First 9mm Reloads

[BuRu]

I started playing around with reloading 9mm today. I have mixed brass and some RMR 115gr FMJRN. I did 2 dummy rounds, one at 1.100 and another at 1.125. I noticed that on both, the COL kept decreasing after cycling on my Springfield XD. The 1.100 dummy round has a lite crimp and the 1.125 has a medium crimp. It sounds I would need to go with a heavy crimp but wanted to check if anyone has run in to this?

[SandDiegoDuner]

Did you size the brass prior to seating the bullet?

[BuRu]

Did you size the brass prior to seating the bullet?

Thanks for the reply. Yeah, I sized the brass and flared the mouth just enough to have the bullet sit straight. Then I followed with seating the bullet and crimping.

[Fizz]

Did you full length resize your brass? What diameter are your projectiles as measured with a micrometer or caliper?

9mm shouldn't need any more crimp than what's necessary to remove the flare and a smidge more.

What kind of crimp are you applying? Roll or taper?

9mm headspaces off the case mouth, so the balance between crimp and a good purchase of the case mouth is important.

Take an piece of sized brass and plunk it into your pistol chamber. Measure how much it protrudes. Make a dummy cartridge and plunk that. Does it stick out further than the empty? If so, your COL is probably too long for that given cartridge.

115 gen FMJ RN is almost always the same profile make to make, but you need to verify. Arbitrarily going with a COL for a given projectile that may have a different profile will get you sketchy ammo.

Also, how are you measuring the shrinking COL and HOW MUCH are we shrinking?

[Donny1]

I have a 9mm XD Tactical, with target loads it is not violent enough to do this without crimp, odd.

[TomReloaded]

The extractor is really holding the brass in the chamber. You could fire a 380 out of a 9mm handgun. Not that you should make a habit of it, but 9mm certainly isn't holding tight against the case mouth. Some crimp or not isn't a make or break.

Generally 9mm has a ton of neck tension. How much setback are you getting? Usually 115gr is set further out too. I'd plunk check your gun, but closer to 1.150 would likely be better.

[BuRu]

Thanks for all the replies.
I full length sized. Using the Lee 4 die carbide set. I'll measure the projectile when im back at the bench. The crimp is a taper crimp. I just followed the instructions on the Lee pamphlet to set it up. I'll play around with it more. I'm measuring the shrinking COL with my calipers. The difference is not much. The 1.100 now gives me 1.098 and the 1.125 gave me 1.124 after two cycles from my magazine then after a couple of more cycles it was 1.118.

[Fizz]

The extractor is really holding the brass in the chamber. You could fire a 380 out of a 9mm handgun. Not that you should make a habit of it, but 9mm certainly isn't holding tight against the case mouth. Some crimp or not isn't a make or break.

Generally 9mm has a ton of neck tension. How much setback are you getting? Usually 115gr is set further out too. I'd plunk check your gun, but closer to 1.150 would likely be better.

I don't believe this is accurate in these style pistols.

While an extractor CAN hold a cartridge, it isn't its primary responsibility.

It's something you can test. Take off the slide and reassemble the slide with a dummy cart and main spring installed. If you can slide a feeler gauge or other probe behind the base of the case, with the extractor manually moved off the case rim, then the extractor isn't doing any holding. Alternatively, you may be able to visually observe that the extractor 'hook' isn't making contact with the rim.

Re: your .380 example. It would certainly be very easy to insert a probe behind the case base if you moved the extractor off the brass.

I remember my first 9mm reloads for my Shield. I WAY overcrimped the case, this caused the the case mouth to become tapered inward. When I chambered the round at full velocity of the slide spring the case wedged itself in the chamber and I had to muscle the the slide back to extract it. What this signifies to me is that the distance between the slide and the chamber ridge for the case mouth is an interference fit; the slide was willing to push the brass into the chamber if not for the case mouth stopping it. This also means that the extractor likely doesn't make contact with the rim when fully chambered, proper rimless cartridge.

[Fizz]

Thanks for all the replies.
I full length sized. Using the Lee 4 die carbide set. I'll measure the projectile when im back at the bench. The crimp is a taper crimp. I just followed the instructions on the Lee pamphlet to set it up. I'll play around with it more. I'm measuring the shrinking COL with my calipers. The difference is not much. The 1.100 now gives me 1.098 and the 1.125 gave me 1.124 after two cycles from my magazine then after a couple of more cycles it was 1.118.

That could also be explained if the nose becomes dented by the feed ramp after repeated loadings, or hitting the ground after extracting.

Unless the COL is so large as to push back the projectile into the case, almost every part of a pistol action would cause the bullet to move forward in the case (increase COL), not shrink. The chambering of a round accelerates the cartridge, pretty linearly/gently but comes to a sudden stop on the case mouth (think bullet puller). Subsequently, extracting the round by hand as inertial trying to separate the case from the projectile.

My guess is your crimp is fine and your COL is fine.

If you can post a picture of your dummy load we can probably spot if there's anything glaringly wrong with the crimp.

[Donny1]

The difference is not much. The 1.100 now gives me 1.098 and the 1.125 gave me 1.124 after two cycles from my magazine then after a couple of more cycles it was 1.118.

Not scientific but you can test your crimp by pushing the loaded bullet hard against the bench and see if it gets shorter. If that is ok it's not going to move.

Also, are you measuring every round because you will have variations in length of .001-.002.

[tabascoz28]

Can you neck size a pistol case? Chamber is just probably tight. I had the same problem with my glock for the first few hundred rounds. Then it slightly opened up.

[the86d]

I read that just hitting the ramp and feeding can shorten the OAL when slingshot-chambering (close to real world cycles when firing), even w/HD/SD factory loads.
I have never tested mine for OAL chambering-shrink-creep though. After a few years I typically just buy a new box, and range-time the HD stuff that looks bad (oxidation with fingerprints and such).

I give my 9mm a pretty solid crimp, and it'll leave a ring on plated, PC, or lead, but it shoots better than I do, with my aging eyes, & iron-sights...

I have no problem with the rifling and longer-reloads in my handguns, and COULD load my 9mm pretty-long, but not so much anymore with the Ruger PC-Carbine, as it has a MUCH SHORTER jump to the rifling, like substantially shorter...
AKA... loading to spec...

[Raiderh20boy]

as far as the COL being different from round to round, make sure you are doing a full stroke. really don"t need a tight crimp! try pushing the bullet down on a solid surface. if it moves then its too light. all my 9mm rounds are OAL of 1.49-1.50. the crimp is .379-.3795 and my bullets are xtreme plated 115 gn and .355 dia.

[bruce381]

Not scientific but you can test your crimp by pushing the loaded bullet hard against the bench and see if it gets shorter. If that is ok it's not going to move.

Also, are you measuring every round because you will have variations in length of .001-.002.

do this 100% best way to tell when setting up
also use LESS mouth exspansion

[pacrat]

I started playing around with reloading 9mm today. I have mixed brass and some RMR 115gr FMJRN. I did 2 dummy rounds, one at 1.100 and another at 1.125. I noticed that on both, the COL kept decreasing after cycling on my Springfield XD. The 1.100 dummy round has a lite crimp and the 1.125 has a medium crimp. It sounds I would need to go with a heavy crimp but wanted to check if anyone has run in to this?

First off ..............Pull the expander out of the die and measure it. Also measure your bullet diameter. The expander should be at .002" or a bit less than your bullets. That assures a good firm "interference fit".

Then, when you seat your bullets, set your die body to JUST make the flared case mouth "straight". That is all the "taper crimp" that is needed EVER. Any further squeezing of the case wall to increase taper crimp, is DETRIMENTAL to maintaining proper interference fit.

Brass is "springy stuff". Lead is not, it has no spring back AT ALL. If you squeeze the brass into the lead past straight. You are compressing the bullet inside the case, then the case springs back away from the bullet, disrupting the "interference fit". And leaving the bullet undersized within the case neck.

Second ............. It is quite common for bullets to move rearward slightly when fed into a semi auto chamber from the mag. Happens all the time. The more you cycle a round the farther it moves.

DON'T WORRY ABOUT IT. Just don't do it repeatedly. Or you will be creating a pressure problem with rounds you have done so to.

Typically round nose Hard Ball move less than HP, SHP, Cast, or Plated bullets. During normal slingshot loading or cycling during firing. A lot of force is applied to the bullet by the slide, which hits the feed ramp HARD.

If you think otherwise. Clear your weapon...........Lock the slide back ..........stick the tip of your pinky finger into the ejection port against the barrel hood .............AND HIT THE SLIDE RELEASE.

OR, .................You can just take my word for it.