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Thread: Cetme Sporter .308 cal. Chamber Size?

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    Cetme Sporter .308 cal. Chamber Size?

    The title may appear contradictory. My Cetme's markings further states: Century Arms Inc., Georgia, VT, Made in USA. Serial Nr. C334xx. I've read somewhere that some barrels were produced in this country. I assume most were imported from original manufactures in Spain or Germany. My question is: Is there any way for me to determine whether the barrel on my rifle is .308 or 7.62x51 NATO. The reason I ask is that the NATO shoulder of the cartridge may be slightly longer than the .308. If so, chambering a NATO 7.62x51 round in a .308 chambered barrel might be like craming it into a "short" chamber. Yet, all seem to say to fire the NATO round in this rifle. Where is my reasoning going wrong, or is it???

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    Senior Veteran bladeworks123's Avatar
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    No your thinking is not wrong. It most likely is chambered for 7.62 NATO and the receiver is marked .308. And because the delayed roller blow back action does not headspace in the manner of any other rifle, the longer 7.62 x 51 will usually not cause you any problems. The reverse, however, firing .308 Win can sometimes cause separated cases, due to the shorter .308 case not fully filling the chamber. With the case walls on .308 commercial brass being thinner, they do not easily tolerate the stretch that occurs and can separate. That is a grab bag on these rifles, some will shoot .308 flawlessly and some will not, it all depends on how deep the chamber was cut, and sometimes on the brands of ammo.
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    Thanks Bladeworks123. I have written Century, with my serial number, requesting actual chamber size. They may have a record as to whether mine was a new made in usa barrel (.308) or an imported 7.62x51 NATO. I hope Century can tell me. Otherwise, I wish I could tell from a marking on the barrel or a positive measurement. I would hate to "cram" a NATO into the shorter .308.

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    Typically, they are chambered in 7.62x51. It never made much sense to me as to why Century stamped them .308. As for the origins of the barrel, you'd want to examine it for markings. Those stamped with a "C" are US made Century barrels. There are others, although I think the US are more prevalent. The Santa Barbara barrels have a cross in a circle stamp.

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    I just re-read your reply about delayed roller blow back not headspacing as other rifles and 7.62x51 NATO should not be a problem. I believe this answers my concerns. Thanks

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    Senior Veteran bladeworks123's Avatar
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    Quote Originally Posted by IraO View Post
    Thanks Bladeworks123. I have written Century, with my serial number, requesting actual chamber size. They may have a record as to whether mine was a new made in usa barrel (.308) or an imported 7.62x51 NATO. I hope Century can tell me. Otherwise, I wish I could tell from a marking on the barrel or a positive measurement. I would hate to "cram" a NATO into the shorter .308.
    On DRB platform rifles like the CETME and Hk, you would not be cramming. The 7.62 NATO chambers were designed for the bolt to be held back away from the chamber face by the cartridge headspacing. And they were built to accomodate a very wide range of cartridge lengths that vary from country to country. CAI is most likely going to tell you flat out, that the rifle is chambered for .308 Win, as indicated on the receiver. IIRC their owners manual for all the CETMEs even specifies that.

    But if you are interested in the subject it has been pretty well discussed to death in this thread....Including the same question you posed here, starting at post #47.

    http://www.militaryfirearm.com/Forum...s-Gap-and-Ammo
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    Senior Veteran bladeworks123's Avatar
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    Quote Originally Posted by Kyle View Post
    Typically, they are chambered in 7.62x51. It never made much sense to me as to why Century stamped them .308. As for the origins of the barrel, you'd want to examine it for markings. Those stamped with a "C" are US made Century barrels. There are others, although I think the US are more prevalent. The Santa Barbara barrels have a cross in a circle stamp.
    That is true but not always a guarantee either. Some of the Santa Barbara barrels were cut at the breech either to maybe true up the breech end of the barrel or to bring them down to a chamber headspace length closer to the .308 win cartridge, although Century will not confirm that, (Like they won't confirm grinding bolt heads to create false gap) I have measured several that range .010 to .020 shorter than 7.62 NATO Spec. Or Maybe Santa Barbara sucks at their quality control. My money however is on the first theory. A long time ago now I resolved my self to the fact that if somebody else built it,,,,it either shoots .308 win. or it doesn't, and I have not found one yet that would not shoot 7.62 NATO if the flutes are correct and clean. So my advice to everybody is pretty much the same. Buy it, check the bolt gap and shoot it. Live with what it does when it comes to it's ammo diet.
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    Quote Originally Posted by bladeworks123 View Post
    On DRB platform rifles like the CETME and Hk, you would not be cramming. The 7.62 NATO chambers were designed for the bolt to be held back away from the chamber face by the cartridge headspacing. And they were built to accomodate a very wide range of cartridge lengths that vary from country to country. CAI is most likely going to tell you flat out, that the rifle is chambered for .308 Win, as indicated on the receiver. IIRC their owners manual for all the CETMEs even specifies that.

    But if you are interested in the subject it has been pretty well discussed to death in this thread....Including the same question you posed here, starting at post #47.

    http://www.militaryfirearm.com/Forum...s-Gap-and-Ammo
    I just read your reference. I think I can see where the NATO ammo is the correct ammo. I believe I can see where the rollers are providing for the correct headspacing. And, I believe Century will tell me what is stamped on their rifle. Thanks for all the info. I have some NATO ammo ordered and am waiting on it to get here. Again, Thanks

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    NATO for my Cetme. Less pressure, less wear on mechanism and parts. Thanks
    Last edited by IraO; 10-16-2013 at 08:38 AM.

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