Grandpa's gun.

I think Pikie is right but who cares what it is? It is a Mauser type rifle, so find out what caliber and let 'er rip 'tater chip! I bet it will shoot beautiful groups whatever the caliber. Bet it is a 7mm.

Old Fred

 

If its a 7mm I bet it kicks like a Czech mule! Light gun might as well be a 300 win mag.

Sent from my SAMSUNG-SGH-I337 using Ohub Campfire mobile app

 

Not 7mm Magnum! Just 7mm! I had a friend when I was young who had one and it was one fine shootin' rifle!

Old Fred

 

It shouldn't cost that much to drive a lead slug through the barrel and measure it. That will tell you the bore size.


The gunsmith will have to do a chamber cast to determine the actual caliber of the rifle. From the pictures you have posted the rifle looks as if it still hast the original barrel. As others have posted there are only a few choices as to the caliber, 8X57, 7X57, and 7X53.

 

Mine shoots a 7.9 mm bullet. I'd follow OP's suggestion slug it, measure it, and have fun. Its also a favorite test bed for bench rest shooters, lots of wildcat rounds have be3en tried out on that reliable proven action. Shots straight and well out to 250 yds. with the iron sights. I have seen many of these guns used for various purposes.

I am still eating up the mil surp ammo that I got with it. Pops and I redid about five of them. Some had mismatched bolts, an armorer told us mil did that with many of the weapons that were packed in cosmoline for storage. as long as the bolt fits, and has proper head space, and the right ammo is used should be fun. As long as your not on the receiving end

 

It is a WWII Czech VZ24 military rifle made at the BRNO Works and if it is the original barrel it is 8mm Mauser. All the best...
Gil