brass prep for .284 Win

[RJinTexas]

I've never loaded for the .284 Win, so I read the feathered articles for gun of the week #53 by Jerry Tierney and #88 by Charles Ballard along with the cartridge guide for this caliber and found a lot of helpful information.

One thing I noted was that Jerry Tierney advised that this cartridge needs a minimum of .0015 to .002 per side of neck clearance to achive best accuracy. Also noted that Charles Ballard stated to use a bushing that .002 smaller then your turned neck measures with a bullet seated. After expanding the 6.5x284 Lapua case necks I used a K&M carbide tipped turning mandrel to assure there wouldn't be a inside donut. My new 30" 8.5 tw Kreiger HV barrel has a .311 neck so I turned the neck thickness to .0125 this gave me a finished neck measurement with a bullet seated of .308 the turned case had just enough neck tension to allow me to seat a bullet long in a dummy round, snug but still just enough tension to allow the closing of the bolt to finish seating the bullet which left the OAL @ 3.230 that seemed awfully long to me so I repeated the process with a second case the OAL was exactly the same. Being that the base of this long bullet is already at the case body/shoulder junction which is deeper then I like, I'm reluctant to seat this bullet any deeper. Being I'm having Forster make me a bushing bump neck die and if I follow the customary sizing advise I'm assuming I'll need a .306 bushing. Any advise or criticism with what I've done to this point from you folks who have loaded for this cartridge would be deeply appreciated.

Regards
RJ

 

[Steve Blair]

It sounds good, RJ. The only point I would make is that the donut will only appear after sizing. If you ran the expander into the case, the full neck I.D. should be expander diameter. You may need to repeat that step after firing and sizing.

I use Winchester brass in .284 and do not do the neck expansion step. My barrel is throated to seat Berger 180s at 3.240". That allows a little movement as the throat erodes. My Bergers are moly-coated and usually need .003-.004 tension as I hard-seat. Finally, I anneal every three firings.

 

[Flybuster]

I am just getting my F-Class .284 up and running too. Necked up Lapua brass, what is the idea of neck turning to get rid of donuts if your bullets bearing is seated above the donut?

The Berger 180s shoot allright jammed with 53gr H-4831sc, got 2nd in grouping at our local 500M BR match w/ no load development. Some 5 shot groups under 1/4" @ 100. Still getting used to a bigger caliber.

I'm all ears if anything makes this shoot more consistent I'll listen.

 

[expiper]

sounds good

RJ...you have a grasp of clearance-squeeze-springbak-etc....tell us what your freebore is (Im guessin around ~.140") it sounds a lil' short .....Try 54.5 4831--read the primers and watch when the temps are over 80* ...Roger

 

[RJinTexas]

Roger, I'm ashame to say I honestly don't know what the free bore is on this barrel. I purchased this barrel new from Speedy about two years back at the time he was having a fire sale and closing up shop here in Ft.Worth to pursue a teaching position at Trinadad Collage. He stated that he had chambered this barrel himself originally planning to use it on his SS Viper. Being I'm always looking for a bargain I purchased this barrel chambered with a Spider Web finish for the just price of new barrel blank, it sat in my gun safe until I recently purchased a Diamondback which has the same 1.115 head spacing as the Viper. This will be my first true custom action rifle my safe is full of trued 700's and XP's. I'm trying hard to get everything correct right from the start. Speedy did tell me he'd set this barrel up to shoot the 180 VLD's, but I was also wondering if the free bore might not be a little short.

Flybuster, Yes the bullet's bearing surface ends right at the neck/shoulder junction leaving the base of the boattail right at the case body/shoulder junction. Being I had to purchase a 7mm K&M turning mandrel I opted for the carbide tip to insure I didn't experience a donut problem being I didn't know the free bore of my chamber and just how deep I need to be seating the bullet.

Steve, Do you think that .002 neck tension will be enough for naked bullets as I probably won't be shooting moly? I'll certainly heed your advise about annealing.

My biggest concern was getting the neck turing clearance correct, man with the price of 6.5x284 Lapua brass these days I surely wouldn't want to end up trashing a couple of boxes of it. So I'll proceed with my neck turning and maybe get a few test rounds loaded up and get to the range early next week to see if my new rifle shoots as well as it looks.

I thank ya'll for your help and advise.
RJ

 

[Steve Blair]

.002 is fine for naked bullets in a bench gun. Some folks use less when soft-seating but I often put the bullet just short of the lands, say .010 short. Bullets and rifles are just like people, they all want something a little different.

 

[expiper]

FB ..estimate

Hi RJ...no shame in not knowing the dims. on a used or 2nd hand bbl....most Benchrest Gunsmiths put the neck dia. (ND) and freebore on the bbl shank ritght along with the cal. designation...it shure helps avoid confusion!!!hahah...A typical .284 win. has (.250/.285) aprox. .250 useable neck length of a .285 neck....I like to stay aprox. .030-035" away from the mathmatical/actual neck shoulder jct. to avoid the donut....they are usually .020-025" 'fat' ...sit a bullet on the case mouth and measure it...then...seat that bullet to the point that it contacts the lands with a square to slightly rectangular mark and measure that length...what ever the diff. is ....is the ammount of shank or bearing surface that is being grippped by the case neck....this will tell you if you are near or touching the donut....a FB of ~.170 will give you aprox .020-.030" clearance....chek it out....then you will know if the bullet you are using has enuff elbo room to work...if not I wuld lengthen the FB to simplify life....Roger

 

[TonyR]

I have found the 180gr Berger VLD to be very sensitive to seating depth and they seem to like being jammed 0.010 to 0.015 for best results at least in my guns chambered for the 284 Shehane. I confirmed this seating depth through extensive round robin testing so I know it is right for my equipment but there seems to be enough variation from gun to gun and bullet to bullet that testing is well worth doing. This seating depth usually gives me a COAL of at least 3.200 inchs with trimmed and pointed bullets. I run a .310 loaded neck in a .313 chamber neck which appears to work very well. I don't like much neck tension and since I just punch paper, I use a custom F/L sizing die with a .309 neck diameter. This gives me light neck tension with the Bergers but seems too loose with the 162 A-Max and sometimes too much with the 176 and 177 GTB. I have found these differences to be due to differences in the diameters of the bullets from different lots and/or manufactures so don't assume that they are the same.
Good luck with your project.