Need a little help with a Whisper Upper Problem

[DonT]

Thought I would check to see if someone could give me some direction. I am having a real issue with a Model 1 Sales upper I just bought. It was used and is in 300 Fireball.

My issue is in functioning. It will feed fine using 168 gr FMJ, RP 223 brass formed and trimmed to 1.355. For the most part it feeds fine but when you drop the bolt on a single round you cannot get the gun open to eject the loaded round. It starts to open then just hangs, like the bolt is not turning far enough in the carrier to unlock. I can rap the butt on the bench while pulling on the charging handle and it will not move any further. The only way to get it out is to fire it.

Now the interesting part. It has a MGImilitary adjustable gas tube. If I turn it closed then back it out 1 1/2 turns as recommended as a starting point the rifle fires but does not eject. Another 1/4 turn and the round ejects but does not lock open. Another 1/4 turn and gun jams up when fired. The fired round remains in the chamber, the bolt either does not move or pulls a portion of the rim off and the round needs to be tapped out with a cleaning rod and it takes a bit to get it loose.

My loads are 168gr FMJ pushed with 12.8 gr of H110 and remington benchrest primers. Certainly not a hot load by any stretch. I have checked the loads on a digital and Ohaus beam scale and they are right on.

I am perplexed to say the least. I have never had this type of problem with am AR style rifle before, although the others have all be .223 or .308.

The brass does not have any signs of excessive headspacing. I have, on a number of occassions, had to remove the lower and manually cock the hammer, put the gun back together and fire it a second time to get it to clear. I have also had to remove the butt, recoil tube & spring because the gun did not go into full battery and the forward assist would not move the bolt closed enough to break it open. I have a small brass hammer and have had to use this to wrap the bolt carrier forward to get it to lock in place (not something I cherish doing with a live round stuck in the chamber) then manually cock the hammer reasseble everything and fire the rifle.

I am very very furstrated and about ready to use the upper as a tomato stake in the garden. Actually I was planning on polishing the chamber and pulling the extractor appart, polish lightly and see if there is anything hanging it up around the return spring.

Anyone got any other ideas. The gas adjustment has me really baffled. My first thought was timing but so many folks use H110 I would think this would not be the issue. The person I bought the upper from said he had no problems and I have the stock gas tube, I am considering putting that back in it and starting from scratch. I was told the upper was assembled by Model 1 Sales with the exception of changing out the gas tube...

HELP>>>>>>>>>

thanks,,
DonT