Custom die problem?

[shawnba67]

I picked up a set of rcbs 30-06 Ackley dies cheap. Had my machinist ream them out for my 8mm-06ai. I seem to have missed the presence of a bevel maybe? When the neck goes into the resize portion the now crisp sharp edge shaves some of the brass off? There is a little sliver of brass wool at the shoulder when I pull them out! The outside of the neck measures the .343 I wanted it too and while it looks thinner to my eye my calipers can't seem to tell a difference between the resized and not I have posted a picture but it is hard to see Can any one offer me any advice with the limited info I am able to give? What we did was Simply ran a .3395 carbide reamer thru a 30-06ai die Shaved on left

[shawnba67]

Oh calipers are starret digital to the fourth place,not cheap calipers. Again father is a machinist

[ray h]

Maybe you could open the neck up to .500 and use Wilson or Redding bushing. JLC has done several for me over the years. You would need a new threaded top.

[GRUMPA]

It looks like it has a sharp edge after the reaming operation. My guess is if you were to put a .01-.02 radius on the die in that spot the problem wouldn't be there....

[lmcollins]

I don't know where to start: grasshopper.

First: congratulations on finding a carbide reamer. Where did you come up with the dimension that you reamed to? You should have measured over a loaded round with a QUALITY bullet i.e. Speer, Hornady, etc., seated bullet with mics. Don't trust old junk military. You then measure the neck thickness of a fired case with a tube mic. You then DOUBLE the case neck thickness, add the bullet diameter. Add a GOOD three thousands to this diameter and that is what you want the neck of your chambering reamer to be.

Size die diameter: Read what Reading has to say about their bushing dies. They state a bushing at least .003 smaller than your seated-bullet case neck diameter. Check their web site to be certain. If anything I'd make it .oo5 smaller. It can always be polished out. You just don't want setback in the magazine from recoil, or handling.

You are correct in that you missed something. All neck/shoulder junctions have a slight radius. I'd take some scrap larger in diameter them you reamer cut about a 60 degree on it, place a strip of wet or dry paper in about 400 grit over it, run the lathe slow with the paper oiled, and polish a slight radius on your neck/shoulder junction. Look at your AI reamer when you get it. It will have a slight radius. Without the radius you will find it harder to start the fired case into the die, and perhaps, might start case separations at the neck/shoulder juncture.

FYI: calipers are not made to measure as fine in dimensions as you seem to think they are. They are too susceptible to differences in pressure by their user, and not being held at a right angle to what you are measuring. Just because they read to three or four decimal places doesn't mean that you can measure that far accurately.

The old wildcatter's saying was that you should be able to seat a bullet in your case, rap Scotch Tape 7/8 of the way around it and chamber your round to insure safe bullet release. The tight neck bench rest shooters, that turn case necks, go much tighter than this. They make their seated rounds barely chamber by turning their case necks to fit their chambers. That's precision for bullet and bore alignment.

When you expand or reduce case necks you often make them uneven in thickness. So, measure in several places to stay out of trouble.

Your 8mm/06 loaded rounds might well require you to open your 06AI seating die up. Just remember to make it larger than your round with the seated bullet. A standard 8x57 seating die may work for you.

With your unpiloted reamer you may have given yourself eccentric ammunition. Try a loaded round. Also remember that to do an AI you must set the barrel back a bit to get a crush fit on a standard 8mm06 round when you rechamber. There are many botched jobs out there.

[shawnba67]

Lmcollins you have confused me a little. But you have given a lot of good info. Rifle is already an 8-06ai came to me that way. Loaded round measures .346-347. Another fellow here had pin gauged all his 8mm dies smallest was 340 biggest 343. My dad found a dull carbide reamer at work it was 3395 after sharpening I figured it was worth a shot, could hone it bigger if need to. Also had to ream bullet seat die as it was .343 in the neck portion so a bullrt wouldn't fit. So I figure on my radius the outer edge of the bevel would need to be slightly bigger than the expanded neck of a fired round correct?

[lmcollins]

Sorry my mistake.

I thought that you had an 8mm06. Had found some cheap dies to remake, and were going to AI your standard 8mm06 into an 8mm06AI.

Yes. The die radius would need to match that of your fired round as much as possible. I think that you have got it. Just get a small radius.

[EDG]

Just take a wood dowel say about .250 or 5/16 in diameter and a piece of 400 grit wet or dry silicon carbide . Use it wet with light gun oil, kerosene or WD-40.

tear a strip of the 400 grit paper
cut a split in the dowel with a coping saw
wedge in the paper.
spin the die in the lathe - shove the wet carbide paper into the sharp edge with about 5 to 10 lbs pressure for about 20 revolutions. Then use very light pressure for about 50 revolutions.

Wipe out the die and eyeball the edge. If the edge looks broken clean the die really well and size a case.
Still shaving? repeat the polishing

Size another case.

the edge should be radiused by the second pass at the most so go lightly...
Use at least 7X magnification and look at the sized case. When the radius at the junction of the shoulder and neck begins to look right under the magnification your are done.

[shawnba67]

I made a "slobber tube" out of a wooden dowel and put a fold of 1000 grit in there. Bucked it I'm my drill and went at it for 5-6 seconds eliminated 85% of the shaveing So I figure with another few seconds it el be golden. Thanks for all the help. I am pretty pleased to save the bulk of what a set of 8-06ai dies would have cost me.