9mm crimp ?

[Jeff9mmM&P]

I am reloading with 115 gr RN 9mm and used brass on a Dillon SDB press.

I don't have a clue how much crimp I should apply? I do have a digital caliper to check.

Any help would be appreciated.

Thanks

[robertbank]

I am reloading with 115 gr RN 9mm and used brass on a Dillon SDB press.

I don't have a clue how much crimp I should apply? I do have a digital caliper to check.

Any help would be appreciated.

Thanks

All you want to do is remove any belling you have applied to the case. The 9MM uses a taper crimp with the bullet being retained by case friction.

Take Care

Bob

[Wayne Dobbs]

I am reloading with 115 gr RN 9mm and used brass on a Dillon SDB press.

I don't have a clue how much crimp I should apply? I do have a digital caliper to check.

Any help would be appreciated.

Thanks

My suggestion would be to adjust your taper crimp die until the case mouth edge measures .379" and then lock the ring and get to work. This dimension has always worked very well for me in a variety of 9mm pistols.

[Hi-Power Jack]

I have a caliper but could never measure the crimp

very accurately, so I loaded a few rounds and tried

them - if they didn't chamer, I'd screw down on the

crimp a little more until the rounds chambered, then

just a little more and tightened it down.

Then I loaded 20 and tried them for accuracy/feeding.

If you overcrimp, you can lose accuracy. If you

undercrimp, they won't feed at all.

I know this is not The Right way to do it, but it worked

for me.

Good luck.

Jack

[M.E.Anglin]

I have a caliper but could never measure the crimp

very accurately, so I loaded a few rounds and tried

them - if they didn't chamer, I'd screw down on the

crimp a little more until the rounds chambered, then

just a little more and tightened it down.

Then I loaded 20 and tried them for accuracy/feeding.

If you overcrimp, you can lose accuracy. If you

undercrimp, they won't feed at all.

I know this is not The Right way to do it, but it worked

for me.

Good luck.

Jack

If it works for you then it is is right....

[Jay870]

I'm new to reloading so take this for what its worth, but I have not had any feeding, set-back or accuracy issues with the following in my Glock 17...

147gr BBI into cases belled at .380-.381 and crimped at .376-.377.

The minimum belling seems to keep good case tension on the bullet, and I haven't noticed any probelms with it scraping the moly during seating. The crimp at .376 does not appear to cut the moly at all. The good accuracy and lack of barrel fouling or excessive smokiness seems to support that.

[UW Mitch]

I've found a micrometer with a clutch in it helps me get better readings than my dial calipers. I'm crimping to 0.379" - but I do get a +/-0.002" variations.

~Mitch

[Jeff9mmM&P]

Thanks for the input guys. It looks like I'm good to go.

My readings have been .375"-.377" at the case mouth on the finished cartridges.

Thanks again.

[BMartens]

I use one simple method that works for all .45, .40 and 9mm.

Measure a loaded round just below the rim, then set the crimp .002" less.

Measure with the tip of the caliper by holding a little pressure on the caliper and slip it up the case to the rim. You'll see the crimp measurement just before the caliper slips off the case.