Bad scope?

stoggie

stoggie

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Hello everyone. I'm trying to sight in a new rifle with some home loads, and seem to have a 12" grouping at 100 yards. Its the oddest thing and I have never experienced such a thing. The rifle is a new Mossberg Patriot in .243 that came with a "Dead Ringer" 3-9x40 scope.

I'm wondering if the scope is readjusting itself after each shot. From my point of aim, I can have one bullet go 6" high and 3" left, the next 6" low and 2" left, and the third 1" high and 5" right. I've tried the scope zoomed in to 9, and pulled back to 5, same result.

The first question is: is it me? I've had bad days at the range, but never like this. On a good day I can pull off a tight 1" group with my Sako 7mm Rem Mag. I would suggest a 12" group seated off a table with bipod is highly unlikely for me.

Ammo? These are home loads that work very well in another .243 rifle that can also pull off a tight group at 100. Maybe this rifle doesn't like these bullets, but I would expect some consistency.

Everything on the rifle is nice and tight. Double-checked all screws/mounts, and the barrel is nicely free-floated.

Has anyone experienced something like this? Before I shell out a wad of cash for a new scope - any suggestions?
 
Scope re-adjusting itself - sure sounds possible - that the reticle is being bounced around inside, as a result of recoil. I have never used bipods - I only use sandbags - had read that bipods come with their own "issues" - purely guessing - as per above - a ding in muzzle might explain, a spare "known to be good" scope, or a few shots from sandbags might show different results? Always a challenge to find cause when all new-to-you outfit does not perform - rifle, scope, rings, barrel, muzzle, etc. all possibilities.

You said that you "double checked" that all screws are tight - including the scope base mounting screws? Rifle's action screws?

Won't be comforting to you, but I bought a "dud" from guy here on CGN - and he had found what both he and I think is the issue already - groove diameter in barrel was cut about .005" larger than the bullet size for that cartridge - 4" 3 shot groups at 25 yards, with multiple hand loads and several factory ammo. So went through a lot of possible "reasons", before that bore got slugged to find a glaring "error"... Was a rifle from 1950's - hard to imagine someone had been hunting with it all those years... Rifle had been tried with scope, with a second scope, with iron sights, with different scope bases, and so on - nothing changed much in performance. Last hope - not yet tried - all test were done with jacketed rear end bullets - going to try some Partitions and see if the open "rear end" might swell up to fill that "gap".

Just looked it up - apparently Mossberg Patriot does not have iron sights - was going to suggest to remove scope and try at 25 yards with irons - should be able to get 2 holes touching, even with irons - but does not appear as an option for you.
 
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Best is to put another scope on it. Test at 50 yards.
What is the twist on your gun ? Shooting a too light bullet in fast twist can make it to come apart or give you that kind of results.
A heavy bullet in a slow twist will not stabilise and also give you the same.
Try a box of commercial ammo in the mid weight for .243 to remove that variable.
 
Never heard of a "Dead Ringer" scope but if it came with the gun as part of a package, the quality on package gun scopes tends to be complete garbage.

My first steps would be to pull the rings and scope mounts off, clean and degrease the threads, re-install the base(s) with blue thread locker and a torque wrench, then rings (no thread locker), then check for level (making sure the bottom of the rings are the same height). Align and reinstall the scope. Bore sight it to get you on paper.

Set up a target at 50m instead of 100 and try some cheap hunting ammo. 3 shots with a minute between each should be fine to gauge POI. If it shoots fine, your gun doesn't like your reloads. If it doesn't shoot well, I would try a different scope, then call Mossberg (either to replace the scope or RMA the rifle).
 
Mossberg is not known for good rifles, only mediocre shotguns, so a package deal of a rifle and scope combo from Mossberg is not likely going to have decent glass. A buddy of mine got sucked in to a Mossberg rifle combo. It may or may not have been the same scope with which you are dealing, but it was complete junk. Even after testing the rifle with one of my spare Leupolds the rifle still only turned out a 4 inch grouping.

If you already have a Sako, ditch the Mossberg and save yourself the disappointment. Even a low end Sako is way ahead of anything Mossberg turns out.
 
I would try to feed some alternate ammo through it. If that doesnt work, remove the scope, place it at 20 yards and then blast it with a 12 gauge. From my experience if a rifle comes as a package deal with a scope, the scope is not going to be great. I took the scope that came with my sako and through it on a 10/22.
 
Thank you for all the advice everyone!

The rifle in question is the Mossberg Patriot Youth: https://www.mossberg.com/product/mossberg-patriot-youth-super-bantam-scoped-combo-28142/

The specs say it is a 20" with a 1:10 twist, and the crown looks perfectly fine. I don't see any anomalies in the barrel. The rifle is for my 15 year old daughter who wants to try deer hunting this fall. Hopefully we can get this down to a 2 or 3" group so she can have some confidence in deer hunting.

A friend of mine has a known good scope I can borrow. I will put that one and try again with some factory ammo to see what I can pull off.

Thanks again!
 
Duncan Idaho said:
Mossberg is not known for good rifles, only mediocre shotguns, so a package deal of a rifle and scope combo from Mossberg is not likely going to have decent glass. A buddy of mine got sucked in to a Mossberg rifle combo. It may or may not have been the same scope with which you are dealing, but it was complete junk. Even after testing the rifle with one of my spare Leupolds the rifle still only turned out a 4 inch grouping.

If you already have a Sako, ditch the Mossberg and save yourself the disappointment. Even a low end Sako is way ahead of anything Mossberg turns out.
Click to expand...

While a Mossberg will never be a Sako, the Patriots do get a lot of good reviews on line as do many other current entry level rifles that do turn out some very good groups.

I'd ditch the scope and go with a better one while checking the R&B as well.

Which Mossberg rifle did your buddy buy?
 
Honestly the patriot is a far better rifle than the credit it’s given will indicate. Sure, they took some of the cost savings design shortcuts that many manufacturers do but that’s reflected in the price. In my experience, they’re superior in both design and manufacture to a savage axis or ruger American.

I’d bet good money the issues is somewhere above the receiver. Bases, rings, scope.
 
Update - it was definitely the scope!

I replaced it with a friends spare Bausch and Lomb scope and it holds a group nicely. I only tested at 50 yards, but was able to pull off a some tight groupings with factory and home made ammo. I have a Leupold VX2 coming from a fellow CGNer, so I will get the rifle sighted in proper this summer.

Has anyone used the Talley one piece mounts/rings?
 
stoggie said:
Update - it was definitely the scope!

I replaced it with a friends spare Bausch and Lomb scope and it holds a group nicely. I only tested at 50 yards, but was able to pull off a some tight groupings with factory and home made ammo. I have a Leupold VX2 coming from a fellow CGNer, so I will get the rifle sighted in proper this summer.

Has anyone used the Talley one piece mounts/rings?
Click to expand...

Prob on my 50 + set now - I LOVE the LW 1 piece Talley rings - bases ! RJ
 
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