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Spacecase wrote:According to the manufacturer of the gauges, the "Field" gauge is military specs which are more forgiving than the "No-Go". The bolt came closer to closing with the "Field".
Are you sure that you identified the gauges correctly - that seems bass-akwards to me. The bolt should come closer to closing with the no-go gauge than it does with the field gauge.
I remember his posts on the old forum when he was designing his gauges and I have full confidence in his gauges. So I have to think there is something you are doing wrong.
"I spent most of my money on beer and women. The rest I just wasted."
It was my understanding that the field gauge measured the maximum headspace the rifle could have and still be nominally safe to fire, nothing being mentioned about accuracy of course. As a rule if it fails the NO?GO gauge it becomes a wall hanger unless I can fix it with a bolt head swap.
Leave it as it is. The ages have been at work on it and man can only mar it.
Don't hit at all if it is honorably possible to avoid hitting; but never hit soft.
Theodore Roosevelt
Yes the field gauge allows for maximum headspace and it does that by being thicker. If the no-go test "fails" (ie closes on the gauge) then the thicker field gauge is tried - if it closes on that then it may be a candidate for a position on the wall.
"I spent most of my money on beer and women. The rest I just wasted."
It's mostly the Mauser's I worry about, the rimmed case 7.62x54r is a bit more forgiving of crap headspace, and Mosins are much easier to fix with a bolt head swap than the Mauser. I have a limited number of spare Mauser bolts.
Leave it as it is. The ages have been at work on it and man can only mar it.
Don't hit at all if it is honorably possible to avoid hitting; but never hit soft.
Theodore Roosevelt
Junk Yard Dog wrote:It's mostly the Mauser's I worry about, the rimmed case 7.62x54r is a bit more forgiving of crap headspace, and Mosins are much easier to fix with a bolt head swap than the Mauser. I have a limited number of spare Mauser bolts.
I agree with all of that.
"I spent most of my money on beer and women. The rest I just wasted."
Hombre wrote:Yes the field gauge allows for maximum headspace and it does that by being thicker. If the no-go test "fails" (ie closes on the gauge) then the thicker field gauge is tried - if it closes on that then it may be a candidate for a position on the wall.
That is based the way the terminology is being used by us civilian users of old military rifles and is not quite the way I remember the terms being used by the military.
Long ago I read an article on military use of headspace gauges but I cannot find it in my stuff.
Here is the way it went as best I can remember:
go and no go gauges were initialy used by the factory to set and check the headspace to be within specifications.
In the field the armorers used the no go gauge to see that nothing had caused a significant change in the headspace. If a bolt closed on the no go gauge and it was not war time, they would send the rifle back to a main armory to be inspected.
In war time the if the bolt closed on the no go gauge the field gauge was tried. If the bolt did not close on that, they would permit the rifle to be used but would slate it to be sent to the main armory at the first opportune time.
"I spent most of my money on beer and women. The rest I just wasted."
That is based the way the terminology is being used by us civilian users of old military rifles and is not quite the way I remember the terms being used by the military.
Long ago I read an article on military use of headspace gauges but I cannot find it in my stuff.
Here is the way it went as best I can remember:
go and no go gauges were initialy used by the factory to set and check the headspace to be within specifications.
In the field the armorers used the no go gauge to see that nothing had caused a significant change in the headspace. If a bolt closed on the no go gauge and it was not war time, they would send the rifle back to a main armory to be inspected.
In war time the if the bolt closed on the no go gauge the field gauge was tried. If the bolt did not close on that, they would permit the rifle to be used but would slate it to be sent to the main armory at the first opportune time.[/quote]
This is exactly the logic that I understood from the Okie headspace gauge instructions. But I retested it and the "Field" gauge seems to allow the bolt to tun about 1/4" to 1/3" more than the "No-Go", which defies logic. The thickness of the gauges (as measured by my digital caliper) is as follows: "No-Go" 1.86 mm (0.073"), "Field" 1.93 mm (0.076").
In any case, the headspace seems to be OK, so we can discard that as a possible issue.
Spacecase wrote:.....This is exactly the logic that I understood from the Okie headspace gauge instructions. But I retested it and the "Field" gauge seems to allow the bolt to tun about 1/4" to 1/3" more than the "No-Go", which defies logic. The thickness of the gauges (as measured by my digital caliper) is as follows: "No-Go" 1.86 mm (0.073"), "Field" 1.93 mm (0.076").
....
Sorry but I just cannot understand how the bolt would close further on a thicker gauge. (Provided that you are using the same amount of force on the bolt handle of course.)
"I spent most of my money on beer and women. The rest I just wasted."
This has taken a most interesting chain of discussion. The original issue was the casings splitting at an area that does not appear to be a result of incorrect head space. I know I am a new member and am certainly not as knowledgeable as most on this forum, but isn't the original issue simply a faulty batch of ammo? The head space angle is starting to worry me.
andrewd41 wrote:This has taken a most interesting chain of discussion. The original issue was the casings splitting at an area that does not appear to be a result of incorrect head space. I know I am a new member and am certainly not as knowledgeable as most on this forum, but isn't the original issue simply a faulty batch of ammo? The head space angle is starting to worry me.
Yes. You have assessed the situation correctly.
“Freedom is the right to tell people what they do not want to hear.” George Orwell, English novelist, essayist, and critic, 1903-1950
Of all tyrannies, a tyranny sincerely exercised for the good of its victims may be the most oppressive. It would be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience.
Headspace worries are easy to deal with, just get the gauges from Okie and test it, takes twenty seconds to do. If it's good then off you go, if it's bad then you have some bolt head swapping to do until you find one that passes, at least with the Mosin rifle. The Mosin isn't the most sophisticated rifle action on the planet, or the most expensive, it's wasn't the first bolt action, but has been in service the longest. What the Mosin has going for it is that it's incredibly hard to f*** up with this rifle. People fire these rifles every day with headspace so bad the fired cases look like balloons about to burst, yet they go home safe with no clue, They fire them with firing pins out of adjustment, with bores choked with grease, without ever even taking them apart to check to see if all the parts are there. 60 years of raw Russian conscripts hauled off the farm to have these rifles shoved into their hands, and then have their asses dumped into a war and the rifle stood the test. Snow, rain, dust, mud, heat, and cold so extreme that piss freezes before it hits the ground and the rifle stood the test. You have to work hard and be very inventive to get one of these rifles to hurt you. Mosin, and Nagant knew going in that the soldiers being issued their rifle would do everything possible to ruin it and kill themselves in the process, they did an incredibly good job of making it as tough as they could.
There is nothing to worry about, headspace checks are dead simple, visual inspection takes care of the rest. So what if there are a few splits in the ammo, forget about it, millions of rounds downrange and we are all still here, you want to shoot cheap shit relic ammo then this is something you will just have to put up with. There is a reason why I buy the highest quality commercial ammo for my defensive weapons, and pay out the ass for it, to be assured that this bullshit is never an issue if I need to use it with my life on the line. For the plinkers, and casual shooters I ain't spending a buck fifty a round, the crap ammo will do, and I will put up with the crap it does as I have been doing for 30 years. Trust the Mosin, it's as bulletproof an infantry rifle as was ever made, the Mosin never gained a rep for blowing receivers as the US M1903 low numbers did, so far as I know it never gained a rep for any problems at all except it's occasional problems feeding from the mag, and sticky bolt. The 7.62x54 rimmed round is very forgiving of poor headspace, much more so than the rimmless 8mm Mauser, or .30-06, so even the cartridge itself is working to keep you safe.
Leave it as it is. The ages have been at work on it and man can only mar it.
Don't hit at all if it is honorably possible to avoid hitting; but never hit soft.
Theodore Roosevelt
andrewd41 wrote:This has taken a most interesting chain of discussion. The original issue was the casings splitting at an area that does not appear to be a result of incorrect head space. .........
That is correct but that fact was not apparent to some so their questions needed to be addressed.
andrewd41 wrote:but isn't the original issue simply a faulty batch of ammo
Yes and if desdem12 and millman's advice had been listened to it could have been a very short thread - but to me it was lots more fun the way it turned out. Plus questions came up about other possible causes and those needed to be answered.
"I spent most of my money on beer and women. The rest I just wasted."
On this forum we like to talk, and we tend to drift around in threads all the time, it's a trait here that is not encouraged on some of the more stick up the ass types of forums that many here escaped from because of that. Here you can learn how to clean corrosive ammo residue from a rifle, check headspace, identify some odd marking and learn how to make a proper fried spam sandwich all in the same thread
Leave it as it is. The ages have been at work on it and man can only mar it.
Don't hit at all if it is honorably possible to avoid hitting; but never hit soft.
Theodore Roosevelt
Junk Yard Dog wrote:….. The 7.62x54 rimmed round is very forgiving of poor headspace, much more so than the rimmless 8mm Mauser, or .30-06, so even the cartridge itself is working to keep you safe.
That is true with all rimmed cartridge rifles because with that type the head of the case can be supported more fully. Also with rimless cartridges, slamming the bolt forward can compound the effect of excessive headspace, which will not happen with rimmed cases.
"I spent most of my money on beer and women. The rest I just wasted."
Thanks for your understanding. I have two Mosins, 1942 Issy and a 1943 Tula. Both a CAI import. I got these to teach my son (13). He and I have lots of fun at a local outdoor range. They are both dead on at 110 meters which is the longest range around here. My son has much more fun with this rifle than playing Call of Duty.
If there were no circumferential splits in your cases, the fact that you have fired several rounds means that you do not have to worry about headspace problems.
In the old days they used to tie the rifle to a tire and shoot a few rounds through to see if there was any signs of excessive headspace.
In the future if you get more Mosins it is not a bad idea to have the headspace checked first or get a gauge so you can check them yourself.
Mostly the refurbished rifles will be found to be ok but you never know if someone had used it and maybe fired some overpressure hand loads in it. That could stretch out the receiver and cause very excessive headspace.
If I ever find one that that fails the field gauge test, then I would not use it. You could get full head separation and even though full head separation will probably not cause catastrophic damage to the rifle, you don't know if the receiver was stretched enough by overpressure loads to cause the receiver to possibly fail with further use with normal pressure levels. Even that is fairly unlikely but I would not take the chance.
"I spent most of my money on beer and women. The rest I just wasted."
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