I have had a Bushmaster Predator for approx. 2 years. I do my own reloading for it and use the following load: 25gr of H335 with a 55gr V-Max. I have had numerous problems with the gun missing the next round out of the magazine after I have fired a round. I will shoot and the round will get ejected and then I will pull the trigger again for the next shot and no round will be in the chamber. I have tried 3 different mags wondering if it the magazine's fault and they all have the same problem. It seems like the problem gets worse when the gun gets dirty so I'll clean it and it definately gets better but still misses appros 1 in 10-15 rounds when it's clean. When it's dirtier (but definately not extremely dirty, maybe 50-100 rounds through the gun) I've seen it miss every other round to 1 in 3 rounds. People have told me to check the gas tube which I did the last time I had it completely disassembled and it seemed to be open. I did not remove the tube but took a pipe cleaner and shoved it up as far as I could and it seemed to be open. I've also been told that I should be using a small base resizing die when sizing the brass, which I don't have yet. I have noticed it will miss the rounds on once used brass (that has been full length sized before being reloaded) and brand new brass that's been reloaded. This makes me wonder if it's really the brass's fault and makes me question if I need a SB die. I questioned someone... is it possible that my brass is under loaded with powder and doesn't have enough power to push the action back after a shot and he said he didn't think so. My Nosler manual says that 25gr of H335 with a 55gr bullet is the max load so I don't think that is the problem either. Anyways if there is any advice from anyone on what I could try next I would greatly appreciate it cause I'm just about ready to send the gun back to Bushmaster and see if there is a factory defect in it. Thanks to all! Chech P.S. My brother has a Bushmaster Target rifle (SS barrel) that he purchased approximately the same time I bought mine and with the exact same load his rifle performs flawlessly.
If the ammo worked for two years and now it does not, I would likely rule it out. Try some factory ammo to be sure. Your rifle has a free float forend, I presume? It sounds like the action is short cycling. You need to look at the gas tube where it connects with the front sight base/gas block. Look for carbon build up on the exterior of the tube indicative of a gas leak. If you see much carbon on the tube, replace the tube. Clean the inside of the tube by flooding it from the receiver end with a good solvent like Shooters Choice. Stand the rifle up on the muzzle and dribble solvent into the tube. Get some of the special long pipe cleaners made to clean AR gas tubes. Soak an hour or so then swab out the tube. If the pipe cleaner comes out green, you may want to consider removing it and cleaning it more thoroughly. Check the bolt carrier group. Make sure the gas key is tight. The allen screws can loosen when not properly staked. Torque is 40 INCH/pounds. Check that you do not have a broken or missing gas ring. Position of the gaps is NOT important (contrary to urban legend). Remove and clean the gas rings and their groove. Leave them dry. You may consider replacing them as they have a life expectancy of about 3000 rds. Finally check the buffer, spring and retainer. Make sure they are not binding. Remove buffer and spring. clean the tube looking carefully for debris. Your load sounds very reasonable. I doubt a small base sizer die is needed.
robocop, I should have clarified that this rifle has what I would call "short cycling/stroking" from the day I purchased it. It has been suggested that first off to try and lube it good. I have lacked on lube cause I thought it would just attract dirt/grime. I would also try some factory ammo to rule out that possibility also. I was hoping that I wouldn't have to do this cause some of my rounds I've reloaded are new brass which to me should be the same as factory ammo. After these two simple things to try if it still doesn't take care of the problem, I will dig deeper and try some of your suggestions. This gun has fired approx. 500 rounds through it so nothing should be worn unless the problem is a factory defect. Thanks so far!
I purchased this rifle brand new. I have completely disassembled this rifle's action clear down to the firing pin numerous times to clean it. As far as the gas tube I have not removed it to thoroughly clean it. I did push a pipe cleaner part way up the tube to see if it was obstructed in any way and I didn't notice anything. Although I don't think I made it clear up to the barrel port. I've been informed that there is a specific gas tube cleaning kit/rod available to clean this. Is this true and can someone steer me in the direction where to find one (i.e. Cabelas, MidwayUSA, etc.)? Thanks!
