Potential Damage - Firing 7mm Rem Mag in a .300 WM barrel

[Pistol]

Maybe a split neck but more than likely a fire-formed 300 mag case with a short neck.

This. Wouldn’t have been a big deal.

^^ this

I have seen a 5.56 fired in an AR that had the barrel changed out for a 7.62x39mm bore. I have the bullets too. Pretty neat. Case was split and stuck, and took a pair of pliers to get it out. Then the gun was successfully fired with the correct ammo, no problems.

[trophy8]

There’s been a TBHer do it. On a hunt

I won’t name who it is. Seeing if he chimes in lol

[TX_Kevin]

Potential Damage - Firing 7mm Rem Mag in a .300 WM barrel

There’s been a TBHer do it. On a hunt

I won’t name who it is. Seeing if he chimes in lol

That was me. I can tell you that you can’t hit a nilgai at 120 yards with it, or at 138 yards either. That is all that happens though. Custom Horizon Firearms gun too.

[Old Bald Guy]

Backstory:
Fireforming 22-250AI cases and 22-6mm AI cases. Shooting 5 in one gun then letting that gun cool while shooting the other gun. Ejectors were removed from both guns and we were removing the bolt each shot and putting the case in behind the extractor. My son was doing the shooting.
First mistake was having both ammo boxes on the bench at the same time.
Second mistake was not telling him to be careful because a 22-250 case fits in a 22-6mm chamber.
He shoots, no difference in sound or anything and bullet hits in with the rest. Extracts the case and thinks the case separated from the neck and left the neck in the gun.
Nope. 22-250 case in a 22-6mm chamber.
No harm, no damage but very lucky that we had the case snug against the bolt.
Might have a case head separation other wise. IDK

[Prairieboy]

No help to the op here as for the original question.
I recently got an old mosin nagant 7.62x54R in a trade and as with all guns new to me I check the breach&barrel for any obstruction. Couldn't get any light thru the barrel. Long story short there was a cleaning brush lodged in the barrel about 3 inches from the breach... at that point I was sure glad I checked!
Had a uncle that used barrel plugs to keep dirt dobbers from getting in his rifles. In his later years he forgot to remove one and blew up the barrel in his face.

[Chase4556]

The other week my brother in laws father fired 300win mag in a 300wby. They had no idea, and were seemingly okay with the terrible groups.

My dad went with them that weekend. They brought back all the random brass from their shooting range so I could sort through and keep what I wanted for reloading. Two really weird pieces of brass caught my attention. Asked my dad about it and that’s when I put two and two together. Sent photos to my brother in law and told him he needed to tell his dad to knock it off.

[BLACKFINTURKEY]

I shot a 260 in a 308 once no issues whatsoever besides hurt pride. I may have got lucky.

[PondPopper]

Nothing much.

[dustoffer]

How about a .270 Win in a 7 Mag chamber?