K&m Neck Turner Problem

[Shooting in the wind...]

So i ran across a rather unusual problem with my k&m turner, i got my 6mm expanding iron and 6mm pilot in the mail and needless to say after i was done preping my 243 winchester cases i ran the through the expander which went nice and smooth as usal but the problem lies when i try and put it on my k&m 6mm pilot, the fit is so tight i have to force it on and my drill stalls out trying to turn it also it absolutely will not go on any further and say less that 1/4 inch. It is so hard to turn the casing pops out of the shell holder, i am usim 3 in 1 oil for lube. I have the riser window so i know its expanding the entire length of the neck. I have a 30 cal set for my 300wsm and it works perfectly. What would cause this??? Im dissapointed cause i only have time to shoot on the weekends and just got my rifle back together after getting some upgrades. Couldnt wait to shoot, now looks like im going to have to wait for the following weekend. You can see on the pic below the dark line where the case stops and wont go any further.

 

[Straightshooter1]

How many firings on the cases?

Have you done any annealing on the cases any time before?

 

[mike06]

Did you mic the expander and the pilot? Then last mic the inside of the case neck.

 

[Shooting in the wind...]

Only 1ce or 2ce fired, no i dont have an annealer. Its on my wish list though. I trimed brass prior to expanding and it doesnt seem hard, cut nice and smooth like soft necks do. Its starline brass.

 

[Shooting in the wind...]

No i only have calipers, i know i need to mic them. Just using calipers expander is .242 and pilot is .241, but i cant tell if the problem is in the half thousands. They are starret caliper and have always been very accurate.

 

[mike06]

Try putting in a bullet in the case by hand that will tell you something. Also sometimes I use a brass brush with steel wool on it to clean the case neck inside.

 

[Straightshooter1]

Only 1ce or 2ce fired, no i dont have an annealer. Its on my wish list though. I trimed brass prior to expanding and it doesnt seem hard, cut nice and smooth like soft necks do. Its starline brass.

It's not unusual for some brass to be thicker down near the shoulder even if there's no donut formed as yet. Also and in addition, the brass may have a lot more spring back due to not being annealed enough or not at all . . . so though you've run an expander mandrel through the neck, it very well could be springing back enough to cause such a tight fit (particularly near the shoulder).

As suggested above, you might want to measure you're turning and expander mandrels to be sure they're the dimensions they're supposed to be. Calipers won't give you accurate enough measurements to help you much with this.

 

[Shooting in the wind...]

My cases are all run through steel pin media so there really clean. I guess i could see the brass having spring back but my 300wsm brass was once fired and it worked fine. I might go ahead and order a mic, what kind of tolerance range are we looking at as acceptable for the diameter of both??? My last attempt to anneal brass didnt go so well, my groups opened up and shot all over the place. I used a propane torch.

 

[mike06]

Try this on 2 or 3 cases. Run them thru the expander again but let them sit a minute or two before you pull the expander out but do that real slow in raising the arm on your press and use plenty of lube on the expander and case neck. I just bet spring back is your problem.

 

[Shooting in the wind...]

Im starting to think it is, ill def try your suggestion tomorrow and see. I know i was going to eventually need an annealer but i could find alot better things to spend 300 bucks on...

 

[Straightshooter1]

My cases are all run through steel pin media so there really clean. I guess i could see the brass having spring back but my 300wsm brass was once fired and it worked fine. I might go ahead and order a mic, what kind of tolerance range are we looking at as acceptable for the diameter of both??? My last attempt to anneal brass didnt go so well, my groups opened up and shot all over the place. I used a propane torch.

One would typically want a .001 difference between the expander mandrel and the turning mandrel. In this case, I would try an expander mandrel that's .0015 or .002 and see, if after expanding a neck of one of those cases with a larger mandrel, if the case would slide onto the turning mandrel and doesn't wiggle when you try to do so while it's on the mandrel, then you should be good to go.

Some of that problem is still going to remain and if the upper part of the neck doesn't spring back as much as the lower part do to the difference in thickness, you're turning won't change the difference on the inside diameter of the neck . . . only the outside. Proper annealing will reduce the spring back to where you're not going to see such a variance on the inside remain after running the expander mandrel through.

Am just curious about your annealing experience . . . did you anneal before or after you cleaned your brass?

 

[mike06]

Built this annealer myself about $200.00 bucks total.

 

[Shooting in the wind...]

One would typically want a .001 difference between the expander mandrel and the turning mandrel. In this case, I would try an expander mandrel that's .0015 or .002 and see, if after expanding a neck of one of those cases with a larger mandrel, if the case would slide onto the turning mandrel and doesn't wiggle when you try to do so while it's on the mandrel, then you should be good to go.

Some of that problem is still going to remain and if the upper part of the neck doesn't spring back as much as the lower part do to the difference in thickness, you're turning won't change the difference on the inside diameter of the neck . . . only the outside. Proper annealing will reduce the spring back to where you're not going to see such a variance on the inside remain after running the expander mandrel through.

Am just curious about your annealing experience . . . did you anneal before or after you cleaned your brass?

I annealed after i cleaned the brass. It was for 7mm. Was getting tigh groups then i annealed and group size tripled. Went from moa to about 3moa not to mention the amount of brass i believed i ruined so i didnt use them.

 

[Shooting in the wind...]

Built this annealer myself about $200.00 bucks total.

Nice i see you have an unused annealeez in the backround. I applaud you for building a better one, just a shame to see that one just Sitting around.... nudge nudge....

 

[mike06]

Nice i see you have an unused annealeez in the backround. I applaud you for building a better one, just a shame to see that one just Sitting around.... nudge nudge....

That belongs to a friend of mine. I did some work on it for him.

 

[Straightshooter1]

Built this annealer myself about $200.00 bucks total.

Very nice!

The cost isn't much less that the one sitting behind it, huh??? I use one like the one in back.

 

[mike06]

Very nice!

The cost isn't much less that the one sitting behind it, huh??? I use one like the one in back.

My big cost was in the gas pressure regulator fittings and hose kit and one gallon propane tank that added almost a hundred bucks to it and when my friend added that to his annealeez his final cost went way up.

 

[Straightshooter1]

I annealed after i cleaned the brass. It was for 7mm. Was getting tigh groups then i annealed and group size tripled. Went from moa to about 3moa not to mention the amount of brass i believed i ruined so i didnt use them.

I suspected so. I found I got similar results when I anneal after cleaning and I figured it was due to the oxidation and/or burnt on residue left on the inside of the neck that increases the grip the neck has on the bullet. So, now I anneal right after I decap and then clean my brass. It worked much better for me.

 

[shoot4fun]

SS pins for cleaning in tumbler. I would suggest you try putting a light chamfer on the inside of a couple of the necks before trying them on the turning tool.
Many times I see badly peened case mouths after SS media is employed. That would cause the issue you are having.

 

[Shooting in the wind...]

I suspected so. I found I got similar results when I anneal after cleaning and I figured it was due to the oxidation and/or burnt on residue left on the inside of the neck that increases the grip the neck has on the bullet. So, now I anneal right after I decap and then clean my brass. It worked much better for me.

I graphite my necks before seating bullets just for that reason ... just dont remember if i did thoes thay way or not.