K98 frosted bore (long)

[andyo5]

A few years ago, I acquired a German K98 rifle from the WWII period. It is a 'Russian captured' K98, meaning that it was captured, re-blued, and stored in a Russian arsenal for many years.
When I bought it, I was impressed with the appearance of the bore. The grooves and lands appeared sharp. The bore was dark, and I assumed this was due to the Russian's re-blueing process that all these guns received.
The gun shoots pretty well. Using the battle sight and shooting at an NRA 100 yard smallbore target, I can group 10 rounds into a 4" group repeatedly at 100 yards.
The only notable issue has been copper. The bore seems to collect copper more than any of my other guns. I have used Sweet's Bore Cleaner (with ammonia) and i usually need to do this 3 times after shooting. Even so, I can still see some copper on the lands by just looking into the barrel.
I recently used Remington Bore Cleaner (the brown liquid with very mild abrasive). After two go arounds, the lands are mostly copper free but I still see a little bit in the grooves.
So I have concluded that the bore must have gotten a bit frosty from corrosive ammo, probably during war service.

My Question: Is there a reliable method for smoothing or at least improving the frosty surfaces?
Thanks!

 

[dusty3030]

Kroil and JB bore lapping compound on a patch and jag. Use a steel one piece rod and a rod guide that fits in the breech end.

 

[LVSteve]

I have a bunch of milsurps and extra thick copper fouling is just part of the fun. Three to five passes to remove the copper is a low number compared with some of the copper mines I have purchased.

I STRONGLY doubt that you will get the bore perfectly smooth, corrosive ammo just does too much damage. Keeping the copper manageable is sufficient to maintain accuracy, at least with the ammo currently available now that Yugo M75 has dried up.

 

[andyo5]

Keeping the copper manageable is sufficient to maintain accuracy, at least with the ammo currently available now that Yugo M75 has dried up.

I have alot of 1954 made Yugo ammunition. It uses a 198 grain bullet. Is this the M75 ammo that you referred to?
I mostly shoot 195g to 200g reloads.

 

[sheepdawg]

No the M75 is a newer round, sold as sniper ammo. Most of mine is from the 90's. It's good stuff. I bought a bunch of surplus before it dried up and the absolute best I have is stamped 12-50. It's as good as any M75 I've got, maybe better. I've got some stamped 59 that's good too. 2 inch groups at 100 yds. out of my 37 Sauer K98k when I'm on.

The copper problem just comes with the territory. I swear some of my Mausers seem to shoot better with the barrel a little fouled. A few trips to the range might help your bore just remember to clean it real good right after you shoot. I run hot water down the barrel at the range.

 

[andyo5]

The copper problem just comes with the territory. I swear some of my Mausers seem to shoot better with the barrel a little fouled. A few trips to the range might help your bore just remember to clean it real good right after you shoot. I run hot water down the barrel at the range.

I use Sweet's first thing after I shoot military ammo. It contains ammonia, which supposedly neutralizes the corrosive stuff. With handloads there is no need to worry about corrosion since nothing is corrosive.

 

[Arik]

The dark bore is from use. The best way to smooth it out is to put ammo through it. I mean.....Metal on metal at 2700fps. Your barrel is as smooth as it's going to get without being a smooth bore. You could clean that barrel all day for a month and still have fouling from a century of use. Enjoy it for what it is

Sent from my XT1650 using Tapatalk

 

[Fishinfool]

Since you reload, I might try "fire lapping" the bore. There are kits made for this, but any soft lead bullet coated with fine lapping compound, and fired at low velocity - 1000 fps - should do the trick. Might need 5 or 10 shots, with a good cleaning between rounds. Same basic theory as hand lapping a bore with a lead plug and abrasive, just faster and easier.

I have done this with two rifles with bad bores, a .22 rimfire, and a .54 muzzleloader. Worked wonders both times, improving accuracy, and reducing future leading. I know several people who have done the same, and had similar results in other rim & centerfire firearms.

Don't know it would be my first option in an expensive, new rifle with accuracy / fouling issues, but would certainly be worth a shot in a frosty barreled military bolt action.

Larry

 

[alwslate]

I have alot of 1954 made Yugo ammunition. It uses a 198 grain bullet. Is this the M75 ammo that you referred to?
I mostly shoot 195g to 200g reloads.

I aqlso have a lot of the mid 50s Yugo 8mm ammo with the
198 gr FMJ ammo that I shoot in one of my 98Ks occasionally.
You do realize that this ammo has corrosive primers and so you
must clean your rifle very shortly after firing it don't you? I
find that light copper fouling in the bore of new or nearly new
rifles fired with modern ammo is normal and I don't worry
about it.

 

[andyo5]

I think I will try the JB bore paste route. I read the reviews on Amazon.com and noticed several posts about successfully restoring bores on milsurps. The ratings were almost all five stars.

 

[gregintenn]

I've had some success with scrubbing the bore with mag wheel polish. It's slow going, but you'll finally slick the bore up.

Lapping, rubbing, or polishing compound would be faster, but I'm afraid I'd end up with a smooth bore.

 

[Ivan the Butcher]

There is a right way to lap or fire lap a barrel, and everything you have talked about is only a half or less of the process! Nobody has mentioned measuring the bore. That id done with 2" long lead slugs shoved or driven (with wood rods) down the barrel then repeated 2 or 3 times. Then you have a measurement of the barrel's smallest area. as you push the slug (called a billet) down the barrel it will be easier and harder as the diameter changes. Putting a very thin coating of lapping compound on the billet will smooth the tight areas. then you start over to get the next larger diameter (probably .00025 or .0005).

As you can see, it takes a while! But what you end up with when completely finished, is a mirror smooth and almost perfect bore of a somewhat larger diameter! I knew a man with a O3A3 with 2 groove rifling that lapped his out and ended up at .3125, so he used 303 British bullets in his 30-06. It shot phenomenally well, but only with custom non-standard ammo!

Mostly what people end up with when fire lapping, is a bore that is larger in the rear and smaller at the muzzle: a taper bore. AKA a choked bore (yes like a shotgun). Anschutz 22 target rifles do this by a different process, but it works great!

In military rifles; a lot of work for little gain with lots of risk!

Ivan