Giraud trimmer question. When to trim?

[DngBat7]

I know it’s a dumb question. Was wondering do you trim with giraud before or after sizing brass? I am assuming after it is sized.

 

[Turbulent Turtle]

I know it’s a dumb question. Was wondering do you trim with giraud before or after sizing brass? I am assuming after it is sized.

Correct, since it indexes from the shoulder.

 

[ricco1949]

I trim after sizing and after every cleaning in pins to trim away any peaning at case mouth. Most of the case holders I have are cut with the finishing reamer so the case won't fit properly until sized. Rick M.

 

[DngBat7]

Correct, since it indexes from the shoulder.

Yea. That’s why I asked. I had a Wilson. New to indexing of the shoulder

 

[Straightshooter1]

Yea. That’s why I asked. I had a Wilson. New to indexing of the shoulder

As long as your shoulder bump in consistent, your trim length will be as well.

+1 on trimming with this trimmer as the last operation.

 

[MikeMcCasland]

I trim after sizing and after every cleaning in pins to trim away any peaning at case mouth. Most of the case holders I have are cut with the finishing reamer so the case won't fit properly until sized. Rick M.

Where'd you get the blank inserts you finished with the reamer?

 

[Sheldon N]

Yes, after sizing. And even more important than the fact that it indexes off the shoulder is the fact that the cutter head is set for a specific case mouth diameter. If you tried to trim unsized brass the chamfer debur would be all messed up because the diameter of the mouth would be too large.

 

[Ned Ludd]

Yes, after sizing. And even more important than the fact that it indexes off the shoulder is the fact that the cutter head is set for a specific case mouth diameter. If you tried to trim unsized brass the chamfer debur would be all messed up because the diameter of the mouth would be too large.

I'll add to Sheldon's observation that varying neck wall thickness with different brands of brass can also make a big difference in the inside/outside chamfer obtained with the Giraud. There are several nuances to using the Giraud that are markedly different from more conventional case trimmers, but the end results are most definitely worth the learning curve.

Like everyone else, I trim/chamfer after re-sizing as the very last step in the brass prep process.

 

[DngBat7]

Yes, after sizing. And even more important than the fact that it indexes off the shoulder is the fact that the cutter head is set for a specific case mouth diameter. If you tried to trim unsized brass the chamfer debur would be all messed up because the diameter of the mouth would be too large.

I though I was asking a dumb question, But this is why I asked. Never would have thought of this.

 

[Sheldon N]

I though I was asking a dumb question, But this is why I asked. Never would have thought of this.

Not a dumb question at all, and way better to ask than to muck up a bunch of cases.

 

[ricco1949]

Where'd you get the blank inserts you finished with the reamer?

I made them.

 

[DngBat7]

I made them.

Does not giraud sell the blank inserts?

 

[Bradu]

Does not giraud sell the blank inserts?

Yes, they do sell the blanks.

 

[NorCalMikie]

Not a dumb question at all

The only dumb question is... "Did I really do that last night"?

What you need to do is get the actual "measured length" of YOUR chamber. That way, you'll know if you really need to trim. Most chambers are cut .020" longer than Max Trim Length. And depending on the type of die you use, you may not need to trim for a looong time. I have BR brass with 25+ resizes that still don't need trimming. All sized with Forster Precision Bush Bump Dies. Brass doesn't get a chance to grow like standard dies with the neck button that pulls the necks longer with the up stroke. YMMV.

 

[ricco1949]

Does not giraud sell the blank inserts?

Yes. I make them because I can.