OAL is killing me

[blastfact]

I'm having a hell of a time with my OAL with my 9mm loads. It's all over the place.

Loading with mixed brass. Setup for a 1.130 OAL. Producing any were from 1.140 to 1.120. Lee Breechlock with Lee die's. The 115 gn bullets seem to fit the set die well. Die setup: Screw die in until it mates with ram. Then back off 3 turns. Lock and adjust. No crimp. Stroke from stop to stop.

Bullets are bulk 115 gn. FMJ. I have spot measured and weighted them. All looks to be good. The die/anvil is not putting any marks on the bullets.

I've never had this problem.

 

[Tell Sackett]

What is the make of the bullet? Are they "bulk" type of bullets? Where does the "die anvil" hit them?

Do a test. Take about 20 to 50 bullets out of your batch and compare the ogive. Even with quality bullets you will have variations. I have had this problem quite a bit with plated bullets, different calibers though. The ogive from bullet to bullet can change a little during a production run. More often then not though, it is from different runs. If they are bulk bullets, you may be getting bullets from many different runs.

The other thing is the mixed cases. Take a bunch of the same case brand and seat the bullets consecutively. Measure the results. I'll almost bet that they are virtually the same.

FWIW and I hope this helps! Let us know!

 

[Reloader Fred]

In all likelihood, the bullet to seating stem mating isn't perfect. This usually causes the seating stem to contact a point on the ogive of the bullet, rather than the nose. Due to differences in friction when seating the bullet, the stem doesn't push the bullet into each case the same distance, hence the variations in OAL.

You can either modify the seating stem you have by relieving some material from the inside edge a little bit, so the bullet will go all the way into the cup portion of the stem, or you can get another stem that better fits the bullet you're using.

You can test to see where contact is being made on the bullet by coating it with black ink from a Sharpie. Then seat a bullet and see where the ink is rubbed off. If it's down on the ogive, then you'll know where you have to relieve the mouth of the seating stem to obtain a better fit. I do this on my drill press, but it can be done with an electric drill by chucking the seating stem in it and using a tool to remove a small amount of metal, similar to a lathe. If you have a lathe, that's even better. Just play with it until you get a perfect fit, or at least have the nose of the bullet contacting the bottom of the cup on the seating stem.

Hope this helps.

Fred

 

[blastfact]

Thanks

Will check ogive. I will pull the anvil out of the die, place a bullet in it and measure a bunch of them and see how much they vary.

I forgot all about ogive,,, sorry. Funny,,, I did not have any issues with the first 25 I ran.

O-well

 

[Jellybean]

No crimp? You should be using a taper crimp on them, that will hold the bullets in place after being seated. If your dies are too far out to apply a proper taper crimp they may not be tight enough to resist being pushed deeper by normal handling or pushed out by compressed powder.

The Lee dies will perform both a taper and roll crimp. Adjust them just to the point where there is no roll.

 

[tdan]

You mention "no crimp". Do you taper crimp at a separate stage? Crimping while seating can cause issues, especially when loading mixed brass of unequal length.

 

[Mortech]

I crimp AFTER seating using Lee dies .

 

[blastfact]

Hello all,

I've read all the post. Lot's of good info!

I have been very busy and have not made it back to the bench.

But!!!! Friends from Arkansas came with gifts for me Sat. evening.

A brand new Lee Loader kit made it to me complete with 38/357 dies. This is a last gen kit that has never been used. It's all there as if it was produced last month. Clean and ready for the bench.

Also a old MEC Super 250 made its way to me. It's old and in need of some major TLC. I'm just the man for the job.

You might by chance notice a bullet chunker setting there.

Many of you will know what it is. It's my all time fav. handgun! CZ Vz-52 a work of Iron Curtain art work to me. It's .30 cal / 7.62x25mm, maddness! It's all original. Never was re-armored. All serial numbers match, barrel is clean, finish holster worn pretty bad. Has the oem firing pin. And the decocker does not work. It's a 1953 model and came with enough Chez surplus, fast stuff to start a small war. It shoots very good. I plan on changing out the firing pin, rollers and making the decocker work. I may repark it and update the grips.

My buddy's in Arkansas love me and worry so much about my gun needs once I told them I was back.

And all free,,, as it should be.