Home Forums Hunting & Shooting Ask The Gunwriters Gas venting and modern bolt actions

PA thanks for sharing that I use Lapua brass in my 9.3 X 62 LH Win 70 and RCBS dies fit to my chamber will keep an eye on my brass.

Yeah, no idea why I never felt anything, not that I'm complaining mind you. And hopefully I never get to 'test' it again. One stupid brain fade moment has hopefully taught me to slow down and think things through.

You should note the differences between the CIP specs for 9.3x62 case dimensions compared to new Lapua brass and the stuff you've re-sized. Personally, I'd obtain new dies.

It seems to me that there are a couple of separate considerations here, with regard to how safe an action is. Gas venting is only one of them. Others include the extent to which the action actually contains and supports the case head, with some leaving more exposed/unsupported than others, thereby increasing the likelihood that gas may actually need to be vented. The Winchester M70 and the Springfield are examples of actions which allow more of the casehead to be unsupported than, say, a Remington 700. All well and good as long as the case does its job, but a potential failure path if the case is defective or overloaded. An action which more or less envelops the case head may reduce the likelihood of the case actually letting go in the first place. As well, it may be better able (and failures I've seen support this) to contain the product of a case-head failure rather than directing it out of the action.

Having said that, I think the risk of a case head failing is rather less now than it was when Mauser was designing the 1898 model.

As well, there's how well-supported the primer is, with some actions having a larger amount of clearance around the firing pin than others, and in some cases a more or less direct path to the shooter if the primer fails.

Shear strength of locking lugs is also a factor, but perhaps more important than strength is the work of fracture of both lugs and receiver. A safe receiver, even when grossly overloaded, should bulge and distort plastically, thereby absorbing energy rather than flying to pieces. A brittle failure is much more hazardous because even though the strength may be there the ultimate failure mode does not absorb appreciable energy but instead releases it into flying pieces of rifle. As well, if the rifle really is to let go, the design should, to the greatest extent possible, prevent the bolt and other parts going back into the shooter's head. You see such thinking in the design of actions like the 1898 Mauser, with a lug in reserve intended not to engage when the action's locked, but to prevent the bolt going back into the shooter if the locking lugs fail.

Might just replace all my rifles with Savages. They’re just about the only brand I can find in stock these days. At the very least might replace my Tikka 223 with a Savage 223, since that will be the rifle I will start my son on when he’s old enough to shoot center fire. Or is this worrying all for nothing for someone who doesn’t reload?

Have you seen or heard of a Tikka action blow-up or are you basing your decision on supposition? There was an issue a few years back with some bad alloy in stainless Sako/Tikka barrels but as i do not recall any action blow-up issues.

drover

I’m basing my worries on a lack of information. A lack of bad stories about Tikka rifles does not mean it’s as safe a design as others.

https://www.americanrifle.com/shop/product/mausingfield-bolt-action-2

Scroll down and theres a section on the testing of this reciever and gas venting. At least to me it was interesting

I don't care how good a Savage action handles gas, There so ugly, I cant stand to look at one. RJ

I have retro-fitted the gas block to a few Model 70's I have also modified the bolt to allow a shallow counterbore in the barrel. I don't know if either mod does all that much good but it's something! GD

I thought that too until I ran into my Savage 114 Walnut. I can't stop looking at it

After firing a piece of nosler brass around 22 times, i had a partial case head separation in my kimber 84. No gas blow back. Didn't realize what had happened until extraction. I am now older and wiser, and don't push brass life that far anymore.

Thanks, gte901m. I will still faithfully wear my glasses, but am glad to hear your report. I usually pitch brass after about 6 loadings, just to stay on tbe safe side.

The safest when we ran the test (in 1969) was the Remington 700. The second safest was the Weatherby Mark V.

At the end of the test we tried to see what it would take to blow up a 700. We put multiple 220 grain bullets in front of a factory load. I don't recall the number but it was something like 6 or maybe 8 ea. 220 grain bullets.

The rifle was in a containment chamber, with just big enough hole in the chamber for a string - to pull the trigger. The stock cracked and the bolt was solidly locked into the receiver after firing the round.

I was 52 years younger then and much stronger. I thought I could open the bolt, but I could not.

If a person was holding that rifle with those bullets in the barrel he would not have been hurt.

Those bullets were placed directly one by one in front of the cartridge, no spaces between the bullets. Those bullets did not move perceptively, when the machinists got the bolt out of the receiver.

I mostly have 700's for rifles anymore, I wear safety glasses all the time when firing rifles, even 22's. I do have Mauser's, CZ's, Winchester's, Marlin's, Mossbergs, Tikka's, and Ruger's. I've owned other brands. I am very careful in avoiding over-loads.

The only problem I've had with hot loads:
#1 temperature sensitive powder - I am getting away from heat sensitive powder!
#2 back when I was a pup - Winchester changed from 760-BR to 760 and I took a load from Lyman's 45th manual. Replacing the 760-BR with 760. That 760 load was HOT. It was fired in a Mauser 98 with a 6mm Sharon Barrel. The case stuck in the chamber and the Mauser extractor did not budge it. I'm not sure what dad had to do to get that case out of the chamber. I see that I wrote in that book "DO NOT USE 760 FOR 760-BR!"

I had a Marlin 57 22 LR that in the end shot gases back into my eye upon firing a 22LR. I had fired that rifle a lot. Besides shooting gases back it would often fall apart while in use. I didn't have money for another rifle and I went back to my single shot 22 until I could buy another 22.

In my career as an engineer I was on many safety committees. "Safety is number 1." There is no reason to endanger ones self by intentionally over-loading - getting an extra 100 fps is not worth taking a chance. If your eye sight is worthwhile to you then be careful. I might be overly safety conscious, but I am glad to say that I still have my eye sight. I've made mistakes and I believe that I learned from them.

Stuart Otteson discussed gas handling in his two volume set "The Bolt Action."

That's a really cool book - I wish there was an updated version for the 21st century.

If you read (and comprehend) Otteson's books you'll be able to analyze gas-handling in 21st-century actions.

It might be helpful to remember while handloading that a rifle (or other forearm) is a device which touches off a small enclosed “bomb” inches from our face while hopefully directing the “effluent” out through a tube of small diameter.

I expect there is still much evolution of this process to take place.

I have only had one failure which I discovered after the fact had been caused by a failure on my part. It was a Tikka .222 heavy barrel. I got my face speckled and had maybe 1 drop of blood drawn. Repairs cost me about 1/3 the cost of the rifle. I'm an old man so hopefully I'll never have another experience like that.

Jim