7.62x 39 FAQs Frequently Asked Questions about the 7.62x39 AR Rifle
We have been getting alot of feed back on our 7.62x39 upper receivers, most has been positive, but some problems were found on the earliest uppers, and due to the feed back we have been able to make the needed fixes. There are still some individuals who experience problems.
The 2 most common issues are failure to fire and failure to feed. These are usually fixable by the customer.
The 7.62x39 round is a very finnicky round in the AR, and with the variety of ammo out there it is really impossible for us to make one and one only setup that works with everything perfectly with no work on the end users part.
Lets look at the first problem, failure to fire. There are 2 things that always are linked to this problem:
1. This is always reported by folks using steel case russian ammo or other surplus ammo, and this includes Herter's cheap ammo as it is basically import ammo that should be considered the same as all the other import 7.62x39 ammo.
2. These same folks are using ultra light trigger setups, and or speed hammers in their lowers. What this means is that there is not a whole lot of energy in that hammer when it strikes the firing pin.
When you combine the 2 of those things together, you simply do not have enough energy in your hammer to reliably detonate hard primer military type ammo.
Your Kies upper was built to be a percision hunting upper, and yes it will work just fine with cheap ammo, think of it kind of like an SUV, it can go to the prom or to the treestand, it can do it all.
If you put it on a lower designed to be a sports car (ultra light trigger, speed hammer, designed for use on the bench or hunting with good ammo). You will have issues with cheap ammo.
If you put it on a lower designed to be a work horse (heavier hammer and hammer spring) you will have a fully functioning rifle.
Then there is the 3rd option, a lower built to be an SUV. this is one that has a full power hammer spring and full weight hammer, that is however a good crisp trigger, generally if you keep your trigger pull above 4 pounds you should not have these failure to fire issues in cheaper ammo.
Basically what you have to do is decide if you want a 7.62x 39 rifle for fun shooting cheap ammo or do you want one that is meant for precision work. Your Kies upper can do both, but if you want to do both you may need to consider 2 lowers, one for serious shooting with higher end ammo, and one for fun shooting with cheap ammo.
Issue 2: Failure to feed
Due to the vast quality differences, power differences and consistancy issues in 7.62x39 ammo, it is impossible to set up one gas system that works with everything every time. This is why your Kies upper has come with an adjustable gas block so that you can tune it to fit the ammo you are using. This will almost always fix your feeding issues. Please see our section on how to tune your gas block for more information on this.
