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Posted: 5/7/2008 10:21:53 AM EDT
| I would like to know if there is anything wrong with trimming a case after each firing I know that I will creating extra work for my self by trimming so often, but is it bad for the rifle case? |
Sir, FWIW I trim my .223 Rem. match brass every time I prepare it for reloading. After resizing I trim each case to 1.758" which is only .002" below the max case OAL. I do this because I want each and every case to be the same OAL instead of somewhere within a given min/max dimension. I believe it contributes to more uniform barrel harmonics which is related to better groups within the velocity range I shoot. I do not perceive this is particularly detrimental to the rifle case rather most of the cases I use are discarded due to primer pocket enlargement long before I begin to notice neck cracks. Neck cracks usually occur as a result of work hardening of the brass and I don't believe there is any relationship of trimming to cracking. I guess the best answer I can give is that trimming as you suggest is not directly detrimental to the case rather other factors such as charge weight, primer type, etc. have significantly greater affect on case life. HTH, 7zero1. |
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Blasting ammo loads (ie. Federal "FC" brass, once fired only) I just check OAL with the Lyman gauge after full length resize/deprime. Match ammo, it goes under the trimmer (Lee) and sorted into lots based on weight. SHTF reloads, gets the same treatment as match, but, no weight sorting. |
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Why are you trimming the case? To make sure they are all the same length to crimp them on the bullet? To make sure none are too long and result in chambering or pressure issues when fired? As a step in insuring all the cases in a particular lot are uniform (resize, trim to length, outside turn the neck and then weigh and sort by weight)? I don't crimp rifle bullets (especially match bullets) so I don't need the cases the same length for that reason. I trim once to make sure they are the same length, then I'll measure them again after a couple reloadings to see if they need trimmed again. Not only is it a lot of extra work (unless you are doing something that really requires it) but depending on the trimmer you use you may not get "exactly" the same length cases anyway. |
Yep, the major advantage of the Dillon trimmer is that its always on your case prep toolhead and every time you decap/resize you just cycle it through the toolhead and any long cases get trimmed without a separate step. And, once you get it set up there is no need to measure your cases except to check every 1K cases or so that the trimmer blade isn't worn out. Also, like 7zero1, I've set my trimmer to 1.757" case length to ensure I have adequate neck bearing surface while avoiding any over length case issues. |
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