ORIGINAL: New York Hunter
I put my fathers 11-87 20 ga. together and shot it today for the first time. It has a 21 inch fully rifled barrel with the cantilever scope mount. A Nikon 2-7x32mm Prostaff Shotgun Scope mounted in Leupold PRW low rings. As I do with my 11-87 12 ga., I tighten the barrel nut as tight as I can get it with my hand and then I put a piece of nylon around it and I tighten it one more click with pair of channel locks. The gun was clean and the barrel was dry. I was shooting with both the front fore-end and rear stock resting on sand bags.
I shot at 25 yards first to make sure I was on paper. The first round hit about 4 inches low and two inches to the left. I adjusted the elevation and my next shot was about two inches high and still 2 inches to the left, right where expected it would be.
Then I move to 100 yards. My first shot was about five inches high and about four inches to the left. I then made both elevation and windage adjustments to bring my group to the center of the target where I was aiming. I fired two more shots and I couldn't believe it. All over the place. The first shot was about 8 inches high, the next shot was about three inches low. Both shots stayed to the left. All my shots at this point were with Hornady SST slugs. I then tried a few Winchester Partition Golds and a few Remington Core Lokt Ultra slugs. I got the same results.
I was extremely p*ssed off. As I always do I took out my Remington 700 Classic in 280 Rem. and fired a four shot group at 100 yards that was about an inch and a half. I then fired one shot at a 8 inch steel plate hanging at 200 yards.....ping and it rocked back and forth.
I'm getting similar groups with my 11-87 12 ga. That problem is more of a scope problem. I took my Leupold off of it and I can hear and feel something moving around inside when I shake it back and forth by my ear. It's even more apparent when the scope is turned all the way down to 2 power. Leupold told me I shouldn't hear anything and I sent it back.
This 20 ga. is killing me though. Right before I left the range and the 20 ga. had cooled down for about 20 minutes, it was about 40° out, the gun was stone cold, as cold as the steel chair I was sitting on. I fired my last three shots at 50 yards. I moved on the first shot, the next two shot were touching. The whole group was about three inches. Again I moved on the first shot. I'd like to think that my problem might be the barrel getting to warm. I'm really not sure about this either though. My first couple of shots at 100 yards were after the gun had cooled down for a while.
I was really hoping that both our shotguns would shoot the higher velocity slugs 1900 to 2000 fps slugs. I'll take all advise I can get. I'm leaving for hunting camp Friday the 17th. I'll probably only get to go to the range one more time before Friday.
I'm also going to try Lightfield slugs. I just got off the phone with a friend of mine. He knows a few guys that just couldn't get the 1900 plus fps slugs to shoot out of their guns. They went with slower velocity slugs and now they shoot great. I had a 870 12 ga. that would group Lightfields under 3 inches at 100 yards. Suddenly I regret selling that gun!
I certainly could be wrong about this, but it is possible that the problem is due to over-torquing the barrel nut so that when the barrel gets hot, things expand and relax to the point that the barrel starts pointing somewhere else than it did when cold. Try it again with the barrel nut just hand-tight, and see what happens.
An alternative would be to let the barrel get completely cooled off before firing the next shot. This might be better anyway, since it is generally where the first shot from a cold, clean barrel goes that determines if you will be eating venison or tail feathers!