My 455 22lr Varmint

[billwunder]

I have a 455 22lr varmint that I have never been happy with.  Manufacturing stamp is 2013.  Originally it came with a Boyd' thumbhole stock.  Looked great, patterned like a shotgun.  I have had the rifle pillard and bedded and that helped some.  Finally purchased a used standard walnut CZ stock that was a new gun take off.  That was better but still encountered fliers.

Here is the issue.  The rifle has 2.000 - 3,000 rounds.  i usually shoot SK Standard Plus.  Last fall I purchased some SK Pistol Match and Rifle Match ammo.  Rounds started sticking in the chamber and would not extract without going in from the front of the rifle with a bore rod.  I have cleaned the bore in every manner possible and still having problems.  Lapua Center X will stick roughly 2-3 times out of every 10 rounds.  Sometime they will extract if I wait a few seconds and try again.  Obviously and expansion issue.  I am seriously considering converting the rifle to a Full Stock model if I can find a used full stock and purchasing a new barrel., or selling the rifle outright.

Any suggestions??  I have used lead remover, carbon remover, Hoppe's, and lacquer thinner.  I see nothing in the barrel.

Oh, I have a 452 American and 452 Ul  that are both stellar shooters and outshot the 455 out of the box.

[DeltaPapa]

I suggest you call CZ USA in Kansas City and describe your problem to them.

[david s]

Did you by chance remove and replace the barrel? The reason I ask is if you over tighten the two barrel retaining set screws it is possible to put an internal bulge in the chamber. That would be my first W.A.G.. Another guess is a faulty extractor spring or if the bolt was ever disassembled putting the extractor and holder (the two pieces that guide and pull the case from the chamber and are held in place by the extractor spring) on the wrong side. Another option is a pitted/rusty chamber. You may not like this suggestion but you might try a 243 bronze bore brush and some 4 ought (0000) steel wool. Wrap the bore brush with a little steel wool add a bit of oil and turn the brush carefully in only the chamber. This will get any thing in the chamber out if it's there.

[billwunder]

Thank you for your reply.  Everything you mentioned has happened.  The bolt has been apart and the extracter, shell holder and spring have been replaced.  I am sure they are in the correct orientation.  I did run for a short while with two extractors in the bolt.  Actually worked OK but did not eliminate the problem.  I am back to a standard config.  I have removed the barrel a couple of times for reaming.  I torqued the barrel to 45 in. lbs.  I read that somewhere.  The cases sticking in the chamber started before the first occurance of FTE.  I will try the steel wool when I return from traveling (2 weeks).  And will update.  All your points were on target.  Thanks again.

[david s]

You stated that you torqued your barrel to 45 in. lbs. On the CZ web sight in the FAQ section CZ list 25 in. lbs. Torque specs are also for dry threads. So if there was oil, grease or even Loctite things tend to get over tightened. You may have damaged your chamber. Hopefully not. One other possibility, in the first post you mention that the rifle has been fired 2000 to 3000 times. Rimfires are notoriously dirty what with dry bullet lube, shaved lead and burnt and unburnt powder residue. Is it possible the cuts in the barrel where the extractor and holder fit have filled with enough gunk to push the extractor a bit off the case rim enough to allow it to slip? Just another thought.

[billwunder]

Thanks for your reply.  You make good points.  Regarding torque specs, 25 is correct for the action bolts.  Cz states the barrel is torqued in something like 5 newtons.  Whatever that is.  Looked it up.  Translates to 45 in. lbs.  I am traveling but going to try using a brush and a little steel wool with oil to clean out the chamber next week.  The extractor channels are clear.  Thanks again.

PS:  the extraction issued started before the barrel was removed from the action for the first time.

[david s]

Sorry about the torque mistake. Went looking for the number from CZ and then didn't read it thoroughly. Hopefully the chamber scrubbing solves the issue.

[billwunder]

David S - Thanks for your input.  Cleaned the chamber with carbon remover  then used a brush with steel wool in a drill.  Problem solved.  Runs perfectly.  Thanks!

[Trblshtr]

Thanks for your reply.  You make good points.  Regarding torque specs, 25 is correct for the action bolts.  Cz states the barrel is torqued in something like 5 newtons.  Whatever that is.  Looked it up.  Translates to 45 in. lbs.  I am traveling but going to try using a brush and a little steel wool with oil to clean out the chamber next week.  The extractor channels are clear.  Thanks again.

PS:  the extraction issued started before the barrel was removed from the action for the first time.

There is a school of thought shared over at RFC that the torque specs for the barrel grub screws are way too high at 45 in. lbs, with a belief that the chamber can be distorted at such a setting.  I have been torquing the grub screws in my 455 Varmint to 30 or 35 in. lbs.  This holds the barrel in place with no wiggle, the screws have never loosened and I've had no problems extracting spent casings from the chamber with any ammo from bulk plinking stuff to mid-range match ammo like Center-X.