Bolt head thickness variation

[juanvaldez]

Just went to swap out a bolt head and found my replacement to be 15 thous thicker? The bolt will not close with the new bolt head on. Is this common? How do I fix it? Both bolt heads are short action and appear identical other then the 15 thous difference in thickness.

Cheers

[earl39]

Is it common? Yes What to do? Just reset the headspace and you are good to go.

[Rifleman51]

Savage retooled with new CNC machines about the time the Accu Stock came out. If you have numbers on the bottom of the tang, your rifle was made on the new equipment.
The tollerences on the new rifles is much better and more consistant than on the older models.

They use the numbers to keep track of how many cuts have been cut with each cutter so they can be changed out before the cutter gets dull. Other manufacturers don't keep anywhere near as good of track of the sharpness of the cutters in their CNC machines.
If your rifle is an older model, that may explain the difference.

The new bolt faces are really parellel and seldom need truing, the old one's usually needed truing.

Cutos to Savage for upgrading equipment during the resession. Just one more reason the Savage is the best mass produced rifle available.

John K

[juanvaldez]

Is it common? Yes What to do? Just reset the headspace and you are good to go.


Ya thanks...came to that conclusion too. Bit of a brain fade their.

[GaCop]

+1 on headspace reset. I just had a similar problem when I forgot to remove the .473" bolt head form a new 223 AI build. I set the headspace on the 308 BH before I caught it. Changing the bolt head to the proper .378" and the bolt would not close so I had to pull the rifle apart and reset the head space. Now all is well and the rifle is shooting between .3s and .6s with the first loads tested.

[sharpshooter]

Savage retooled with new CNC machines about the time the Accu Stock came out. If you have numbers on the bottom of the tang, your rifle was made on the new equipment.
The tollerences on the new rifles is much better and more consistant than on the older models.

They use the numbers to keep track of how many cuts have been cut with each cutter so they can be changed out before the cutter gets dull. Other manufacturers don't keep anywhere near as good of track of the sharpness of the cutters in their CNC machines.
If your rifle is an older model, that may explain the difference.

The new bolt faces are really parellel and seldom need truing, the old one's usually needed truing.

Cutos to Savage for upgrading equipment during the resession. Just one more reason the Savage is the best mass produced rifle available.

John K

Savage doesn't manufacture the bolt heads, they are a contracted part. They have changed slightly in design, but they are no better or worse than before. They are still polished in a vibratory tumbler and have dished surfaces, although I have seen some on target actions that have had the lug surfaces ground. They still have tolerance, but .015" is a bit big, most of the time they won't vary over .005".

[Rifleman51]

I'm going on what I've been told by a Mastergunsmith I know who builds well over 100 Savage rifles a year.
According to him, you used to have to true the bolt face on the old Savage rifles, since the Accustock and since Savage has re tooled, the bolt faces are so true that the very few times he has found one that is not true, he just throws it away and puts another one on.
So there is now a difference. I don't know if Savage makes the bolt head or not, I can't believe they wouldn't, but I do trust the word of the smith.
The tollerances on all parts of the action are now much better, far less metal needs to be removed from the face of the action to true it, same goes for the bolt lugs. Savage has made a pretty big improvement. Replacing almost all their CNC machines and now tracking exactly how many pieces have been cut with each cutter, so a new cutter can be installed has made a big difference in the precision in which their rifles are made. My hat is off to Savage for making these kinds of changes. That's why they are on top and will stay that way.

This is not to say that there may not be some variation in bolt head thickness. This depends on when the rifle and bolt head were made. One should expect to have to change the headspace a little anytime a bolt head is replaced. There are just too many variables that will require the H.S. to be corrected.
John K