My 4x fired brass has the donut. On a fired case, a bullet will not go into the case. Would I be better off trashing the 4x fired Lapua brass and just buy Hornady brass? Also, should I stop using a bushing die and just use a standard sizing die?
6.5 PRC donut in Lapua brass
- Thread starter KyleC
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Might be okay if you can fine an inside neck turning tool. I would never use hornady brass, ADG or more lapua.
I was wondering about the inside neck reamer. Hear good and bad. I can't even re-chamber a fired piece of brass without stiff bolt close which tells me the donut is probably pushing outwards as well.
Varmint Hunter
Well-Known Member
That ^^^ sounds like an issue of excessive pressure. For the donuts - I'd run a mandrel in there and just neck turn the cases.
Forgive my ignorance as neck turning is new to me.
1. Would I just run the brass onto a standard .264" mandrel after sizing or do I need a special size mandrel?
2. Are there special neck turning tools that will do the neck and also kiss the neck/shoulder junction?
I figured that, but if I have to replace brass every 3-4 firings it could get real expensive
If you don't mind sharing. What die are you using? What bushing size? and if any what mandrel size? If you don't want to post on forum send me a pm please. We all want to learn, help others and avoid potential problems. Thanks
epoletna
Well-Known Member
KyleC: You do not want the same size mandrel as your bullet, or else you will not have neck tension to hold the bullet in the brass. Typically, people use a mandrel around .002 smaller than the bullet, but then experiment up or down .0005 from that to find the neck tension they prefer. If your neck is too thick to chamber after running the mandrel in and out, you can turn the outside of the neck down to about .013- .015 thicknes. Sometimes that will show up as turning off one side and not the other. Don't worry about that -- go for a consistent turn from one piece to the next.
Kmccord
Well-Known Member
You should be looking at K&M neck turning tool, there is a lot to it. As for donut in the case neck, you can search this forum, it was and still is a big problem in some 28 Nosler cases. One of the work around is to seat the bullet above the donut, however, you need enough freebore to do that, second is not to overwork the brass when sizing, you really only need to bump the case .002 of an inch to allow it to load in the field. When you overwork the brass say resize .006-.008 and then doing this over and over, brass will flow to cause the donut.
K&M has a carbide mandrel with a cutter at the end to eliminate doughnuts.
100 pieces of Lapua brass should last the length of the barrel life if you take care of it, discard the brass when you get a new barrel, and start over.
A good test for the doughnuts is after you fire a case, try to drop the case over a bullet of the next round in your loading block or box of loaded ammo. You can sort cases with and without doughnuts, and deal with doughnuts at some point and time.
As one poster mentioned, doughnuts have nothing to do with dies, and Hornady brass should be your last option.
Necking down brass always leads to doughnuts, and I turn the parent brass necks first, then neck down, which ******* the neck thickening. Necking up seems to have less effect on the forming of the doughnut. Shoulder angle is of major importance to ****** brass flow, with 35 and 40 degree shoulder angles retarding the most. The double radius of the Weatherby case stops brass flow in my experience more than other approaches.
Learning to deal with doughnuts is simple advanced reloading and K&M products simplifies the whole project. This Tube Micrometer really helps:
100 pieces of Lapua brass should last the length of the barrel life if you take care of it, discard the brass when you get a new barrel, and start over.
A good test for the doughnuts is after you fire a case, try to drop the case over a bullet of the next round in your loading block or box of loaded ammo. You can sort cases with and without doughnuts, and deal with doughnuts at some point and time.
As one poster mentioned, doughnuts have nothing to do with dies, and Hornady brass should be your last option.
Necking down brass always leads to doughnuts, and I turn the parent brass necks first, then neck down, which ******* the neck thickening. Necking up seems to have less effect on the forming of the doughnut. Shoulder angle is of major importance to ****** brass flow, with 35 and 40 degree shoulder angles retarding the most. The double radius of the Weatherby case stops brass flow in my experience more than other approaches.
Learning to deal with doughnuts is simple advanced reloading and K&M products simplifies the whole project. This Tube Micrometer really helps:
SHARS 0-1" Tube Micrometer 0.0001" Graduation Carbide Tipped NEW P} | eBay
Accuracy of <0.3µm +(L(mm)/1200) µm. You may ask for freight cost before buying tools.
www.ebay.com
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Varmint Hunter
Well-Known Member
Neck turning require two mandrels. One is the expander mandrel which is used first to expand the neck to a proper size to accept the turning mandrel on the tool itself. The two mandrels are usually .001" different in size. Your cases should fit perfectly on the turning mandrel as you cut the necks.
The cutter itself can be bought with different angles to match the shoulder angle. You should cut the neck low enough so that the cutter just touches the shoulder.
There are probably videos on YouTube that better show/explain the process.
