You'd really need to be more specific to pinpoint the problem. On the assumption that it's short stroking, and failing to cycle for that reason, the problem usually lies in the gas system - a fouled gas port, misalignment of the gas port, etc.
The most likely answer is that you simply have a poorly constructed firearm. Most "M70" rifles sold in the US are not actual Zastava M70 rifles manufactured in the former Yugoslavia - due to 922r parts count laws, they're parts kit guns, manufactured from decommissioned rifles, and grafted onto new receivers, with the appropriate number of US made parts so as not to be considered an imported rifle under BATFE regulations. Some companies have done a very poor job of this, and the end result is that they end up manufacturing and selling a defective rifle.
You need to take it to a gunsmith (note: all gunsmiths are required to have a Type 1 Federal Firearms Licence in order to be able to legally do work on firearms for hire - if they cannot or will not show you their licence, do not leave your gun with them) and have them determine the cause for you.
The original Russian rifle was called AK, no number. The Yugo rifle is really Zastava M70. They fire the same round and the action is pretty much the same. However, the M70 is heavier because it has both a thicker receiver and a thicker barrel. This makes it a bit more accurate and reduces felt recoil. The Russian rifles have chromed bores and the M70 does not, which means it must be cleaned with extra care when used with military ammunition. Military ammo leaves corrosive residue which can eat up the unlined bore. Also, the M70 has grenade launching sights. They are kind of neat, but given the absence of grenades on the civilian market they are quite useless.
M70 means it was made in 1970
There are several websites that one purchase a Dell Precision M70 from. Among them are Dell, eBay, Amazon, and Overstock. There are also quite a few websites that sale parts for Dell Precision M70.
1873
Browning does not make a M70 semi auto 7mm nag
How much a Zastava m70 costs, varies depending on where you buy it. The price can range from $350 to $750. This concerns a non military version of the rifle.
No.
1937
@ 1950
1:1.74:2.82
The value of your Browning BAR which was made in 1970(M70) is between 450-650 dollars,depending on overall condition,and a good bore.
Winchester M70 .30-06