In his article "Preparing Cases for Long-Range Accuracy" by Jacob Gottfredson, he waits until Step 11 to ream the inside of the neck to make sure it removes any "donut: that may have been introduced by the sizing process.
This makes sense to me if your process involves radical case dimension modifications. For more standard case preparation it seems to me it's better performed early on in the process. I'm experimenting with this to try to achieve the most consistent bullet seating force... a factor I consider as important as any other in hand loading. My procedure with new .308 cases starts as follows:
1) Anneal necks. I don't care if it's Lapua or whatever, there are no negatives to doing it that I know of.
2) Full-length resize with a Forster die and a big .3090" ball.
3) Ream using the Forster Original Trimmer and Forster .308 reamer
Note: The reason I do it this way is to smooth the inside of the neck removing as little brass as possible. This has to be performed carefully. Everytime you remove the reamer, use a toothbrush to remove the brass shavings. Continue to ream until you feel almost no resistence.
4) Neck size with the Lee neck sizer (In my case it leaves a neck I.D. of .305").
5) Outside neck trim with the Forster case neck trimmer set to give you the desired final neck wall thickness.
6) Minimally chamfer and debur the neck.
At this point I have a decision to make
7a) Full-length resize with Forster die and .3085 ball for soft-seating
7b) Neck size again with the Lee neck trimmer regular regular seating
8 ) Check neck wall thickness with a ball micrometer (no margin for error)
9) Check neck concentricity with a dial indicator (max .001)
10) After bullet seating, check bullet run out with a dial indicator (max .002)
I don't see that any of the steps 1) through 7a/7b would introduce a "donut' on standard .308 brass by any mfgr.
The proof they say is in the pudding. My first time out adding the reamer step, I shot the first sub 4 SD strings ever as measured through my Shooting Chrony Gamma Master.
I have more testing to do to prove that this reaming technique makes more consistent the seating force, but I'm almost positive it was the critical factor.
This makes sense to me if your process involves radical case dimension modifications. For more standard case preparation it seems to me it's better performed early on in the process. I'm experimenting with this to try to achieve the most consistent bullet seating force... a factor I consider as important as any other in hand loading. My procedure with new .308 cases starts as follows:
1) Anneal necks. I don't care if it's Lapua or whatever, there are no negatives to doing it that I know of.
2) Full-length resize with a Forster die and a big .3090" ball.
3) Ream using the Forster Original Trimmer and Forster .308 reamer
Note: The reason I do it this way is to smooth the inside of the neck removing as little brass as possible. This has to be performed carefully. Everytime you remove the reamer, use a toothbrush to remove the brass shavings. Continue to ream until you feel almost no resistence.
4) Neck size with the Lee neck sizer (In my case it leaves a neck I.D. of .305").
5) Outside neck trim with the Forster case neck trimmer set to give you the desired final neck wall thickness.
6) Minimally chamfer and debur the neck.
At this point I have a decision to make
7a) Full-length resize with Forster die and .3085 ball for soft-seating
7b) Neck size again with the Lee neck trimmer regular regular seating
8 ) Check neck wall thickness with a ball micrometer (no margin for error)
9) Check neck concentricity with a dial indicator (max .001)
10) After bullet seating, check bullet run out with a dial indicator (max .002)
I don't see that any of the steps 1) through 7a/7b would introduce a "donut' on standard .308 brass by any mfgr.
The proof they say is in the pudding. My first time out adding the reamer step, I shot the first sub 4 SD strings ever as measured through my Shooting Chrony Gamma Master.
I have more testing to do to prove that this reaming technique makes more consistent the seating force, but I'm almost positive it was the critical factor.
