Thread: Donuts in 243 necks

Guys (and girls). I'm finding excessive seating resistance in my 243 brass. It's all Norma and was given to me with unknown history. It should mostly be once fired. I thought it maybe be just a bit old so I annealed it all which improved things but 85g HPBTs are soft jackets and show seater marks at the slightest resistance. On further inspection it looks like the neck-shoulder junction has the good old donut.
I'm sizing with a Redding Type-S FL die so the brass gets a light working over each time.
I have a Forster trimmer but nothing has yet to measure oversize and require a trim. I was thinking I can buy the internal reamer for it. Anyone used this setup successfully? Or am I just too mean and I should retire the logo the scap bin?

Have you considered using a sizing button or expander mandrel to push the "donut" to the outside and "skimming" it off with a neck turn

Initiating the process would at least show you if you indeed have a donut

Fairly certain it's a donut. Either way it needs it cut out so inside or outside there's still a job to do. I have both an expander ball and outside cutter for the Forster trimmer but I am not confident it is as concentric as it wants to be.

Turning the OD is way easier to do accurately than an inside ream.

Have a wee go with one piece of brass and measure it up once you're done.

Just the faintest skim off the outside that removes only half the oxidising should do it

A digital vernier should show that you removed half to one thou only

Back off the sizing bushing so that the doughnut is not touched. Solved the seating issue with my 270WSM. My Forster outside neck turner will not clean off doughnuts without cutting into the shoulder.

Originally Posted by killroy

Back off the sizing bushing so that the doughnut is not touched. Solved the seating issue with my 270WSM. My Forster outside neck turner will not clean off doughnuts without cutting into the shoulder.

Good idea. I have a competition seating die for my 7-08 I can throw the 243 bush into. Back off 50 thou or so may just sort it. Nice.
I saw the neck/shoulder being an issue with the Forster too.

Who loads a poo 4 free????
Just kidding, but most who read this will be thinking the same

Personally I wouldn't mess with brass with an unknown history. Is it really worth the hassle?

And I thought I was tight!

Originally Posted by longrange308

Who loads a poo 4 free????
Just kidding, but most who read this will be thinking the same

I do!! Haha...

Those nasty little 95gr Targex pills are the business!

Sounds like the brass is more than once fired and that the rifle used had a chamber way larger than yours. If it were me I'd take the annealed brass, FL size it with the type s (doing the neck) and then see if it chambered. If that made a doughnut then I'd then use the neck turner on them and cut it right to the shoulder. Leaving a few mm there can result in more doughnuts.

Anneal. Use expander mandrel so you get the whole neck then outside neck turn but be careful of cutting too far into the shoulder junction.