the case mouth back against the bullet. For rounds like the .357, using some powders, the roll crimp holds the bullet in place until the powder "really gets going", example is when using 296. Lastly, pistol cartridges for auto-loaders need some "crimp" which usually is no more enough to make sure the case mouth doesn't catch on the entrance to the chamber. These rounds get a taper crimp which doesn't look like a crimp at all if you're used to roll crimps.

For those that are using single stage/turret presses it seems like a waste of time. For those that are using progressives where the crimp die can be the last station on the tool holder, they don't notice it.
 
I guess I crimp because almost every seating die I have is a combo seat/crimp die,so I figure crimping is a part of that caliber's operaton on the press.Also,the few times I've tried not crimping rounds,accuarcy suffered,even fired in a single shot.We'll see how these do ,might be ok as the neck tension is very good with the new die.
 
I guess I crimp because almost every seating die I have is a combo seat/crimp die,so I figure crimping is a part of that caliber's operaton on the press.Also,the few times I've tried not crimping rounds,accuarcy suffered,even fired in a single shot.We'll see how these do ,might be ok as the neck tension is very good with the new die.

There are some good books out there that will explain the how and why. Generally crimping while seating is not necessary a good idea. Generally, crimping is the 4th step, more on lead bullets than jacketed w/cannalure. Notice the Dillon 550b has four stages.

Also one of the big reason for crimping is from inertia energy in recoil. The heavier the recoil the more inertia energy that will unseat the bullet. This is not a issue with single shot, obviously. A lot of 9mm bullets do not have a cannalure on the bullet, they are never crimped. The recoil is not that much. Also as it was mentioned above there may other reasons why crimping would be needed.

As to your notice in change in accuracy, a crimp can/will increase the chamber pressures. Chamber pressure is related to muzzle velocity. That means the trajectories will probably not be the same. Also in crimping the case length is critical. The a case shorter than the set up case will have less to no crimp, a case longer will have a heavier crimp.
 
A lot of 9mm bullets do not have a cannalure on the bullet, they are never crimped. The recoil is not that much. Also as it was mentioned above there may other reasons why crimping would be needed.


I believe you are using the term "crimp" as a generic term when it actually falls into two separate and distinct categories. A Roll Crimp is what you described when the case is "crimped" into the cannelure of a bullet, lead or jacketed. A Taper Crimp is definitely used on 9mm cases to press the case back against the bullet after it was belled to ease insertion.

Yes, the Roll Crimp is used to hold the bullet tightly under recoil to prevent cylinder lock-up in Revolvers and having bullets seated deeper while under recoil in a magazine (especially tubular). The Taper Crimp is used to keep the case mouth from snagging on feed surfaces in an auto-loader, not necessarily to grip the bullet tighter. Two different crimps, two different purposes.

Just as Throckmorton said, many dies have crimping as part of the seater die. The manufacturers include the type of crimp in that die that the cartridge usually requires. Many loaders are "crimping" and don't even realize it.
 

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