case trimming

[Buchan]

Using the attached to trim to the appropriate length of just under 51mm for .308. When the case length guide is snug to the trimming bur and the base of the case is tight in the case holder, it consistently cuts to 51.02/51.03 and no more. I then have to remove the case holder and finish by hand.
Am I missing something or is this just an irritating normal variance and I should get a new case holder?

 

[Cyres]

Is that a Lyman trimmer and if so is the central pilot fully screwed into the handle.? Might need nipping up a bit.
Also do you chamfer inside and outer of the case.?
D

 

[Will the chippy]

File a bit off the guide pin depth stop. Personally I wouldn’t worry about it.

 

[Muir]

Most case trimmers have a learning curve. Maybe you just need more practice?-Muir

 

[Buchan]

Is that a Lyman trimmer and if so is the central pilot fully screwed into the handle.? Might need nipping up a bit.
Also do you chamfer inside and outer of the case.?
D

Lee I think, held in the drill chuck.

 

[Fabnosh]

I have the same thing for all the calibres I shoot and it works well. I've only ever done it by hand and not used the drill. As has been mentioned, I did trim the tiniest amount of the guide pin (the bit that goes through the primer hole) for my .308 but all the others have been fine.

FN

 

[Cyres]

Is the centre pilot heldin by a grub screw if so loosen and ensure it's fully seated before tightening the grub screw.
D

 

[Bavarianbrit]

How that can work ? As the inside (back) of the head is not a controlled dimension in case manufacturing within reason, it will get close but no cigar.

 

[NoIDeer]

As said above check the centre spigot is screwed tightly up to the cutting blades and try again. Mole grips and a vice to get a good grip that thread is tight.

 

[nocturnaldave]

Here is slightly blunt honesty….. there is nothing wrong with it…. Work away… it won’t make any difference.

 

[nocturnaldave]

Ok so I feel bad…. Better explanation of above… 0.02mm is less than a thou. Approximately 3/4 of a thou. The human hand and a normally used standard of callipers can reliably only measure to about a thou. Most loaders accept that a thou is about as good as you can get. If everything you churn out is within a thou then you are doing grand.

 

[finnbear270]

I was / am a little confused here, do you not cut to length first with a depth stop affair & then de burr???

 

[Cyres]

Yes
D

 

[finnbear270]

Ah,! read the OP a bit cock eyed.

 

[Donkey Basher]

As said above check the centre spigot is screwed tightly up to the cutting blades and try again. Mole grips and a vice to get a good grip that thread is tight.

A word of caution if you do this - if you leave any tool marks on the shaft of the guide it’ll snag in the inside of the case mouth! If you really feel the need to use tools to get the guide in nice & tight I’d recommend either that you use long nosed pliers & grip the guide where it is recessed & stamped .308 or use a suitable piece of cardboard from a cereal packet to protect the surface of the guide. If you don’t you’ll end up buying a new guide!

 

[Cyres]

Just checked. Lee trimmer is screw in type the Lyman pilot held in place by grub screw.
D

 

[Buchan]

Sorted. I found a case that was 51mm and filed a gnat's crochet off the pin. Then trimmed a batch of 30 all to 50.99. Thanks folks!

 

[Will the chippy]

50.99 oh no no no. That's not going to work! What about your neck tension? That's knackered it now.