new rifle break in question.

[brushog65]

I have a new rws 48. I'm shooting jsb .177 heavies 10.34gr. I sighted it in last Friday and it shoots great groups at 35 yards. Then I noticed over the next 50-75 shots it started shooting lower and lower. It will still shoot great groups, just 2 inches low. I adjusted the scope up and its dead on again. Is this normal for a new rifle?,or could I have a scope problem?

[Booger]

I have a new rws 48. I'm shooting jsb .177 heavies 10.34gr. I sighted it in last Friday and it shoots great groups at 35 yards. Then I noticed over the next 50-75 shots it started shooting lower and lower. It will still shoot great groups, just 2 inches low. I adjusted the scope up and its dead on again. Is this normal for a new rifle?,or could I have a scope problem?

Check all of your screws in the rifle & scope. Then loctite (Blue) them and let it cure overnight.

[BenjiHunter]

Maybe the heavy pellet has something to do with it.

[brushog65]

Those are the only pellets I have ever shot out of it. I didn't go from a light pellet to a heavy pellet. That's what confused me I didn't change anything it just started shooting low.

[palonej]

Which scope do you have on the rifle??

[Booger]

Which scope do you have on the rifle??

I heard the 48 is a scope killer. That is why I suggested tightening the screws first.

[brushog65]

I have a center point on it. I have heard this rifle is hard on scopes. I guess if it moves again I will start looking for a different scope maybe. I have a center point on my big cat that works great. I didn't think there was a rifle any rougher on one then that thing.

[Booger]

I have a center point on it. I have heard this rifle is hard on scopes. I guess if it moves again I will start looking for a different scope maybe. I have a center point on my big cat that works great. I didn't think there was a rifle any rougher on one then that thing.

The only time a CP scope worked for me was on my Disco, springers destroyed my other two. Hawke makes a fine scope.

[brushog65]

Thanks, I will look at the Hawke line.

[longhunter]

You may have picked up some velocity due to the gun breaking in. That would account for the lower poi.

[brushog65]

I thought with a higher velocity, the poi would be higher not lower.

[lizzie]

My first thought is that it could be scope movement.

[longhunter]

I thought with a higher velocity, the poi would be higher not lower.

Hegher velocity equals flatter trajectory equals lower poi.

[brushog65]

That makes sense. Thanks for explaining it. I hope thats the case. I don't have a chrono yet.

[jfrey]

How many shots went through the rifle before the groups started moving down?     If it was 50 or less it may have been dieseling some right out of the box and now that the pellets are moving slower they are hitting the target lower.       As long as the groups aren't getting any bigger I wouldn't worry too much unless your scope is starting to run out of vertical adjustment.     

[brushog65]

I would say it was 50 to 75 shots. I would have expected the speed to get better as it broke in not slower, but I don't have a lot of experience with spring guns.

[mobilehomer]

Actually, higher velocity means that the pellet stays in the barrel for a shorter time. This results in the pellet being gone before full barrel climb from recoil. Slower is affected more by recoil, thus higher POI.

[Bullit]

Keep shooting it, finish the tin of pellets...and then clean the barrel again.  Assuming you cleaned the barrel, before you started.  Don't worry about the scope settings until you've got some of the 2nd tin of pellets lead down the barrel.  Many don't mount a scope, until the gun has settled in.   You'll enjoy your new rifle

[palonej]

^ +1.
Don't worry too much about groups or pinpoint accuracy yet. Get lots of lead down the tube first....then check out some different pellets!
Enjoy