[barrington]

This phenomenon occurred with my PTR but I'm posting it as it might be a common issue. Anyway I bought a new PTR GI. I shoot some 2.5 inch 100 yard groups. The rifle was shipped with a BW hand guard which is worn loose enough at the receiver end to move almost an 1/8" up and down. Side to side its 1/32 or so. I installed a newish BW 1997 hand guard which fit so tight I had to tamp in the pin with a piece of wood. My groups opened up to about 5". I relieved some of the plastic and aluminum at the muzzle end to clear the barrel all around. still no better so I sanded a bit at the receiver end to shorten it over all so I could put the pin in with finger pressure although hand guard still fits snugly. Now its groups tightened up a little but as I shot the center of groups move about 5" across the target. So I put the beat up loose hand guard back on and presto I am centered with a nice group aligned right down the middle of the bulls eye.

 

[Steve_in_29]

Anything that puts stress (sideways, up/down, etc) on the barrel is going to affect accuracy/POI.

 

[eodinert]

The barrel is completely free floated, and doesn't touch the hand guard anywhere... unless your rifle isn't made right.

 

[Rokchukrslave]

The barrel is completely free floated, and doesn't touch the hand guard anywhere... unless your rifle isn't made right.

This. Maybe the cocking tube is not centered in the triple frame and the extra pressure from the new handguard is pulling it into the ring somewhere?

 

[Conelrad]

Get a cheap surplus slimline forend and see how it works.

Dennis

 

[Kisara]

Help me out- What does "BW" mean?

 

[Rokchukrslave]

Bundeswehr. Meaning slimline.

 

[Conelrad]

In that case, your gun may be welded crooked...

Dennis

 

[Axxion89]

If you have the gun sandbagged or in a rest, the handguard might be defective in some way that its crooked or when you forced the pin in, warped the handguard so that its no consistent. I have a hard time believing its anything with the gun mechanics. Maybe its just something mental about the handguard, who knows. Try other handguards or shoot without it & see what the results are