general newbie question...to crimp or not? 9mm

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basicbill

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I'll be starting into the world of reloading this weekend and I would like to know if using the factory crimp die is necessary or not....or whether it has negative repercussions or not.
From reading this forum, it seems that many don't crimp, but I haven't read why they don't.

BTW, Lee turret....strictly 9mm for now.
 
I'm presuming you mean 9mm luger for handgun
Remember the 9mm headspaces on the front of the case. All you want to do is remove the bell in the case that you created to seat the bullet. In handgun ammo you need a taper crimp die NOT a roll crimp
 
By all means I am no Professional when it comes to reloading, but I can offer you some first hand experience on the topic. For the 9mm a firm taper crimp is suggested. This prevents bullet setback which is always a concern in Hi pressure cartridges. A firm taper crimp will produce a much cleaner burning cartridge as it has more time to burn off before the bullet starts to move down the barrel. An appropriate taper Crimp for the 9mm should be 0.374" give or take a few thousandths. Just remember to only flare the case enough to accept the bullet. Anything more and you are fatiguing your brass causing premature case mouth splits.
 
And remember to always crimp for YOUR gun. Do not take blind advice to put X type of crimp. For my 4506 it has a great ramped barrel and a light crimp is all that is needed to ensure no bullet setback when chambering. Remember it does not take much bullet setback to create dangerous over pressure. Now for my Norc 1911 in 9mm I need a firm crimp to ensure minimal bullet setback when chambering. My method for determing the right level of crimp is to make a dummy round (no primer or powder) and then crimp lightly, measure load and rack the round. Re-measure. If I'm happy with the minimal amount of bullet setback (you yourself need to determine what that level is) I'm done. If not I make another dummy and repeat. I do this with all bullet and gun combos. Overkill? Maybe, but I'd rather be extra safe then missing fingers!

Definetly a +1 for FCD on all handgun rounds, especially for a semi auto.
 
I dont use a FCD, the bullet seating die does a fine job of crimping if its set up properly and I've never had any setback or pressure issues in over 6500 rounds
 
I've never liked the term 'taper crimp'.

If you size your brass and then slightly bell the mouth as one normally does, I've found that there's enough tension from the brass to hold your bullets in place. All the taper 'crimp' does is take out the bell at the mouth, restoring the proper profile or taper. As noted, the round headspaces on the front of the case mouth, so anything more is both counterproductive and potentially dangerous.

Best way to do it (and the idea of dummy trial runs is excellent) is to use calipers to confirm that your final mouth diameter is IAW spec - 9.65mm or 0.380". If it is, your round is properly 'crimped'.
 
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