reloading 9mm OAL inconsistent

[rp85]

hello
basically can't get consistent OAL reloading for the 9mm press is a hornady pro-jector (pre l.n.l) using the lee 358-125rf and tl356-124-2r. variance occurs with both bullet types. bullets are cast from lee's six cavity molds. variance is @.012". tried 2 different seating dies and 3 different seating stems but nothing works. target length for the 358-125rf is 1.050", 1.125" for the tl1242r. thx for any suggestions.

rp

fix? the hornady pro-jector has a large nut to hold the shell plate in place. instructions says to tighten and then loosen slightly. well the nut was backed off @3/4 turn. shell plate actually wobbled. went back and tighten the nut, then loosen a little less than 1/8 of a turn. round nose bullets were right on desired length and @80% of flat nose bullets were right on desired length. different bullet setter plug might fix that problem. not smart enough to understand why a loose shell plate was the problem. noticed the "bullet crimps" just did not look right, bullet crimps now look o.k.

thx for inputs.

rp

[plainsman456]

This is written in isn't it?

[rp85]

OAL seems a little inconsistent

[JeffG]

I see variances on mine, maybe not that much, but I attribute it to the fact I'm not using a dead length seating die. Since there are variances in the cast bullets and the seating die is making contact on the ogive and not the end of the bullet, there will be variances because the bullets are not perfect.

[John Boy]

Buy a Lee Carbide Factory Crimp Die and give it a good hard crimp after you determine correct seating depth for the bullets... http://leeprecision.com/carbide-factory-crimp-die-9mm.html

[bedbugbilly]

As JeffG points out . . . you're going to get a minimal variance. I have no experience with the Hornady press you're talking about but I still can't figure out how you are getting anything other than a very minimal difference. If your seating die is locked in to your press tight and you seating stem is locked tight . . . the only variance I see that you could get is due to the seating stem profile not matching your bullet profile? If it is pushing on the nose of the boolit, it should seat the same COAL everytime you seat. If it doesn't and is pushing on the profile and not the nose . . then you're bound to get some variance. The big question is . . . do they feed and shoot O.K.

I load Lyman 358-242 RF as well as Lee 356-120-TC with my Lee 4 die set and use the same seating die/stem for both. I measure with my digital caliper and have very very minimal difference in COAL. The only other thing that I can think of that might give you a variance of any large amount is if you are measuring with a digital caliper but when you measure, you are not getting the loaded cartridge centered in your calipers the way is should be each time? Any possibility of that?

[Ed_Shot]

I'd say you might normally expect a +/- .003 press-variance but .012 seems a little much. You don't say....are you using mixed headstamp brass?

[376Steyr]

Try measuring the length of several sized and lubed bullets. My guess is the bullets are getting squished to various lengths as they go through the sizing process, with the ogive location, where the seating punch contacts, moving about from bullet to bullet.

[mongoose33]

I have the newer LnL AP progressive. Depending on the bullet you're using and the seater die, you'll have some variance in the OAL. Let's face it, unless the bullets are perfect, and the seating die perfect, and there's no lube or other detritus inside the die keeping the OAL inconsistent, you're going to have variation in OAL.

.012 is a lot of variance. One thing that makes a huge difference is whether you are setting up the die without all the other stations being filled at the same time. You will seat the bullet deeper without all the other stations filled than you will with the sizing die, powder drop, casemouth expander, and crimp die creating resistance.

How much? I figure at least .008--that is, I figure the seating depth will be .008 longer with all five stations occupied than if you just check the seating die by itself. Sometimes a bit more. And that is within shouting distance of your .012 variance.

Since you've checked different dies and different seating stems, this is the only thing I can think of that's different. What you get as a depth depends on whether all stations are used or just the bullet seating station.

[runfiverun]

never mind all that if they feed through the pistol you got a non issue.
take some of the long ones and feed them from the magazine 3-4 is enough just rack them in/out by hand.
if they feed and chamber fine,,, shoot them.

[OptimusPanda]

I actually had that problem with my LNL and 45 auto...when I went from 230gr FMJ to 200gr SWC I never changed the seating stem from concave to flat. After correcting that I only see a couple thou +/-. Though you said you changed the stem and still see it.

[Shiloh]

Measure your boolits for length. Pick out 10 that are the same length. Load, seat, measure. My guess is that the margin of your variance will be greatly reduced.

Shiloh

[emorris]

Are you resizing the brass as you load, or are you running the cases through first to resize only? The reasion I ask is the shell carrier has some flex on these presses, and if your resizing brass as you load the col will vary. A harder to resize case will require more force and put more strain on that sid of the shell plate, which results in the opposite side of the carrier to raise slightly higher ( think about a lever with the ram being the pivot point). This is more pronounced if the resizing die is set up to allow the press handle to move completly down. If there is a dead stop in the travel it's not as bad.
I now resize, with lube on brass, before i run the brass through to reload. This has made my col alot more consistent. For the FN bullet see if you can find, have, or make a flat seater stem.

[rp85]

thx for input. note fix(?) in first post.

[therealhitman]

...target length for the 358-125rf is 1.050"...


"Target" length? Careful, I'm pretty sure that's the minimum OAL. Might be misinterpreting the load data there.