RegionRat
Gold $$ Contributor
I realize the OP's question didn't make mention of sizing, but just asks about annealing and trimming.
However, for most of us the annealing order is more tied to sizing and as a result trimming/chamfering follows sizing.
I would typically anneal before sizing, and as a result that would put trimming after sizing since the amount of case growth is variable but not settled till after sizing and there can always be dented necks which need to be rounded. Even this order is arbitrary in some instances depending on the condition of the necks, however,
another reason to size before trim/chamfer, is to give the tool the opportunity to have a rounded neck to cut.
There is no hard rule that says "you have to anneal before sizing" but it is my opinion this is more beneficial.
So, since it is more often the case that one would anneal before sizing, for the same reason you would then trim/chamfer after annealing.
If you are not picky at all, it wouldn't matter, but if you are being picky, then your length isn't set till after sizing and that is when you would trim.
Another reason for the order is that when processing large volumes of factory brass for prairie dog shooting, an opportunity for the neck to split comes from sizing and then the trim and chamfer operations will pick it up.
In the last five or ten years, many of my friends have been using factory Fiocchi prairie dog ammo which is notorious for neck splits. In theory, annealing first would help reduce the probability of neck splits.
Then after sizing, the trim and chamfer steps make it easy to detect a split neck. We have had roughly 20 to 40 split necks on the first firing per 1000 which are detected during chamfer/trim. Then I have still has about one or two per thousand split after seating. YMMV
However, for most of us the annealing order is more tied to sizing and as a result trimming/chamfering follows sizing.
I would typically anneal before sizing, and as a result that would put trimming after sizing since the amount of case growth is variable but not settled till after sizing and there can always be dented necks which need to be rounded. Even this order is arbitrary in some instances depending on the condition of the necks, however,
another reason to size before trim/chamfer, is to give the tool the opportunity to have a rounded neck to cut.
There is no hard rule that says "you have to anneal before sizing" but it is my opinion this is more beneficial.
So, since it is more often the case that one would anneal before sizing, for the same reason you would then trim/chamfer after annealing.
If you are not picky at all, it wouldn't matter, but if you are being picky, then your length isn't set till after sizing and that is when you would trim.
Another reason for the order is that when processing large volumes of factory brass for prairie dog shooting, an opportunity for the neck to split comes from sizing and then the trim and chamfer operations will pick it up.
In the last five or ten years, many of my friends have been using factory Fiocchi prairie dog ammo which is notorious for neck splits. In theory, annealing first would help reduce the probability of neck splits.
Then after sizing, the trim and chamfer steps make it easy to detect a split neck. We have had roughly 20 to 40 split necks on the first firing per 1000 which are detected during chamfer/trim. Then I have still has about one or two per thousand split after seating. YMMV
