Need help - Shoulder bumping inconsistency issues

[Castle Rock]

Thats interesting. I've never heard that before. Admittedly, I dont have much experience with reduced loads. All I've observed is that as I increase powder charge, I see a slight increase in growth so I wouldn't have guess that it would reverse at some point if you keep going down.

Dont want to derail the OP too much but help me understand why that happens.

The firing pin drives the case forward with a fair bit of force wedging it into the taper of the chamber and it grips and stays there

 

[EastHumboldt]

I’m getting much better results today. Bumping .003 with an occasional deviation of .001 or so, which could easily be attributed to my measuring process.

I changed my lube process from spray the crap out of em with one shot in a plastic bag and shake the bag. Now I’m spraying a foam pad and rolling the cases one at a time, so I get a more uniform film only on the sides of the case and almost nothing on the shoulder taper. I’m also letting the lube dry, which I wasn’t really before.

I changed my press process to just steadily pushing the handle down to bottom out one time and holding it there for a count of four.

So at this point thanks everyone for the help, and it looks like I’m getting results within my idea of tolerable.

I did notice a couple weird things.
1) I started with body die just touching the shell holder and an additional 1/8 turn tighter. This consistently made each case .003-004” longer to the datum line instead of shorter. This trend continued up to about .006” longer until I got past 1/4 turn on the die, and then it started to shorten the datum line….. huh….. I could feel resistance as the die compressed the sides of the case on the way to the shoulder. My theory is as the brass was squeezed inward on the sides it was bent slightly out on the shoulder slopes effectively increasing the length of the datum line, until I actually got the shoulder part of the die engaged which pushed the shoulder slope back where it belongs and then some.

I had 3-4 cases that had almost no resistance going into the die and were a good 8-9 thou short At the datum line. So they were in fact kind of shrunken compared to a new case. I think these may have been undercharged cases from test ladders as mentioned by castle rock.

I almost always enjoy taperpin’s posts because he’s all about empirical experience and results as opposed to endless time spent at the far end of some theory rabbit hole. I can’t say that I’ve seen an improvement in group size on any of my rifles specifically from any one change in my reloading process. My early trials with neck sized only annealed reloads have been a small sample size, but they have certainly shot no worse than prior full-size/trim/and stuff reloads.

My group sizes are improving lately (last week a couple 1-1/4” 10 shot groups at 100yds, and a 1-1/2” 5 shot group at 200) but I think it’s because reloading and thinking a lot about accuracy are making me shoot more. I’m also thinking more about form, pre shot routine, proper eye box positioning, parallax, follow through, recoil management….and other things I didn’t used to think about. I think my shooting has improved as much or more than my reloading, partly because of reloading.

I’m annealing because it seems logical to me that it will extend case life, and most of the info out there seems to bear that out. It’s really a snap to do with the burst fire system and I can anneal a couple hundreds cases in an hour with reasonable repeatability. At least so far I find running the annealer kind of fun. I can’t see the cost/benefit for me in spending 2000+ on an inductive annealing system. YMMV

 

[WhoGarrDen]

I’m getting much better results today. Bumping .003 with an occasional deviation of .001 or so, which could easily be attributed to my measuring process.

I changed my lube process from spray the crap out of em with one shot in a plastic bag and shake the bag. Now I’m spraying a foam pad and rolling the cases one at a time, so I get a more uniform film only on the sides of the case and almost nothing on the shoulder taper. I’m also letting the lube dry, which I wasn’t really before.

I had similar results using One Shot case lube. I set up 2 trays of 50, hit them at a 45 angle to get inside the neck and shoulders (hit it from a few angles, quick passes). By the time I got to the end of the first tray of 50 things started to get sticky and bumps were inconsistent. The cases on the outside of the tray also seemed to resize better than those inside getting slightly less lube? The 2nd tray was all over the place so I went down to just spray and resizing 30-40 at a time. Might try your method..

I do clean the die before each session with One Shot cleaner, wipe clean, then hit it with One Shot lube and let dry 15+ minutes while I set up. Still a lot of black coming out after 100 cases when I went to clean it to see if I could fix the inconsistency... Cases were tumbled in walnut media for 2hrs so they shouldn't be THAT dirty?