Case Trimming

[Devildog99]

Curious what guidelines others are using on how often they trim their rifle brass for overall length, before disgarding the brass. I am loading for .223, 22-250, and 6br. All bolt action rifles, all mild loads. Typically with new brass I size the cases, reload and shoot. I often neck size only, (Wilson Dies) till the shoulder reaches the measured headspace for that rifle. At that point I typically full length resize the cases, (Redding Type S Dies), moving the shoulder back about .002. The cases seem to grow a few thousands of an inch with each firing. After being fired a few times the cases are within a couple thousands of the published max. overall length. I trim the cases back so as to be .010 short of the published max. length. After being fired two or three more times, the cases are once again approaching the max. length. After trimming again so as to be .010 short of the max. length, I start wondering how many times can I do this before a case head separation becomes likely.

I have cut open a few cases, can't see any thinning of the case just above the case head. I can see a noticeably bright ring around the exterior of the case, just above the case head. It is my understanding that the bright ring I am seeing is evidence that the case is stretching. Any comments? Thanks.

 

[DennisH]

I usually find the shortest fired brass and trim all of my about .002 less. After the first trimming, I find very little difference in my brass thereon.

Dennis

 

[Shynloco]

About a year or so ago, I adopted what some probably would think is an "ANAL" method of checking and trimming my brass. And that is that I use RCBS Precision Mics for all of my calibers to determine what actual bump is needed when FL sizing, which I do with each reload, regardless of caliber. I determined the "index" point for each Precision mic by finding the shoulder setting that allows my bolt the easiest closure point. So the markings on the precision mics are only relevant to what Index or reference marking I've determined for each caliber. Hence I resize to that index mark with each piece of brass which, yes is time consuming and some would probably say is a complete waste of time. But that's ok because it's my time and it works for me. Then AFTER FL re-sizing, I measure the length of each piece of brass and trim if necessary.

Perhaps sounds like going overboard and a waste of time. But it works for me and I have as much fun prepping brass as I do shooting it. Some have called me a perfectionist and I guess I admit I am. But I've also found it's the little things that help me get closer to that elusive 5 shots through the same hole for three straight targets. That's my overall challenge that I'm chasing. Will I ever get it??? Probably not, but I do love the challenge nonetheless.

Alex

 

[Joe O]

I don't use the trim length as published in the manuals.I measure each chamber with a sinclair case length gage ($7),and trim .010 less than that,after the first fireing.I check the length after two more fireings,but haven't had to trim again.I don't shoot the same cases often enough to be an issue,as I'm loading 1000 rounds for each Varmint gun,for a once a year safari.

 

[DennisH]

Everybody's method is different . . .

After shooting, the brass is perfectly fireformed to your chamber. I then measure 10% of the brass and get a COL, I take the shortest one as my baseline and go .002 more.

I trim my brass before FL sizing, again, there perfectly fireformed. I measure them and all are withing .0005.

After I FL size the brass, I recheck the COL and all of them are within a .001 of an inch.

I use a Giraud trimmer which uses the shoulder of the brass as it's measuring point.

It works for me,

Opinions ?

 

[37Lincoln1]

Are you sure the "bright ring" just above the case head you are seeing isn't the point on your case that is reached at the bottom of your die?

If you had the case separation ring, you would have noticed the impending groove left inside the case when you cut open your case.