Action with set back lug recesses, what would you do?

kaferhaus

New member
Savage 110 action has .003 set back on the bottom lug and .001 on the top. A 308 was fired in a 25-06 chamber.

Magnaflux shows no cracks and hardness is 46R.

Is re-facing this an option?
 
As long as you are confident that no other damage was done, I see no reason why the action could not be set up and the locking lug abutments faced just enough to get them square again.

Not sure how this will affect the primary extraction, as it will move everything back that amount. But then, we are only talking about a few thousanths.

By the way, what do the bolt lugs look like?

That says something about the strength of a modern Bolt Action Rifle. That 46RC, that is on the upper end of the hardness scale as far as most Chrome Moly Steels are concerned. I would have thought it would have been in the 36-38 range. Ductility starts to drop off pretty drastically in the upper 40's. But apparently it took it........jackie
 
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I had previously trued the action, so I used a depth mic to measure the set back. It's obvious with the naked eye on the bottom lug. I'm aware the surfaces can be trued as I do it routinely. Just have never dealt with a kaboom before...

It does speak to the strength of the action though... a third of the bolt head was missing (not the locking lugs), baffle came out in 5 pieces and the bottom of the stock was blown to pieces through the mag well. Savage stated that that is how the action is designed to handle over pressure.. the baffle is designed to absorb a good bit of the shock and the blast is designed to route out the gas port and through the magazine.

The pin that fixes the bolt head to the bolt body was "u" shaped but the hole in the bolt body is still concentric... so the pin yielded but didn't break. The barrel suffered no damage at all.

I'm impressed with the way it took the abuse. The shooter said he didn't even get any gas in his face and other than the recoil being more than normal didn't even know it had blown up until he tried to open the bolt.
 
By the way, what do the bolt lugs look like?

Sorry I missed that the first time.

The lugs look fine. Although not tested they're obviously harder than the abutments.

The top of the bolt head is blown off just above the ejector hole. Ejector, spring and pin survived but the pin was left partially exposed do to missing section of bolt head. The blown off portion was found in the receiver upon removing the bolt. In fact the only part not found was the detent ball for the extractor.
 
The shooter was very lucky indeed! How in the world did he get two extremely dissimilar cartridges mixed up?? Also Iam amazed the barrel didnt bulge. Shoving a .308 bullet down a .257 hole is quite a feat involving huge pressure especially when the bullet was entering the throat. I suppose after the initial swaging is done the pressure falls off. It's been a widely accepted fact that the Savage actions are as tough as any and I guess this incident just helps confirm it.
 
Savage 110 action has .003 set back on the bottom lug and .001 on the top. A 308 was fired in a 25-06 chamber.QUOTE]

Wow! That had to be a huge over pressure event. Did the bullet make it through the barrel?

I realize this will probably be a minority report, but I have to say it anyway.

In my opinion (as an engineer with 35 years of experience in aerospace), that receiver should not be used again. It was subjected to pressures way beyond what it was designed for - there is no data anyplace on the planet showing it is safe to use after that exposure. The fact that you don't see anything with the eye or magnaflux isn't proof it's good. The owner shouldn't make the mistake of assuming that because there is no evidence it is broken, it is OK. Wrong logic.

The correct logic is: unless there is data proving it is good, it isn't safe to shoot. IMO neither you or he has that data.

Replacing a savage action is not expensive. Banking the risk to save the cost of a Savage action that has been exposed to such an overpressure, even a Savage Target Action, makes no sense at all.

The guy made a serious mistake and got out of it uninjured. At this point his only loss is the action and barrel (I wouldn't use it either). He ought to quit while he is ahead.

Fitch
 
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Replacing a savage action is not expensive. Banking the risk to save the cost of a Savage action that has been exposed to such an overpressure, even a Savage Target Action, makes no sense at all.

The guy made a serious mistake and got out of it uninjured. At this point his only loss is the action and barrel (I wouldn't use it either). He ought to quit while he is ahead.

Fitch

Fitch,
That is what I was thinking too.

James
 
That is probably a good idea. I deal with abused equipment all the time, and as long as it will pass a non-destructive test for integrety, (magnaflux, ultrasonic, or die check), then the customer will usually say "use it".

But then, if it does fail, it is not likely to do great bodilly harm.

I would think that a modern bolt action should be able to handle 100,000 psi with no ill affects. But, since you can actually see, and measure, a certain amount of metal distortion, the prudent thing might be to use it as a paperweight........jackie
 
Thank you Fitch!!!

I was gonna' stay out of this one but THANK YOU!!

Here's what I ask mt Hunter Ed students, "what's the difference between a hand grenade and a 300Win Mag?"


answer



"You'll probably never detonate a hand grenade 8 inches from your right eyeball...."

Is your face worth a 350.00 action? How 'bout the next guy??? You "save" this action and it's on the earth forever.....

Dude walked away..... Holy CRAP!!!!........ say "Thank You God" and do the right thing.

al
 
I think that the question that needs to be asked is whether the absence of detectable cracks is an absolute guarantee that there has been absolutely no loss of mechanical properties in this highly stressed part. I tend to go with the throw it away crowd.
 
Maybe I'm just not very bright, but how does one get a .30-06 round into a .25-06 chamber? Even a factory chamber throat is tight enough to make it a REALLY hard job. But like I said maybe I'm just not very bright, or way too weak....

It'd seem that even a .30-06 case should require a lot of effort to chamber in a .25-06 chamber.
 
Maybe I'm just not very bright, but how does one get a .30-06 round into a .25-06 chamber? Even a factory chamber throat is tight enough to make it a REALLY hard job. But like I said maybe I'm just not very bright, or way too weak....

It'd seem that even a .30-06 case should require a lot of effort to chamber in a .25-06 chamber.

It was a .308, not .30-06. The .308 is quite short compared to the .25-06. If you look at cartridge drawings the .308 will fit - it will be snug unless it is a loose chamber. The bolt might have felt a bit snug when it closed, but the .308 cartridge would go in there.

Fitch
 
One of the worst failures I know of was the result of a 260 or 7-08 in a 30-06. They do fit.

al
 
I saw what was left of a Husqvarna 270 Winchester after a 30-30 was fired in it... total destruction with the bolt blown out sideways... not really a great action for handling excessive gas.

I saw a Remington 700 without any damage done after firing a .303 British in a 7mm Rem Mag.

A 308 case (which is fatter) will jam into a 25-06 chamber... unless the chamber is minimum diameter wise and the round maximum size.
 
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There are no marks on the bolt handle or handle recess. The bolt was still stuck in the action when it was brought to me and the handle was no where near the back of the recess. In fact, to the naked eye it looked like it was just where it should be.

The baffle is a sintered metal part and according to Savage is designed to shatter just like it did in absorbing the shock.

I forgot to add in the original post that the bolt head shank (portion that fits into the bolt body) also had a rupture that looks like a crease with a split in it....

What was left of the case was still in the chamber, brass was welded to the bolt face.

The fellow I talked to at Savage said during their routine testing to destruction that they perform on random samples, they've never had a receiver ring failure below 150K psi and never has a bolt come out of the receiver. The ring bursts first.
 
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