less than minimum headsapace

[John K]

Something I never knew before:
My 112v always had a hard bolt opening I have fired 120 rounds through it
It chambered fine and shot "ok" but you really had to smack the bolt to open it.
I put it back in the safe as a "later" project.
I recently bought a Hornady headspace guage set. Turns out my fired cases are .007
below min spec.Whoever put the barrel on really must have cranked it or use a worn guage
I got it to a Savage authorized service center here and he reset the barrel. Now the front scope mounting block pointsto
2:30 instead of 12.
Just goes to show you it can happen.
I

[geargrinder]

What does your headspace guage read now? Running the numbers, a move of the barrel from 12:00 to 2:30 extends the headspace 0.010".

I'd prefer to be on the short end of headspace, than long. I anneal and FL size my brass every firing. So, I set my headspace a couple thou beyond that. Running with a long headspace may be an easy fix for your issues, but may not be the root of your problem.

Did your service center check the primary extraction? That is a known cause of your issues, and occurs more frequently than headspace issues.

[sharpshooter]

Head space gauges vary from different manufactures. One getting out of the factory with a short head space....not bloody likely. You have a primary extraction issue.

[Arky 223]

If your front scope base moved from 12:00 to 2:3o they removed head space not added to.

[OLEJOE]

You could reclock your barrel straight and use a finish reamer to adjust the headspace if the headspace is short. No trouble Chambering and having hard ejection sounds like a timing issue.

[243LPR]

I don't understand how the base would get moved,it's attached to the receiver,not the barrel??

[geargrinder]

I don't understand how the base would get moved,it's attached to the receiver,not the barrel??

I'm assuming he was talking about the sights on the barrel.

[L11.11]

I'm very confused. You say the front scope mounting block...but you mean the front sight post? Where you typed "scope" you meant "sight"?

Also, I'm not seeing how an extraction problem causes fired brass to be -0.007 under min cartridge headspace length. Have you measured the cartridge's headspace length before and after firing to determine just how much that case changed?

If I'm not mistaken, factory rounds are generally at the low end of the headspace tolerance in order to ensure the cartridge fits in most chambers. But factory rounds shouldn't be below the minimum headspace length. So I guess I'm also wondering how firing a round in a chamber w below-minimum chamber headspace dimensions causes the cartridge's headspace to be reduced...not saying it can't happen, just saying I'd like to understand how that happens.

[Bunky-Shooter]

Yes i am confused and lost at the same time.. Not understanding how a casing got shorter when you were able to chamber and fire the round. The bolt should have been
really hard to close at minimum. .007 short the bolt should have not closed to begin with. WOW ????

[John K]

Youmake a good point. I measured a box of Hornady factory rounds. They are 4-5 thou below sammi minimum. Therefore the 2-3 crush I was putting on the cases was from the camming action of the bolt. When fired. the rounds had no room to expand causing the hard opening. The bolt alwas cycled fine empty.The Savage gunsmith said it was the first one he had come across like that.

[tobnpr]

Youmake a good point. I measured a box of Hornady factory rounds. They are 4-5 thou below sammi minimum. Therefore the 2-3 crush I was putting on the cases was from the camming action of the bolt. When fired. the rounds had no room to expand causing the hard opening. The bolt alwas cycled fine empty.The Savage gunsmith said it was the first one he had come across like that.

Surprising that you didn't notice difficulty closing the bolt initially. Factory Savages aren't the slickest actions, but...
All above is true, apparently whoever set the "zero headspace" at the factory over rotated the barrel.

Like the other comments above, not clear what "mounting block" you're referring to??
While simply screwing the barrel in/out can certainly be used as a fix, you obviously can't do it on a barrel equipped with open sights- and even on those without it ends up unsightly because the "Savage" logo/chambering engraving ends up in some oddball, random location instead of just above the stock line. Best to just deepen the chamber, for small "tweaks" of a few thousandths sometimes I've taken it off the boltface.

Are you measuring the Hornady rounds with the comparator, using a "go" gauge as the standard?

[John K]

Yes I measured it with the Hornady and my RCBS mic using a Forester and Clymer headspace guage.Oncethe snow drops below 2ft deep on the range I will reshoot the cases and get the proper readings.:) In thinking about the problem it could not be an over-tightened barrel or the scope mounting blocks would not have been at 12 o'clock in the first place unless the holes were drilled after everything was assembled which is unlikely..
Where does the pressure go when there is no clearance in the chamber for the case to expand? THe brass expands at the base which it did. I can only attribute the problem to possibly a reaming error. The next range session will tell. Thanks fotr all your help. I will repost if anyone is interested.

[tobnpr]

^^^
Could have been reamed too shallow- but the only way to know is to measure gauge protrusion from the breech with a depth mike to see if its within spec.

[mnbogboy2]

John K did you buy the Savage new? Some dealers remove the bolts for safety & liability purposes.
Is it possible the dealer, inadvertantly, could have switched bolts from another rifle?
My mind is looking at an 18 year old kid at Walmart looking for the bolt under the gun case; "Here it is. Oh, there are two of them. Must be this one it fits". (He could have been waaay older than that) !!
Do you see where I am going with this? On another post this was discussed. Bolt head dimensions vary a lot and this scenario would easily account for short headspace. Pity the guy that bought the other one.

Just a thought,
Randy

[geargrinder]

Actually, sights are done after the barrel is installed on the action.

Savage chambers all of the barrels prior to being installed on an action. Then they are installed on a headspace guage. Then the sights are drilled and installed, as well as the rolled stamps for the caliber and manufacturer markings.

That's why it is very unlikely that you had a headspace problem to begin with.

[John K]

yes i bought it new. it was still in the sealed box when I got it. If I was smart Iwould have returned it after I first fired it. I didcontact Savage about it years later but I was too late.