bumping back the shoulder
- Thread starter sealevel
- Start date
You will have to sacrifice a shell holder and lap it down using wet/dry sandpaper on something flat like a piece of glass. Measure it, take it down a couple of thou and try the sizing again while adjusting the die so it comes down hard on the shell holder.
hunters home
CGN Regular
When your case is in the die does the shell holder touch the die. If not try to adjust it until it touches if you can. I happen to have on hand some 7mm brass. I will try and size one with my 257 Froster dies and see if it chambers in my 257 Vanguard. I'll be back
hunters home
CGN Regular
Just tried in and it worked good with my Forster die Chambered good in my 257.. Mabey what Ron AKA stated would work. Sure worth a try.The Lyman shell holder that I have for belted mag cases is shorter that the RCBS/Lee ones. If you have one of these then give it a try.
Ouch! You must have a bad combination of a longer die to the shoulder and a shorter chamber to the shoulder. Find another die to try/borrow?
There are some small differences in the specs between the two cartridges, but not obvious why it shouldn't work:
.257 Weatherby
7mm RM
Is this new 7mm mag brass or once fired? Are you sure its the shoulder preventing chambering?
Make sure the die is making hard contact with the shell holder and the press cams over.
Then pause at the top of the ram stroke for 4-5 seconds when sizing the case, this reduces brass spring back after sizing.
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I usually adjust 1/3 turn past that point to make sure there is no gap between the shell holder and die with a lubed case, handle fully at the end of the stroke.
What you are experiencing is not unusual when reforming. The brass "springs back" a fair bit. You may have to send it through twice, wipe clean and relube before you send it though again.
If the bolt closes without undue force, load the cases and fire them. This usually cures that. As slight as it seems, the cases need that fireforming step. Real (or dedicated) reforming dies usually account for this and are a little smaller than FL dies. I've used RCBS trim dies as an intermediate step, sometimes helps.
Don't get me wrong, I've reformed cases, and sometimes it seems like the only way to load ammo, but it should be your last resort.
Biggest problem is correcting the headstamp, a step which is most often skipped.
Nitro
There is no need to remove the case, wipe the lube off and lube again. Just size the case pausing at the top of the ram stroke, lower the ram and rotate the case 180 degrees and size pausing again. Its the pausing at the top of the ram stroke that lets the brass know who's the boss and to stay put and not spring back as much.
Good point! I have seen cases where the die was set up to bottom on the shell holder, but with a case in place, the press flexed enough to leave a small gap. This was with an aluminum framed LEE press.
This is where the Redding competition shell holders really shine, you can adjust your shoulder bump and the die still makes hard contact with the shell holder and the press cams over.
Meaning any slop in the press is gone and no longer a problem and the shoulder bump is more even. And you never touch the die you just change the shell holder for the proper amount of bump.
