284 Win reamer

[Eric_F]

If you're using a regular caliper to get wall thickness that's the issue. A ball anvil micrometer is really needed.

 

[Roughrice]

Ah..Okay... That is the problem.
Well... The Winchester neck wall is slightly thicker than Lapua. I will fire a few Lapua cases today to get a second loading and really compare them to Winchester for accuracy.

 

[sierracharlie338]

Do you have the Lapua brass in hand? If so, do you know the loaded neck diameter? Many guys are running tight neck reamers (0.313" or so) because the necked up Lapua 6.5-284 brass ends up with such thin necks. I've got a bunch of Norma brass, I've also heard good things about Peterson and both have much thicker necks (mine is 0.315" loaded). Someone over on Accurate Shooter posted this reamer print that's supposed to be good for no-turn Norma and Peterson brass, if the factory 284 Lapua brass has similarly thick necks that's what I'd go with.

Yep Lapua brass is in hand but no 180s yet haha. Thanks for that print I think that's real close to what I'll be going with.

 

[Roughrice]

Ok. Went shoot the loaded new Lapua brass to reload and get measurements.
Once fired Lapua 284 brass fl resized w/ .312 bushing and loaded with 180 Hybrid: Loaded Neck is 0.315
Forth reload and once trimmed Winchester brass fl resized w/ .312 and Loaded Neck is 0.314
Press resistance felt exactly the same on sizing and neck tension during seating felt exactly the same.
I did use Redding expander ball when sizing.

 

[Roughrice]

After loading and measuring neck diameters of both brands of brass... My caliper measurements of neck wall thickness are certainly invalid as Eric F suggested.
Apparently the dimensions are relatively close as I got within 0.001 loaded neck diameter on both cases.
Happy to know that now as I hope they perform equally when I compare groups with each later today.

 

[Roughrice]

Yep Lapua brass is in hand but no 180s yet haha. Thanks for that print I think that's real close to what I'll be going with.

Did you get that reamer yet?
If so, What dimensions did you go with?
I'm still trying to figure where to get a reamer to match my current chamber for my hunting build.

 

[sierracharlie338]

Did you get that reamer yet?
If so, What dimensions did you go with?
I'm still trying to figure where to get a reamer to match my current chamber for my hunting build.

No I have not yet. I'm still trying to finish two other builds!! Haha. I will probably go JGS or Manson when I decide to order. Just wanted to get all my ducks in a row ahead of time so when I'm ready to order I don't have any questions.

 

[DavidA]

I custom throated my 284 win McGowen Precision 28" -8 barrel. My 180 VLD's at 15 thousandth off the lands has a COAL of 3.269 This was done optimizing bore for 180 to 197's. So in the end it is close to a .220 freebore. If I place 197 SMK's 15 thousandths of lands their COAL is 3.393. My virgin Peterson Brass measures .015 neck thickness with .312 od.
Not sure where that would put a 168 off the lands if you place the bearing surface to the end of the neck. A quick guess is you are probably 70 or 80 thousandths back. hard to say some bullets like a lot of jump in certain rifles. In the end though as you push out the throat you are committing yourself to long long bullets. So maybe you go .200 or .188. Give you a broader bandwidth of bullets.