Inconsistent Trim Lengths

Wilson is popular with many reloaders.

my limited experience is getting things set up correctly, and getting consistency is difficult and time consuming, but possible with a few sacrificial cases. I use a forster case trimmer. once it is set up, and then tightened, and nothing moves, and actual trimming is very mechanically consistent, they all come out pretty close.

I've been happy with the consistency from my WFT trimmers. Plus/minus one or two thousandths of an inch.

The WFT trimmers do require consistent operation to get consistent results. Too much or too little pressure while trimming will alter the outcome but it is not too fussy for getting good results.

There are other brands on the market that are similar to the WFT trimmers and I'm sure they would be as effective as the WFT brand.

I use a Wilson lath trimmer for bottle neck cases and a Lyman universal for straight wall.
Maybe not the best but it works for me.

Make sure before you measure the case is deburred inside and out, AND there are no "hairs". Twist mouth on one of the green or blue plasitc pot scrubbers.

I’m sure you already do this.
Resize and deprime before trimming on Universal trimmer.

Make sure your cutter head is sharp.Even a Wilson will give some variance when getting dull.I.ve never had a problem with a Wilson or a Forster when the cutters are sharp.I have had issues with trimmers that measure off the shoulder.

Henderson Precision is an expensive but great choice. It's basically a motorized Forster trimmer on rails. Quick, accurate, and little to no hand fatigue.






.40

What are you using now? What are your results and what are you looking for?

I can get within a few thousandths with a simple jig and a belt sander.

Can you post your setup jmorris? I'm intrigued.

jmorris said:

I can get within a few thousandths with a simple jig and a belt sander.

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sparkyv said:

Can you post your setup jmorris? I'm intrigued.

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I wouldn't say this is the way I always do it or even often do it but once I found myself away from home with a press and brass that was supposed to be sized and trimmed, that wasn't.
Folks were going to be there for some belt fed fun the next day so I was kind of forced to find a solution.

I did have a lathe available, so I took a section of 1.25" barstock and drilled an 11/32 hole all the way through it, then drilled a 29/64 hole through all but 3/8 of an inch or so from the end. Then bored the small hole to .345 and the large one to
.475.

Then I just faced the small end to the trim to length. Place it up against the belt sander I had previously made from an old dryer motor, part of an old john deere hay baler and old roller skate wheel and I was in business.

jmorris said:

I wouldn't say this is the way I always do it or even often do it but once I found myself away from home with a press and brass that was supposed to be sized and trimmed, that wasn't.
Folks were going to be there for some belt fed fun the next day so I was kind of forced to find a solution.

I did have a lathe available, so I took a section of 1.25" barstock and drilled an 11/32 hole all the way through it, then drilled a 29/64 hole through all but 3/8 of an inch or so from the end. Then bored the small hole to .345 and the large one to
.475.

Then I just faced the small end to the trim to length. Place it up against the belt sander I had previously made from an old dryer motor, part of an old john deere hay baler and old roller skate wheel and I was in business.

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Ingenious idea. Wouldn't the sander eventually wear the jig down causing inconsistent lengths?

.40

Are you measuring before or after deburring and chamfering? My Hornady is very consistent, but not used on anything bigger than 223 and mostly my handgun brass in search of consistent revolver roll crimps.

forty_caliber said:

Ingenious idea. Wouldn't the sander eventually wear the jig down causing inconsistent lengths?

.40

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At some point it would, as even water can wear away granite. I am not sure at what point that would be though. After the hundreds I did using it, I can still see some of the radial marks left from facing the part, so it would be awhile.

The concept is not new though, one can buy hardened dies that fit in a regular press that a file can't cut the surface of but can trim brass flush with it.

https://www.natchezss.com/rcbs-trim-die-group-a-popular-rifle-cartridges-308-win.html

FWIW I just went through 7, 1 gallon ziploc bags of .223 brass I prepped using a Dillon trimmer on a progressive press, just a hand full out of each bag but there wasn't more than .001 difference between any two and even the carbide cutter will wear but 7 gallon bags contain a little over 5600 cases.

Brings me back to the question I had in #11, what does "inconsistent" mean in thousandths of an inch and what is the sample size?

Walkalong said:

About as good as it gets.
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Like Walk said the L E Wilson case trimmer is the bomb. Accurate all the time everytime.