Giraud trimmer variance

[mdmp5]

I really enjoy my Giraud trimmer. However, the inherent design uses the shoulder to index off for trimming. In effect, I find variance in my case lengths as much as .006". Not a very big deal, but I would like to chop that number down. I do know that depending on how much shoulder setback is introduced, that can affect the trim length. However, for some brass that measures the exact amount of setback, I still get some variance. Anyone else experience this phenomenon?

 

[poison123]

It ain't the trimmer but the inherent inaccuracy of sizing brass. On average I get +/- .002 variance on the sizing.

 

[morganlamprecht]

i use a worlds finest that indexes off the shoulder as well and have noticed that if i full length size cases it trims really consistent, within .001-.002" but if i only neck size try to trim i have the same issues u describe...havent really thought of a way to correct it

 

[gasdoc09]

Lube choice and annealing appears to make a large difference in sizing consistency, and therefore case length when trimmed off the shoulder with a Giraud.

Case lube, sizing consistency, annealing, and trim length - AR15.COM

 

[427Cobra]

Big Giant +1 to what GasDoc09 said, another thing to consider is, can you shoot the difference in .010 trim lengths, these ain't tight chambered Benchrest guns where every single .001 of a inch of everything matters, so no you can't.

 

[ZiaHunter]

I like the Giraud for the fact that it indexes off the shoulder which give you uniform neck lengths which is especially important if you turn necks. The two critical factors affecting overall case length as mentioned above is adequate lubrication and annealing. Improper lubrication especially at the base of the case will cause stretching as the ram is lowered. This is the first thing I check if getting variances in sizing. Cases with variance in case hardness will also size inconsistently and is resolved by annealing.