Neck bushing and Imperial sizing wax

[patriotnation]

I seem to be having trouble with my neck sizing coming out almost 2 thou smaller than my bushing and that was never a problem with my last rifle.

I have once fired new Lapua brass in 6.5 CM. Shot in a new build for PRS with a GA Precision bartlein barrel. I now have a MEC press and use a Redding type S full size bushing die with a .290 bushing installed since a loaded round measures .292. Neck wall thickness of 14/1000. Neck OD was .289 when new, .293 fired and after sizing with 1 thou shoulder bump I am getting .288 or possibly .2885 or so at most neck outside diameter. I don't get it. I use sparingly Imperial neck sizing wax, then after I wipe it off with a microfiber cloth. Brass was deprimed then cleaned in a SS tumbler with detergent and a little lemishine, then I double checked for any leftover pins and annealed it in an AMP before resizing. I have 167 pieces to do and am halfway thru. I was thinking about changing the bushing to a .291 but it will mess up my setup I am sure. It looks like I will need to put them all thru the expander. The AMP instructions suggest ,when expanding after annealing, not to use imperial dry lube as it tends to not stick to the brass. I think I should try it anyway. I don't like the idea of lubing the inside with the wax.

Can you think of any reason my necks are not coming out at .290?


EDIT
I had the .289 bushing in by mistake, I had the .290 bushing in another die marked wrong.
it’s always something stupid

thanks

 

[Rocketmandb]

The first thing I'd do is validate that the bushing is actually the size that's stamped on it.

 

[patriotnation]

Well it worked on some Alpha brass just a couple weeks ago but good point, measure twice cut once.

 

[Supersubes]

Let me guess, a Redding bushing? I have several that do that and some even more. The bushing is mismarked.

 

[patriotnation]

My mistake

you were right

I checked it

I have another die it is a Redding neck sizing due and that one I had set aside labeled it .289 but the .289 was in this full size S type. Doh!

I guess after annealing there is not any spring back at all

I will swap them out

Thanks

 

[Threadcutter308]

I have never used anything but L.E. Wilson bushings, so I can't comment on others. But......when you measure the bushing, there is a good chance that it is tapered, just like Wilsons. I wasn't initially aware of that when I first started using them.

With the Wilsons, the ID is larger on the end opposite the size marking. The ID then tapers down to, and matches what is marked on the bushing as far as size.

So, if you see that characteristic on someone else's bushing, it was "probably" manufactured that way intentionally.

BTW, I run all my bushings upside down so that I get constant neck diameter/tension in the area of the neck that the bushing comes in contact with.

 

[patriotnation]

All set now

changed it out and I get .290 exact

thanks

 

[Kadams1563]

So do numbers go up or down in the redding die?

 

[Supersubes]

So do numbers go up or down in the redding die?

It doesn’t matter too much. There is a bit of taper to them, with the narrow end being the numbers side If you’re concerned about it, or would like to test it, size one case numbers up and measure, then flip it and size another case for comparison. Remove the expander ball for this.

 

[Tchitcherine]

EDIT
I had the .289 bushing in by mistake, I had the .290 bushing in another die marked wrong.
it’s always something stupid

It's always nice to arrive at a straightforward conclusion where things make sense, even if a bit humbling. Congrats on getting to the bottom of it.