I have a question here. It is all about concentricity in the loaded rounds for my precision AR15
This is for my .223 ar15 so full length resizing is necessary. I only neck size for my bolt guns and I really want to try it on my precision ar.
I want to eliminate the expander ball in my forster full length resizing die and neck size them after full length resizing. Now I tried just removing it but when I ran the brass through the die the neck was too small to accept a bullet.
I know Lyman makes a mandrel expander and Redding has the bushing dies. I am using the lee collet neck sizer with good results on my bolt guns. Don’t really want to use bushing dies for neck sizing because of the donut. Seems like using the mandrel expander could mess up concentricity as much as the expander ball.
I wonder if you just left out the bushing in the redding die and used it for the full length resizer and then ran it through the lee collet neck sizer if that would work.
any suggestions would be appreciated. I know the first one is that I am just overthinking this thing but I do this for entertainment. I like trying different ideas.
Just curious, have you measured runout with your Forster dies? I suspect it’s minimal and would likely be on the outside due to the neck having thin/thick spots. What kind of press are you using?
Just how deep are you willing to go down the rabbit hole too?
This is what you need. It’s part of the process in producing .5moa ammo for me and a few others around here. The expander ball tends to stretch the shoulder when pulling out, resulting in inconsistent headspace. I removed the expander ball from all of my dies and I find neck sizing to produce more consistent neck tension.
you made me think. That is a dangerous thing. So I took brand new untouched lapua brass in .308 and .223 and that same lapua brass after sizing and after loading and ran it on my case comparator.
Now I am kind of new on this thing so the last step I basically had the tip of the bullet in the notch in the case gauge. Don’t know it that is the right way or not. this is the one I have.
anyway here is what I found. Brand new untouched. the dial hardly moved not even near .0001. Sized with forster match resizing die. less than .0002. Finished rounds using forster micrometer bench rest seating die .0002 to .0004.
obviously at each step its is getting worse. Is there room for improvement? Will it get better with practice.
as for the rabbit hole. I am scampering down it as we speak. New bartlein barrel on my newly trued rem. 700 action .308. New kraiger going on my AR15. Removing a perfectly good Shilen match barrel just because I can’t get what I want out of it. Hell it might be me.
I am working with the bergers right now. I have shot the match kings so much I just want to try something different. Found out I need special seating stems for the VLD. Redding here we come two benh rest seating dies with VLD stems to go with my redding mandrel expanders.
This is exactly what I do. This way I can use the Dillon Carbide die for sizing. Then I run the brass through an RCBS .223 neck expander die. Works good for me.
I think you added a zero, maybe 2-4 thousandths not ten-thousandths. If your runout is between .002-.004 keep doing what you’re doing and invest time shooting if you want to improve. As for the seating stem, Forster ultra dies come with a vld stem.
You mentioned neck turning I think, unless you have a tight chamber causing problems use that time for something else, especially if you’re using lapua brass
I full length resize and then I neck size to make sure the neck where it meets the shoulder is where I want it. I used to go without the expander ball in the neck resizer but I was squashing shoulders when I would use flat based bullets about 50% of the time and about 10% of the time when I loaded boat tail bullets. Most of the time it was hard to see the squashed shoulder and I had problems with the rounds chambering. The softer the brass, the more likely I was to squash a shoulder.
I put the expander ball back on the neck sizer and I reduced the size of the ball by spinning it in Emory paper. I reduced the size by about .005 and it has since reduced the number of squashed shoulders. I might go another .005 in the future. This also made pulling the ball out of the resized necks easier. I’m looking for that sweet spot where I don’t squash shoulders but I can pull the resizer easily. Just my solution.
kwg
The Forster full length resizing die is the greatest thing since sliced bread “and” it will produce the “least” amount of case neck runout of any full length die on the market. If your worried about neck pull then reduce the diameter of the expander button .001 and “LUBE” the inside of your case necks. I do “NOT” have any problem with increased case headspace length when using full length dies and lubing the case necks. If you want even better results then turn your case necks and find the sweet spot for neck thickness and expander ball diameter. This would be a waste of time for simple blasting ammo but if your looking for long range accuracy you will need case neck uniformity and neck tension.
If your runout increases after bullet seating then use a Lyman type M die and expand the mouth of the case neck to except the bullet so it starts easily into the case mouth.
I just started equipping my RCBS dies with the Forster spindle and expander unit because of the reduced amount of neck runout.
If you have problems with a Forster full length die, squashed shoulders or neck runout then you are doing something wrong.
