My new used Savage barrel

[Kevin Stenberg]

I purchased a Savage barrel that came off of an axis rifle. I made a chamber cast of the barrel tonight and I am kind of concerned about the # I am geting.
Hornady manual says the shoulder dia. should be .454 The base of the neck should be .343 and the mouth should be .343 My chamber cast has a shoulder of ..4585 the base of the throat is .347 and the end of the throat is .345 Those aren't too bad but when I go past the throat it gets awful small.
At the mouth of the cartridge there is a decrease to the dia. of .3095/.310 This decrease is done in a .033" length. There is a smooth transition from the .3095 down to .308 in a distance of .244" which is the start of the rifling. From the start of the rifling cuts to the deepest of the rifling the .308 decreases to .3065 Isn't .3065 awfully small for cast bullets?
I was also concerned that the gruves are only .034 wide. But there are 6 of them

 

[Ian]

I'm assuming .308 Winchester, and assuming you measured with a clean, calibrated micrometer and not digital/Vernier calipers.

The drawing in the Hornady manual is likely a cartridge drawing, at maximum dimensions, not a chamber drawing. A SAAMI chamber drawing is what you should be comparing your pound cast to, and the neck should indicate about .003" taper. The cartridge neck will not be tapered.

Sounds like most of the Savage factory barrels I have. They shoot very well with cast bullets but do the best with bullets sized about half a thousandth below throat entrance diameter and with well-fireformed brass which is only neck sized in a shoulder-bump die.

 

[RBHarter]

I have a an 06' and a 308 very much like that the 06' is fast for data in spite of its 9.5 twist . The 308 is just average and shoots well with jackets and equally well with cast.

 

[fiver]

 

[fiver]

here is the saami numbers.

 

[Ian]

Holy cow, Fiver's getting this linking thing down pat.

I remembered wrong, the chamber neck only is supposed to have two thousandths taper, not three.

When the cartridge manufacturers fade toward the minimum spec and the firearms manufacturers fade toward the max spec on their chambers, it's easy to see how we get so much slop. I have to chuckle a little when someone says "SAAMI-Spec" chamber, because being within the window isn't very specific.

 

[Brad]

Wow, fiver gets all tech savvy? What's next, a haircut?

I need to get another barrel for my Savage. I'm thinking a nice 358 Win would work.

 

[fiver]

that wasn't easy, they changed their website.

anyway I like how it's also specce'd at 4 lands and grooves and with a 12 twist barrel.
anyway you can see how much tolerance they give you to work with.

what we are concerned with is from 1.7" to about 2.4"
pulling the trigger takes care of the other numbers.

 

[Kevin Stenberg]

Brad eventually I want to add another savage in the 358 flavor also