I recently purchased a new Zastava M70, .30-06 rifle. After bringing it home, I noticed there are four digits etched into the bottom of the bolt handle. These digits, have nothing in common with the rifle’s serial number. I am accustomed to having these digits match the last digits of the firearms serial number, but I am unaware of Zastava’s custom.

Century Arms, is clueless, and can not or will not answer my question. Does anyone here have any information pertinent to this issue?

The number you see is NOT the rifle serial number; it is a factory assembly number for the receiver and bolt. You should find the same number under neath the receiver. Completed rifles were given a unique serial number, un related to the receiver/bolt number.
Century arms is just an importer; most customer service people are not aware of those details.

dpcd is more or less correct. The United Nations rammed a bunch of legislation up our butts a few years ago. As per the act, every firearm imported into a country must posses a unique serial number, the make and model of firearm, manufacturer name, and the name of the country the firearm was imported into (end user).
This firearm marking will essentially end violence in the world and gun crime because the guns are all stamped legally now. Most of the manufacturers are incorporating the two digit, country code ex. (CA = Canada or US = United States) and the last two digits of the year of manufacture ex. (17 = 2017) into their existing serial numbers. Others like Zastava, seem to be using a United Nations code number, plus their own unique serial number.



This is how PZ handled the problem. (Perazzi made in Italy) is clearly stamped on the upper portion of the bores as usual. Then on the water table it is stamped Canada (end user), the year of manufacture (2013), the serial number and the model (TM9). This PZ can no longer be used in a crime because it is stamped by the UN.

United Nations numbering by Rod Henrickson, on Flickr

This is copied from the; United Nations Firearms Marking Act.

Article 8
Marking of firearms

1.
For the purpose of identifying and tracing each firearm, States Parties shall:

(a)
At the time of manufacture of each firearm, either require unique
marking providing the name of the manufacturer, the country or place of manufacture and the serial number, or maintain any alternative unique user-friendly marking with simple geometric symbols in combination with a numeric and/or alphanumeric code, permitting ready identification by all States of the country of manufacture;

(b)
Require appropriate simple marking on each imported firearm, permitting identification of the country of import and, where possible, the year of import and enabling the competent authorities of that country to trace the firearm, and a unique marking, if the firearm does not bear such a marking. The requirements of this subparagraph need not be applied to temporary imports of firearms for verifiable lawful purposes;

(c)
Ensure, at the time of transfer of a firearm from government stocks to permanent civilian use, the appropriate unique marking permitting identification by all States Parties of the transferring country

thank you for taking the time to reply to my question. My knowledge of the bolt number matching the receiver is outdated.

The bolt does match the receiver; what you see on the external surface is the RIFLE serial number. The bolt number and another hidden number are placed on the parts as a set, when they are manufactured, but before the rifle is built. They are stored as a set until an order for a rifle comes in. US makers don't do it that way. They fit the bolts when building a rifle. Europeans fit the bolt to the receiver, maybe far in advance of any rifle assembly.
As I said, there is no correlation between the bolt and receiver assembly number, and the rifle serial number.
They were doing it that way before the UN got involved.

I did find the receiver numbers that match the digits on the bolt. thank you to all for the advice.