Major P.O.I. Change...

[BCB]

I just got back from my range and I am posting a pic of a couple of groups…

Yesterday this rifle was hitting approximately 2.5” high and dead center horizontally. At 50 yards…

Today it is shooting as shown in the pic. I did fire a few rounds at my silhouettes at 200 yards and certainly did not hit them..

So I fired a couple of rounds at 50 yards and a couple at 100 yards. Impact has changed unbelievable. 2 shots were fired at each range…

Would a barrel that is somewhat leaded cause this much change in impact, yet still allow potentially very acceptable groups?...

The rifle is an Encore with an 26” MGM 30-40 Krag barrel…

Any thoughts?...

Discouraging for sure…

Thanks…BCB

(I notice the pic needs rotated 90 degrees counterclockwise to be as it was oriented during the shooting)

[country gent]

Did you change the rest points any between the 2 days? leading may have an affect but I don't believe that much with out loosing accuracy too. Did you change pressure points on the rifle? More pressure or less will affect poi also.

[BCB]

Did you change the rest points any between the 2 days? leading may have an affect but I don't believe that much with out loosing accuracy too. Did you change pressure points on the rifle? More pressure or less will affect poi also.

I'm shooting from the same bench, same sandbags and nothing touched or moved on the rifle at all. Same rest and position on the bench...

I have never seen a situation that was this radical...

I do know, and it is just my opinion, that Contenders and Encores are very finicky, or at least that is what I have found. I have many many Contenders and barrels and have been shooting them for nearly 30 years...

Thanks...BCB

[BCB]

To eliminate the leading as a problem, I thoroughly cleaned the bore with solvent and J&B. The bore had zero point zero lead coloring in it at all--shiny as the day it was new...

Fired 3 rounds at 50 yards and superimposed them over the 2-shot group I previously posted and all 5 could be covered with a nickle. So, leading is not the issue...

I wonder if a ‘scope can change P.O.I. and then stay there for some time and then change again? I have adjusted this ‘scope several times as I was working up a load and it always shot good and then all of a sudden I couldn’t hit the groundhog silhouette at all at any range greater than 100 yards…

Of course with P.O.I. changing as noted in the pic, the silhouette would probably be safe at 75 yards!...

Always something…

BCB

[country gent]

Scope may be sticking or have play in it allowing it to continue moving thru vibrations and time. Try shooting the square with it. zero scope. up 10 clicks and left 10 clicks shoot group then down 20 clicks and shoot group, right 20 clicks and shoot group, up so clicks and shoot group, left 10 clicks and shot group then down 10 and shoot group. square should be square and 1st and last groups superimposed on top of each other.

[17nut]

Does it shoot straight with jacketed?
Reason i ask is because i have seen barrels with holes/bores that arent straight and that led to POI shift sideways on top of the usual vertical.

[BCB]

Does it shoot straight with jacketed?
Reason i ask is because i have seen barrels with holes/bores that arent straight and that led to POI shift sideways on top of the usual vertical.

I've never shoot jacketed out of it. I purchased the barrel strictly for cast boolits...

Exactly what do you mean by holes/bores?...

Thanks...BCB

[Bzcraig]

When I was at the range Wednesday I had an issue with a rifle not hitting a 9" paper plate @ 25yds! Pulled the bolt, bore sighted it, adjust scope, same out come. Frustrated! Repeated firing 11 rounds and gave up. Rifle shot fine last time I had it out before we moved. This one has a muzzle brake, so I checked it for any signs of lead, nothing there. I'll swap scopes next time out and hopefully eliminate the problem. Good luck.

[HeavyMetal]

check your scope mounts for tightness, then rings, it is possible the scope is bad but check these things first!

[ravelode]

Picked up a Savage 10F, with the factory installed scope, .223 for $125 [it was almost new] at a gun show. This was because the owner was frustrated by not being able to hit a paper plate at 50 yards from a bench with "match ammo". I took it home and checked it out. The front vertical split ring would move under finger pressure. Took the scope and ring/bases off and loctited the weaver style bases on. then put Weaver Quad rings (lapped of course) and my IOR 6x42 SSG on and took it to the range, that "darn worthless rifle" shot a 3 shot group under .5 inch at 100 with Hornaday 55 channelured spire points. It's my got to walking varmint rifle.

[BCB]

check your scope mounts for tightness, then rings, it is possible the scope is bad but check these things first!

I was planning on doing that, but I am still not certain that is the problem...

In the past when I would get a good zero, I could shoot dozens of rounds and all was good. Then, the P.O.I. would start to change until it finally became absurd...

I wonder if the base and/or rings being lose would allow for a good many shots that were O.K. and then suddenly make a mess of the P.O.I.

The cast loads I am shooting are very little recoil so maybe it takes a good many "jolts" for the 'scope to move? If that is the problem...

BCB

[Digital Dan]

Scope problems; 10:1 odds..........

[BCB]

Scope problems; 10:1 odds..........

So your saying there is a very very good chance it is the 'scope. I never really understood odds!!!

BCB

[Whitespider]

I agree that much change almost has to be the sighting equipment... 10:1.
*

[Digital Dan]

So your saying there is a very very good chance it is the 'scope. I never really understood odds!!!

BCB

No, I'm saying there is a very, very, very, very good chance.......

[RickinTN]

Most likely scope or bases/rings. Could be a scope that is "walking" which is not uncommon, mount system loose, also not uncommon, or a scope that responds to heat/temperature cycling. Think about hot or cold the rifle has been through since your last outing. Could it be a temperature sensitive scope?
Good Luck, and I hope you find it,
Rick

[Naporter]

Tight groups but major POI change makes a compelling case against the sighting system (whether it be irons or scope). Possibly loose, but the reticle inside could be damaged and is moving about. Cheap scopes are known to suffer the issue under stresses, even as minor as transport (or in the case of really cheap ones, recoil).

[runfiverun]

a single poi change that doesn't change again?

the front stock piece was not settled in, or your holding-resting the gun differently.

[BCB]

Well, it appears it likely could be the optics and the mounting system. The ‘scope is a Burris and I have had good luck with them—I probably own nearly a dozen of them without going and actually counting. The base is Redfield and uses the Redfield 3-ring system. I have this on other firearms and no problems…

I have been using the Fullfield II and on this firearm I went to the Timberline. Both have parallax adjustments and that is what I was looking for. I don’t know if I have another Fullfield II just setting on the shelf or not. I’m certainly not going to take one off of a firearm that is shooting well…

Maybe put the sandpaper to the forend as I think it touches the barrel. I don’t know if this should be the case or not. I have Boyd stocks on other T/C’s and have never sanded the inside of the forend at all…

I had similar problems with a factory 308 barrel and I finally gave up on it. I couldn’t get it to even shoot acceptable groups. At least the MGM shoots pretty good accuracy, but the P.O.I. changing is lousy. It is not predictable as to when it does it…

I wonder if the Encore frame could be part of the problem. What on a frame could cause these issues?...

Guess I’ll start by taking the mounting system off and grinding the base mount screws shorter, although it did this in the beginning. Then continue to work my way up to finally mounting another ‘scope. If this works, I still won’t know if it is the ‘scope on it now! I really hate to put the Timberline back on as I have burnt up hundreds of cast boolits and nearly 2 pounds of powder…

Almost too many variables to deal with…

Thanks…BCB

[BCB]

Checked all the screws in the mounting system and all were tight. So tight that I had to put a #15 torx in a ¼” drive ratchet to get them to snap loose…

Put an old Fullfield ‘scope I had on the dust shelf on the rifle and went to my range yesterday…

I had a limited number of reloaded rounds so I just fired ½ dozen and got the boolits on paper at 50 yards…

Came back home and put the info into Quick Target and it gave me the adjustment numbers for a 150 yard-zero…

Made adjustments at my range this morning and fired 2 rounds each at 100, 150, 200, 250 yards at groundhog silhouettes. All good hits by using the holdovers…

I realize that 8 or so rounds might not be enough to see if the P.O.I. is going to change again, but the accuracy is back—at least for now…

Maybe it was the Timberline ‘scope? Or, would that be too simple?...

Thanks…BCB