Slug barrel sights

[Sonofagun]

I just received a combo barrel 930:

http://www.mossberg.com/product/sho...29,2431,2432&redirect=1&filterNodes=2431,2432

Let me say that this is the first that I've shot sabots through a rifled barrel and didn't have good results. The front sight was centered in the rear sight and even with the notch in the rear sight. With a "bullseye hold" the first shot was 2" high and 2" to the right. I loosened the top screw to adjust the windage and it moved so easily that it almost fell out. The 2nd shot was almost on top of the 1st shot so I moved the rear sight to the left.

After 4 shots the windage adjustment was steadily moved to the left but it really didn't move the impact as far as I thought it would. A 6 o'clock hold got me very close to the bullseye so the elevation screw wasn't touched.

Maybe my expectations were too high in thinking that this setup was going to shoot just as good as a rifle?

With the price of sabots being so high does anyone have any ideas that might help me with getting more proficient with this slug barrel on the 930?

FYI the barrel(s) and gun were cleaned before shooting. I thought I did a good enough job cleaning the bolt, action, etc. without taking out the trigger group. The gun was striped down at the end of the shooting session and there were some areas that had the red assembly lube on them.

 

[Sonofagun]

This is an update on the slug barrel sights. After firing 20 sabot rounds I was perplexed to the holes in the target. Rounds were all over the place (50 yards) so I decided to do a field strip and good cleaning.

When I cleaned the barrel the first time (before firing) it was with Hoppes 9 and a bore brush. This time I decided to run a patch with some CB Gun Scrubber. The exterior of the barrel was covered in oil and left the patch in the bore for ~10 minutes while I took the bolt, trigger group, and action apart to clean. The bolt, trigger group, and action weren't too bad so the wear areas on bolt and action were lightly greased with Tetra gun grease. The trigger group was sprayed down with Rem oil and lightly wiped down.

Going back to the barrel the patch came out black. A 12 gauge cotton swab was doused heavily sprayed with the CB Gun Scrubber, passed through the barrel once and then run through again until it was just coming out the end of the barrel. The CB Gun Scrubber cleaned the barrel pretty good so I then ran the wire brush with Hoppes 9 through the barrel ~10 times. A wet patch with Hoppes 9 was still coming out black so it was another round of the wire brush and Hoppes 9. After 8 patches the bore was starting to get a lot better. A light oiling of Hoppes oil in the barrel and it was time to put the shotgun back together.

The shotgun was assembled and when I was wiping it down I noticed that the elevation ramp was moving a little while vigorously wiping the sight. I tightened the elevation and windage screws just to make sure they wouldn't come loose on the next trip to the range.

The next trip to the range I had much better results. I had to change the elevation (too high) but during the sighting in session the gun was capable of consistently getting rounds in the red.

To anyone else getting a new Mossberg 930 slug gun make sure to:
1) clean it REAL GOOD. I thought I did a good job the first time without taking out the trigger group but found some of the red assembly lube around the elevator and the action when it was field stripped for the 2nd cleaning.

2) clean the slug barrel even better - the CB Gun Scrubber really got a lot of junk after the first trip to the range, just be careful while using it as the CB Gun Scrubber can ruin some finishes,

3) when you need to make sight adjustments just use enough force to get tension off of the sight - if you unscrew the sights too much they will slide very easily.

4) when you tighten down the sights adjustment screws don't be afraid to torque down on them with a good screwdriver - you might want to do this before you shoot the gun because I never messed with mine and it was loose enough to move after firing the gun

 

[MikeD]

Good advise and glad you got it figured out.

I have a slug barrel on my 835 but I do not use the sights I have a scope mounted to the receiver. I think shotgun barrels are very susceptible to accuracy problems as a result of fouling because the rifling is not as deep as you find on most rifles and the plastic sabot is not as resistant as a copper jacket.. I have no research to back this up, just observation.