what velocity ammo are you using? replace the stock flash hider to make sure it's the can. Low velocity ammo might not be cycling the action with enough force. Make sure the spring screw is backed out even with the spring housing. (flush) :beer:
Go to M&P 15/22.com, they manufacture the barrel nut tool that slides around the barrel and reaches up inside the handguard and loosens the nut. The barrel must be clamped in a vise. Two hardwood blocks will protect the barrel, or aluminum blocks to hold the barrel can be bought for $55.00. DO NOT attempt to hold the arm by the upper or lower receiver, or the arm may be ruined. The Smith & Wesson website might offer the barrel tool also.
Welcome to the site! Your part of the country is sure beatiful, me and the bride spent a week in the White mts and crossed Maine to go puffin watching. Sure did enjoy it. Welcome again!
I believe ANY mil-spec stock will work, but the receiver extension is Umarex ONLY. The threaded nut is there for looks only, there is actually a screw holding the extension to the lower. Research this further..... :beer: the receiver extension cap comes off by removing the set screw on the bottom of the extension. Then you can reach down to the base of the lower and remove the screw.
Well my FRIENDS and I really do mean that I hope this Christmas season brings PEACE to you and yours. It is a big commercial holiday but the true meaning is peace and fellowship. The old Testament warned of God's vengeance but with the coming of Christ the world and its sinners were assured of His Love and Forgiveness. May the glow of God's Love fall over each and every one of you and yours during this holiday season. MERRY CHRISTMAS!!!!! ;D ;D