284 Win reamer

[Roughrice]

If you notice... the pointer is at the bottom of bearing surface before boat-tail begins and is just above the neck-shoulder junction.
Boat tail sets in the case some but doesn't bother me because the 284 case has plenty of room for the powder I use and still get a full neck surface contact for concentricity.
Others may like seating further out... its all about
what works for their need or situation.
284 w/Berger 180 Hybrid @ 3.270 COAL @ 20k off.

 

[Roughrice]

If you notice... the pointer is at the bottom of bearing surface before boat-tail begins and is just above the neck-shoulder junction.
Boat tail sets in the case some but doesn't bother me because the 284 case has plenty of room for the powder I use and still get a full neck surface contact for concentricity.
Others may like seating further out... its all about
what works for their need or situation.
284 w/Berger 180 Hybrid @ 3.270 COAL @ 20k off.

2860 fps with 30" barrel and shooting small, small, itty bitty, tee tiny groups...if I'm on my game.
I'm not a professional but have sent these to 1000 yards under 1 MOA in 15mph and variable winds.
Just sayin... I'm not blowing out primers to get magnum velos, but Dammit... this thing shoots sooo gooooood!
So good that... I'm building a long range hunting rifle with these exact specs!
Yeah... I have many other calibers to hunt with but, this relatively new to me 284 thing just has me completely enamored!
I am loading different hunting bullets and shooting em thru this rifle to see if specs would handle the hunting bullet I want to use. So far...So great!
I think I'll use the exact chamber dimensions for the hunting build.

 

[sierracharlie338]

2860 fps with 30" barrel and shooting small, small, itty bitty, tee tiny groups...if I'm on my game.
I'm not a professional but have sent these to 1000 yards under 1 MOA in 15mph and variable winds.
Just sayin... I'm not blowing out primers to get magnum velos, but Dammit... this thing shoots sooo gooooood!
So good that... I'm building a long range hunting rifle with these exact specs!
Yeah... I have many other calibers to hunt with but, this relatively new to me 284 thing just has me completely enamored!
I am loading different hunting bullets and shooting em thru this rifle to see if specs would handle the hunting bullet I want to use. So far...So great!
I think I'll use the exact chamber dimensions for the hunting build.

Very nice exactly what I was thinking. Thank you

 

[sierracharlie338]

For a no turn neck shooting 180 Hybrids the standard is .320" neck/.225-.250" freebore. My .284 no turn reamer has .225" freebore for the 180/184 Hybrids but, if I were to have it reground, I would go with a .250" freebore so I could have the base of the bullet a closer to the base of the neck. For a hunting gun I would go .225" so you could still run shorter bullets and have plenty of bearing surface in the neck. A friend of mine just measured a new Lapua .284 case with a 180 hybrid seated and the loaded neck diameter was .315"; this gives 0.005" total clearance which is perfect for the .284 Win.

Outstanding info thank you sir

 

[KU_Geo]

Any suggestions on free bore if I only plan to shoot up to 168 berger VLDs?

 

[AZShooter]

KU_Geo:

My other 284 win is in a Ruger SA. I had it throated for the 168 Berger. Pacific Tool and Gauge reamer says .315" neck and OFB. (Zero freebore)

Setup for my magazine for a 3.050" OAL with bullet engaging lands .010".

FYI the rifle shoots other lighter bullets just fine including the 120 Nosler BT.

 

[Roughrice]

KU-Geo,
Don't know what your action length is but all of the freebore info we exchanged is too long for a short action.
AZShooter sounds like he has the information you seek.

 

[KU_Geo]

I'm going to build it on a tikka action, so I've got plenty of mag length to play with (3.34"). Just don't have a need or desire to sling 180s, thinking 162 eldx and 168 Vld will accomplish all I want out to 800yards. Action and barrel are inbound, now just trying to figure out what's specs to make the chamber. Definitely don't want to neck turn.

 

[Roughrice]

I'm going to build it on a tikka action, so I've got plenty of mag length to play with (3.34"). Just don't have a need or desire to sling 180s, thinking 162 eldx and 168 Vld will accomplish all I want out to 800yards. Action and barrel are inbound, now just trying to figure out what's specs to make the chamber. Definitely don't want to neck turn.

I agree with no turn neck chamber. You should have plenty of mag length.
My loaded Berger180 Hybrid is 3.275" COAL.
I have .220 freebore.
I'd bet .188-.200 would do fine.
But, load a dummy with what you'd like the COAL to be and send it to your smith to get it right.

 

[highdrum]

I'm going to build it on a tikka action, so I've got plenty of mag length to play with (3.34"). Just don't have a need or desire to sling 180s, thinking 162 eldx and 168 Vld will accomplish all I want out to 800yards. Action and barrel are inbound, now just trying to figure out what's specs to make the chamber. Definitely don't want to neck turn.

A 162 eldm/eldx will have as much or more bearing surface as a 180 hybrid.

 

[Eric_F]

Ive decided to start gathering parts for a 284 win build, even found some Lapua brass to start off the build! This will be on a long action.

My question is on reamer specs. Is there a reamer spec already out there that is worth looking at or using? Initially I planned on sending a dummy round in to have one done but figured I should check if anyone was aware of a decent one that already existed.

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.

 

[Roughrice]

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.

I just measured neck thickness: New Lapua 284 brass: .015 Min -.016 Max with most measuments at about .0155
New Winchester 284 brass: .016 Min -.0175 Max with most measurements at .0170
Loaded neck diameter with my Winchester 284 brass is .3135 and using a .312 bushing in Redding S die.
Just got the Lapua brass and didn't load and fire in chamber yet so can't give good measurements there yet.

 

[Eric_F]

I just measured neck thickness: New Lapua 284 brass: .015 Min -.016 Max with most measuments at about .0155
New Winchester 284 brass: .016 Min -.0175 Max with most measurements at .0170
Loaded neck diameter with my Winchester 284 brass is .3135 and using a .312 bushing in Redding S die.
Just got the Lapua brass and didn't load and fire in chamber yet so can't give good measurements there yet.

0.0155" walls ought to be 0.315" loaded, so that print (or at the very least a 0.319" neck) should be great. Somewhere around 0.220" freebore is what most guys run for 180 hybrids, less for lighter bullets, but the SAAMI spec and that primt don't have a traditional freebore, just a taper.

 

[Roughrice]

0.0155" walls ought to be 0.315" loaded, so that print (or at the very least a 0.319" neck) should be great. Somewhere around 0.220" freebore is what most guys run for 180 hybrids, less for lighter bullets, but the SAAMI spec and that primt don't have a traditional freebore, just a taper.

Yep. I have a .319 neck and .220 freebore Criterion
My caliper showed the aforementioned neck thickness measurements of .017 on new Winchester brass and loaded neck comes out .3135-..314 with 180 Hybrid... go figure. I know the math doesn't work out.
My caliper is good but not a $250 good. Perhaps not quite good enough to accurately measure neck wall thickness.
That may be where some error comes from.