Bore corrosion

[clover]

Hi guys - it's been a while!

Sadly yesterday's gloriously sunny Bisley trip was spoiled by the usual pre-shoot dry patch through the bore coming out brown.

Long story short the gun still shoots well (actually potentially better than it has with 8 ex 10 shots into around half a minute at 300yd and plausible excuses for the other two) but the bore scope shows many fairly small, isolated areas of black corrosion inside. 

I'm still relatively new to CF cleaning and from memory the rifle had an oiled patch (then maybe a dry one..) put through it after the last time it was used in August last year. I take pride in looking after my gear so obviously I'm pretty ashamed that I've allowed this to happen.

My inevitable questions are how can I best remove the existing corrosion, and how can I prevent this happening again in future? For now I think I'm do a good few passes with an oiled PB brush followed by some dry patches and finally a liberally oiled one while I decide how best to proceed. 

For what it's worth the rifle is a stainless Tikka T3x in .223, the internal bore finish is (otherwise) good and typically collects very little carbon or copper fouling. The humidty in the cabinet it's kept in ranges from maybe 45-65% and there is no other corrosion evident on the rest of the gun that I can see, nor on the other two blued firearms that share the cabinet.

I'm thinking this might be a good excuse to lead-lap the barrel..

 

 

 

[Andy RV]

Any damage is already done so I wouldn’t worry too much about trying to clean any more evidence of corrosion away, if it wasn’t scrubbed off by the bullets I doubt you’ll shift it with a bronze brush.

All you can do now if keep on top of it by running an oiled patch through before storage and leave the dry patch until you’re ready to use it again.

 

 

[Popsbengo]

You're not the only person to suffer corrosion in a Tikka T3.  I recall a previous thread on here.

[Chris-NZ]

Too many shooter fail to realise "stainless" barrels are only corrosion resistant, not corrosion free. If you leave patches of carbon especially in there, corrosion can occur under them. The cleaning regimen the vast majority of casual shooters use can easily lead to this outcome. That's where borescopes are helpful at determining how good a job you've done at cleaning.

[Andy RV]

I missed the part of lead lapping the barrel. Bullet to bore fit is absolutely critical and on .223 you’ve got a 0.025mm tolerance on bullet diameter, this should serve to illustrate this point. 

Remember that to remove pits you have to remove the material surrounding them, thus increasing the diameter of the barrel.

There is a very good chance that you’ll wreck your barrel if you lead lap it! 

 

[banus02]

buy your self some ballisol or gunex oil.it wont remove the rust/pitting but it will stop it getting worse. after cleaning /shooting the rifle push two soaked patches through the bore and stnd the rifle barrel down in the cabinet ,put a rag or container under the barrel to catch any excess oil. push two dry patches down the bore before firing the rifle

[clover]

Thanks guys for giving me an easier ride over this than I've given myself.

The barrel has been thoroughly cleaned and hopefully protected with an oiled patch.

If anyone subsequently reading this is in any doubt about an appropriate bore cleaning regime; I've learnt the hard way that it should be cleaned until spotless after every use; which is certainly the route I'll be taking from now on.

[gunner]

i remember watching a good rust removal vid on youtube , i think they used white wine vinegar and soaked it (test pieces) over night . btw it wasnt a barrel . but im thinking if you were to be inclined to remove the rust , one could get one of them golf ball stacker thingys and cut to length , take barreled action out of stock , and leave it soaking in that tube muzzle down over nite making sure the level only went upto say the throat or just before ? just a thought . sounds like you have caught it before it bacame a real problem tho . atb 

[VarmLR]

Bitter experience has taught me that failing to remove all or most of carbon fouling then storing the rifle for prolonged periods in a relatively humid environment for prolonged periods between shooting can lead to corrosion and pitting.  I had this in one barrel.  I now use copious amounts of carbon cleaner followed by wipeout after shooting, even just a few rounds, which conditions the barrel helping to prevent corrosion and leave a few sachets of silicon beads in the gun safe.  Never a problem with any of my rifles since then.  Your best bet might be to patch out using carbon cleaner to remove all traces of carbon fouling then dry patch and add a little ACF50 to a patch or nylon brush to arrest any remaining corrosion before a patch with barrel conditioner like wipeout or M Pro-7.  I don't use oil patches because they contaminate the chamber leading to poor obturation which has its dangers.  I had a few issues when oiling barrels until I cleaned the chamber with meths to remove all oil traces which alerted me to the cause.  Obvious when you think about it. If using ACF50, you still need to remove all traces from the chamber using a solvent.     

I have heard stories about Tikkas and rust, yet none of my T3 or TAC barrels have ever had any such issues.  Perhaps I've been lucky but I am very careful about cleaning and conditioning barrels.