Crimping 9 mm

[Buck13]

My first time reloading 9 mm. I have a Lee taper crimp die. Planning to load some once fired cases with HAP125 and coated Missouri SWC125. Any suggestions on crimp measurement?

To get the front band under the case mouth, the SWCs will need to be loaded quite a lot deeper than needed to plunk without binding, something like 0.015 or 0.02 shorter.

 

[LiveLife]

My first time reloading 9 mm ... Lee taper crimp die ... HAP125 and coated Missouri SWC125. Any suggestions on crimp measurement?

Since case wall thickness average .011" at case mouth, I usually add .022" to the diameter of bullet to return flare back flat on bullet and skosh more for slightly thicker case wall brass - https://www.thehighroad.org/index.p...-and-discussions.778197/page-10#post-11419509

Taper Crimp amount = bullet diameter + .011" = .011" = .356" + .022" = .378"

So I use .378" taper crimp with .356" diameter bullet (115 gr HAP measured .355" for me while 125 gr HAP measured .356") to not squish the bullet smaller (Taper crimp die set using shorter resized cases as longer cases will apply slightly more taper crimp) - https://www.thehighroad.org/index.p...re-sized-the-same.818806/page-2#post-10567453

HAP125

Max OAL/COL should be determined using the barrel "plunk test" and then Working OAL determined by feeding dummy rounds (No powder, no primer) from the magazine and releasing the slide without riding it - https://www.shootingtimes.com/editorial/reloading-tips-the-plunk-test/99389

These are various Working OAL for HAP 125 gr depending on the leade length of barrels used so Working OAL for your barrel/pistol/magazine may differ - https://www.thehighroad.org/index.p...-in-9-mm-bullseye-loads.913795/#post-12495668

• Glock 22, KKM 40-9 conversion barrel - Hornady 125 gr HAP: 1.125"
• M&P Shield - Hornady 125 gr HAP: 1.120"
• Glock 22, Tactical Kinetics 40-9 conversion barrel - Hornady 125 gr HAP: 1.070"
• Glock 23, Lone Wolf 40-9 conversion barrel - Hornady 125 gr HAP: 1.045"

To get the front band under the case mouth, the SWCs will need to be loaded quite a lot deeper than needed to plunk without binding, something like 0.015 or 0.02 shorter.

For SWC (which is usually made from RN profile with non-feed ramp bump contact areas removed), most load with thumbnail thickness of shoulder above the case mouth to determine the OAL. For MBC 124 gr SWC, that's 1.045"

 

[Buck13]

Yes, I cycled dummies through the action before starting. My 1911 will feed the SWCs set rather long, at least to 1.14" is OK. Got a little setback but that length has the case mouth over the lube groove so no chance to crimp on the bullet, so I am trying the longest seating that will crimp at all.

One problem I'm running into: I flared all the brass with a Lyman M-die and loading in the dummies seemed OK, but as I try to make live rounds, I realized that both bullets are tricky to get started straight. Maybe I didn't inspect the dummies quite as carefully. The HAPs in particular have an annoyingly large number with the bullet just barely visibly not square. It's easier to tell with them because I set the seater to put the lower edge of the cannelleur JUST at the case mouth, so if it's not straight a sliver of the shank is visible on one side. I went ahead and seated all that I had already flared and charged, but the next time I'm going to try setting the M-die a little deeper to see if that helps, unless anyone has a better suggestion. I should probably start a separate thread about this.

 

[lordpaxman]

My first time reloading 9 mm. I have a Lee taper crimp die.

Got a little setback but that length has the case mouth over the lube groove so no chance to crimp on the bullet, so I am trying the longest seating that will crimp at all.

For 9mm and several other semi-auto cartridges, it’s not the crimp that prevents setback. Neck tension, established by the sizing step, is all you need. The taper crimp only removes the bell or flare. Either your sizing step isn’t correct, or you’re expanding too much before bullet seating. Over crimping in a taper crimp can actually reduce neck tension as well. Also, 9mm is a high pressure cartridge and the load data specifies a charge range and COL - If you shorten the COL you need to adjust the charge as well.

 

[BW460]

I use an M Die to flair the mouth and a Hornady seating Die. That eliminated my issues with bullets going in crooked. To determine crimp diameter at the mouth, I seat a bullet to the proper depth. Then measure the outside diameter of the case near where the base of the bullet is. Then crimp the mouth at least to the previously measured diameter at the base or 0.001 smaller. This has always worked for me.

 

[ericuda]

Don't crimp 9, just remove any bell. As stated measure to .378.

A Redding taper crimp died may be a good investment for you.

 

[243winxb]

crimp measurement

Take measurements of your brass. Not all case wall thicknesses are the same.

About .001" smaller then case body. Note that the Lee seat die is said to taper crimp first, then turn into a roll crimp. When brass trim lengths is different, may cause issues. Set crimp on the LONGEST of the brass lot.

 

[243winxb]

Lyman M-die

The RCBS die set has the M type expander. Works well.
https://www.thehighroad.org/index.php?media/albums/taurus-g3c-9mm-luger.317/

 

[DMW1116]

I just use the Lee Factory Crimp Die set on the minimum recommended crimp, which I think is only 1/4 turn past starting position. I have not tried other manufacturers dies. I am interested in SWC bullets for 9mm now though.

 

[Buck13]

Take measurements of your brass. Not all case wall thicknesses are the same.

About .001" smaller then case body. Note that the Lee seat die is said to taper crimp first, then turn into a roll crimp. When brass trim lengths is different, may cause issues. Set crimp on the LONGEST of the brass lot.

I'm not crimping with the seater die in this instance. Have a separate Lee Taper Crimp die (not FCD) to crimp with.

 

[mdi]

FWIW; I do not "crimp" any semi-auto handload. I just deflare the case mouth (expanded to make bullet seating easier). Using a taper crimp die. I just smooth out any flare, check visually or by feel, and double check with a plunk test. For straight sided cases (or slight taper) neck tension holds the bullet in place, not a crimp. This has worked quite well for me with 4 different semi-auto cartridges (32 ACP up to 45 ACP) and several thousand 9mms.

K.I.S.S.

 

[ericuda]

Buck13 can you throw a couple pictures on here.

 

[1-cavediver]

All you need is a Lee Carbide Factory Crimp Die. I use them for all my pistol loads and not just with Lee dies, I even use them with my RCBS and Hornady dies.

 

[Walkalong]

All it needs is a proper taper "crimp", whatever method is chosen.

 

[Buck13]

I use an M Die to flair the mouth and a Hornady seating Die. That eliminated my issues with bullets going in crooked. To determine crimp diameter at the mouth, I seat a bullet to the proper depth. Then measure the outside diameter of the case near where the base of the bullet is. Then crimp the mouth at least to the previously measured diameter at the base or 0.001 smaller. This has always worked for me.

Do you do that with 9 mm? Unlike most handgun cartridges, it has a tapered case, so I don't see how that would work right.

 

[Buck13]

All it needs is a proper taper "crimp", whatever method is chosen.

The Bullseye guys make a big deal about the exact magnitude of crimp affecting accuracy, although I can't remember if that was in 9 mm or .45 ACP. I've barely started reloading for either

Not that my shooting, even off a sandbag, is likely to be good enough to see the difference unless it's severe.

edit: My guns in question are a DW Pointman9 and a Springfield Range Officer .45, so a little better than the average Glock but nothing exceptional.