AP20 POI low and inconsistent

[DaveBeal]

I'm a new air gun shooter; the Hammerli AP20 is my first air gun. I've had it for a couple months with about 2000 rounds through it and it seems to be getting less accurate the more I shoot it. With the butt of the gun on sandbags, its point of impact is low and inconsistent (varies more than an inch vertically at about 20 feet), even with the rear sight as high and as far forward as possible. Horizontal point of impact is good and consistent, so I don't think it's me. The gauge that came with it indicates that the pressure in its tank is at least 100 bar. I have no way to measure muzzle velocity. Any ideas what's wrong? Thanks!

[DaveBeal]

Even though the gauge said 115 bar, I refilled the tank and tried a few more shots. The first two didn't even make it to the paper at 20 feet. The third stuck in the barrel.

Maybe I was overzealous in putting silicone grease on the air tank fitting, and it got into the chamber?

So what's the procedure for removing a stuck pellet from a barrel? Thanks.

[Rover]

Send the whole gun to Pilkington with a note saying, "Buck, help please."

[Gwhite]

Even though the gauge said 115 bar, I refilled the tank and tried a few more shots. The first two didn't even make it to the paper at 20 feet. The third stuck in the barrel.

Maybe I was overzealous in putting silicone grease on the air tank fitting, and it got into the chamber?

So what's the procedure for removing a stuck pellet from a barrel? Thanks.

You can buy small wooden dowels at hardware or craft stores. Push the pellet out slowly, don't hammer on it. You don't want to expand the pellet and make it even harder to remove.

It sounds like your regulator is flaky. That's generally a job for a factory trained repair facility. The only other possibility I can think of is that the velocity adjustment (if it has one) has backed all the way out. That might be something you can fix.

[kevinweiho]

Did you try shooting the pistol a couple of times without a pellet to hear the sound of the report? If there was excess silicone grease in the chamber/valve, it’ll help clearing some of it out. As for the stuck pellet, you can also use a bamboo skewer.

[DaveBeal]

Did you try shooting the pistol a couple of times without a pellet to hear the sound of the report? If there was excess silicone grease in the chamber/valve, it’ll help clearing some of it out. As for the stuck pellet, you can also use a bamboo skewer.

Thanks, Kevin. Yes, I did try that and the shots sounded normal to me. That was just before I fired the three unsuccessful shots described in my second post.

[DaveBeal]

Even though the gauge said 115 bar, I refilled the tank and tried a few more shots. The first two didn't even make it to the paper at 20 feet. The third stuck in the barrel.

Maybe I was overzealous in putting silicone grease on the air tank fitting, and it got into the chamber?

So what's the procedure for removing a stuck pellet from a barrel? Thanks.

You can buy small wooden dowels at hardware or craft stores. Push the pellet out slowly, don't hammer on it. You don't want to expand the pellet and make it even harder to remove.

It sounds like your regulator is flaky. That's generally a job for a factory trained repair facility. The only other possibility I can think of is that the velocity adjustment (if it has one) has backed all the way out. That might be something you can fix.

Thanks, Gwhite. The owner's manual doesn't mention a velocity adjustment. I think the gun is going back to the dealer or manufacturer.

[DaveBeal]

Just to follow up on this, I sent the gun back to Umarex. Got it back about 10 days later and it now shoots great. No indication of what was wrong; the invoice just says "Repair Product" and "Adjusted velocity to 495 fps". No charge; it was under warranty.