Reamers / Chambers for 284 Shehane

[bsumoba]

New to the forum and have been on calguns, snipershide, 6.5 creemoor forum, etc. I am located in the San Jose, CA area.

I am in the process of building a long range / F-Class Open rifle. here are the specs:

B.A.T Model M Multiflat Action w/ RBRP, 308 bolt.
Bartlein 1:9 Twist 30" barrel - 1.25" taper to 1.00"
PR&T Lowboy Stock
Jewell BR Trigger - 1.5oz
Nightforce Rings
Nightforce 2014 Competition Scope
Shooting the following:
* 6.5x284 Lapua Brass necked up to 7mm with Sinclair Mandrel
* 180gr Berger Hybrids
* 4831SC or H4350
* BR2 or 210M primers

I just bought a 284 Shehane reamer from PTG. See below. This is going to be a sort of no neck turn setup.

Brass: 6.5x284 Lapua necked up to 7mm using Sinclair Mandrel.

My question I wanted to ask you was whether or not this chamber cut with this print/reamer would work with a whidden die that was cut with the last image? From what I can tell, there are a few differences in the neck area. i also would own the reamer so i could get my gunsmith to cut me a FL resizing die but I could save a few hundred if i go with whidden (assuming it works).

From the looks of it, I will have about 0.004-0.006 neck clearance. is 0.006 neck clearance too much (0.003 on each side) and how much is too much clearance? I will be ordering bushing dies. In measuring a couple pieces of brass, I am getting around 0.0145-0.015 thickness (used calipers, so not entirely accurate. This means a .310 bushing if I want 0.002 neck tension.

any advice would be great

If you are interested, here are pics of the BAT action. I havent seen too many pics of one online so maybe some of you are interested in seeing pics of one at different angles:

 

[ridgeway]

Can't answer your question, but you really have a nice build going on there!

 

[lrgoodger]

I hate to tell you this, but I bought a reamer with .189 freebore when I first started with the .284 Shehane. It was not enough to keep the pressure ring of the 180 hybrid out of the problem (donut) area created by necking up the Lapua brass. I sent it back and had it re-ground to .220 freebore. The pressure ring stays ahead of the donut now, but it still slips into the area just ahead of the donut. That area is where the groove is inside the case where the original neck/shoulder junction used to be. no matter how slowly I seat my bullets, they go down with an even tension until the pressure ring reaches this area just before final seating, and then the grip of the neck goes way down and the seater die snaps down the last few thousandths. This has to result in inconsistent neck tension, because the size and location of the groove is going to vary from case to case. If I had it to do all over again, I would order a reamer with .250 freebore. If you shoot any of the 180 VLDs like JLK, you will need it. Some guys inside bore their necks to alleviate this problem, but I find that a real PITA. It's much simpler to just get a deep enough throat to stay ahead of the problem area caused by necking up. That would only ever be a problem if you decided to shoot much lighter bullets and get them near the lands.

The alternative, which quite a few on this forum have done already, is to use a throating reamer to extend the freebore. Also watch for the neck being tight right at the tip after firing as discussed in this thread;

http://forum.accurateshooter.com/index.php?topic=3844573.0

I see my question on this exact same issue just got resurrected on the 'big stuff' forum. Wish I had known then what I know now!

http://forum.accurateshooter.com/index.php?topic=3798150.0

 

[lrgoodger]

Also, since you are getting a Bartlein barrel that I presume will be a 5R type rifling, you should bone up on this issue (read the link I pointed to in that thread);

http://forum.accurateshooter.com/index.php?topic=3821878.msg36265902#msg36265902

I highly recommend Gordy Gritters to chamber the barrel for you since I believe he knows how to get the best results on that type barrel. I've not had a problem with 5R on other calibers, so I now tend to agree with Mark Penrod that the trouble with my Shehane chambers is on account of my reamer. Maybe yours will do better.

 

[GSPV]

To head off one issue, a FL sizing die simply can not be cut using your clambering reamer. The FL die reamer must be smaller than the chamber reamer.

I have a Whidden FL sizer for my Shehane. Works great. One of the better dies that I own. I had a very good experience working with them.

 

[BradY]

The good thing about a no turn chamber is that the donut wont affect you if you size only half the necks. You can run an inside neck reamer (donut cutter) tool in and cut them out, but if you size only half the necks, the donut shouldnt have any contact with the projectile. Im using a 318nk and 180gr vld's in a 220 thou freebore and the bullet is inside the donut area. But inside neck reaming and sizing half the necks, gives me no issue what so ever. Looks like you are building a quality rifle that anyone would be happy to own. Good luck with it.

 

[Erik Cortina]

Order a 7mm uni-throater, that way if you are not happy with freebore it takes you 5 minutes to extend it and done.

A chamber reamer can not make a F/L sizing die. The die reamer has to be smaller than the chamber reamer so it can size brass down. Just buy a F/L bushing die from Whidden and you'll be fine.

Last but not least, it's ludicrous to think that ONLY Gordy Gritters can chamber a 5R barrel. Find a reputable gunsmith that has F-Open guns in the winning circle and you will be fine.

 

[bsumoba]

has anyone heard if having too much neck clearance is bad or detrimental to accuracy (0.005-0.07 clearance, so .0025-.0035 per side)?

thanks for the advice. i will ask my gunsmith if he has a uni-throater. if not, then ill try out the one i am getting with its current freebore dim and see how it works. my gunsmith is Spartan Rifles out of San Jose, CA and he has a few guys competing nationally and winning so i am confident he can make a stellar rifle.

according to PTG, the 188 freebore should be ideal for hybrids, but it seems that some people have issues. i dont see donuts in my necks from what i can tell. i am using a 7mm mandrel and am using plenty lube so hopefully that part is minimal.

i cant find 180 hybrids anyways so i am hoping berger will have a run soon. anyone have leads on some? im willing to pay paypal... i also have 308 175gr SMK, 6.5mm 140gr hybrids, 6.5mm 140gr A-Maxs, 210Ms and H4350/H4831SC (if you live in the San Jose, CA area) for trade.

Ill be ordering the whidden die. its a bushing die so it should be gtg. i just cant see myself pulling the trigger on a $400+ custom die setup...although i think whidden can make a custom die for cheaper than that.

 

[nhm16]

I shoot a variant of the Shehane with a 40 degree shoulder and before that a straight 284. The best way to eliminate or minimize the donut is to do at least a light neck turn that bites into the shoulder, preferable using a 30 or 40 degree cutter. My reamer has a .188 freebore.

 

[Alex Wheeler]

Too much neck clearance wont hurt your accuracy.
I agree with the .250 being good for the vld. I have a .220 that was supposed to be for the 180 vld, its too short.

Are 5R barrels common in f-class? I have not had the best experience with them, other shooters I know who have tried them in 1000yd br also report less accuracy.

 

[Lbart]

Alex,
I have been using Bartlein 5R barrels for F-Class for many years. They are Team Berger's favorite brand. Many records have been set and many Championships won using 5R's. If we didn't think they were at the top of the heap we would not use them. A great many FO shooters use 5R's. F/TR I don't know.

Bsumoba,
I am not a riflesmith but I would advise you to check with John Whidden as to the dimensions of his sizing die. The reamer die drawing you posted has the same sizes as the reamer you are ordering from PTG. As Erik wrote - " A chamber reamer cannot make a F/L sizing die. The die reamer has to be smaller than the chamber reamer so it can size brass down."

Larry Bartholome
Team Berger

 

[bsumoba]

Hi Larry,
Thanks for the update. I think what Whidden meant by the print they said they used for their FL die is that their die is meant for a chamber that was reamed with the following print.

I thought the F-Open guys were sponsored by Bartlein...or was it Berger...or was it both?

Nevertheless, the only thing now that I am concerned about is the .188 freebore for 180gr Hybrids (I probably will stick with hybrids and not VLDs) and whether or not this is going to be an issue with my necked up lapua brass with possible donuts.

 

[Lbart]

Bsumoba,
I use the same lead (0.200" + the 0.014" from the 45 degree in the transition from the neck in the chamber to the lead) (freebore?) in both my Shehane and 7/270 WSM chambers. There is only 0.012" difference between my chambers and your PTG print. I would prefer a bit more lead than 0.188, but it may work depending on your jump or jam. You MAY have to use a throater with your reamer. I use all 180 Hybrids.

My Shehane has a 0.314" neck and the WSM is a 0.318 neck. I wind up with 0.004 total clearance in the Shehane and 0.005 in the WSM after turning the necks. I am not sure how far I am off the lands, but the body boattail junction on the bullet is ahead of the donut area. None the less, I use a K&M donut cutter as I turn the necks.

The 2013 US FO Team got some support from both Berger and Bartlein. Team Berger is now Team Berger/Bartlein/SEB.

Best of luck with your project.
Larry