In my post a couple of weeks ago I showed you groups with the .50 GM/LRH Renegade that were an inch or less wide, but three to five inches high. ( http://huntingnet.com/forum/black-po...-renegade.html )

Those groups were with 300 grain Gold Dots and Triple Seven. I couldn't figure out why I was getting that vertical stringing.

Whenever I have a grouping problem I give GOEX a try, as I always seem to be able to find a GOEX load that will shoot well. So Friday afternoon I gave it another try, but with 250 grain XTPs and GOEX.

The two targets below are typical of what I got in the shooting session. One group is only 5/8" wide, the other has four shots that are 1/4" wide. But the groups are really strung out vertically.

If any of you guys have any ideas or suggestions, I'm willing to try about anything. I'm convinced those narrow groups are telling me this gun will shoot one-inch 100 yard groups if only I can solve the vertical stringing problem.

Shooting procedure:

- Shot #1 on the first target was from a fully clean dry bore, after that the bore was wiped with both sides of two fairly wet alcohol patches between every shot, followed by two sides of a dry patch.

- A stop collar was used on the loading rod and set so that the load was compressed 1/8" each time. There was no variable there.

- The forestock and buttstock were placed at the same spots on the bags each time.

- The gun was not held with the left hand.

- I paid particular attention to gripping the wrist with the same amount of tension with my right hand, and holding the butt against my shoulder with the same amount of pressure - snug, but not tight.

- The sight picture and trigger action felt good for every shot and I concentrated on "follow through" to the extent that I know the crosshairs were on target as each shot went off.

The barrel wedge on this gun is easily removed with finger pressure. I began to suspect some sort of bedding issue. So I shimmed the underside of the barrel with a double layer of duct tape for the second target. That made the barrel really snug in the stock, but didn't have any effect on groups.

Was the barrel heating up? I have noticed on smokeless rifles that if the barrel heats up that it will make those 'heat waves' rise up in front of the scope and will change the site picture in the scope. You will be aiming at a point that really doesn't exist where you are seeing it. I have never had this problem in a ML though because the barrel usually has time to cool off during the reload process. I know it sounds dumb, but I have experienced it before in CF rifles when I am shooting 5 shot groups and don't allow enough cool down time. With the exception of shots 3 and 4 being swapped in the groups, they seem pretty consistent in the order and placement. Is it possible you have actual scope issues?

I see these are targets 15 and 17. What did 16 look like?

Looks like you did slightly better with your glasses on.

On the bright side though, at least the first shot was on for both groups. Spells dead deer to me.

By looking at your targets I don't think it is the gun or the load. Most of your shots are are in the 1inch range from center of bull to the left. But the elevation is all over the place tells me it is not the gun or load if it were you would see not just up and down but side to side as well I think the problem is in the scope or mounts

Maybe try a touch of shim at the breech end of the barrel if there is room? Make it a bit more snug at the hook?

Like Underclock said a sloppy hookup or a sloppy wedge can cause that problem.
Normally a vertical string is caused by the wrong amount of powder, but what you are showing indicates a mechanical problem. Lee

You're an astute observer MO Archer. Target 16 is below. It's not as extreme as the other two, but the stringing problem is still apparent. I was shooting with my glasses on, and got to wondering if something having to do with how I was seeing the scope reticule through the glasses was causing the problem. So I shot #16 without the glasses.

You might be right Sproket. It's pretty clear it's not the load because I had the same results with a completely different load in the range session two weeks ago. When 105 grains of T7 under a 300 grain bullet and 95 grains of GOEX under a 250 grain bullet produce the same stringing results, you have to figure it's not the load. Actually, I would be happy to find it's a scope/mount problem.

UC / Lee, I shimmed it with duct tape right in front of the wedge pin. Didn't think to try a shim near the hook. The first thing I checked was the tang, because I've seen loose tang screws cause grouping problems on a buddy's gun. But the tang was good and tight and barrel fit at the breech is about a tight as it could be.

It sure does seem to be a mechanical problem. I guess I'll have to try shimming different spots on the barrel. The only other thing I can think of is to go with Sproket's theory and pull the scope and bases and re-mount them (man, I hate doing that), or try the iron sights, or mount a different scope.

Usually when I have a scope go bad it doesn't do that. They fly all over the place. One trick that I was told once was after you shot a group take a handle of a screwdriver or something similiar and tap on the scope. Then reshoot a group. If the bullets are all over or shooting a different group, then the scope is bad. If you shoot that same, then the scope is good. Maybe mounts then? But I've never had mounts go bad.

I've seen vertical stringing from the scope slipping in the rings. Doesn't take much movement of the scope for the next shot to be way off. Other than that, don't know what to tell ya. Looks like it really wants to shoot, though. Good luck.

Man, I am a DUMB A$$! I just realized that I had two other Renegades in the truck when I was shooting last Friday, and could easily have tried that barrel in another stock. Why I haven't thought of that before now I can't say - tunnel vision I guess.

So here's the plan for the next range session.

1. Shoot a five shot group with everything "as is" for a base line.

2. Put the barrel in another stock and shoot another five shot group with the same load.

3. If nothing changes, replace the scope with a 3x9 Tasco that I have sitting in the closet and shoot another five shot group with the same load.

4. If still nothing changes, remove the scope and mounts and shoot another five shot group with iron sights and the same load.

Maybe something good will happen somewhere along the way.

I use one renegade for all my change over barrels. Also I noticed with one barrel, my .45 caliber stainless steel LRH it was a loose fit. So I chalked the barrel and put it in the stock and locked it down. After that I examined it and saw there were points touching the wood and points that were not...



see the yellow duct tape poking out of the wood.. these were loose spots. Whether it helped my rifle's accuracy or not, I can not swear, but it did make mine shoot a tight group. I also put one layer of duct tape inside the wedge lock on the barrel just to keep the wedge pin extra tight.