Opinion on setting headspace with factory round

**spook1** · 07-02-2013, 02:19 PM

I have a 450 Bushmaster barrel and can't find a go gauge. I did pick up 2 boxes of ammo from cabelas and picked up a few pieces of new brass from a friend. Can I set the headspace to the factory loaded rounds, and then after I shoot them all, I will resize some brass and reset the headspace for my dies. I just haven't heard much mention about using a factory round to set headspace.

I figured I could add a piece of scotch tape to the factory round, set headspace, and then check with another piece of tape added. If anyone has any advise, let me know. I have set the headspace on all of my other barrels with resized brass. But I couldn't find brass in stock and did find a couple of boxes of ammo. I figured I could shoot them and then use the brass later.

**J.Baker** · 07-02-2013, 03:23 PM

Shouldn't hurt anything just to get the ball rolling, but you'll want to remove the firing pin from the bolt to prevent any possibility of an accidental discharge occurring.

**spook1** · 07-02-2013, 03:48 PM

Should I put one piece of tape to set headspace, and then 2 pieces of scotch tape as a no gauge?

stangfish · 07-02-2013, 03:56 PM

No. Use the case bare and ad the tape to the no-go operation. You really should check the thinckness of the tape. .004 is, IMHO good. .010 would be bad. Something everyone that headpaces a savage should understand is the distance one rotation of the barrel moves the headspace, or as I like to call it linier movement. There is .050 linier movement in one rotation of the barrel.

Divisions of rotation are easy from there. .050:360*, .025:180*, .0125:90*, .0062:45*, .003x:22.5* etc..... .003x:22.5* means you move the barrel just over .003 in 1/16th rotation. Use pencil or marker for indexing marks once you touch off on the case head with the bolt. When its tight see how much rotaton you have made giving you a piece of mind you are close. Double check and your good to go.

And let us know how it shoots. Pictures and paragraphs are cool.

**stomp442** · 07-02-2013, 04:08 PM

Do you have a bullet puller? You could always pull two run them through your dies and then head space as you normally would.

**spook1** · 07-02-2013, 04:27 PM

Originally Posted by stomp442

Do you have a bullet puller? You could always pull two run them through your dies and then head space as you normally would.

I just figured if I pulled the bullets and sized them, then the remaining 2 boxes of ammo probably wouldn't fit. I was wanting a way to atleast shoot the factory ammo as I paid good money for it. 450 Bushmaster is pretty hard to find.

**J.Baker** · 07-02-2013, 06:21 PM

Most factory ammo is a little short of a go-gauge, so unless your sizing die is noticeably short I don't see where you'd run into a problem headspacing off a sized case and then firing factory ammo. Besides, to check all you have to do is try to chamber a factory loaded round. If the bolt has any noticeable resistance when closing the headspace is a little snug.