Henderson Trimmer Upgrade (Inside Neck Reamer)

Nick - How do you verify if you have mis-reamed a neck with a concentricity gauge? How has your BR accuracy improved in relation to adding this neck reamer process?

The easiest way to find out that I made a mistake when reaming is when the case mouth starts removing a bunch of material and then moves. That's a facepalm 🤦
If you watch the video you will see that I locate the case mouth on the reamer chamfer to ensure concentricity. Then I turn it on and run it.

To find outliers in the brass you will find that a small amount after reaming that the neck won't hold enough tension for bullet. These I flip the bushing around and that takes care of it.
Again some the reamer won't touch. I sort these all out and use as foulers.

I do check concentricity and don't see a measurable difference.

As for accuracy. I am off the belief that accuracy, precision and scores have more to do with the trigger puller than anything else. I won't make any claims of grandeur.

I will stand behind the data collected.
 
I've been using a trimmer from Henderson Precision for awhile. The repeatability and speed is amazing.
After talking to Todd Henderson I developed a reamer to clean up and true the case neck.
I've made a couple different types. First I modified a LE Wilson neck reamer to fit into a blank Henderson cutter head. That reamer was for .243 cases. The Wilson reamer is .2455 - .246. I used this after firing. While it did a great job cleaning up the neck and removing doughnut the real winner was improved ES and SD from better seating pressure consistency.
That pushed me to try reaming after sizing. I bought a .242 reamer and ground it to fit into another blank cutter head.
This is where things got interesting… ES, SD improved significantly. Even on rifles with really good numbers.
Now I made a reamer to replace the pilot in the cutter head. Now I can inside neck ream, trim, chamfer and deburr in one step.
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Very Interesting!
We have probably two dozen Forester trimmer 3-1 Heads and can adjust the Heads for almost any cartridge with all the Pilots we have. Plus we modified the Henderson Trimmer with our own Motor. We also Neck Turn all our Cases.

If you are going to use this ID Trimmer do you first Neck Size the Brass? How do you keep it consistent? When neck sizing? Would like to talk to you about your process. If using this ID Trimmer to get the ID "Uniformed" then "Neck Turning" would be the next process for consistency and bullet release.
FCLASSPRODUCTS has a Machine/Lathe that trims Necks the AUTODOD

Thanks for this new process, again would like more info and would be glad to have a conversation with you this may be another way and less expensive than the AUTODOD!

Thanks
Len & Jill
 
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