The Accurate Reloading Forums
What is the proper counterbore?
08 January 2021, 01:36
257 RobertsWhat is the proper counterbore?
I am about to undertake my first pillar bedding adventure, and I have a some adjustable pillar kits from Score Hi gunsmithing.
My question is the piloted counterbore, I believe a 9/16" is recommended, but I am wondering what the proper pilot size is for a Winchester Model 70?
I am bedding two rifles. First one will be a test installation before I tackle a pretty fancy one.
14 January 2021, 21:17
AtkinsonIts a matter of choice as to the type of rifle I suppose, bench guns seem to have deeper crowns and sporters less..Its a personal thing and any agruement over it would be useless IMO..
Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120
rayatkinsonhunting@gmail.com
14 January 2021, 22:18
dpcdYep, take that 9/16ths counter bore and run it into your muzzle to get the crown you want. Since 9/16ths is .5625, make sure your barrel is bigger than that; otherwise you get a flat crown.
Yes I know you are pillar bedding; a task with which I no longer bother.
14 January 2021, 23:15
tsturmquote:
Originally posted by 257 Roberts:
I am about to undertake my first pillar bedding adventure, and I have a some adjustable pillar kits from Score Hi gunsmithing.
My question is the piloted counterbore, I believe a 9/16" is recommended, but I am wondering what the proper pilot size is for a Winchester Model 70? I am bedding two rifles. First one will be a test installation before I tackle a pretty fancy one.
Maybe my reading ain't so good any more?? As I read it,
Big enough to get plenty of epoxy between pillar & stock.

15 January 2021, 00:02
Duane Wiebe (CG&R)quote:
Originally posted by dpcd:
Yep, take that 9/16ths counter bore and run it into your muzzle to get the crown you want. Since 9/16ths is .5625, make sure your barrel is bigger than that; otherwise you get a flat crown.
Yes I know you are pillar bedding; a task with which I no longer bother.
Pillars? I'm with you...havent seen one bit of advantage and it weakens the stock at it's most vulnerable point
But. if carrying an apple in your pocket makes you feel betteer....carry that apple!
15 January 2021, 00:22
dpcdOk, now that we are actually talking about pillars and not barrel muzzle crowning, I am with DW; pillars are useless.
But if you have to; just measure your pillar. Drill the hole bigger. You're done. Don't overthink it.
15 January 2021, 00:56
tsturmquote:
Originally posted by dpcd:
Ok, now that we are actually talking about pillars and not barrel muzzle crowning, I am with DW; pillars are useless.
But if you have to; just measure your pillar. Drill the hole bigger. You're done. Don't overthink it.

15 January 2021, 03:51
JTEXquote:
Originally posted by tsturm:
quote:
Originally posted by 257 Roberts:
I am about to undertake my first pillar bedding adventure, and I have a some adjustable pillar kits from Score Hi gunsmithing.
My question is the piloted counterbore, I believe a 9/16" is recommended, but I am wondering what the proper pilot size is for a Winchester Model 70? I am bedding two rifles. First one will be a test installation before I tackle a pretty fancy one.
Maybe my reading ain't so good any more?? As I read it,
Big enough to get plenty of epoxy between pillar & stock.
I think "your" reading is just fine. And yep!
15 January 2021, 03:53
JTEXquote:
Originally posted by dpcd:
Ok, now that we are actually talking about pillars and not barrel muzzle crowning, I am with DW; pillars are useless.
But if you have to; just measure your pillar. Drill the hole bigger. You're done. Don't overthink it.
No disrespect intended.........but you guys don't really build rifles for ultimate accuracy.......
A well bedded rifle, with pillars. Will make for a more accurate rifle. It all depends on what you are building and what the final intent is.
19 January 2021, 19:14
Bill LeeperI have, for the last forty-five years, been casting acraglas pillars of 9/16 to 5/8 inch diameter, in the stock. I don't like aluminum pillars. I don't pillar glass stocks Regards, Bill.
30 January 2021, 17:20
ggruberI never felt comfortable using flat topped aluminum pillars due to the reduction of contact to a single point. However, shaping the pillar to match the action diameter is an option as long as you can get them oriented properly.
I have been using glass stocks with aluminum bedding blocks for some time now. While many recommend skim bedding these blocks, I have not found that necessary. I prefer to build a rifle more accurate than required. That minimizes any complaints from the St. Vitus dance crowd when they get nervous before an important shot.
30 January 2021, 18:59
Jim KobeFor quite a while now I have been boring out the stock for pillars in my Bridgeport. It is a simple operation to level and then locate the hole placement. I have made a boring bar of the correct diameter needed and simply put it in my drill chuck and bore out the stock. If a round bottom action is used, I turn the pillars to fit and bore the ends to match the action radius.
Jim Kobe
10841 Oxborough Ave So
Bloomington MN 55437
952.884.6031
Professional member American Custom Gunmakers Guild