Runout after neck sizing

[seajay]

I have been loading for a 308 Win. without many good groups. I checked runout on a loaded round and it was 004-005. I then checked a fired case and it was less than .0003. I did find that the neck sized case had about 4-5 thou. All of the necks have been turned to .013. All of the rounds were loaded with Wilson dies. Has anybody had any problems with these dies? I do have some older Wilson dies and the runout has not been a problem.

 

[fdshuster]

What kind of brass are you using?

 

[seajay]

Winchester and Lapua with same results.

 

[artbosco]

All of the rounds were loaded with Wilson dies. Has anybody had any problems with these dies?

The Wilson dies that I use produce concentric rounds. They're excellent dies.

I do however, F/L size, each and every time I reload. I believe sizing the whole case, at the same time, makes for an overall more concentric end product. That way, you're not doing bits and pieces.

 

[STS]

The die itself is not your problem. The hole through the sizing bushing isn't straight. I've had quite a few over the years that were crooked. You can check the bushing with a tubing micrometer for wall thickness variation on opposite sides of the hole top and bottom.

 

[queen_stick]

Are you lubing the necks?

I had this exact same problem, and asked the exact same question a few months ago. I was getting runout because I was not lubing the necks.

Also, you're starting out with .003" of runout on a fired case. Ideally, they should come out of the chamber with a lot less than that (half a thou or less). With that said, your resizing operation is only adding about one thou of runout on top of what's already there... that's not bad!

I'll also add this... Before I realized I had .004 to .005 of runout, I was using those rounds to win relays at 1000 yards. Take it for what it is, but I shot a couple 8" groups at 1K with rounds that had .005" of runout in competition, and even shot a 6" group during practice one time. (These are 10-shot groups). I have since resolved the runout trouble because it's counterproductive to accuracy, but I haven't seen a noticeable difference on the target at 1k either (I only had the issue fixed just before the last match last year, so I don't have too much of a before/after comparison)

My point to the rambling above... if you aren't getting good groups now, then removing .003" of runout will probably not get you to where you want to be in terms of accuracy.

Walt

 

[seajay]

Walt,
I have not tried any lube on the necks.The runout on a fired case is .0003 or less not .003.
Thanks,Chris

 

[seajay]

I tried Walts lube on the neck with the same result- .003-.004 runout. I then found another bushing in a .308 Bear neck die that produced a sized neck with .0003-.0005 runout. I installed that bushing in the .308 Win.-Wilson neck die and lubed the neck on a fired case and sized it......... .004" runout. Do you think the body of the die could be reamed crooked?

 

[queen_stick]

sorry seajay... I misread your measurements... that's a big difference!

the only other idea I have is to check your die to verify it's reamed straight. Spin the die with a test indicator on the inside of the 'chamber wall' and see if you get any runout.

 

[LHSmith]

The die itself is not your problem. The hole through the sizing bushing isn't straight. I've had quite a few over the years that were crooked. You can check the bushing with a tubing micrometer for wall thickness variation on opposite sides of the hole top and bottom.

This is why Redding advises to let the bushing "float" in the die by backing out the top ~1/8 turn.........if it doesn't rattle when you shake the die ...it's too tight.

cj- If the gun ain't shooting, why are you thinking it's concentricity? What is the history of this 308's performance? What level of performance is it shooting now? i.e group size, # shots /group, range, wind flags? What kind of rifle is this?

 

[STS]

The die itself is not your problem. The hole through the sizing bushing isn't straight. I've had quite a few over the years that were crooked. You can check the bushing with a tubing micrometer for wall thickness variation on opposite sides of the hole top and bottom.

This is why Redding advises to let the bushing "float" in the die by backing out the top ~1/8 turn.........if it doesn't rattle when you shake the die ...it's too tight.

cj- If the gun ain't shooting, why are you thinking it's concentricity? What is the history of this 308's performance? What level of performance is it shooting now? i.e group size, # shots /group, range, wind flags? What kind of rifle is this?

Reddings advise is noted. But the simple fact of the matter is if the hole is not straight through the bushing, and perpendicular to the top of the bushing, it will not size the case necks straight. It doesn't matter if the bushing floats or not, it still has to come in contact with the top of the die at some point. If the hole through the bushing is not perpendicular when the bushing stops against the top of the die the hole is not coaxial.

 

[LHSmith]

STS-that's interesting. What brand were the bushings? Wilson's do have a hole that has a taper.

 

[fullersson]

I may catch a lot of grief for this, but on the next batch of brass don't turn the necks down so far that you have to use a bushing. After you fire the case just knock the primer out and reload the brass. I've done this with good results. I would be doing it now but the new Laupa brass is a little thinner and in my no neck turn chamber the brass just won't hold the bullet after firing.

 

[STS]

STS-that's interesting. What brand were the bushings? Wilson's do have a hole that has a taper.

My experience has been only with Wilson bushings. You can measure the wall thickness of the bushing with a tubing mic and test whether the hole is in the center of the body of the bushing. If you do this top and bottom you can clearly see if the hole is straight. I made a fixture to hold the bushings by the hole and surface grind the ends perpendicular to the hole. It was more trouble than it was worth. I simply find another bushing that is true with the hole. I have several in a box that are rejects. Sad but true.

 

[seajay]

Guys,
I could not think of any more test to make on the dies with the tools I have so I sent die,bushing and once fired lapua cases to Wilson. I will keep you posted on the results.
Thanks,Chris

 

[LHSmith]

STS-that's interesting. What brand were the bushings? Wilson's do have a hole that has a taper.

My experience has been only with Wilson bushings. You can measure the wall thickness of the bushing with a tubing mic and test whether the hole is in the center of the body of the bushing. If you do this top and bottom you can clearly see if the hole is straight. I made a fixture to hold the bushings by the hole and surface grind the ends perpendicular to the hole. It was more trouble than it was worth. I simply find another bushing that is true with the hole. I have several in a box that are rejects. Sad but true.

Fine, if what you're doing works for you, but I am just trying to inform you that the Wilson bushings have a tapered hole......the amount of taper?...... I have heard anywhere from .0001" to .0005". I would think this info would be crucial to determine if the hole is actually crooked. It may very well be crooked, as I have found numerous reports of out of spec bushings researching this reply.

 

[STS]

STS-that's interesting. What brand were the bushings? Wilson's do have a hole that has a taper.

My experience has been only with Wilson bushings. You can measure the wall thickness of the bushing with a tubing mic and test whether the hole is in the center of the body of the bushing. If you do this top and bottom you can clearly see if the hole is straight. I made a fixture to hold the bushings by the hole and surface grind the ends perpendicular to the hole. It was more trouble than it was worth. I simply find another bushing that is true with the hole. I have several in a box that are rejects. Sad but true.

Fine, if what you're doing works for you, but I am just trying to inform you that the Wilson bushings have a tapered hole......the amount of taper?...... I have heard anywhere from .0001" to .0005". I would think this info would be crucial to determine if the hole is actually crooked. It may very well be crooked, as I have found numerous reports of out of spec bushings researching this reply.

I'm well aware that Wilson bushing are tapered. In fact I've been aware of that for nearly 40 years. They are tapered .0005, it's not that difficult to measure with the right equipment. My point is not to get into a pizzing match, it is to help someone understand why their die/bushing is not performing well. I incorrectly assumed that the bushings were all created perfectly until about 25 years ago when I ran into the same problem that the OP is having. I investigated where the problem was and discovered crooked holes in the bushings. Check some of them yourself. If you don't find any you haven't checked enough. Crooked bushings are more common than you think.