Turning necks for 284 Shehane (.313 nk) question.

[bpmoss1]

My new 284 Shehane is almost done. I want to get busy turning 300 pc. of new Norma cases. Will turn for .004-.005 clearance. Smith is off moose hunting in Alaska so I can't ask him this question and I don't have the reamer print.- I'm assuming I should turn the whole neck to touch shoulder and fire-form with bullets jammed. Is this correct? And will a portion of the turned neck end up in the shoulder?

Thanks in advance, Barry.

 

[bsumoba]

If you can fireform first, then turn, that might make the cut more even. Sometimes the shoulder angles on new brass are not exactly 35 degrees. If you have to turn, then turn them similar to the brass on the right. You can even go further down a bit more as well. This is a 284 Shehane case by the way.

 

[21shooter]

Hi Barry, The norma brass has thick neck walls. I take 2 cuts, leaving
1/2 tho. .0005 for finish cut. Do this in 2 separate operatons.
I load 54.2gr. 4831sc For fire form W/180berger hyb. .008 off the lands
I have shot some 199-13x fire-forming to shehane Thanks, John

 

[bpmoss1]

Thanks guys, would it be to any advantage to first turn for .0035 clearance then finish turn (for .004 target clearance) after initial fireforming?

 

[bsumoba]

Thanks guys, would it be to any advantage to first turn for .0035 clearance then finish turn (for .004 target clearance) after initial fireforming?

I like this plan a lot. Do enough so you can chamber it, then fireform and turn to final dimensions.

 

[ShootDots]

I am not a fan of turning necks AFTER they are fired. Prior to firing, you have a nicely defined neck-shoulder junction. AFTER firing you have a slight radius at that juncture. Personally, I expand the necks with an expander mandrel. I turn the brass (about 1/3 turn each "turn") 3-4 times running it up into the mandrel each time. You will see that by doing this, the brass by the 3rd or 4th turn goes up into the mandrel nice and smooth. Then I turn off to exactly a 12 thousandths neck wall thickness. This will give you 4 thousandths clearance, with a .313 neck. Turn ever so slightly into the shoulder (BSUMOBA's pic is perfect). Then anneal that brass. Then run it into your bushing die with a .306 bushing. This will hold the bullet tight enough to jam them (about 15 thousandths in) into the lands and hold that case against the bolt face. Use 54.0 to 54.5 grains of H4831SC and go shoot a 300 yard match. You probably won't win>>>but you will do fine. This makes fireforming fun! Use a 180 VLD. Remember, with a .313 neck you MUST turn down the necks first or you will NOT get your brass into the chamber. Personally, I turn right down to 12 thousandths PRIOR to fireforming>>>I do not turn off a half thousandths or whatever later after firing. TURNING TIP: Norma brass has a thick neck wall. If you try and cut all or most of it off with the first cut, you may experience the cutter having a hard time going up over the lip of the case mouth. Try this: Before you turn, put a pretty good OUTSIDE chamfer on the case mouth (knock that edge off). This will aide greatly in allowing the cutter to get up on the case mouth-wall so you can turn the walls down to your desired thickness. ADDITIONALLY, make sure you use a good mandrel cutting lube such as the PMA Tool cutting lube. I hope this helps..

 

[bpmoss1]

Thanks for the info guys, I appreciate your time. Barry.