Bushings and expander mandrel? .223 to start

mark5pt56

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I think I have this correct, confirming in the event I'm missing something?
Reference, moving however so slowly from the polished expander ball on standard RCBS 2 piece die set. I was using the die with the spindle removed and then a Sinclair expander mandrel-I know, over working the brass. My rifle is shooting good, I want to lower the numbers to minimize those outliers. I also felt that the measured mandrel(.2225 where the wear pattern is) didn't give me enough neck tension, I don't know. I polished the expander to give me .003, best I can tell.
My plan is to get the Redding Type S bushing die set, nitrided bushings--and should I also do the mandrels in which I was leaning on the 21st Century set-or at least the ones that will be one above/below the desired .002.
Anyhow, measured the 80smk loaded rounds-.246, as I understand if wanting .002, I should use a .244? If also adding the mandrel to give me the .002 +/-, should I go down to .243 on the bushing?

I'm all ears, please keep it simple for the retard and without suggesting gauges to check seating pressure, etc--joking in a sense.

I just shot at 300 the other day, 100% on a 4" plate with the 10 impacts under 2" or less as observed. A couple pics with what I'm doing now. The tic marks indicate my 1st 3 rounds on each group.
24" HawkHill, Area 419 HFM adapter, Nomad 30 with Ebrake. Debating putting the ATS tuner back on to piddle. Blue Mountain Precision build, the gun with my redneck mirage shield.
 

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Anyhow, measured the 80smk loaded rounds-.246, as I understand if wanting .002, I should use a .244? If also adding the mandrel to give me the .002 +/-, should I go down to .243 on the bushing?

As long as the brass is the same, then your .246 to .244 is going to give you .002" difference. However, the brass will spring back open a little bit when you size. .244 will likely be a little too big to engage the mandrel. I'd guess that a .243 would be about right, and .242 gives you another option. I'd get a few bushings and play. At ~$20 per, they don't break the bank.

When using a mandrel, I like to find the bushing that causes the brass to barely engage the mandrel on every case.
 
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Expanding on what @Rocketmandb explained & using your numbers for brass w/ 0.011” necks… on average, your brass won’t be affected by a 0.2225” mandrel after being size by a .244” bushing due to ~0.001” spring back, (.244-(0.011x2)+0.001)=0.223

.243 will be your starting point, but still may not work well if you have considerable variance in neck thickness. I initially determine my bushing diameter off thinner necks, e.g. if I saw 0.0105” necks in your case (although I set aside pieces that deviate too much)
 
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Lake City, the first lot/rifle will be 04 and the lot I will use on the other 2 is LC12, annealing each firing.
Okie, I'll try the .242 and .243, maybe I can measure after the bushing to see where the insides end up and choose mandrel? Or if there's 2-3 sizes I can work from. I will be moving the semi over to this process after the bolts, I know I will want at least .001 more tension.
Do you guys use the 21st CI carbides ones with a dry lube?
 
I used to use those & Porter’s, but I’ve mostly switched over to Corntina’s w/ the armaloy coated mandrels. There are reasons to select each of those 3 listed, although they’ll all work fine.
I see they offer .2220 and .2225, without getting to far down the rabbit hole, .2220? Open to suggestions and not having to use the media helps reduce the process.
 
I have .2220” & would probably go .2220 in your case as well

Your 23.8 & 24.0 loads w/ annealed brass @ 0.003” interference look good. I also prefer 3k interference for AR.
 
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