Sinclair/Wilson trimmer weirdness

[ftrrookie]

I have the stainless version of the Sinclair/Wilson trimmer with the micrometer head and am having a weird problem.
After setting up the trimmer it'll work fine trimming the cases to the exact length then it'll cut one short. You can tell when it's dong it because of the amount of brass being shaved off. I'll stop and check the locking screws and all adjustments are still correct then for the next few cases I'll trim a little, check for length, trim some more, check again etc... I'll go back to trimming full speed and it'll do it again. Trim one short. Some times as much as .005. I've checked everything I can think of making sure all it's all tight and as far as I can tell nothing is slipping or out of wack. I'm going to call Sinclair but I was wondering if anyone else has had this problem
By the way it does it on both of the calibers I load, .308 and .223

 

[gotcha]

Recently bought a Wilson myself. Its a wonderful tool compared to others I've had. I don't have the micrometer on mine but I've found that tapping the case into the case holder in a consistent fashion aids in uniform trim lengths. Its a "knack" you'll master with time....... On the cases that trim too short check the case head to shell holder measurement with the depth gauge portion of your calipers. Once you "get the knack" that measurement will become very consistent.

 

[bradleya479]

Jay make sure if your using a sharkfin clamp that your casehead is butting all the way against the threaded stop on the trimmer. I have left a gap there a few times an the sharkfin holds enough down pressure on the shellholder that it will not slide back when you start trimming thus taking off way to much brass.

Bradley

 

[bow shot]

+1 to all of the above!

 

[Dos XX]

Recently bought a Wilson myself. Its a wonderful tool compared to others I've had. I don't have the micrometer on mine but I've found that tapping the case into the case holder in a consistent fashion aids in uniform trim lengths. Its a "knack" you'll master with time....... On the cases that trim too short check the case head to shell holder measurement with the depth gauge portion of your calipers. Once you "get the knack" that measurement will become very consistent.

Not disputing this, but help me understand it. I thought all the shell holder did was keep the shell from turning. Isn't trim length a function of the micrometer spindle or threaded bolt acting as a dead stop?

I struggled with this rig at first as well. The trim length can vary by how much feed pressure you are willing to put on the cutter. I now have a feel for what it takes to trim .001-.002. I'm not sure I even need the dead stop now.

 

[bradleya479]

I guess I need to clarfiy what in meant, the casehead need to be firm against the spindle everytime, sorry I said shellholder earlier.

 

[ftrrookie]

I guess I need to clarfiy what in meant, the casehead need to be firm against the spindle everytime, sorry I said shellholder earlier.

That's what I thought you meant and it's what I hope the problem is. Get in a groove trimming cases and not double checking the position of the base against the spindle. I thought that the sharkfin clamp would push the case back against the spindle but apparently that's not the case.

 

[Shynloco]

I guess I need to clarfiy what in meant, the casehead need to be firm against the spindle everytime, sorry I said shellholder earlier.

+1. I caught myself not checking that casehead tightness when I first bought my Wilson trimmer which led to exactly what the OP stated was happening. Since then (and checking each case for a firm bit against the stop) I've had no variations whatsoever as described.

 

[jlow]

One of the things about using the Wilson trimmer is apart from having the case head pressed firm against the stops, the pressure you put on the cutter also affects the depth of the cut. It sounds obvious but in actual execution, it is easy to put more pressure sometime especially if you are using a cordless drill. In my experience – inconsistent pressure = inconsistent case length.

 

[gotcha]

As I said earlier, if you check the case head to case holder measurement and it's consistent then the erratic measurements are caused by a different function. Either inconsistent pressure you are applying to the cutter or a gap between case head & micrometer stop. The longer you use the tool, with these variables in mind, the more accurate it gets. Ay least that's how it worked for me.

 

[Ecomeat]

I was having exactly the same problem a couple of years ago. I finally realised that my handgrip on the case holder , with hand directly over the "shark fin" as well as finger grip pressure on the case holder , was inconsistent.
I don't clamp the base down onto a bench, and had/have got into the habit of using my left hand with a grip on the shell holder/shark fin, and downwards pressure to make sure nothing moves.
Once I started consciously pulling the shell holder in towards the micrometer stop, with my left hand, the problem ended.