is .317 neck too much for .284 shehane with 180's?

[jayjaytuner]

I decided to go with a 284 shehane, that bill shehane is gonna build.

he has a .317 neck reamer...

I planned to lightly turn the necks for uniformity...

and shooting the 180's....

is this neck gonna be too excessive for my application? loaded round should measure .312 ish, minus maybe a thou to clean/uniform the necks....

so .311 or so loaded round in a .317 neck chamber leaves 6 to 7 thou clearance...

am I overthinking this, or should I be alright, don't want to overwork my brass more than needed....
thanks for the input.

jason

 

[Jeffvn]

I have had a straight .284, using a tightneck (0.313 chamber, 0.310 loaded dimension) chamber. My brother runs that rifle now, but converted it to a shehane with the same neck dimensions. For Target rigs, clearances of 2-4 thou seem to be the norm.

The 6 or 7 thou clearance on a loaded round is not too unusual in a tactical rig (certainly for the .308s and 300WM I've seen and owned), as clearance and running when very dirty is a key. Other than working the necks pertty hard, that clearance does not seem to pose a significant problem. If you are going to anneal, it may not pose any problem at all. When I ran a .308 with 6 thou clearance, I sized the necks using a two-stage process, as doing it all at once seemed to stress the brass (just didn't feel right when I had my hand on the press handle). Either way, I went from annealing every 3 to 4 firings to every other firing. It worked just fine and held very tight waterlines at distance.

Jeffvn

 

[yukonal]

Have you already loaded up a dummy round with the intended bullet seated into the intended brass...and measured outside diameter? You need to do that first.

That said, .284 is rumored to like some room around the necks. Mine does.