Screw it down until you get the case mouth back straight with the rest of the neck at most, unless you are crimping into a cannelure. Any more won't help without a cannelure. I don't crimp at all unless loading a bullet with a cannelure and a flat base, and unless the bullet has a flat base I will not expand the mouth and therefor no need to crimp. If you have .002-.004" neck tension even a super hard kicking lightweight won't pull the bullet out of the case, and any decent running rifle won't set the bullet back when feeding, not even semi-auto.
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Lee factory crimp die in an RCBS press
- Thread starter GW Hunter
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ericbc7
Well-Known Member
If you have carefully trimmed brass you can use the cam-over style presses to achieve more consistent repeatable crimps. the difficulty is in setting the die on an RCBS or other press to approximate 25lbs on a Lee press. With different mechanical advantage and length of handle, the 25 lb goal is kind of meaningless.
treat crimping force like load development. Take your good loads and adjust the crimping die to provide a range of crimping force and either measure the force needed to cam over or measure the precise die position. If you want to use your RCBS press like a non-cam over press, just screw in the die far enough that the cam over is not reached. Remember that 25 lbs force on the RCBS is not likely to produce the same crimp as 25 lbs on the Lee press.
I bought a "consistent crimp" torque wrench handle for this purpose some years ago but rarely used it because I preferred Seating bullets on my co-ax press.
p.s. The Consitent Crimp product was fine, I just didn't take the time to incorporate it into my process - I may look at it again in future.
treat crimping force like load development. Take your good loads and adjust the crimping die to provide a range of crimping force and either measure the force needed to cam over or measure the precise die position. If you want to use your RCBS press like a non-cam over press, just screw in the die far enough that the cam over is not reached. Remember that 25 lbs force on the RCBS is not likely to produce the same crimp as 25 lbs on the Lee press.
I bought a "consistent crimp" torque wrench handle for this purpose some years ago but rarely used it because I preferred Seating bullets on my co-ax press.
p.s. The Consitent Crimp product was fine, I just didn't take the time to incorporate it into my process - I may look at it again in future.
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xsn10s
Well-Known Member
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I haven't any experience with the Co-Ax press but I always use shellholders from the same manufacturer as the dies. That might be where the problem is.
I use a co-ax. Put die in press with loosened locking on ring. Screw die down to contact with raised jaws, and give it just a bit more, maybe an eighth of a turn. Try on a loaded round. I just give enough to flatten my case mouth belling/M die swell, and a touch more. Maybe a thousandth of an inch, or so.
On a Dillon 550, the bottom of the crimp die (body, not collet) is too fat, so I grind/file them to the minor diameter. Could also just cut the threaded part off, but I don't.
I have a couple long nosed bullets that require shortened brass. I have separate lee crimp dies for these and I have cut off the bases of the collets to fit the shorter brass.
Maybe think outside the box?
Highbrass
Well-Known Member
Not sure but 25# seems a bit too much.
I set mine up like this...
Put a case in the holder and run the ram all the way up( handle down)
Start screwing the FCD down until the collet makes contact with the neck. Lower the ram slightly and screw down on The FCD raise the ram again and look down at the FCD collet when adjusted correctly you should feel the slight resistance and see the collet close If you measure before and after it is only about .001 difference.
I set mine up like this...
Put a case in the holder and run the ram all the way up( handle down)
Start screwing the FCD down until the collet makes contact with the neck. Lower the ram slightly and screw down on The FCD raise the ram again and look down at the FCD collet when adjusted correctly you should feel the slight resistance and see the collet close If you measure before and after it is only about .001 difference.
RABAZ
Active Member
Glen Zediker recommended the following: Take a piece of resized brass. Measure ID of the throat. Play with your crimp to crimp to 2-3 thousandths less ID for match shooting, and 3-4 thous for semi auto - ARs and the like. See what you think.
Good choice on die I've used Lee FCD forever, love them. How do you get 25 lbs... good question, I have no idea, crimp... lite, medium, or heavy... you just learn the feel. Good luck Cheers
I screw mine in and pull down on the press. If you look in the top of the die( no round in die) you can see the collets closing. Screw it in until they are closing about 1/4 to 1/3 of the way. Now crimp a round and see what it looks like. Just remember once the collets are touching that is maximum crimp.
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No Sir it will work just fine
SMDunn
Member
I believe the trick for consistency is cases always trimmed to the same length. I am also using a Lee press. As the setting up method is infinitely variable I start at less than 1/8 turn and keep increasing until I get the crimp I was looking for. I aim to get a slight crimp that smooths the point where case ends and projectile starts. I also rotate the case a 1/4 turn and repeat the process several times. All this in the hope that it promotes a centered projectile with a repeatable let off pressure and it stops the OAL from changing when banged around in the magazine.
SMDunn
Member
I believe that for this to work reliably all cases need to be trimmed to the same length.
I use a Lee press.
As the setup process is infinitely variable there may be a little bit of "art" in getting it right. I start at less than a 1/8 turn and keep adjusting till I get what I look for - which is where it is a smooth transition from case neck ending and projectile. I also turn the case 1/4 turn and repeat the process several times. All this in the belief that it provides a load that is centered and with a consistent let off pressure, it also stops OAL from changing from all but the worst magazine abuse. From an aesthetic perspective the rounds feel smooth and slick, like they are all made from a single component.
I am interested to hear how other use this for their process.
I use a Lee press.
As the setup process is infinitely variable there may be a little bit of "art" in getting it right. I start at less than a 1/8 turn and keep adjusting till I get what I look for - which is where it is a smooth transition from case neck ending and projectile. I also turn the case 1/4 turn and repeat the process several times. All this in the belief that it provides a load that is centered and with a consistent let off pressure, it also stops OAL from changing from all but the worst magazine abuse. From an aesthetic perspective the rounds feel smooth and slick, like they are all made from a single component.
I am interested to hear how other use this for their process.
yes these dies have been great for me and very easy to use. Can set up easy on dummy or live round and just screw die down in very small increments to get desired crimp. For consistency you would have to leave this one die marked/ locked at the point you decide for further use because it is hard to re set it exactly to the last point of adjustment. Never let the collets touch each other as it can damage die forever...less is best,,
Lefty7mmstw
Well-Known Member
I've got a couple of the Lee fc dies. My 375 H&H one hasn't even been set up yet and may never be. I bought it just in case..
My 405 win die is set up to crimp 400gr Woodleigh bullets a good bit above the cannelure as the cannelure is in the wrong place on that bullet for the 405wcf. I have it set up to put a good crimp on just starting to deform the bullet. It is just getting to a rather stiff cam over on my rock chucker. Still not much of a crimp line but enough to keep things in place.
My 405 win die is set up to crimp 400gr Woodleigh bullets a good bit above the cannelure as the cannelure is in the wrong place on that bullet for the 405wcf. I have it set up to put a good crimp on just starting to deform the bullet. It is just getting to a rather stiff cam over on my rock chucker. Still not much of a crimp line but enough to keep things in place.
