My Crown Continuum seems grumpy

[saitama]

This past Sunday, I took the Crown Continuum to the range with my Impact M3.
I shot 50m with the Impact earlier and confirmed that it was a very good group.
Then I shot 50m with Crown.

Oh my god!
There was almost no wind, but the bullets were scattered about the size of a fist.
Changing the bullet velocity did not change the result.
After I got home, I removed the barrel, cleaned it, and replaced the o-rings.
Adjusted the position of the superlight barrel spacers with reference to AEAC.
And finally, I prayed that he would make me feel better.
I will test again next week.

My Crown Continuum
.22 500mm barrel
reg 140bar 910fps
JSB 18gr pellet

 

[nervoustrig]

Was it a tin of 18.1gr known to group well in that specific rifle?

Also, is the 140 bar regulator setpoint necessary to move the 18.1gr at 910fps? Seems kinda high for a 500mm barrel unless the porting is somewhat anemic. I would have guessed something closer to 110 bar.

 

[pesty3782]

My 22 crown shooting the 18 grainers like 880....When I got near 900 they would not group very well so back to 880. At 880 if the group opens up it is a dirty barrel. My reg is set at 140.

Tony P.

 

[douger]

i thought same thing 140 seemed high foor a 500mm if i remember my 380 was like 130 was shooting 18gr at 910 or so

 

[saitama]

Was it a tin of 18.1gr known to group well in that specific rifle?

Also, is the 140 bar regulator setpoint necessary to move the 18.1gr at 910fps? Seems kinda high for a 500mm barrel unless the porting is somewhat anemic. I would have guessed something closer to 110 bar.

The bullets commonly available in my country are JSB 16gr or 18gr.
I tried both when I bought them. The best at that time was 18gr.
Next, try lowering the Reg pressure a little more.

Thank You

 

[saitama]

My 22 crown shooting the 18 grainers like 880....When I got near 900 they would not group very well so back to 880. At 880 if the group opens up it is a dirty barrel. My reg is set at 140.

Tony P.

According to your opinion, my settings seem a little too high for the projectile speed.
Lower it more and try again.
Thank you

 

[saitama]

i thought same thing 140 seemed high foor a 500mm if i remember my 380 was like 130 was shooting 18gr at 910 or so

Apparently the Reg pressure is high, and it seems necessary to lower the bullet speed.
I assumed the pellet velocity was correct as I was doing well with similar bullet velocities on the Impact M3.
Thank You

 

[woogie_man]

You didn't happen to bump your transferport restrictor did you?

 

[saitama]

You didn't happen to bump your transferport restrictor did you?

I think there is no problem.
It takes 2 hours to drive to the shooting range, but I put it in a case to avoid unnecessary shocks.

 

[tcarlson777]

I hope it was just a dirty barrel. Good luck with your test later on this week.

 

[nervoustrig]

The bullets commonly available in my country are JSB 16gr or 18gr.
I tried both when I bought them. The best at that time was 18gr.

My question may not have been clear enough. I was asking if that exact tin of 18gr pellets is known to have grouped well previously in your Crown Continuum.

Tins purchased at different times can have vastly different performance…something that has always been true but it seems especially so in recent months based on user reports that seem indicative of a quality decline.

 

[saitama]

My question may not have been clear enough. I was asking if that exact tin of 18gr pellets is known to have grouped well previously in your Crown Continuum.

Tins purchased at different times can have vastly different performance…something that has always been true but it seems especially so in recent months based on user reports that seem indicative of a quality decline.

I understand what you mean. The cans themselves are different, but the same lot number.
All the ones I bought this year had the same lot number.
num:58560021

I haven't had any issues this spring/summer.

 

[nervoustrig]

Got it, yes the lot code answers my question. I didn’t want to phrase it that way because I haven’t seen lot codes on JSB tins in years here in the states.

 

[Feinwerk]

Hello @saitama ,
It's hard to decide what needs to be done until you get a chance to shoot again after your cleaning and o-ring replacement. In the meantime, you could check tightness of all your screws, especially for whatever optic or other sights you are using. I am assuming that it used to group just fine and now suddenly it's not grouping well? Check some of the simple things first. I think the cleaning was an appropriate first thing to do.

Good Luck,
Feinwerk

 

[saitama]

Hello @saitama ,
It's hard to decide what needs to be done until you get a chance to shoot again after your cleaning and o-ring replacement. In the meantime, you could check tightness of all your screws, especially for whatever optic or other sights you are using. I am assuming that it used to group just fine and now suddenly it's not grouping well? Check some of the simple things first. I think the cleaning was an appropriate first thing to do.

Good Luck,
Feinwerk

I checked the screws that attach the scope last night before I went to bed. It seemed to be tightly fastened.
To be honest, I'm a little nervous because the hunting season is approaching.

Thank You

 

[Scotty1]

Is it possible that the spacers between the barrel and shroud have moved? They are known for that.

 

[saitama]

Is it possible that the spacers between the barrel and shroud have moved? They are known for that.

I have seen in other posts that the spacer can move.
Before my next trip to the range, I will try wrapping tape around the front and back of the spacer to keep it from moving.

 

[saitama]

I'm back from the shooting range.
I ended up putting both spacers about 2 inches from the tip of the barrel liner.
Bullet speed is 898fps.
At 50y, it collects about 1 inch, but a little flyer comes out.

 

[pesty3782]

On my 600mm barrel I run 3 spacers. One is about 1 inch from end of barrel and I used black electrical tape behind it. The other 2 are evenly spaced out with black electrical tape behind them…check the barrel screws to see if they are snug and even pressure on both sides….

Tony P

 

[saitama]

On my 600mm barrel I run 3 spacers. One is about 1 inch from end of barrel and I used black electrical tape behind it. The other 2 are evenly spaced out with black electrical tape behind them…check the barrel screws to see if they are snug and even pressure on both sides….

Tony P

When I first bought it, the spacers were roughly evenly spaced.
Originally that worked fine.
I placed the spacer at the end of the barrel at the 1inc point and repositioned the second spacer in the center.
The barrel was originally tightened firmly and evenly, so that should not be a problem.
I will try that tomorrow.