Bushing vs collet dies

[ttuxedo]

I am in somewhat of a quandry and need some advise. Here's my story. Just starting out in Benchrest shooting,just got a rifle, dies, tools,etc.,etc., have a 6PPC w/.262 neck, Wilson seater, Newlon FL bushing die. Also have a Lee collet die and seater which I purchased because that is what I am used to using on all my other rifles. I've turned the necks, sized, loaded and fire formed about 65 pcs of Lapua 220 Russian brass. Ok, ready to start over and begin getting serious about tuning. Here's my question, why use a bushing in the FL sizer vs a collet die that squeezes the neck down to a fitted mandrel? If I understand all of this, we're attempting to achieve consistent neck tension, is that right? How does the neck bushing do that by sizing the outside and moving most of the variance to the inside?
I know I can make brass with a more consistent wall thickness than the factory brass and that is a good thing, but it is not perfect. From what I've seen, the inside dia. is not consistent after outside turning and can easily be larger/smaller near the neck/shoulder junction - there is nothing to make it otherwise. Thinner seems to make sense to me as the thinner the wall the less impact wall thickness variance creates, may not be the real reason but is the only thing I can think of. Now, since the O.D. is not perfect, the bushing is going to push all imperfections to the inside where the bullet is going to see them on its way in, I think. By the same logic it seems, to me anyway, the Lee collet die would take these 'good' things one step farther by sizing the inside diameter to a known dimension while simultaneously making the walls of the neck cylinder parallel. This should improve concentricity, neck tension and runout consistency. Having said all that, I suspect, as usual, that I am missing something somewhere. Folks with a lot more experience than me are using the neck turning/bushing approach and getting some pretty outstanding results, so it makes sense to me that there must be a reason or something that I am not seeing or getting. I don't have a problem doing things either way, I am just hoping someone may have tried both methodologies at a competitive level and can steer me straight or give me some insight. Any help would be appreciated. Thanks Barry

 

[oneflyer]

Exactly the reasons that many, many serious BR shooters use the Lee Collet dies. Great product for the money and they perform.

 

[BoydAllen]

My necks have a total variance of .0001 within a given set. I hardly think that moving such a small amount of variance to the inside is an issue. That being said, use what works the best for you, by actual test. Just remember that you will probably need to two stage size, one being body size and shoulder bump. I find that after one has determined what bushing size works best for a particular application, that a one piece FL die,that incorporates that neck ID, does not use an expander, and barely sizes the body will give the best concentricity. I have never seen a collet die at a Benchrest match, but if they turn out to be a better way to size a .262 neck PPC I will make the change. Let us know what your results are.

 

[ttuxedo]

Thanks for the response, Boyd. I do have a Newlon FL Bushing die and since I didn't see anyone at the match I went to using a Lee collet die and my gunsmith friend specifically told me to get a Redding S type small base FL die, there must be a reason. I think stick with the Newlon until I get some more experience behind me. It is a beautiful example of tooling work.
I haven't gotten good enough to turn my necks within 1 tenth yet, my lathe isn't that good and neither are my hands but I am still learning and working at it.
Again, thanks for the input.

 

[BoydAllen]

Was the Newlon die reamed with a FL die reamer? If it wasn't, I doubt that it can do enough sizing on the diameter of the body. Troy sells beautiful die blanks to be reamed and hardened by others. Who finished your die?

 

[ttuxedo]

I don't know who did the die or whether it was done with the same reamer. I got the rifle, Stolle Panda, ~600 to 700 rounds down the barrel, the Newlon die and a Wilson seater were thrown in - I doubt the Newlon die matches the chamber, from what I can see and have checked is was done very well. I do not know what is acceptable,clearance wise on the die. It is sizing the body, down to .439 from .440,as fired), I checked them today and this is about a .001 larger than the Redding small base body die I have, checked and compared all dimensions I could. Neck size seems to be the only tight area, I think I am about .001, maybe .0015 to large. The .258 bushing puts a definite mark on the neck, only sizes about 3/16 of the neck . May have to reset my neck turner and go thru the things one more time. This will be the second firing on these cases. Mickey offered to have me over and work thru some of these issues with him, I guess I should probably quit messing around and just get on over to Alabama an have him go thru the whole setup. Thanks for the input, I've been sizing and measuring cases all afternoon. Your comment was timely and right on, made me think - jumped right up and went checked a sized case in the chamber, whew, it fits. Thanks again.

 

[BoydAllen]

It sounds like you may not have needed the SB die. Why Don't you use the Newlon die every time for a while and see how it goes. It sounds like it may be a very good fit. How much is it reducing the shoulder diameter? This measurement is best done with the tips of the caliper jaws, and takes some practice to get repeatable results. As far as the bushing marking the necks, wrap a patch around an old brush and apply some Iosso, and then chuck the threaded part of the brush in a drill and do a little careful polishing. I solved a similar problem that way once. One more thing, I measure bump from a reference case that I have fired till snug, without bumping the shoulder. It usually takes at least three firings for the shoulder to get snug to the chamber, but that will depend on how hot the loads are.

 

[ttuxedo]

Getting about .001 to .0015, best I can measure. As you noted the shoulders are not sharp yet. I am setting the shoulder back about .001 to .0015 as well from as fired, checked at three different dia. on shoulder using head space gages on calipers.
I am going to go do some load development tomorrow or Sat., that will sharpen out the shoulders, then I'll turn those necks one more time to clean up that last 1/2 thousand to 1 thousands that they are off, so the round chambers easier, from what I've read, std. practice is to have 1 or 2 thou. clearance on the neck in the chamber.
I appreciate all your help.

 

[bsekf]

Barry, why are you bumping the shoulder back .001 - .0015 on a bolt gun? I am not a BR shooter, but thought you only bump the shoulder back after using very hot loads and the bolt won't open easily or close. I understand bumping the shoulder back in a Encore, because of frame stretch.

Bill

 

[flatlander]

Barry, I'd probably set that SB die aside and forget I'd bought it,better yet - list it on e-bay), based on what you're saying about the way the Newlon die is working. Sounds like you're well-equipped to get to where you want to be with case necks.

I dunno whether I'd leave the collet die at home when heading for a match or not - just because you don't see anyone else using on doesn't mean it won't work well for you. I've used a few of them on Ackley Improved cartridges, and have seen a substantial reduction in case neck runout, relative to what I get with a FL die. In your situation, I'd be tempted to use the collet die on a regular basis, and go to the Newlon FL die only when bolt closing effort points out the need to bump shoulders.

 

[BoydAllen]

BSEKF,
In competition Benchrest using a closely fitted FL die is the common practice. This is done for several reasons. If a condition is holding, we need to shoot fast. Loads tend to be hot. Closing or opening a tight bolt disturbs the rifle's position on the bags as well as changing their shape. Waiting till cases get tight and then FL sizing would require checking the fit of all cases in the rifle and bolts are not allowed in rifles except during a match. I could go on.

The practice of avoiding FL sizing is usually the result of using the common sort of FL dies that over size and distort cases, and/or the desire to simplify reloading by eliminating the need to lube and then remove lube from cases. Benchrest competitors' dies are different in that they are designed to just barely size the case, avoiding the problems associated with over sizing and expander balls.

 

[ttuxedo]

Guys, I am so new to benchrest shooting, comparitively if I was a new car they wouldn't even have the plastic off the seats.
Right now I am just trying gain a thorough understand of the whats and whys of my tools and equipment. Hopefully drop some bad habits, discard some erroneous ideas and develop some new better ones.
I think Boyd answered the why one does this or that, pretty well. Clarified a few things for me, for sure. I couldn't have answered yet, I am still lost in the woods somewhere!

I haven't given up on the Lee collet die and will keep the sb die to work fire form brass with. Never hurts to have some good players on the bench. I'll know what's what one of these days and they will either work then or go away, as the case may be.

Appreciate all your help guys. Getting started in benchrest is a challenge and all the help is really appreciated. Hopefully, we'll meet at a match someday.

 

[bsekf]

Boyd, thank you for the concise answer, never too old to learn. Do you size the necks enough to ever have to anneal?

Bill

 

[BoydAllen]

Because the brass moves so little, firing and being sized, I have not annealed my cases, even though they go through quite a number of firings. I never have had a cracked neck.

It has been my experience that 133 likes a lot of neck tension. Annealing cases would be going in the wrong direction for that. I do have to reset my FL die to get the same amount of bump as a given set of cases become more work hardened.