Mystery 06 accuracy issue

[coachk12]

My son has a Mossberg ATR 100 synthetic (no wise cracks please). We are trying to do some load development with 165 gr bullets for elk hunting. Son replaced the scope with a Nikon from a cheap Bushnell and Weaver rings with a one piece DNZ ring & base in the process. The gun has been shooting 1 1/4 groups routinely. Now all of a sudden the gun will shoot 2 rounds touching then flings the next round 2-3" out of the group. We went back to his old scope same results. My thoughts are to check the bedding, terminal clean the gun??? I'm lost other than that, tried different shooters same results..Gun has maybe 600 rounds through it???

Sent from my XT1635-01 using Tapatalk

[CritterGitter]

I'd check the torque on the bases, rings, and stock.

Sent from my Moto Z (2) using Tapatalk

[JeffreyDeGraff]

I'd check the torque on the bases, rings, and stock.

Sent from my Moto Z (2) using Tapatalk

Definitely the place to start. Check all the screws. If everything is tight, a thorough barrel cleaning may be in order ( excess copper fouling can cause accuracy issues). And one last thought, is there any way the crown could’ve gotten nicked or damaged, or even rusted?


Sent from my iPhone using Tapatalk

[JeffreyDeGraff]

One other thought I just had. You replaced the weaver bases with a one piece dnz. When you switched back to the old scope, Did you switch back to the old rings and bases too? Just a thought here, and may not hold any merit whatsoever, but if the holes in the receiver were not drilled straight or square, the strong dnz one piece base could potentially torque the action when tightened down. Maybe try switching back to the old bases and see if that helps any.


Sent from my iPhone using Tapatalk

[coachk12]

One other thought I just had. You replaced the weaver bases with a one piece dnz. When you switched back to the old scope, Did you switch back to the old rings and bases too? Just a thought here, and may not hold any merit whatsoever, but if the holes in the receiver were not drilled straight or square, the strong dnz one piece base could potentially torque the action when tightened down. Maybe try switching back to the old bases and see if that helps any.


Sent from my iPhone using Tapatalk

Hmm thought to ponder

Sent from my XT1635-01 using Tapatalk

[coachk12]

I'd check the torque on the bases, rings, and stock.

Sent from my Moto Z (2) using Tapatalk

I even used a tourque wrench on everything even the action screws...I'll use sweets on the bore

Sent from my XT1635-01 using Tapatalk

[JeffreyDeGraff]

I’m curious as to what it is. Please keep us posted.


Sent from my iPhone using Tapatalk

[coachk12]

I’m curious as to what it is. Please keep us posted.


Sent from my iPhone using Tapatalk

I figure it out I'll do that...

Sent from my XT1635-01 using Tapatalk

[4jorgies]

Is it throwing the third shot the same direction every time?

Is it a new load that could be causing the barrel to heat up faster?

Are you loading one round at a time? Recoil could be Jarring the third round enough to change your seating depth.

Sent from my SAMSUNG-SM-G890A using Tapatalk

[4jorgies]

Another question

Does the POI for the first 2 shots stay consistent between groups or is it moving around?

Sent from my SAMSUNG-SM-G890A using Tapatalk