Long Range Hunting Forum
I'm new to neck turning and am using Sinclair 4000 toolset on once-fired and FL sized Nosler 280 AI brass. The problem I'm having is that on some of my cases I see cut marks high on the shoulder (junction of shoulder to sidewall), even when the cutter isn't cutting near right at the junction of the neck to the shoulder. I am using the 40 degree cutter I purchased to match the 280 AI steeper shoulder angle. I thought I'd see a slight cut / rub where the neck meets the shoulder and stop turning there.
I bumped the shoulders .002" with Redding FL dies and used the expander ball. Before turning, I trimmed all cases to 2.519" to get uniform length, and expanded the case mouths with the Sinclair expander mandrel. From reading, this should push consistencies to the outside of the neck so they can be trimmed. The cases fit with minimal play on the turning mandrel (expander mandrel measures .001 larger diameter than the turning mandrel). It is admittedly difficult to get perfectly consistent case lengths with my Lyman hand trimmer, but I tried to keep them within a thousandth. Note that I did end up with a few cases that were cut into the shoulder all the way around (those must have been slightly shorter from my trimming is what I'm guessing), so I imagine I need to throw those out?
When you look at this case, however, why would the 40 degree cutter be cutting the top of the shoulder but not the neck/shoulder junction? Also does a case like this need to be thrown out? I turned 1/2 to 3/4 of the neck area on all of the cases to try to clean them up to improve precision (group size and velocity) in a hunting rifle with with standard chamber, trued action, and new Krieger barrel (fired cases are approx 10 thousandths larger than sized cases so not a tight chamber and don't want to turn too much and weaken the case). The runout on these cases with my normal loading procedures was annoyingly higher than on my 300WM and 260 Remington, so I took the leap on neck turning. We'll see if I regret it!
I wish I hadn't spun the necks with some steel wool as the photo would be more obvious.
Thank you for the help,
Brad
I bumped the shoulders .002" with Redding FL dies and used the expander ball. Before turning, I trimmed all cases to 2.519" to get uniform length, and expanded the case mouths with the Sinclair expander mandrel. From reading, this should push consistencies to the outside of the neck so they can be trimmed. The cases fit with minimal play on the turning mandrel (expander mandrel measures .001 larger diameter than the turning mandrel). It is admittedly difficult to get perfectly consistent case lengths with my Lyman hand trimmer, but I tried to keep them within a thousandth. Note that I did end up with a few cases that were cut into the shoulder all the way around (those must have been slightly shorter from my trimming is what I'm guessing), so I imagine I need to throw those out?
When you look at this case, however, why would the 40 degree cutter be cutting the top of the shoulder but not the neck/shoulder junction? Also does a case like this need to be thrown out? I turned 1/2 to 3/4 of the neck area on all of the cases to try to clean them up to improve precision (group size and velocity) in a hunting rifle with with standard chamber, trued action, and new Krieger barrel (fired cases are approx 10 thousandths larger than sized cases so not a tight chamber and don't want to turn too much and weaken the case). The runout on these cases with my normal loading procedures was annoyingly higher than on my 300WM and 260 Remington, so I took the leap on neck turning. We'll see if I regret it!
I wish I hadn't spun the necks with some steel wool as the photo would be more obvious.
Thank you for the help,
Brad