Lee seating/crimping die inconsistency

[TheotherMikeG]

Good afternoon, everyone. It's been a while since I've posted, but I find myself with an issue.
I've been using a Lee Classic Turret press and dies for over 10 years, and while I never felt like they offer high precision, they normally provide a decent amount of repeatability once I have them dialed in.

I've set up to load some 125gr lead truncated in mixed brass for practice. I set OAL at 1.057 but I'm getting cartridges that range +/- .20". I didn't experience this using Zero 125gr JHP so I'm wondering if the problem is bullet or die related. Any insight on this is most appreciated.

 

[peels]

My guess is that you are slightly swaging the bullet with the seating stem. With it being lead, it is probably softer than a jacketed bullet.

Next time take note of the bullet seating force (the resistance on the lever pull). You may find that the ones that take more force to seat may be the longer ones, whereas the ones that seat with minimal effort would be the shorter ones.

 

[wrench459]

...
I've set up to load some 125gr lead truncated in mixed brass for practice. I set OAL at 1.057 but I'm getting cartridges that range +/- .20". I didn't experience this using Zero 125gr JHP so I'm wondering if the problem is bullet or die related. Any

+/-.200 is a wild swing

 

[snakeye]

So your saying your OAL's vary between .857 and 1.257. Which is definitely out of whack. Now if you meant .020 then OAL is between 1.037 and 1.077 then I would look at a bigger flare for the lead bullets. My experience with lead bullets that I load has always required a wider flare and results in less seating issues than plated or FMJ bullets with a smaller flare.

 

[TheotherMikeG]

Sorry, math deficient. OAL can range between 1.035 and 1.087, approximately.

Peels, I think you're correct, but even using consistent force I'm getting uneven results.

 

[LiveLife]

I didn't experience this using Zero 125gr JHP so I'm wondering if the problem is bullet or die related.

So load some JHP bullets.

If wild OAL swing goes away, it's the bullets. If problem persists, I would inspect the seating/crimping die and thoroughly clean the inside removing any gunk that have built up and repeat the measurements (I use Hoppes solvent to clean the dies and it does a great job removing gunk from lead bullets).

In a recent myth busting thread, I seated/taper crimped 9mm 115 gr FMJ and 124 gr FP bullets using mixed range brass and got .003" and .002" OAL variance using Lee dies and Pro 1000 press - https://www.thehighroad.org/index.p...progressive-press.833604/page-2#post-10779806

Even though you are using lead bullets, I think 1.035" - 1.087" swing is quite a bit as I usually get less than .010" swing with lead bullets at the extremes and mostly less than .005".

 

[TheotherMikeG]

So load some JHP bullets.

If wild OAL swing goes away, it's the bullets. If problem persists, I would inspect the seating/crimping die and thoroughly clean the inside removing any gunk that have built up and repeat the measurements (I use Hoppes solvent to clean the dies and it does a great job removing gunk from lead bullets).

In a recent myth busting thread, I seated/taper crimped 9mm 115 gr FMJ and 124 gr FP bullets using mixed range brass and got .003" and .002" OAL variance using Lee dies and Pro 1000 press - https://www.thehighroad.org/index.p...progressive-press.833604/page-2#post-10779806

Even though you are using lead bullets, I think 1.035" - 1.087" swing is quite a bit as I usually get less than .010" swing with lead bullets at the extremes and mostly less than .005".

Thank you for the excellent advice

 

[CZ9shooter]

Do the longest rounds tend to be one headstamp, while the shortest are another? If so, sort your brass.

Tougher brass offers more resistance to seating the bullet, causing it to swage further into the seating stem. Some easy seating brass, some tough brass, equals inconsistency.

A custom fit seating stem could help in this situation as well, eliminating any bullet swaging.

 

[Livin_Cincy]

To isolate the problem between seating and crimping have you tried seating a group of them and measuring them without seating & crimping in the same die ?

 

[Walkalong]

Some easy seating brass, some tough brass, equals inconsistency.

Not that much, he has an issue besides mixed brass. Mixed brass can do a .005 spread with good bullet/seater stem fit.

 

[Toprudder]

Do the longest rounds tend to be one headstamp, while the shortest are another? If so, sort your brass.

Tougher brass offers more resistance to seating the bullet, causing it to swage further into the seating stem. Some easy seating brass, some tough brass, equals inconsistency.

A custom fit seating stem could help in this situation as well, eliminating any bullet swaging.

Send Lee a few bullets and they will make a custom seating stem for very little money. I am about ready to do that for some bullets I have a similar problem with.

 

[Bartojc]

I second BDS suggestion.

Something is not right. I've not had variations like that. Maybe .003 or so with mixed brass but nothing like what you are seeing.

-Jeff

 

[wmgeorge]

Measure your brass with your digital calipers, same with bullets. All the same or pretty close? Try expanding the mouth of the case a bit more and check again. I have loaded a bunch of 45 ACP and other calibers, never had to have a custom bullet seating die made.

 

[Mark NM]

Had similar issue (similar OAL range) when loading a substantial # of lead bullets, found was caused by buildup of waxy lubricant, precision returned after thorough cleaning with Hoppe’s. Give it a try ...

 

[NWPilgrim]

Had similar issue (similar OAL range) when loading a substantial # of lead bullets, found was caused by buildup of waxy lubricant, precision returned after thorough cleaning with Hoppe’s. Give it a try ...

Exactly my experience. Doesn't happen with 50 or so cartridges, But a few hundred and the wax lube builds up and eventually drops out in a chunk and then starts over again. Prevent this by periodically cleaning the seating die out with a cotton swab or blast of brake cleaner (non chlorinated). I think this is exacerbated by crimping while seating, too. I get much less build up when I crimp separately, but I still periodically clean the seating die. Bullet shape and seat stem shape may also increase/decrease how much this lube build up is shaved off.