matching numbers?

[scndactive]

howdy.
I bought a yugo. SKS and the guy kind of "warned" me that it did not have matching numbers.

Should I be worried?

Was this gun put to gather from parts of other broken guns?

Sorry, this is my first mil. surp.

 

[Omnivore]

Check Headspace Before Firing!

You should be concerned.

Improper headspace may result if the bolt does not match the receiver. Both are numbered, and if someone put a rifle together with mismatched bolt, they should have had it checked for headspace. If the bolt number does not match the receiver number, find a gunsmith who has a "go, no go" headspace gauge for the 7.62 x 39 mm cartridge, and have your SKS checked.

I once had a defective SKS bolt and got a new one. The new bolt had to be adjusted for headspace. You don't care about the bolt CARRIER-- it is the bolt itself that matters.

Other than that, you don't have anything to worry about in terms of safety, unless something is REALLY amiss. Having owned several SKSs, I have also found that a matching receiver, bolt AND magazine tends to be more reliable than some having mismatched magazines. Aftermarket magazines are also a common source of frustration. Stick with the factory hardware. A good SKS should be totally reliable.

Some people try to turn their SKS into, effectively, an AK. This is usually a mistake. Use your SKS like an SKS. The ten round stripper clips are a decent system. Get an AK if you have the itch for detachable 30 round magazines.

 

[Omnivore]

I forgot my courtesy

Welcome to the Highroad, scndactive!

And; Happy shooting.

 

[Vaarok]

While headspace should be checked, it's a far overrated concern for those of us who do not reload our cartridges.

Headspace is the amount of extra distance between the casehead (base of the round) and shoulder (front edges of the cartridge, surrounding the bullet). When fired, the cartridge will stretch to fill the available space. The reasoning is that with old, brittle, soft, or poor quality ammuntion, the cartridge case could rupture and spew hot gas out. Also, for some cartridges that are straight-walled, too much headspace means that the cartridge will shove forward in the chamber when struck by the firing pin, but won't ignite, or might even break an extractor.

These things are bad, if they happen.

However, most military rifles are built to generous tolerances, and meant to function with enough slop to endure dirty ammunition and poor maintainence. The 7.62x39 cartridge in particular is meant for those conditions, as it has a tapered case that wedges into place when chambered, and thus minimizes both dirty chamber and loose chamber/headspace concerns.

Thus, if you're not going to re-use cartridges and squish them back to proper shape and fire them again, causing repeated stress on the metal of the case, you don't particularly need to worry about it.

Furthermore, the 7.62x39 is not a round that puts out a tremendous amount of pressure compared to the strength of the casing.

You should be fine but you might want to check anyways. Gauges are cheap insurance. Also, a single layer of electricians tape on the base of an unfired cartridge is sometimes used as a rough guesstimate gauge. It's not pretty, but it does work. If the thickened round won't allow the bolt to close, you should be fine.

 

[dstorm1911]

I really love it when "experts" advise new shooters about the importance of headspace and how its over rated as a concern........ ya know maybe if folks started sueing those "experts" for their medical bills then they would figure out how iresponsible posting such "OPINIONS" in a public forum really is....

The pics attached are from an AK that had an excessive headspace issue, the front trunion is extremally hardened steel which the bolt locks into, in this case the shooter got very lucky that he had the scope on it as that took all the impact from the flying steel when it went kaboom as a result of the case not being properly supported........ guess that low pressure 7.62x39 has enough pressure to kill ya huh?......... The magazine was also blown apart, shrapnel hit the shooter in his safty glasses cracking one lens (good thing he was weain em while shooting such a mundane low pressure cartridge) and if ya notice the bolt sheared one of its locking lugs when it blew apart.... thats an effect of the bolt getting slammed back into the locking lugs over and over from proceeding rounds fired leading up to the total kaboom, each time the bolt gets slammed back the headspace increases a lil more, in this case it took 150 rounds to get the results pictured, same peening effect as if ya sit there and keep smacking a piece of metal with a hammer..anyhow...... its easy to correct the headspace on an SKS ya can either swap out the bolt for a brand new one (we sell em vry reasonably) or a smith can swap out the locking shoulder in the reciever for a fatter one........ as far as paying a few bucks to have the headspace checked on a milsurp? thats up to you, are your eyes, your face, your hands, your life worth more than $20?

So who wants to see the devastation created when a Mosin nagant blows apart from excessive headspace? its even more dramatic.........

oh yea and this was a factory built gun........ but it was a factory built WASR ya see even factory built guns can be assembled incorrectly resulting in excessive headspace too... BTW ya will notice thats a Wolf case (or was) it nor any of the proceeding cases which the shooter failed to examine or he woulda noticed the cases swelling further and further ya see a case DOES NOT have to be reloaded to fail ANYONE who actually knows anything about firearms knows this super basic bit of info, by the time this one blew out the headspace was pushed so far back that the case shoulder was completally obliterated turning it into an unsupported tapered case basically........ Some folks I believe post these extremely erroneous comments that are based strictly on their own uninformed lack of real knowledge simply for the sake of posting something...... I really can't think of WHY else they would put themselves or THR at such risk of liability otherwise.......

 

[scndactive]

WOW!! I love the info and warnings. I will get this rifle checked out before I shoot it. thanks guys, I 'preciate it

 

[MMcfpd]

FWIW I just bought a GO guage and a NO GO guage for $17 ea. The actual testing is very easy.

 

[scndactive]

where can i get this guage? will it show me how to use it?

thanx for the info!!

 

[270Win]

It's been my experience here on the boards that the senior shooters almost always advise rookies FOR checking the headspace.

On a side note, I thought the separate bolt head on the Mosin was supposed to somewhat mitigate the headspace issue, and allow interchanging bolts between rifles... or am I thinking of something else?

scndactive, here is a post on headspacing a Mosin with GO and NOGO gauges:

http://www.russian-mosin-nagant.com/headspace.htm

Doing your Yugo SKS shouldn't be too much different.

In fact, here is one for the SKS I dug up by Googling "Yugo SKS headspacing"

http://www.sksboards.com/smf/index.php?topic=8990.0

 

[dstorm1911]

270Win, if you have a large enough selection of Mosin bolt heads you can correct headspace by measuring the bolt heads and going to a longer bolt head, however most smiths do not have access to a couple thousand like I do at Omega to select from and ordering one bolt head after another can get cost prohibitive in a hurry so unfortunately its very common for long headspace to be overlooked........ thats a very bad thing as when a MN goes kaboom the bolt handle snaps up and open launching the bolt rearward as there is no reciever bridge to halt its rearward travel its almost always catastrophic to the shooter, folks are advised to pay attention to empty cases watching for signs of pending failure.... the 98 Mauser is one of the safest designs when it comes to headspace related failure as the rear safty lug usually holds as the gas sheild diverts the gas and debri away from the shooters face as does the gas vent if its kept cleaned out so it can do its job (most people never bother to clean out the lil figure 8 vent on rifles equipped with it and it can be plugged solid with hardened powder fouling dirt etc) the worst failure to be expected in a 98 action is over pressure and even then the heavy action handles it very well unless its an extreme case of over pressure..... in all cases the shooter will be warned if he just takes a second to pickup a few spent cases and look at em from time to time, pay attention to the jammed up bolt and stop shooting until the reason has been determined....... it amazes me how many people I hear say "well the last 5 rounds before it blew up I had to beat the bolt open with a 2x4" !!!! And ya were surprised it blew up why?

Enfields are actually among the best at handling headspace issues, the jammed bolt is your first indicator that #1 ya may have over hot ammo or #2 ya have a headspace issue if ya examine the spent cases proceeding the jammed bolt as well as the one that jammed the tale will be told a headspace issue will jam a bolt just like a hot round as the excess space allows the bolt to get a running start before it slams into the locking lugs causing the bolt to get locked up well with an enfield ya can swap bolt heads to correct even on the earlier NO1MK3s but ya will have to actually measure bolt heads as with the mosin nagant to find a longer bolt head on the NO4 Enfields they are numbered with the longest head indicating excessive reciever stretch if ya get to the last bolt head and it still fails a FIELD GAUGE then the rifle is a wall hanger as its no longer safe to repair it....... the downside of the Enfield is its rear locking lugs however this is also a positive thing in regards to excessive headspace or over pressure as the bolt will bend upward locking itself into the reciever bridge taking the gun out of service beyond any doubt bad in that your rifle is now a wall hanger but at least your forehead remains intact which means ya will be able to go buy a new Enfield....