Case trimmer carbide cutter question

RedHawk357Mag

New Member
Good morning all. I have a question for those that might trim brass or experience with carbide cutting tools. I use a Wilson cutter which I find does a fantastic job of easily cutting case mouths square and at desired length. As the insurance commercial goes...even a cave man can do it. My question is about the carbide cutters. I seem to dull these things much faster than I would expect. I have just ordered my fourth cutter in about 12 to 15 years. I have also used the TiN coated cutter sold by Wilson. When new my cutters cut quickly and efficiently. I set my desired length and slowly and methodically remove thin strings of brass meeting desired length with first attempt. I trim maybe a thousand and notice that I don't meet the desired length as easily or the first time I attempt to trim. It gets deceptive in trimming thing you have met the stop but in actuality you still three four thousand left to trim. During this time more pressure and longer cranking times are required to trim brass are required with additional instances of false feeling of reaching the required measurements. If I attempted to keep pushing through it the cutters give a more mashed appearances of cut as opposed to being a clean sharp cut. I have used small hand wire brushes to clean face of cutter blades and it helps some four three or four cases. The TiN didn't seem to last much longer than the standard cutters. So is this an operator thing, is my understanding of durability of carbide cutting tools in error, or have any suggestions that might help. I estimate useful life of cutters to be a thousand to 1200 cases before degrade results appear. Thanks.
 

fiver

Well-Known Member
are you using any kind of lubricant?
are you setting up the cut depth each time or relying on the old depth and just pushing harder for the last couple of thou?
have you tried champhering the case before cutting it?
is the new batch of cases annealed and soft like the original ones?
 

RedHawk357Mag

New Member
Thank you the questions. No lubricant. For instance a 357 case is set for an end result of 1.280". I set for 1.282 or 1.283 and sneak up to my end result of 1.280". Once end length is set I lock it down. In the time of owning trimmer it's never moved on me by it's own violation. I trim usually in batches of one hundred. Occasionally will do ones and twos if a piece of brass gets lost or gets wrecked. Not often. Most trimmed brass is at least once fired. My reserve brass is new and untrimmed. I ordered the new cutter to prep it. Judging on my current brass in rotation I think the new brass will outlast me. When I remove a cut piece of brass I champher inside than outside and then measure for square and length. If the case is too long still it gets placed back in the Qtype case holder and retrimmed. And process done again. No change is made to trimmer until a different cartridge is trimmed. If I fail the third time to get the desired length I monkey around with rotating the case in the Qtype holder before locking the crossbar. This sometimes works. If it goes to a fourth attempt I trash it. This is 357 and 44 brass. My rifle brass is Laupa and Hordandy and hasn't needed cut back as of yet. My brass annealing status is functional as I have resistance in resizing, expanding, and crimp. I will have ones and twos every once an awhile tend to feel funky in the loading process and I will scrap it. Most my loads are below 1200 fps so brass life has been pretty good.
 

smokeywolf

Well-Known Member
Any vibration or chatter will quickly dull a carbide cutter. I would also venture to guess that Wilson, while one of my favorite brands of reloading tools, is not using the highest grade carbide in their cutters.
 

Ian

Notorious member
I use Forster tooling and have one of their carbide cutters. After going through about 6K .30-cal cases, I noticed what you describe, irregular length, burrs, excess plunge effort. I touched up the HSS cutter with an India stone and started using it again to much better effect. HSS will take a finer edge than carbide, it just needs care. You can sharpen your carbide cutters with fine diamond stones but like SW mentioned, that may not be the long-term solution.
 

fiver

Well-Known Member
that's why I was asking about a little lubricant.
it doesn't totally stop the problem but it can help with the chatter and consequently help keep it sharp longer.
 

KeithB

Resident Half Fast Machinist
1. I would think just about any of the new synthetic cutting oils would help extend cutter life. I'd apply a little to a case lube pad or sponge and stick the case neck in it before trimming. Any tumbler grit or even plain old dirt or oxides on the case surface can also be abrasive and will dull the cutter at specific diameters.

2. Don't EVER turn the cutter backwards. Carbide is amazingly strong under compression but will chip and flake under tension and/or shear. Since the cutter has a positive rake profile (the face to edge profile is less than 90 degrees) the edge can easily be chipped or dulled. With HSS the edge would curl under and you can resharpen it, with carbide it will dull or chip in ways that make it harder to sharpen. And in many cases you can't see it with the naked eye. But the case sees it and throws up a burr and requires more and more force to cut.
 

RedHawk357Mag

New Member
Thank you for all valuable insight. Had not considered lubricant but should not be difficult to start doing. Pretty sure I haven't attempted to turn backwards seems I applied that from forcing cone reemers. I appreciate all the help.
 

Brad

Benevolent Overlord and site owner
Staff member
My Wilson carbide trimmer has lasted for long enough that I don't recall when I got it? Has been at least 15 years.
 

M3845708Bama

Active Member
Your answer may be found in looking at the recommended cutting speeds. Sometimes too slow a cutting speed really causes unanticipated results.
 

RedHawk357Mag

New Member
Interesting about speed. They make a low speed, high drag adapter for power tool attachment. I am hand cranking no power adapter.
The replacement stock cutter
https://lewilson.com/replacement-case-trimmer-cutter/
The TiN upgrade
https://lewilson.com/regular-tin-coated-cutter/
And the power adapter.
https://lewilson.com/trimmer-power-adapter/
After giving this considerable thought today I think probably the biggest issue might have been me. I think my trimming concept was flawed. My brass is always segregated into 100 round case containers from purchase to scrape bucket. I always reset dies to the brass from scratch. When cleaning brass I normally combine a 100 RPs, 100 Wins, 100 Starlines and 100 Feds. So...it really doesn't make sense that I have to always make my brass the called for trim to length from the book. As long as that 100 pieces are the same length I should be good to go as long as I continue my brass maintenance procedures. Some of my new to me brass ranges from 1.293 to 1.287. Before I would resize, measure, check book and see trim to length as 1.280" and spend the next day whacking them to 1.280 and chamfering and confirming trim length. Removing that much brass would probably take a significant toll on cutters.
 

Brad

Benevolent Overlord and site owner
Staff member
I very rarely trim brass. Very, very rarely. If it gets close to book max I trim it a bit but otherwise it is left alone.
New brass is never trimmed by me unless I have a Specific reason to do so.
 

RedHawk357Mag

New Member
Your not alone... I buy brass here and there, probably family selling Dad's stuff on Facebook and mewe most often. And I get brass All the time that makes me scratch my head. I have received brass in every possible condition most often belled like a kids trumpet. I have disassemble reloads that could only have been put together by someone who has reloading material in Braille. It has definitely given me cause for pause when shooting in a public range environment. I tend to go hydrate when the shooting stall next to me gets new occupants.
 

fiver

Well-Known Member
twice in the last week I have seen posts on another website asking for help in reverse engineering some loads that come with a used rifle.
I have both times asked the OP why they didn't just ask the person they bought the rifle from what was in the ammo [and why it wasn't written down on the box] they just took on faith and fired.

'crickets'... is the response both times.
 

Cherokee

Medina, Ohio
I've been using Lyman lathe type trimmers for many years. The older one got a carbide trimmer replacement about 20 years ago; the newer one still has the factory cutter. Both require pressure to cut the cases and always have as I recall. I thought that was normal. I trim all rifle cases to the spec. length. Rimmed pistol cases are trimmed to a uniform length as needed, don't trim any rimless pistol cases except 30 Carbine.
 

smokeywolf

Well-Known Member
I motorized Dad's old L.E. Wilson trimmer about 35 years ago and have used that for trimming stretched cases. For removing greater quantities of material, like trimming 45-70 cases down to 45-60, I use the lathe.