Henderson trimming question

[fattybinz]

For those using the Henderson trimmer...how do you trim brass that is shorter than your target length? So for example, for my 6 Dasher alpha brass, I emailed Alpha and they said they recommend trimming to 1.540". So I set the length screw for that target trim length....but then some pieces are shorter than 1.540", some as much as .015" shorter, so they don't touch the trimmer and therefore are not getting chamfered. So if you set that screw to trim everything to 1.540", how do you deal with shorter cases that you need to let grow to that uniform trim length? Do I just remove the target-length screw and run the brass without a screw so I can get it to barely touch to chamfer, or do I make a second length screw that is shorter? Since the chamfer and trim are done with one carbide blade, and I need to trim some just to get the benefit for the chamfer, won't those cases keep getting shorter or shorter (and never get to the 1.540"), or at the very least stay the same length? OR...do I just find the shortest pieces of brass, which is around 1.525" and then trim everything down to that length so that none will ever be shorter than that?

 

[ToddKS]

Are you trimming virgin brass or fired brass.

On virgin brass, I would not trim with the Henderson. I just chamfer the inside of the case mouth and load.

On fired brass, I would trim to the longest length that makes all the cases even (in your example, 1.525). This will give you consistency.

 

[TTE]

how do you deal with shorter cases that you need to let grow to that uniform trim length?

Here is one option -
https://www.lymanproducts.com/brands/lyman/case-prep-tools/case-prep-tools/deburring-tool

 

[RegionRat]

So if you set that screw to trim everything to 1.540", how do you deal with shorter cases that you need to let grow to that uniform trim length? Do I just remove the target-length screw and run the brass without a screw so I can get it to barely touch to chamfer, or do I make a second length screw that is shorter?

No, shorter ones do not need to be trimmed yet again.

You will want to hand chamfer those and segregate them till you test to see if they group with your "normal" ones. A hand chamfer tool is something fundamental that you should have. It isn't expensive.

OR...do I just find the shortest pieces of brass, which is around 1.525" and then trim everything down to that length so that none will ever be shorter than that?

That is up to you.

There are long discussions on the pros and cons or running brass shorter or longer than "normal". If your chamber is typical, then running it very short isn't where a rookie should start.

Your brass batch should not have been that wildly different. Something caused some to be that much longer or shorter than the rest. That is the cost of the learning curve.

Try to test the difference early in your reloading/shooting journey. Don't fall for experimental errors from small samples, but at the same time you must work hard on your workmanship and learn to set your own tolerances. You can only take good guesses at those tolerances unless you are being mentored by experienced club mates or you learn to test for yourself, preferably both.

 

[Oso]

I have been playing with my Henderson trimming down some short cases (300BO). My unit came with several bolt/locking nuts that are in two (2) different length for different length cases. I needed something even shorter so I went to HomeDepot and bought a shorter length replacement bolt (5/16" x 18 tpi) and locking nut.

It has been my experience with the Henderson that potential reasons that may cause inconsistent cutting length are:
1) Cutting stop bolt is not securely tightened resulting in minor shifting/play that creates minor variations in cutting length.
2) Trimming cases that have a primer inserted whether live or spent. Your primer(s) may not be fully seated flush or below surface.
3) Irregularity of the case rim caused during extraction (bent case rim).
4) Debris from dirty case or other obstruction that is interfering with the case bottom sitting flush against the bottom of the case holder collet.
5) Trimming cases where the case neck diameter is larger than the diameter of the cutting head's arbor. A good example of this is trying to trim fired cases before resizing the neck to match the arbor. Attempting to trim an over-sized neck diameter may result in off-center trimming. Also, if the neck diameter is greater than the specific cutter head's arbor then the only trimming will be to chamfer the outside of the case mouth, and not trim square the case mouth or inside chamfering the case mouth.