What are your 50 and 100 yard groups like with the CCI SV? You need to do some serious carbon removal starting at your chamber, thats a lot of carbon buildup.
I checked shooting logs. Six 5-round groups of Lapua Center X at 50 yards was .738 MOA. Nine 5-round groups of CCI Std Vel at 50 yards was 1.641 MOA. I didn't do any testing at 100 yards.
My CZ 457 American was initially a disappointment accuracy wise. I was getting 2” groups at 50 yards regardless of ammo then it got worse. I don’t have a bore scope (yet) but believed I had the carbon ring. A good clean did away with that and it went back to 2 inches. I generally clean my rimfire rifles at about 200 rounds. After I got to around some 500+ rounds they accuracy suddenly improved and I started getting under an inch at 50 and under 2 at 100. I can’t explain it unless it is some kind of break in thing. My friends with 457s and 455s had better out of the box. I’m extremely happy with the rifle now.
The lands aren’t chewed up, it’s just lead. It builds up over time.
There is no step from the chamber to the lands,
I'm sure my barrel was ported incorrectly.
How can you fix this
Whats up with crown area. Looks a bit chewed up.
Interesting damage to the lands just inside the muzzle. Piloted crown tool ?
I can't understand thaths tools. The grooves don't touch!!!
Lathe crowning or nothink
It’s lead.
What are your 50 and 100 yard groups like with the CCI SV? You need to do some serious carbon removal starting at your chamber, thats a lot of carbon buildup.
Oh probably 1" at 50 yards, 2" at 100 yards? Maybe a bit better.
That gun should shoot a lot better that that
I checked shooting logs.
Six 5-round groups of Lapua Center X at 50 yards was .738 MOA.
Nine 5-round groups of CCI Std Vel at 50 yards was 1.641 MOA.
I didn't do any testing at 100 yards.
My CZ 457 American was initially a disappointment accuracy wise. I was getting 2” groups at 50 yards regardless of ammo then it got worse. I don’t have a bore scope (yet) but believed I had the carbon ring. A good clean did away with that and it went back to 2 inches. I generally clean my rimfire rifles at about 200 rounds. After I got to around some 500+ rounds they accuracy suddenly improved and I started getting under an inch at 50 and under 2 at 100. I can’t explain it unless it is some kind of break in thing. My friends with 457s and 455s had better out of the box. I’m extremely happy with the rifle now.
How do you get a barrel that clean? What are you using?
This barrel wasn't cleaned. Just 5 dry patches.