.284 Loaded Neck Diameter?

[yukonal]

I'm currently using WIN factory brass with a .315" loaded neck.

I'm having a new reamer built, and plan on getting some Lapua 6.5-284 brass and necking up to 7MM.

You guys that have necked up 6.5-284 brass to 7MM for your .284's---what is your loaded neck diameter with the Lapua brass...and say, 168 or 180 Bergers? I'll order the reamer with .003-.004" clearance before cleaning up the necks.

 

[Steve Blair]

My reamers, both .284 Win and Shehane, have Ø.313" necks. I turn neck walls to .012" for a loaded Ø.309".

 

[yukonal]

Thanks Steve. I'm wondering what the Lapua brass measures with a loaded round...before...trimming. Sorry, I should have been more specific.

Looks like you're looking for .004" clearance---.002" on each side?

 

[Steve Blair]

After expanding, the neck walls run ~.0138-.0142". Most folks run Ø.317"-.318" chamber necks for unturned brass. [br]
*** clarification ***

 

[robinhood]

My unturned Lapua brass measures .3125 when loaded with a 180 Berger VLD. I use a .311 bushing for light neck tension. The fired cases come out with .315 necks. Shoots very well. PTG no turn reamer. Hope this helps.

 

[nosualc]

Al,

With unturned Lapua 6.5x284 brass necked up to 7mm and a 180gr berger hybrid, I'm seeing .3125-.3135.

-nosualc

 

[yukonal]

Thanks robinhood and John. Do you guys see any problem with a .318 neck on the new reamer...seeing as how the .284 likes room in the neck?

I'll clean up to prob. .313---that leaves .0025 on each side, or .005 total room. I wouldn't think that's excessive, would you?

 

[robinhood]

Al,

I had Dave Kiff make my reamer for a no turn neck, using necked up Lapua 6.5x284 brass. Throated for the 180 Berger VLD. It has a .317 neck with a .200 freebore. Give Dave a call, he is very helpfull. I have sent him dummy rounds in the past to get the freebore I wanted. Always came out right.

 

[nosualc]

Al,

Are you building a hunting rifle or a competition rifle? I think a tight neck is going too far for a hunting rifle (and may be counter productive), but worth the pain for competition.

-nosualc

 

[yukonal]

Just another LR hunting rifle. But I still set my standards to competition quality parts and specs. I have plenty of time in the winter to play with this stuff. But...I really don't want to go the tight neck route. So, I guess you're thinking .005" clearance on the new neck reamer isn't excessive. I'll go with the .318" neck.

 

[Larryh128]

You can go as large as a .320 neck & not really see any big difference in a LR hunting rifle.

 

[Dave L Kiff]

The 284 reamers our customers have been getting have had .317 to .320 neck size but for the 6.5/284 necked up to 7mm the size is .317 to .318. Make sure you order a throat diameter at .2845 or a few tenths larger so the projectile has the clearance it needs on certain lands and grooves. I have been grinding many 284 win match reamers at .317 neck and .188 freebore. Thanks Dave

 

[yukonal]

Dave,

Glad we got that straightened out. Two dummy rounds heading your way. I'll have Greg run the throater thru this barrel after this winter.

 

[Dave L Kiff]

Yep , I am glad to.The spiral throat reamer will not only get him the size and depth he needs but it will shear a nice finish cutting against the opposite spiral groove . I talked with Greg again and he said the reamer had the . 188 freebore with the 1deg 30 lead but I think it may need to go even .020 to .035 deeper on that tight land and wide groove set up . My rifle shoots great with the same reamer but I set it up to burn into the sweat spot. Tom and Butch may be dead on at .219 but they set there barrel back every 450 rounds they told me . A Longer throat may be the ticket for these bullets but I would like to just shoot all summer with out tearing the rig down so I will stay with the .188 . Well I need to get a few more reamers ground before I go . You have a Happy new year . Thanks Dave Kiff