Missouri 115g Parabellum bullet COL for Kel-Tec pf9

9mm is a really temparmental cartridge regarding seating depth and pressures. In my Speer manual they used an established SAMMI load that was producing an estimated 28,000 cup (psi now). But when they deliberately seated the bullet .030" deeper than SAMMI recomended, pressures went from 28,000 to 62,000 psi. If not for the fact that this was performed in a test barrel, I'm fairly certain that would have resulted in some sort of catrastrophic failure, probably a ruptured case or possibly KB in a porrly made firearm. I've got a pretty nice amount of data for the 9mm because I load for it also. Tell me what bullet brand, type, and or part number you are using, and I'll see what I can find to substantiate a safe COL for that Kel Tec.
Hornady 115 gr. XTP showing a COL of 1.075", the FMJ is at 1.100".
Sierra is @ 1.050" for JHP & 1.100 for FMJ
Speer is @ 1.125" for Gold Dot and JHP. The TMJ is @ 1.135"
My advice would be to load a few with 4.3 grs. which is Winchester's listed minimum, and seat them to the longest COL that will chamber consistently and give them a try. I seriously doubt you'll have a pressure problem given the fact that the COL is in the ball park at 1.070" for some of the bullets listed. If all goes well at 1.070" with the 4.3 grs. of 231 maybe try giving yourself a small margin by going to 1.065" to avoid any chambering issues due to olgive inconsistences. Then if the 1.065" goes well which it should, you can begin working back up to your powder charge of 4.5 grs..
Sound good to you?

The older generations of 9mm lead bullets I have used in past years had similar "Parabellum" pointy nose but stepped down from the bearing surface (part of the bullet that rides the rifling).

When I switched to Missouri Bullet 9mm RN (125 gr SmallBall), I noticed that this newer bullet design had more rounded nose with greater bearing surface to stabilize the bullet in the barrel. Also, there was no step from the bearing surface to the nose of the bullet. If you look at the comparison picture, Berry's plated 124 gr RN bullet on the right shows more traditional "pointy" nose but provides less bearing surface than the "rounder" nose Missouri Bullet. Because of the "rounder" nose, your OAL will be shorter if you seat the bullet down to where the bearing surface transitions to the "ogive" of the nose.

When I did my initial testing in Glock 22 with Lone Wolf 40-9 conversion barrel, I started out at 1.125" OAL and seated down to 1.080" with proper feeding/chambering into the tight LW barrel. I am a proponent of using "Ideal OAL" that reliably feed/chamber from the magazine when the slide is released manually. If your pistol only reliably feeds/chambers shorter 1.070" OAL, I would used that OAL and decrease the start charge and conduct my work up with the anticipation that the max charge will be less than published (as the bullet base will be seated deeper in the case neck and generate greater chamber pressure).

Current Hodgdon load data shows 4.3 - 4.8 gr of W231/HP-38 for 115 gr LRN at 1.100" OAL. For your shorter 1.070" OAL, you could start at 4.0 gr and work up towards, say 4.5 gr while looking for pressure signs and accuracy trends of shot groups.

R.W.Dale said:

So the new course of action is to work up a new load for and use the parabellum MBC bullets in the pf9 loaded as needed. Then buy another thousand of a glock friendly bullet

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Huh? Glock friendly bullet?

Factory Glock barrel will chamber just about any shape nose well due to the larger than typical chamber mouth. Even with the longer leade of the Glock barrel, the rounder bullet nose loaded to typical 1.125"+ OAL will have the bearing surface engage the rifling sooner than more traditionally pointed nosed bullet design. Sooner the bearing surface engages the rifling, sooner the chamber pressure will build and result in more consistent accuracy.

I've loaded quite a few of these using 4.5g of ww231 for full sized autos with nary a problem.

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Since the 1.3" col already leads to an extent that I'm not comfortable with in my Glock 34

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Do you mean 1.130"?

If you are getting leading in Glock 34, it would be due to insufficient expansion of the bullet base (not enough powder charge or wrong powder?) or post-sizing of the bullet. Also, if pushed too hard, the rounded hill/valley rifling won't grip the bullet surface and the bullet will travel down the barrel without rotating with the rifling.

Many reloaders have successfully shot lead bullets in Glocks without leading. Since I have to use high+ range load data of W231/HP-38 to reliably cycle the slide on my Glocks, I prefer to use the heavier 125 gr Missouri Bullet (SmallBall) and mid-high range load data. I do not get leading in either factory Glock or LW barrels at mid-high range load data. I did get full barrel length leading with max load data.

OK, you want to have the same load for both pistols.

So, how about developing a load that's 1.070" in OAL that won't lead in the G34? (may be easier said than done)

But what I'm seeing is just forward of the headspace ring there's a second angled step as you transition into the leade.

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I am not seeing this "second angled step" in my Gen3 G17 barrel. It goes from the chamber where the case neck headspaces and right into about 1/8" of leade then the start of hill/valley rifling.

Lead is building up here and forming a very pronounced bore reducing ring in front if which and into the rifling origin there will be very little lead

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That may be fouling/lead smearing from gas cutting. Have you confirmed that it is indeed lead and not just fouling/lube?

I just checked my 40S&W Glock barrels also and I really don't see the "second angled step" - best I can tell, there is ever so slight "curving" from the chamber end where the case headspaces to the leade area but essentially it is chamber/leade/start of rifling.

Here's crude, not-to-scale picture of the Glock barrel (note very smooth, rounded hill/valley rifling vs sharp, squared-off rifling of traditional land/groove rifling).

I would try the following and see if the leading/smearing decreases:

1. Load the same 4.5 gr of W231 at 1.130" OAL but taper crimp only to .376" (if using FCD, set the FCD aside)
2. If #1 does not decrease the leading/smearing, then increase the powder charge to 4.6, 4.7 and 4.8 gr (Hodgdon max is 4.8 gr at 1.100", so you should be below max pressures at longer OAL)
3. If #1 and #2 works to decrease the leading/smearing, then do a work up with 1.070" OAL starting from 4.0 gr to 4.5 gr using the same .376" taper crimp
4. If #3 produces leading/smearing, try 4.6 and 4.7 gr.

Have you tried the 125 gr bullet? I really prefer the 125 over the 115 gr in 9mm and Glocks.

I had the same problem with those bullets in an XD. Seems like the XD chamber is tapered and first thought is to load shorter. I played with the taper crimp on an empty, till it fit in the chamber, then loaded to 'normal' 9mm OAL. Worked fine.

I can't find the email, but I talked to a fellow at MBC aboutit when I ran into the problem. He loaded short and didn't have a problem, but didn't say what his load was. I found what crimp worked, than adjusted the OAL to get off the rifling. From what I've read, just off the lands is OK for CB. Of coarse you have to be concerned about magazine feed, etc. My concern was high pressure and the long jump to the lands. Just checked OAL, 1.058" for XD 9mm