Case Trimmer Leaving Inside of Case Neck Marred???

[Dave1]

I noticed today that the pilot on my old Lyman Universal (manual) case trimmer is marring the inside of the my 243 case necks.  The scoring marks in the case necks do not appear to be deep but are noticeable.  Not sure if they will effect bullet seating, alignment, fit or not.

I stopped and dressed up the pilot head with some 150, 400, and finally 600 wet/dry paper and it helped but still marred the cases slightly.  I can't tell if there is a problem with the shell holder possibly not holding the case perfectly centered with the pilot and cutter blade or maybe there is some other problem.

Anyone ever see or have this problem?

Thanks, Dave


 

[Steve P]

If cases were sized and cleaned properly, I never had a problem.  Only had problem I did have with the Lyman pilots was when the cutter started to get dull it left a burr on the inside of the case mouth that made it hard to get them off the pilot.   

YOu might try a little imperial sizing wax on the pilot to see if that helps.  It may collect brass debris, but that is a chance you take if you are de-bugging the problem.

Steve

[Dave1]

I disassembled the case trimmer, cleaned all, and noticed there is some wear inside the main shaft brass bushing.  The bushing wear allows some wobbling movement of the trimmer shaft and cutting blade.  It seems the shaft with pilot head inside the case neck should center up in the case neck and not cause any marring, but that doesn't happen.

Using a large magnifying glass and inspecting the trimmed cases, it appears the ends of the case necks are not cut exactly square.  I don't have a caliper so I can't tell for sure how much variation exists, but it is small.  The small deviation apparently does not hurt a great deal as the 100 yard groups fired with these loads were very good.

I went to one of the mail order shooting supply web sites to look at some new trimmers and just happened to read the reviews of the exact trimmer I have and read where others have had the same problem I am experiencing.  A reccomendation was made there by one reviewer to not lock the cartridge in the trimmer firmly and only just enough to keep it from spinning. I tried that and it did help reduce the marring inside the case neck, but did not eliminate it all together.

Dave