9mm Lead Bullet Reloading Issue

[DAB-CC]

The wife and I are new to reloading. I have done 3500 rounds of 45 acp up to this point with now issues on my Dillon RL550B. I switched over to 9mm last week. Today I started to dial powder, flare, cartridge overall length (OAL) and crimp. The first one off the line I asked the misses to try it in here Walther PPS to make sure it would chamber. Just wanted to make sure since it measured 1.165" OAL (Speers#14 1.169"). Glad I did because the round didn't chamber all the way.

Measurements taken from first three reloads:
Case length 0.746" (#14: 0.754" max)
Case diameter 0.377" (#14: 0.38 at mouth, 0.3811")
Cart OAL 1.140" and 1.110". The 1.110" works and the 1.140" does not. These were my 2nd and 3rd attempts.

Factor ammo that we have been shooting measures the following:
Case length ~0.742", best I can do with the calipers
Case diameter 0.376"
Cart OAL 1.164"

I don't have my case gauge for 9 mm yet, on order for 5 weeks. So I'm using the gun barrel. All the rounds go in the barrel it is really a matter of how far they go in the barrel that is killing me. The Walther PPS has a ramp on the barrel. This is what I'm using as a height gauge. If it is at or below the ramp height the slide will shut and gun will operate correctly. This is my assumption.

Measured bullet height out of the barrel:

Factor: 1.164" OAL: 0.124"
Reload: 1.140" OAL: 0.173
Reload: 1.110" OAL: 0.147"
Case only: 0.125

Something I found interesting was the bullet does not enter the exit side of the barrel. It will to a point then when it gets to the 0.356" diameter it stops. The case is 0.38 so figured that wouldn't go in but I was surprised to find the barrel ID to be smaller than 0.355".

Hypothesis I have is that RN lead bullet is more of a spherical head than the factor conical ammunition. The factor ammunition is at 0.355" diameter for a shorter length than the lead round. This length is what is holding the bullet up farther in the barrel. The difference between reloads OAL 1.140 and 1.110 has me thinking that by pushing the bullet in farther that the bullet diameter is fading away and allowing it to fit into the barrel.

Does any of this make sense to my fellow reloaders? Has anyone come across this issue before?

Thanks in advance. The press is down until I get some answers and I am able to test a few rounds at the range.

 

[2in1evtime]

my hornady book list a c.o.l of 1.090. and that is what i follow. i believe you are right on the assumption that the lead round is not quite a spherical as fmj. i haven't had any problems running lead at this measurement. i am using 4.5 grains of power pistol also

 

[XtremeVel]

What is the weight and shape of your bullet ?

Sounds like the bullet might be engaging your rifling before the slide is in full battery. See any witness marks on the bullet ?

The desired OAL of your loaded round will vary depending on the bullet profile.

Edit... I now see you did mention it being a RN profile... By chance, is this the Missouri small ball 124 or 125 gr bullet ?

 

[MikeDVB]

Seating the bullet deeper will decrease the volume of the cartridge resulting in higher pressure. Unless you're seating it a LOT deeper it won't make a HUGE difference.

I tend to go by what the loading book says but I have no issues seating it a little more/little less if it causes the round to cycle reliably.

Remove the barrel and drop the round in it - if it doesn't seat all the way into the chamber on it's own you need to seat the bullet further (for sure). Since it's lead, push it all the way into the chamber and then pull it out and see how marked the round is (i.e. how far it's engaging the rifling, so you know how much deeper to seat the round).

 

[DAB-CC]

Witness marks on the longer COAL 1.14.
Weight is 115 grain, 0.356" diameter, RN

The 1.090 is still under my 1.110 round. Speers #14 has 9mm TMJ RN as the example. at 1.135" I'll seat the bullet further.

Thanks everyone. That was really quick. Back to reloading I go.