CZ 457 22lr Carbon Ring?

[257WHBY13]

I have had a CZ 457 in 22lr for about 3 years, shoot it about 2k times a year with Federal Champion 40 grain@ 1200fps, clean barrel about every 10 times I shoot it. Other day I tried CCI 22 Standard Velocity ( Which I use in my 22lr Pistols), which bolt would not close on most, if it did close, very hard. Only shot 3, with no extraction issues, but any ideas on why I would have this issue? Carbon Ring maybe?

Both brands of ammo are less than 6 months old.

Thanks in advance!

 

[Critter Picker]

Following. Want to hear what everyone has for ideas.

 

[koja]

Next time ya shoot it or go ahead shoot a half a box of ammo through it, clean it right afterwards,when carbon is hot,about anything mention here in the next 20 post will clean it,most will suggest Boretech,but it will eat your plastic mag well and eat the coating on Bergara b14r stock when it leaks down, turn it upside down or remove from stock.I do like facing barrel down,leaning top of reciever,towrds wall,take a patch,shove it in chamber with the small end of an allen wrench,syringe or sports bottle a dab of Boretech,wipe out,kriol,etc,until comes out flush with chamber,20-30 minutes,,longer if it's cold and been a while.

 

[Reelamin]

Did you measure your case head thickness. How many rounds between cleanings. No need to clean it unless accuracy is falling apart then just clean the chamber first. Bore Tech carbon remover on a 6" q tip will remove any carbon ring.

 

[biednick]

The bullet in CCI SV has a different shape or dimensions than most 22lr ammo. I haven't spent the time to figure out exactly what the difference is. If you chamber and extract a round you'll likely find more engraving than you see on other ammo. I experience the same thing with every 22 I own that has a match chamber, even in barrels fresh off the lathe. I used to shoot it for IHMSA but got tired of using a dowel to push every round into the cylinder. I have to smack the bolt forward with my palm to chamber it in my Vudoo. I shoot it in my semis and revolvers with sporting chambers without any issues.

 

[257WHBY13]

The bullet in CCI SV has a different shape or dimensions than most 22lr ammo. I haven't spent the time to figure out exactly what the difference is. If you chamber and extract a round you'll likely find more engraving than you see on other ammo. I experience the same thing with every 22 I own that has a match chamber, even in barrels fresh off the lathe. I used to shoot it for IHMSA but got tired of using a dowel to push every round into the cylinder. I have to smack the bolt forward with my palm to chamber it in my Vudoo. I shoot it in my semis and revolvers with sporting chambers without any issues.

Thanks! My S & W 41 + 617 shoots the CCI SV great, but both hate the Federal Champion, Learn something new every day!

 

[LoneTraveler]

Has the CZ 457 had a shim put in the bolt?

I was putting a shim in the bolt of my CZ 457 last week. In choosing headspace for all shells. I made a false chamber setup to measure rim thickness. I found rims from .039 to .0435, The .0435 was CCI shells. That was the rim thickness I used to pick shim thickness for setting headspace. This rifle has operated good with all ammo I have tried so far.