Has sizing wax increased my ES?

[shaun]

I recently removed doughnuts on my brass with a K+M cutting pilot. I used sizing wax on the inside of the necks. I shot a 5 shot string through my magnetospeed earlier and my ES has gone from 10 to 42!! Could this be down to the sizing wax on the inside of the necks? 

[Catch-22]

I would have thought it’s likely more to do with different neck tension, following your turning of the necks.

If you neck size with a bushing die, you may need to buy a bushing a size or two smaller than before to return to your previous desired neck tension.

[shaun]

I didn’t turn anything off the necks just removed the doughnut.

[MarinePMI]

What catch-22 said.

[No i deer]

I guess the only thing to do is make sure you have some brass that is free of sizing wax and try again.

The donuts would/could of gave you more neck tension but inconsistent neck tension. 

Personally I wouldn't of used any lube to ream out donuts.

Atb NID 

[Ronin]

If you want consistent neck tension I wouldn’t use brass that had donuts or cases that had donuts removed as the area will still be hardened and provide inconsistent release 

 

A small wipe of the inside of the case neck is well known to reduce neck tension and provide more consistent release in properly prepared cases 

Personally, I’d start again with fresh brass and neck turn appropriately to remove any chance of donut formation 

Once brass fire formed you should see a reduction in extreme spread 

 

Uou could seat the bullets above the donut in the old cases but that’s halfway fix really  

[John MH]

I am about to remove some donuts from some Norma 6XC cases that have been reloaded multiple times since I bought them in 2008, they have probably been used at least 10 times. The bullets are currently seated above the donut so it's not really effecting seating or neck tension. I'm guessing the donuts have formed as a result of normal brass flow as the cases have always been F/L resized and should bumped back in a Tubb Dies (combined bump and neck size bushing), shoulders and usually bumped back 0.002" after firing (with new brass shoulder usually moves forward about 0.005"). I could use new brass but I'm going to stick with the old at least until this barrel is changed (these cases have been used in at least 3 different barrels). I will be expanding the necks to 0.2435" (only down to just above the donut) to allow the carbide pilot cutter to enter the case mouth and will lube inside the case neck with dry lube to stop the cutter galling. After removing the donut the cases will be wet tumble cleaned, annealed, resized and trimmed (inside and outside neck chamfer) before reloading; this may make a difference to the ES as with new brass (Peterson SRP 6XC) I get single digit ES but with the old Norma its been in the teens and sometimes more. Nothing else to do during lockdown so its passing the time.

[shaun]

2 hours ago, Ronin said:

If you want consistent neck tension I wouldn’t use brass that had donuts or cases that had donuts removed as the area will still be hardened and provide inconsistent release 

 

A small wipe of the inside of the case neck is well known to reduce neck tension and provide more consistent release in properly prepared cases 

Personally, I’d start again with fresh brass and neck turn appropriately to remove any chance of donut formation 

Once brass fire formed you should see a reduction in extreme spread 

 

Uou could seat the bullets above the donut in the old cases but that’s halfway fix really  

Yeah I think I’m just going to start again with new brass. How far into the shoulder would you turn to stop the formation of a donut? I had already cut into the shoulder a small amount to try and stop this but the donut appeared after 3/4 firings. I neck turned the virgin brass, maybe I should of waited until after the first firing?

[GeorgeB]

If you want consistent neck tension you need to anneal your cases!

[shaun]

53 minutes ago, GeorgeB said:

If you want consistent neck tension you need to anneal your cases!

I anneal my cases after every firing.

[Ronin]

I cut approximately .025” into the shoulder when neck turning to avoid a donut forming 

 

This allows brass to flow into the cut area and prevents the donut forming 

You need an angled cutter to get the appropriate material removed though

Ad others have said I’d also recommend annealing after each firing - especially for a high accuracy gun where consistancy matters 

[John MH]

Well my donuts are now history, the K&M Pilot Cutter works well following expanding the necks to just above the donut, however,  doing 400 cases by hand was a bit of a ball ache. 

[MarinePMI]

1 hour ago, John MH said:

Well my donuts are now history, the K&M Pilot Cutter works well following expanding the necks to just above the donut, however,  doing 400 cases by hand was a bit of a ball ache. 

Ya think?  Ouch (my thumbs hurt, just thinking about turning 400 cases).

[Andrew]

Forster makes nifty neck reamers for handling these problems while sparing the thumbs. ~Andrew

[KABOOM]

On 11/10/2020 at 12:03 AM, No i deer said:

I guess the only thing to do is make sure you have some brass that is free of sizing wax and try again.

The donuts would/could of gave you more neck tension but inconsistent neck tension. 

Personally I wouldn't of used any lube to ream out donuts.

Atb NID 

yes exactly the lube plus the tension change changed things, remove the lube and see what happens