9mm loading help

[sdnative13]

A bit of a back story. I have a hornady lnl press. I had lee dies in it and a hornady bullet feeder die in station 4. I found that if I didn't hold the bullet on the down stroke, it would fall sideways before reaching the seating/crimp die in station 5. After a little web search I saw that several people recommended the lyman neck expander m die to solve this. I bought one and followed the setup directions.

Ok my question is what is the acceptable diameter around the case mouth of a finished round? As though I was measuring the taper crimp. Measuring with digital calipers I get .376 using the lee expander and .379/.38 using the lyman. Just want to be sure with the larger diameter I won't get a round stuck in the barrel. I did load 5 dummy rounds and they seemed to cycle fine manually. It seems if I raise the expander any more the bullet continues to fall sideways.

In case it matters, all rounds will be used in a gen 5 glock 34.

Thank you in advance you and positive/constructive advice or comments.

[Sig so sour of ca]

When you say manually cycle, you mean the plunk test or rack the slide? I usually go based off my barrel and make a small batch to try. I'll measure something that shoots well in my gun(s&b 9mm 124gr for example), measure that, and compare to my own rolled rounds. Then I do the plunk test.

[sdnative13]

Sorry I am not sure what you mean by plunk test. What I did was load 5 dummy rounds (no primer or powder) in a mag. Then racked the slide with my hand to load/eject round. All 5 did this without issue.

[dmy]

I have lots of experience with other calibers, but just started reloading 9mm. A plunk test is where you remove the barrel from your slide and drop the round into the chamber to see if it seats properly. I don't know the diameter, but my RCBS expander also bells in a "M" profile. I taper crimp to .374" with coated lead projectiles which are .356" diameter. The mid-section of my finished round is .377- .378". While my Lyman 50th manual provides a max COAL of 1.169", I generally have to seat my rounds at a COAL of 1.150" or less.

[Chocula]

SAAMI specifies 0.3800, and a typical Glock chamber is very generous to facilitate reliable feeding. Try to flare only the minimum needed to hold the bullet and your crimp die should remove all flare.

Chocula

[nimbus]

You're talking about your taper crimp I think. General rule I follow is .02+bullet diameter. So if you're bullet is .355 then you crimp to .375 give or take .001.

Plunk test means you drop your completed round into your barrel and see if it falls freely. You'll hear it plunk into the chamber. You should also be able to spin the round in the chamber without it hanging up. This means your round fits in that particular barrel. Barrels are different so you should do this for each load you make per gun.

[NeilMo]

Ok my question is what is the acceptable diameter around the case mouth of a finished round? As though I was measuring the taper crimp. Measuring with digital calipers I get .376 using the lee expander and .379/.38 using the lyman. Just want to be sure with the larger diameter I won't get a round stuck in the barrel. I did load 5 dummy rounds and they seemed to cycle fine manually. It seems if I raise the expander any more the bullet continues to fall sideways.

In case it matters, all rounds will be used in a gen 5 glock 34.

Thank you in advance you and positive/constructive advice or comments.

What diameter is your bullet? Looks like your Lyman die is expanding for a .357"-.358" which may cause a setback problem if you're using a .355"-.356" bullet. You can give them a quick check by holding a finished cartridge and giving the bullet a strong push against your bench. There should be no change in oal after you do this. You can also manually cycle them through your pistol, then measure them again to check for a change in length. I only use the Lyman M die for 38 Superb and my cast .358" bullets. For 9mm, the Lee universal expander and the correct size plug from NOE is what I find works best.

NOE Plugs

[boyguan]

you do not flare the mouth wide enough. Adjust the lee sizing die a tad lower and it will flare the mouth open a bit more. I adjust it just enough so the bullet sits in the case. When you seat the round it should push it in and not really expand it any more that it needs to just seat the around. I then do a slight crimp.

[sdnative13]

Response

You're talking about your taper crimp I think. General rule I follow is .02+bullet diameter. So if you're bullet is .355 then you crimp to .375 give or take .001.

Plunk test means you drop your completed round into your barrel and see if it falls freely. You'll hear it plunk into the chamber. You should also be able to spin the round in the chamber without it hanging up. This means your round fits in that particular barrel. Barrels are different so you should do this for each load you make per gun.

So I tried dropping the 7 dummy rounds. 4 dropped in with a plunk and spun freely. 3 did not

[sdnative13]

Response

What diameter is your bullet? Looks like your Lyman die is expanding for a .357"-.358" which may cause a setback problem if you're using a .355"-.356" bullet. You can give them a quick check by holding a finished cartridge and giving the bullet a strong push against your bench. There should be no change in oal after you do this. You can also manually cycle them through your pistol, then measure them again to check for a change in length. I only use the Lyman M die for 38 Superb and my cast .358" bullets. For 9mm, the Lee universal expander and the correct size plug from NOE is what I find works best.

NOE Plugs

Bullets are .356 from Berry's. No idea size of m die. Literature did not say. Will try measuring after manually cycling.

[sdnative13]

Response

you do not flare the mouth wide enough. Adjust the lee sizing die a tad lower and it will flare the mouth open a bit more. I adjust it just enough so the bullet sits in the case. When you seat the round it should push it in and not really expand it any more that it needs to just seat the around. I then do a slight crimp.

I will try lowering the lee die and see what happens.

[sdnative13]

NOE Plug?

What diameter is your bullet? Looks like your Lyman die is expanding for a .357"-.358" which may cause a setback problem if you're using a .355"-.356" bullet. You can give them a quick check by holding a finished cartridge and giving the bullet a strong push against your bench. There should be no change in oal after you do this. You can also manually cycle them through your pistol, then measure them again to check for a change in length. I only use the Lyman M die for 38 Superb and my cast .358" bullets. For 9mm, the Lee universal expander and the correct size plug from NOE is what I find works best.

NOE Plugs

I clicked the link and had no idea what I was looking at. How do I determine the correct size?

[dmy]

Another factor which affects your crimp is the length of the case itself. Shorter cases will not have as much crimp as longer cases. If you are checking the empty case, size it, then measure.

[NeilMo]

I clicked the link and had no idea what I was looking at. How do I determine the correct size?

They're two-step just like the Lyman, except they come in many sizes to fit different bullet diameters. Example- (.357 x .353) will open the case mouth to .357" to allow the bullet to start straight and below that to .353" for bullet tension. Your Lyman die may be just fine but mine didn't have enough tension for the jacketed and plated bullets I was loading.

[sdnative13]

So I think I got things in a better place. After messing with the m die and the seating/crimp die all rounds are coming out with a diameter around .378. I think my issue also stems from the fact that I am using mixed brass. Going to load 20-30 rounds tomorrow and hopefully go shoot this coming week.