Savage pump 22 S, L,LR . SN 34.151 would like to if it's a 1912 model or not. Has detachable Mag .

Look on the roll mark on the barrel near the chamber end. You will find the model there. I am guessing it is a model 32. If it is an ocatagonal barrel pump action 22 lr caliber rifle it is a model 32 Marlin. If you are looking for the year it was manufactured, that is not the model is, like when talking about cars. Contact Marlin Firearms customer service (now part of Remington Arms) for date of manufacture.

see if this link helps.
Mag part 1247110a for colt service model ace 22 LR 1981 10 round mag...

http://www.savagearms.com/manuals

http://www.platformusers.net/rt/savage-model-6a-manual/

http://www.greenbookee.com/savage-model-6a-repair-manual/

https://www.youtube.com/watch?v=vz2HPnmtNm4

https://www.youtube.com/watch?v=wi5PbqsvHNI

Savage had a long history or caliber changes with that rifle. Anything from for .303 Savage, .30-30 Winchester, .300 Savage, .25-35 Winchester, .250 Savage (also called the .250-3000 Savage, .22 Hi Power, .22-250 Remington, .243 Winchester, .308 Winchester, .358 Winchester, 7mm-08 Remington, .284 Winchester, .38-55 Winchester, .32-40 Ballard, .375 Winchester

The most common stamp showing c3 was for 22

You will need to shoot over a chronograph to get the muzzle velocity for you weapon with the ammo you want then you can input the info into a free ballistics programming like chairgun from the telescopic sight company Hawke and print of drop sheets for any range you require or use the manufactures stats for the round and input that

An example is here. You must use "300 Savage" or "300 Sav" only! Great ammo for deer. http://www.ableammo.com/catalog/cheap-savage-centerfire-rifle-ammo-sale-online-discount-prices-c-10480_14658_14743_14905_14822.html

Numrich has them for $20.55 for a ten round mag. They have a five round also, but they're sold out.

http://www.gunpartscorp.com/catalog/Search.aspx?catid=0&filter=115610C