Wilson trimmer poor results with mixed brass?

[dboyles]

I've got the Wilson trimmer with a .223 Rem case holder and have been getting pretty awful consistency with mixed brass. I sized about 90 pieces of range brass (Forster Co-Ax, Forster FL die, Imperial wax) and got good consistency in terms of shoulder bump (+/- 0.001"), but when I go to trim it I get a lot of variation. Five random cases measure:

1.757"
1.751"
1.749"
1.755"
1.756"

I was as consistent as I could be with regards to putting the case into the holder and applying pressure with the cutter (attached to a cordless drill). Even with good, consistent brass I'm only getting +/- 0.002" on trim length, although I consider that acceptable. Is this normal, or a matter of technique?

edit: I will add that the brass is all LC 07 and 08, and there doesn't seem to be any pattern to which headstamp ends up long or short.

 

[jonbearman]

I always tap the case in the shoulder to make sure it is seated.Cases must be clean of course.Are you cranking by hand or using a drill adaptor.

 

[dboyles]

Wellllll, I may have been a little too quick to blame the tool rather than the operator. I was trying to apply the same amount of [modest] pressure on the cutter, but it seems that I wasn't applying enough to have the cutter "bottom out" on the tool. Once I set it up for me to really lean into it, I'm getting consistent trim lengths. I have a ton of brass and don't have to trim much, so I'll take the blame for this little slip-up, but I'll leave this post here in case others search for the same thing.

 

[spclark]

Man that's really hard to do! The way the Wilson's designed the case is backed up by the settable stop block on the left and the cutter on the right, the shaft of which stops on it's housing face on the right.

Only thing I can think of (I've used a Wilson trimmer for ALL my brass for years) is you're cranking down on the case holder locker before the case inside is in really FIRM contact with the stop block. So in effect some cases are getting trimmed short 'cause the case holder's too far to the right when they're being trimmed.

Be careful too when measuring trimmed cases that your neck de-burring opertions aren't raising a new burr that's interfering with your measuring accuracy. Easy to do so measure your trimmed cases BEFORE and again after neck chamfering.

What kind of caliper you using? Analogue (slide rule or mechanical dial type) or digital? I use and recommend the latter for their inherent accuracy.

 

[nosualc]

Did you decap your cases first?

-nosualc

 

[spclark]

Good you figured it out!

Here's another tip: do NOT tap the case mouths on anything to get trimmed cases out of the case holder. Instead get a length of birch dowel rod at a local hardware store, trim off a couple suitable lengths to slip inside a trimmed case then use THAT as a case removal tool. I use a Wilson manual decapping stem, kind of like a pin punch for this, tapped sharply on a Delrin block.

Brass rod works too but costs more & is harder (for some folks) to cut and square the ends of. Will outlast wooden dowels 100:1 unless you lose it....

 

[jonbearman]

It seems that you were alittle insulted and I meant no disrespect,I was trying to give you pointers.If you want to make it easy,get the power adaptor from sinclairs and it wont be as hard to bear down.I have been using this method for ten years with no problems.

 

[dboyles]

It seems that you were alittle insulted and I meant no disrespect,I was trying to give you pointers.If you want to make it easy,get the power adaptor from sinclairs and it wont be as hard to bear down.I have been using this method for ten years with no problems.

Not at all, Jon - just a little embarrassed that I posted before really taking time to think about it.

I do use the drill adapter. Purchased it several years ago right after trimming 1000 pieces of brass. :-[

 

[jonbearman]

You must have had really sore hands after that lot.

 

[michaeljp]

When i bought my wilson trimmer from a multiple Australian benchrest champ for my 6PPC he said once ive trimmed the case mouth turn the case and holder around and trim up the base aswell. He said that i will get more consistant measurements this way as the bases are not perfect, and to also turn the case holder half a turn as you trim the mouth.