Savage magnum bolt head mystery?

[Engineering101]

First a little background and then a question. I own three relatively new Savage actions, several stocks and several barrels I can mix and match as needed. I have two short actions (12FV, 12LRP) and one long action (114), everything push feed. The 12LRP requires a 1.120" large shank barrel being based on the target action and the others take a 1.055" standard shank.

I recently picked up a 270 WSM 26" large shank stainless barrel and a similar 300 RUM in standard shank and thus I needed a few more magnum bolt heads. I got one for the long action and one for a short action and I already had one for a short action (7mm WSM).

Though I got the second short action bolt head from the same source as the first one, it is not at all the same. The one I have on the 7mm WSM measures 1.439" long and will work on either of my short actions. The new one has the same shaft but a thicker bolt head and consequently measures 1.543" long and will NOT work on either of those actions. Being so much longer, the firing pin can not be adjusted to protrude through the hole in the bolt face though it works otherwise.

This is a Savage factory original complete bolt head. So that brings up a question or two for the Savage experts out there. What the hell is this thing, or better said, what Savage rifle does it fit?

I plan to pull the parts off this bolt head and install them on a new PT&G performance bolt head so I'm not stuck but I am curious as what this could be. Until I opened the package, I had no idea such a thing existed. It is between a long and short action in length as long action bolt heads measure 1.620".

 

[jcoop]

It sounds like you have te heavy magnum short action bolt head. They started putting it on the shortmags a while back. I believe they are 5/8" (could be 9/16) thick instead of 1/2". They require a longer firing pin which I was unable to find. I made the standard pin work for my heavy magnum bolt head but it required a lathe.

FYI I the PTG shortmag head is also deeper like this.

 

[Engineering101]

jcoop

Great info. It all makes sense now. I knew that Savage went to the large shank barrel in the WSMs and RUMs but I didn't know that they beefed up the bolt head. I've been using a standard magnum bolt head with a standard shank 28" 7mm WSM barrel running 168 grain AMAXs at 3,150 fps with no issues so it makes me wonder why Savage would do this. I heard that it was to get "more margin" for their legal staff but that is just rumors.

If it wasn't for the lawyers but for the engineers, worst case, I suppose a lot of rounds could beat up the thinner bolt lug and warp it. But if you mix and match, bolt heads are easy to check, cheap to buy and take maybe 5 minutes to change.

By the way, the PT&G website has no option to select a WSM bolt head, only "magnum" and I have one of those here and the lug measures 0.441" (the same as the Savage standard magnum lug as well as the non magnum lug).

Looking at the high quality of the PT&G bolt head and the difference in the steel I'm guessing that it doesn't need to be thicker for the WSMs. Also, given that the thinner bolt lugs handle a 300 Win Mag which runs a mere 1,000 psi less, I don't think I'm going to get too concerned.

Thanks for solving the mystery.

 

[Engineering101]

Oops. I meant to say 168 grain Barnes LRXs not AMAXs.

 

[jcoop]

By the way, the PT&G website has no option to select a WSM bolt head, only "magnum" and I have one of those here and the lug measures 0.441" (the same as the Savage standard magnum lug as well as the non magnum lug).[/SIZE][/FONT]

Thats crazy I have a PTG that measures .560. I just got it from them a couple weeks ago. I called them because i wanted the 1/2" ish size and they said this is what they make for the magnum in a short action. So I made it work.

 

[Engineering101]

jcoop

Now I'm worried. I got one of the short action magnum PT&Gs when they first came out several months ago. They may have changed since then. I just ordered two more assuming they were the same size as the first one. I don't think I'm going to like it when I open the package. Thanks for helping me connect the dots though.