Tri Trimmer/ full length sizing question

[needham]

been reading a bunch of old threads on the giraud tri trimmer. and I think I am going to get one and connect it to a bench buffer.

here is the question:

I have a pile of true 1x lake city brass. It was not fired from my rifle.

I plan on annealing then full length resizing with a redding die without the expander ball installed . Even though it has not been fired from my rifle, will annealing/ FLS produce consistent enough shoulders for the trimmer to be super accurate?

 

[Lunchbox27]

You should have no problem achieving the desired trim length. Keep in mind, you will see a variation of +\- a thousands in length. This will be from head spacing being +\-.

Brass spring back, using too much lube from one case to another, etc.

But... again, a thousands or even 2 will hurt nothing.

 

[straightshooter1]

been reading a bunch of old threads on the giraud tri trimmer. and I think I am going to get one and connect it to a bench buffer.

here is the question:

I have a pile of true 1x lake city brass. It was not fired from my rifle.

I plan on annealing then full length resizing with a redding die without the expander ball installed . Even though it has not been fired from my rifle, will annealing/ FLS produce consistent enough shoulders for the trimmer to be super accurate?

As mentioned, there's some variation in the head spacing which will transfer to the COAL you'll get when trimming, but it's typically not anything significant. I get something less than +/- .001 after trimming. Trimming with my Giraud is my very last step in case prep.

Not too, to get good consistency in you trimming, you'll want to develop a consistent feel for pressing the case into the trimmer as varying pressure can add to having a wider variance than you might want. It's not a really big deal, but thought I'd simply give you a heads up about that.

Note too, since you're not using an expander ball (I don't either), you'll want to expand the necks with an expander mandrel to whatever neck tension you're after BEFORE your trim. This way you get the proper chamfer on the case mouth.

 

[needham]

As mentioned, there's some variation in the head spacing which will transfer to the COAL you'll get when trimming, but it's typically not anything significant. I get something less than +/- .001 after trimming. Trimming with my Giraud is my very last step in case prep.

Not too, to get good consistency in you trimming, you'll want to develop a consistent feel for pressing the case into the trimmer as varying pressure can add to having a wider variance than you might want. It's not a really big deal, but thought I'd simply give you a heads up about that.

Note too, since you're not using an expander ball (I don't either), you'll want to expand the necks with an expander mandrel to whatever neck tension you're after BEFORE your trim. This way you get the proper chamfer on the case mouth.

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yes, I will also be adding a sinclair mandrel to the operation.

I have two, dillon 1050s now and will be downsizing to a 550 with a couple of tool heads. just seems easier overall to go that route, as I dont use the 1050s to their full capacity.

with the regulator mod to the annealeez and grinder mod to a giraud trimmer coupled with a couple of tool heads on a 550.....all that will serve my purpose with a couple hundred rounds a hour, make excellent ammo, and have time for local steel matches or step up in competition when and if I want to.