Frustratingly inconsistent trim length

[Reformedcitykid]

Hi all, I’m losing my mind here and hoping you can help. I’m trimming some 223 brass with the Lyman Universal Trimmer and getting incredibly inconsistent trim lengths. The lengths are different both from one to the next, but also on the same case mouth from spot to spot. The trimming rod seems to wobbling and it looks like the lock nut is spinning off center, but I can't tell if it's an illusion or actually off, and if so how to fix it.

What gives? Anyone have any tips or advice?

Trimming
Finished lengths
Trimming rod wobble

 

[Maurygold]

Giraud or Henderson. You need a precise tool for precise outcomes

 

[spife7980]

Three thousandths. 1.748-1.751 is plenty consistent for what you’re doing it with. I saw nothing wrong with your pics.

 

[moonstalanda]

I just went from the Lyman to the Giraud last week. The lyman would be in the +- .005 but I could get that number down if I applied the right pressure to my drill. The giraud is dead on every single time I measure. Its honestly amazing. The main reason for my switch wasnt trim length for me but the fact that it deburs/chamfers too. I figured, if I get sick of reloading, I can sell the Giraud and get most of my money back based on the listings I have seen on this site. But I think I'm gonna hold onto it. Will keep the lyman for trimming brass I rarely shoot like 375 H&H and 264 WM

 

[B y r o n]

Don't know what attachments you have on the calipers but suspect they could contribute to number differences. Moving the case up and down the length of the jaws is also not desireable.

Assume you are trimming sized brass per instructions otherwise the case mouth could wobble on the pilot and that could affect trim length as well.

 

[Charlie Papa]

Don't know what attachments you have on the calipers but suspect they could contribute to number differences. Moving the case up and down the length of the jaws is also not desireable.

I thought the same thing. I measure right on the caliper jaws and have never felt a need for anything additional.