I just bought an almost new Rock River LAR-8 M4. According to the seller , it only had 38 rounds through it. Finally got to shoot it this weekend. After the first shot, the second round will not fully load. It is always about an inch short of the receiver being fully closed. I have to remove the clip, eject the jambed round and start over. Every time. I was shooting Remington PSP 150 grain rounds. Could it be the ammo or do you think there is something wrong with the gun?

Try some quality brass FMJ and only load about 5 at a time. What mags are you running?

What Old_Town said and, Lube the bolt and bolt carrier, think "run it wet" as a continuing course of action.

I tried the original mag and the new RR polymer mag. Both had the same result. I did spray some Rem oil in the area but no luck on it. After extracting the jambed round, I did notice the soft point bullet was scarred. Can you not use a soft pointed bullet in the ARs? I got the gun mainly for hogs and varmits. It will be a real bummer if it only shoots FMJs.

I shoot soft points through my 15 all the time. Is this a factory gun or a "custom build"? I know some times people buy uppers with M4 feed ramps but their barrel isn't cut for them. When you try to chamber a round the nose of the bullet catches where the barrel extrudes past the feed ramps causing FTF.

The soft points are a little blunt but you should be able to run them still.

Something like the federal fusion or better yet any of the ballistic tips would be other options to try.

When DPMS had issues when they first released they were magazine related , so I would start with FMJ or something pointier, then worry about the magazine.

Try using pmags and FMJ federal red box--I had similar problems trying to run winchester white box lead noses. I have gained an appreciation for a forward assist...

Pmags won't work in it, I think RR uses FAL mags.

What kind of gas block is on it? Could be a misaligned gas block, not giving it enough gas.

I agree with others, you need to try some different ammo as well.

The gun is a RR LAR-8 A4 with a 16" barrel and mid-length forearm. All parts are stock, from what I can tell. I did buy it used but the original owner said he bought new 8 months ago in College Station and he has only had 38 rounds through the pipe. Looks brand new from what I can tell.
The gas block is stock. How could one tell if the gas block is misaligned?

When the BCG does not fully close and lock is the round loose in the chamber or is it actually jamed between the bolt and something else?

If the round is loose then it sounds like your BCG is in a bind as it nears the chamber. Could be a misaligned gas tube or gas key.

Like others have said I would change ammo and mag to rule that much out. After that I would start looking at something like the BCG binding or misalignment of gas key and tube.

Best way to tell is to remove the gas block and look at the carbon fingerprint around the hole in the barrel. If you have a good burnt powder circle completly around the hold then you are aligned properly. If the burnt powder circle looks off center then the gas block may be slightly blocking the gas port. There is even the remote possibility that you could have a gas port or gas tube blockage as well.

If you want to check the gas tube and key alignment just pull the bolt out of your bolt carrier and slide the carrier back into the upper without puting the upper and lower back together. Now just move the carrier back and forth in the upper and see if it moves freely or if you feel any resistance as it gets closer to the chamber.

I saw a thread awhile back on another forum where the cam pin was binding against the upper reciever as the bolt would lock and unlock causing a similar issue as well. But if its jamming a full inch away from lock up I doubt thats your problem.

[quote=JCB]When the BCG does not fully close and lock is the round loose in the chamber or is it actually jamed between the bolt and something else?

The round is tight. The bolt will not go forward any further. It is actually difficult to pull the bolt back to eject the jambed round.

Y'all are giving me some great information. Even though some of it is over my head but I'm learning as I go. I really appreciate it and please keep it coming.

Then you can probably scratch the gas tube/key alignment off your list. I bet a different mag and/or ammo will fix this problem.

I had a RR 308 and never did have a problem with mine. When they first came out they did have a problem with the bolt release poping up during firing and hanging the bolt partly open. You might want to remove the upper from the lower and insert a mag with about four or five rounds and push them thru to simulate the action and see if the bolt hold open tab pops up! If not give RR a call they are very helpful when it comes to the 308 problems.

maxflipper, where you at?

Sure you have the bolt facing the right direction and is the bolt lubricated.

Check to see if the bolt is in the BCG the right way.

I have put one in wrong a couple of times...

Any answer to the problem?