I was going through some old stuff I had and in a box with some 7mm mag I had from years ago, this bullet was in there. It’s obliviously not even close… I have no idea what it is.

To get the caliber of a bullet, you have to measure the diameter of it.

Looks like a 7.5x55mm Swiss to me.

Hard to tell from the measurements in your picture. It looks like a 7.62 x 51, but the shoulders look goofy.
The TA makes me think Israeli (Tel Aviv).
Put a set of calipers on the round, let us know what it mics out, and we could help a little more.

Ahh…. When you said Swiss, I remembered what it could be. My neighbor is from Switzerland and he has two rifles I borrowed one time. They were both the same caliber. I don’t remember the guns, but they were both old military weapons. One was an old iron site sniper rifle and one was some Swiss automatic AR style rifle. I just texted my neighbor and I’ll put what they were .

Yeah, he said it’s a 7.5x55. He is in his 60’s and he said this is the assault and sniper rifles he used when he was in the service when he was young. The assault rifle is heavy as [censored]!! I couldn’t imagine having to carry it around. These are what they look like.

Do you know if he still has the Sig semi auto rifle and would he be willing to part with it?

I will certainly find out for you

Sorry buddy, he said he doesn’t want to part with them

That's not just a bullet...it's a loaded cartridge.

His story is a little hard to believe for several reasons . The K-31 is not a sniper rifle and was out of service before a 60 would have served with one . The Swiss military STGW was a full auto weapon and could not have been brought into the US by a private citizen .

K31 was likely still in service long after it was officially replaced. There was a crap ton of surplus rifles imported in the 00s. Everyone likely had a K31 in their home in Switzerland. Probably similar to an AR15 in Texas.

It was not an issued service weapon in that time period . People having them is not the same as the military issuing them . Also he would not have been issued both . The K-31 is not a sniper rifle . The US army does not issue AR-15's . You could buy yours from the Swiss military when you left service and the rifle was marked as such . Most were just turned back in to the military who stored them . They were sold as surplus by the military . I get my info from a friend who is a Swiss military weapons master in Switzerland .

I could be wrong with the exact rifle, I just remember it looked just like it. I’m pretty sure the assault rifle is correct, but the sniper I’m not sure. I know absolutely NOTHING about those weapons, I was just guessing from memory

Most of the K-31s have a card under the butt stock plate with a name and other information to whom they were issued. Males, I believe were citizen soldiers at the 18th birthday for 2 years. The K-31 is a fun rifle to shoot. That bullet as many have stated is a 7.5x55swiss. It does use a .308 bullet (30cal). I reload for mine and use 150gr and 168gr bullets. Pretty accurate for a carbine rifle. The swiss ammo has a wax ring around the case mouth and bullet. The sniper rifle version of this rifle is called schmidt rubin zfk55.
The original is the schmidt rubin K-11, then the newer shorter carbine was created called the K-31.

Actually the original was the Schmidt-Rubin M-1889 rifle . Then the M-1911 rifle . The K-11 was the carbine , the K-31 has a longer [ not shorter ] barrel by over 2 inches than the K-11 .

Love my K31. With the bayonet it’s long. Very accurate rifle and cool design for sure.

It could be a PE57 which is a commercial version of the same rifle in semi auto. Rifles bought by soldiers were apparently converted to the PE 57 designation as well. The story of it being his personal rifle is possible if he had an importer bring it in for him before 1989. Pre import ban. It would be a very rare rifle if it is a PE57, especially if it has provenance showing military issue to him. If he had the rifle imported with or bought an original Kern Aarau scope at the same time as the rifle it is crazy valuable.

I believe the cartridge was made in September of 1978. Manufactured at Altdorf Switzerland and assembled at Thun Switzerland. I have several hundred rounds of the stuff and at least three or four of the Swiss rifles. K11 and k36s with bayonets. One with a wicked 24+ inch Engineers Sawback bayonet.

Swiss military STGW-57's were not converted to semi auto , the PE-57 was a commercial made rifle from the start . Nobody in Switzerland converted their EX military rifles to semi auto , they are all still full auto , there was no reason to as it was a select fire to start with . The PE-57 was expensive , even for the Swiss , where as an EX military STGW-57 is very cheap over there , about $150.00 . The ATF says once a full auto rifle , always a full auto no matter if it has been converted to semi , so a private person is not going to get it imported . Just look up US law . The PE-57 was made new as a semi and was never a Swiss military rifle . Yes the OP could be talking about a PE-57 , but it was never his service rifle .

Diablodog, I admit I don't know. Just that online I have seen several mentions, articles, auctions, etc that mention them as such. I cut and pasted a couple I found from the top of a simple google search. If the Swiss military did convert some to semi auto, perhaps it involved replacing the receiver. The receiver on a STGW57 or PE57 is a very small part of the overall rifle.

http://www.stephenhalbrook.com/law_review_articles/citizens-in-arms.pdf

"Today, every male when he turns twenty years old is
issued a Sturmgewehr 90 military rifle and required to keep it at
home.38 When one is no longer required to serve—typically at
age forty-two—he may keep his rifle (converted from automatic
to semi-automatic) or pistol (in the case of an officer or
specialized unit).39"


https://www.ar15.com/forums/General/-ARCHIVED-THREAD-Swiss-PE-57-Semi-Auto/5-1110973/?page=1

"Check out this auction. This rifle was converted to semi auto by the Swiss authorities and was brought in as a semi auto rifle. Would this be legal that way? Either way its a beautiful rifle"

I don't normally like fufu rifles, but I have to admit I'm impressed what the Swiss have done with these civilian rifles. https://www.besser-treffen.ch/design/

I did a walkabout in Switzerland. Really neat place. Especially enjoyed meeting the people. I once tried to take a picture of some Swiss soldiers holding their rifles who were guarding something or someone across from the World Bank. Being a gun collector I was very interested in the rifles they were using. They strongly objected and started towards me. I got the hell outa there.

In the US the receiver is the firearm , so if you use a new receiver you could put old 57 parts on it . But it is then not a old military rifle . My friends in Switzerland who have kept or bought ex military 57's all have select fire rifles . I have a friend who is a Swiss match official , he says the 57's are still select fire , he checks them out to people with ammo . You do have to shoot them on semi auto if you are at an official match . Also the 57 is pretty much hated by the shooters over there . My friend says you can't hardly give one away . Also the 90 is still select fire and is much more popular .

To clarify this a little . About 8 years ago the Swiss made it where you needed to get a permit for full auto , but that would not apply to the OP guy at his age period . Also some people did have their rifles set on semi only as many ranges did not allow full auto fire . But you did not have to to own yours . But as stated a Swiss military rifle set to semi would still be a full auto rifle by US law and would not be allow to be imported . The PE's were imported for a few years before even their importation was stopped , in about 1986 .