RT1200 problem

[Zamble]

I was checking my brass length after processing it.

1. 1.736
2. 1.736
3. 1.746
4. 1.737
5. 1.736
6. 1.737
7. 1.737
8. 1.742
9. 1.746
10. 1.748
11. 1.739

Ok, I understand the 1.736 and 1.737 are very close. But why such variations? Should not every one be that close? The 1.748, I ran it through a second time and it did not trim any off. For what it matters the ones above 1.737 I ran through a second time and not change.

The first thing I checked was to make sure that everything was tight and then I re-lubed everything. Same results.

Any suggestions?

[Bigtls1]

Is it all the same headstand? Varying headstamps will give you some variation I believe.

[joelogic]

What brand caliper are you using? Most are only rated to the hundredth.

Maybe the shoulders are not being bumped back consistently.

But the thousandth doesn't matter anyway.

[Zamble]

All the headstamps are federal.

I am using the Dillon digital caliper.

[Solus]

You might need to adjust it a bit more. 1.738 is way to small or m length should be between 1.740-1.750. 1.740 being the absolute minimum case lentgh

[tiller]

Everything is not tight if you are getting that much variation...

Max you should get is .003- soo set it 1.752 and the lowest you should see is 1.749 max of 1.752 Maybe even 1.753

[74c5]

Temperature? Everything changes as a function of temperature.

[joelogic]

You might need to adjust it a bit more. 1.738 is way to small or m length should be between 1.740-1.750. 1.740 being the absolute minimum case lentgh

There really is no minimum. If you measure once fired .223 you will often find pieces under 1.735".

[EL_NinO619]

Are you resizing first then just bumping the shoulders a little with the trim die? If the trim die does all the work it tends to give you those variances.

[tiller]

Temperature? Everything changes as a function of temperature.

Temperature does nothing to something mechanical

[Zamble]

I took it all apart and everything including the cutter was tight. I will run a few through when I get back home.

[joelogic]

Why chase trim length when there are so many other things to chase?

Neck thickness
Run out
Primer pocket uniformity
Flash hole
Meplat trimming
Anneling

[EL_NinO619]

Why chase trim length when there are so many other things to chase?

Neck thickness
Run out
Primer pocket uniformity
Flash hole
Meplat trimming
Anneling

IMHO if your trimming with a RT1200 you really shouldn't be worrying about any of those much (your not loading BR ammo) Make sure its under max and above min. Those small variance are not much to worry about for bulk loading.

[Zamble]

Well I ran some more after making sure it was all tight. There is like a .011 variation. I understand that it be within the min and max, but I want to understand why the variation is so great.

[tiller]

Well I ran some more after making sure it was all tight. There is like a .011 variation. I understand that it be within the min and max, but I want to understand why the variation is so great.

Is your tool head tightened down all the way? Shell plate too?

Also like asked before are you sizing after trimming? Do you still have it set up the way when I came down?