Bore erosion, pitting and tool marks

JB bore paste & bore bright have arrived, so i started the cleaning and polishing job.

Following Geoff’s advices, started with bore paste with 10 full strokes, with the patch wrapped around a worn brush.
It cleaned more carbon away immediately and lightly polished lands and grooves.. but my patches are smaller then the suggested so it felt not so snug when working… I decided to use VFG bore pellets around a “spiral threaded” jag to do the job



Very snug fit inside the bore, you can feel it scrubbing when pushing the cleaning rod.

The result unfortunately is not the best I hoped, even after 3 complete treatments, but it signifantly cleaned and polished the bore.
I believe this barrel is irreversibly damaged by pitting, I’m maintaining it since this rifle shoots moa at most distances.
For those who don’t know this rifle is a fazakerley (PF) no.4 mk2 from 1949, converted in sr(B) target rifle with center bedding, ajp tz4/47 rear sight and target sling.

Here’s the before and after:



After 3 complete treatments:

For bores that are pitted, the best we can hope for with using JB is removal of all fouling and any high spots created by either tooling or by the oxides from the corrosion process. What is left is relatively clean pits in the steel.  

I agree,I have oiled the bores with clp after the cleaning..
Do you believe it is a bore tolerances or harmonics matter?
I have an m16 a1 with the pencil chromed barrel, it is super sensible to fouling, I had to remove the flash hider to clean it because the previous owner have never cleaned the bore, do you believe me if I tell you I had to break the carbon out with a chisel and a hammer? There was a huge carbon build up inside.
After that cleaning and reinstalling the flash hider within torque specs, the carbine is shooting horribly…
This had me think, sometimes gunk and carbon may be help accuracy in some way?

Usually when I deep clean guns it take almost 20 rounds to restore accuracy, one of my Swiss k31 took 30+ rounds to get on point.

Yes, that does not surprise me. 

Usually since I don’t compete, I start measuring groups at the second 10 round target.. my no4’s starts 1/2” high and right when cold.
I once listened to a metallurgy engineer that said, some copper and lead fouling is needed exactly because of micro pitting and tooling marks…

You are a lucky man Geoff, it is impossible to find a dcra or fultons rifle nowadays!
Indeed that is an excellent barrel, you can see why those where target rifle just by the bore finish from the factory, much more superior then the service rifles standard barrels.
OT, have you ever tryed a L39 or envoy?

I can’t imagine how much could cost to produce a barrel with the same specs today, probably more than an entire rifle in good conditions

This is the barrel of my uf55 no4 mk2 it has about 1000rds thru it, I’m going to JB treat it as well.


It is a very strange bedding indeed, I’ve seen some other dcra fully bedded in other forums.
Same style used on Mauser rifles, does it have any pre load or it just hangs in there?
Let us know how it shoots!

britrifles wrote: Even though these were target rifles, clearly the cleaning and preserving routine that was used by previous owners was seriously lacking. Not what you might expect from a serious competitive rifle shooter.

I should get onto the JB clean for my Resistance No4Mk1 this weekend. And some crappy borescope pic's to see how it does.