So I am trying to come up with the best die to get consistent neck tension. Its between a FL sizer or a body bump die and a neck sizer,so I was wandering if I went with the neck sizer would I have to start turning necks which I don't want to. If anybody has any other suggestions please let me know. I have a lee collet die but I have never used it until today and I tried it on a couple of cases and it resized the neck like it is suppose to but the bolt was hard to close.
Do you have to turn necks?
- Thread starter Brux
- Start date
Neck sizing has nothing to do with turning necks. Turning necks is to remove the differences in brass thickness to make everything equal piece to piece. Often times for benchrest level chambers/reamer designs they will know that you are lessening the brass thickness and will tighten the neck up accordingly to avoid the necks blowing up overly large with each firing. Typically one would have to spec a neck that tight and be conscious of the choice.
Neck sizing is leaving the body imprinted to the chamber and only squeezed the neck enough to hold another bullet. When neck sizing eventually you will have to body die as well as the brass will harden to the chamber dimensions and there will be no release or room for separation. A full length sizing die does both parts at once. Some chamber brass combinations could be 10-15 rounds before requiring body sizing. Some will be every other. Sounds like yours is there the if the bolt is tough and your bullet isn't seated overly long and jamming in the lands.
For consistent tension it's not necessarily what you do so much as how you do it. You came have necks uneven as hell and have the inner side concentric. That's the purpose of the expander ball or mandrel. With turned necks people will often use bushings or honed dies to a certain neck diameter and only do a sizing down and eliminate the expander or mandrel. Without turned necks only using a bushing will leave the imperfections pushed towards the inside and that can lead to uneven consistencies but with good brass that's negligible. Larpa is like .001 out but rp brass can easily be .002-.003 out from side to side.
Annealing is also a method as it relieves the stresses and hardness differences formed during firing and cleanses the palate as it were. Blank slate each firing.
The lee college is renowned for low runout but you will want to introduce a body or full length to the process to moves the shoulders and case walls down a bit.
Neck sizing is leaving the body imprinted to the chamber and only squeezed the neck enough to hold another bullet. When neck sizing eventually you will have to body die as well as the brass will harden to the chamber dimensions and there will be no release or room for separation. A full length sizing die does both parts at once. Some chamber brass combinations could be 10-15 rounds before requiring body sizing. Some will be every other. Sounds like yours is there the if the bolt is tough and your bullet isn't seated overly long and jamming in the lands.
For consistent tension it's not necessarily what you do so much as how you do it. You came have necks uneven as hell and have the inner side concentric. That's the purpose of the expander ball or mandrel. With turned necks people will often use bushings or honed dies to a certain neck diameter and only do a sizing down and eliminate the expander or mandrel. Without turned necks only using a bushing will leave the imperfections pushed towards the inside and that can lead to uneven consistencies but with good brass that's negligible. Larpa is like .001 out but rp brass can easily be .002-.003 out from side to side.
Annealing is also a method as it relieves the stresses and hardness differences formed during firing and cleanses the palate as it were. Blank slate each firing.
The lee college is renowned for low runout but you will want to introduce a body or full length to the process to moves the shoulders and case walls down a bit.
Dont dismiss the Lee Collet just yet... the bolt being hard to close should have nothing to do with the neck sizing, rather it could be from your case shoulder length. I have been using my Lee Collet neck sizing die for reloading 308 with great success. There are a few short videos on youtube about how you can get a little more precision with the collet sizer; basically take it apart, and polish up the contact surfaces of the collet and also the mandrel with some fine grit sand paper and make sure to put a little bit of good grease in there.
If you are firing these rounds from a bolt gun, and only from the same gun, you could JUST neck size using the collet sizer UNTIL the shoulder length becomes excessive, at which point you will need to either FL size or bump the shoulder back a few thousandths. My plan is to only neck size with the collet die until excessive shoulder headspace prevents me from closing the bolt (or it starts to get a little hard). So far I've neck sized 6 or 7 times on Federal ammo with no issue closing the bolt yet. Once shoulder headspace becomes an issue (probably in a few more reloads) I will use either a FLS die or a bump die to push just the shoulder back about 0.002". Then I will be good to go with just collet neck sizing again. This process is only acceptable in a bolt gun, and for reloading fire formed brass for one specific rifle.
That is the problem with the lee collet die,its hitting the shoulders. This rifle was chambered with a palma match reamer with very minimum head space which I like so its not a sloppy chamber. If I use the Lee die I think I would have to shoulder bump on each firing.I also have a forster FL die that I am waiting on a new expander ball for. I was thinking about buying a shoulder bump die and a neck bushing die but I don't know if I went that direction if I would have to start turning necks with Lapua brass.
Measure the outside diameter on the neck of a loaded round. Compare that to the reamer or print and see how much space you have. .003 is a tight but safe spot to shoot for. If it's less than that it would be advisable to turn a bit off u less you're keeping it benchrest clean. Might even be necessary once the shoulder migrates up the neck a bit in a few firings. I would just wait for the Forster expander ball and be done with it.
I use a bushing at -.002 from loaded diameter then I use 21st century expanding mandrel which ends with -.001 neck tension and imperfections pushed to the outside (to a degree, brass springs back and whatnot). If I wanted 2 thou thension I would use a -.003 bushing and 21st century turning mandrel.
