Can't get bore clean

[gregintenn]

I've dealt with stubborn bores, but this one takes the cake.

 

I have an old Spanish Mauser I've sporterized, and I can't get it to group very well, I'm confident it is because of all the fouling built up in the bore. Through the years I've had it, I've scrubbed it with various bore solvents, brushes, etc. I've plugged the end of the barrel and filled it full of copper solvent and let it soak for days. I've even scrubbed it with polishing compound. Try as I may, I can't ever seem to get to that magical clean patch. Your suggestions would be appreciated and experiences would be appreciated.

[frankmako]

some old war guns the bore is shot out and the gun will not group.  there is nothing you can do for it.  

[peejman]

Heat.

It could be that the barrel steel is somewhat porous and has soaked up crud over the years.

The easiest thing is to remove the barrel. Then you can get it hot, up to 400 deg won't hurt the steel, though it might ruin the finish.

[NRA]

I have noticed with some of my surplus rifles that the round makes allot of difference...........  boat tail vs Flat base

[Guest tangojuliet]

your first mistake was sportering it ;)

[Garufa]

You might want to slug the bore to find out it's true diameter, as mentioned it may be shot out but you might be able to load to bullets of a greater diameter to compensate.

 

If you really want to get it clean you can always try science.  I used the electrolysis method explained in the following link on a Mosin once.  It was amazing the amount of sludge that came out of the bore, I literally went through dozens of patches just removing the gunk loosen by the method.

 

http://www.thedolk.com/borecleaner/index.html

 

I used a regular steel rod, not stainless, as that's what they had at the hardware store and AA batteries.

 

Still, I'm not sure you can ever get a clean patch to come out of a milsurp.

 

Might also check the crown for any nicks or whatnot.

Edited January 5, 2014 by Garufa

[Jonnin]

and supposedly you can have it counterbored (?) which is basically a gunsmith cuts a new crown and then new rifling down the last bit of the barrel (not the whole way) which can give "decent" accuracy to a worn out gun. 

 

As for getting it clean, just be careful to not do more harm than good. 

 

Also, expectations....  what ammo are you shooting?  What groups are you getting?   If its under 2 moa and surplus ammo, that may be all you can do.

[Garufa]

Actually, counterboring does not cut new rifling, it simply removes bad rifling at the muzzle by increasing the bore diameter enough that the bullet does not even touch the barrel for the length of the counterbore.

[gregintenn]

I recrowned it when I cut the barrel and sporterized it. I just can't get the thing clean.

 

I'm handloading and know what to expect. I'm not going to see it with this barrel till its clean.

Edited January 5, 2014 by gregintenn

[gregintenn]

You might want to slug the bore to find out it's true diameter, as mentioned it may be shot out but you might be able to load to bullets of a greater diameter to compensate.

 

If you really want to get it clean you can always try science.  I used the electrolysis method explained in the following link on a Mosin once.  It was amazing the amount of sludge that came out of the bore, I literally went through dozens of patches just removing the gunk loosen by the method.

 

http://www.thedolk.com/borecleaner/index.html

 

I used a regular steel rod, not stainless, as that's what they had at the hardware store and AA batteries.

 

Still, I'm not sure you can ever get a clean patch to come out of a milsurp.

 

Might also check the crown for any nicks or whatnot.

This I may try.

[gregintenn]

your first mistake was sportering it ;)

I paid $30 for the rifle. I haven't ruined a museum piece. Spanish mausers aren't rare, nor are they priceless works of art.

Edited January 5, 2014 by gregintenn

[Guest kingarmory]

Try this stuff, I've had a lot of fouled bores over the year that this stuff has cleaned up.  Got a lot of customers that have brought in guns that looked had bores that looked like sewer pipes and this knocks it out.  Obviously doesn't fix pitting/rot, but if its fouling you're dealing with, this stuff is the best I've found yet

http://www.kingarmory.com/Blue-Wonder-Gun-Cleaner_p_109.html

[NRA]

I paid $30 for the rifle. I haven't ruined a museum piece. Spanish mausers aren't rare, nor are they priceless works of art.

People said the same thing 30 years ago with 1903's and Enfields. But it is your rifle so it really makes no difference what others think. 

Edited January 5, 2014 by NRA

[gregintenn]

People said the same thing 30 years ago with 1903's and Enfields. But it is your rifle so it really makes no difference what others think. 

and if all the millions made were meticulously cared for and kept in like new condition, they'd be worth little more than a stick of firewood today. I'm actually doing a public service for the guys who collect original specimens.

[gregintenn]

I'm still scrubbing, and it's still dirty. :shake: I guess I just need more patience......and patches. :x:

[Caster]

A paper patched boolit will lap that puppy to a mirror.
There's also a method for using lapping compound and a cast boolit.

As far as a worn bore, it'll still shoot as long as there is rifling left to work with. Slug the bore, size to .001-.002 over.

Is this a 7x57 or a .308?
Either is easy to cast for. Most people WON'T because of the lies, myth and BS.

[gregintenn]

It's a 7x57, and has all matter of rifling. The bore doesn't appear to be pitted; it's just friggin nasty. I'm starting to see a few shiny spots come through. I'll get a few black patches, then a few green patches, and so on and so on....

[peejman]

It's a 7x57, and has all matter of rifling. The bore doesn't appear to be pitted; it's just friggin nasty. I'm starting to see a few shiny spots come through. I'll get a few black patches, then a few green patches, and so on and so on....

My yugo Mauser was like that. I knew I was finally making progress when the patches changed from black to green. I scrubbed it with hoppes and a brass bore brush for a while and it finally cleaned up.

Mine shot ok before I cleaned it, hope I didn't mess it up.

[ironsniper1]

Try this stuff, I've had a lot of fouled bores over the year that this stuff has cleaned up. Got a lot of customers that have brought in guns that looked had bores that looked like sewer pipes and this knocks it out. Obviously doesn't fix pitting/rot, but if its fouling you're dealing with, this stuff is the best I've found yet

http://www.kingarmory.com/Blue-Wonder-Gun-Cleaner_p_109.html

I may have to look into that when I get around to cleaning my mosin some more

[Randy L]

I have had a few Spanish Mausers and none of them grouped very well and they all had very good bores. What kind of groups are you getting ?

[dlm37015]

cast bullet and valve grinding compound

[gregintenn]

I have had a few Spanish Mausers and none of them grouped very well and they all had very good bores. What kind of groups are you getting ?

3-4 inches at 100 yards.

[bajabuc]

Sporterized.  must be you're going to shoot it for sport.  What kind of sport?  Target?  Hunt?  Hunting…close is pretty good.  Target…I'd use a different gun.

[gregintenn]

Sporterized.  must be you're going to shoot it for sport.  What kind of sport?  Target?  Hunt?  Hunting…close is pretty good.  Target…I'd use a different gun.

Bad weather deer rifle.

[Randy L]

3-4 inches at 100 yards.

Sounds about what I was getting only advice I can give is use the heaviest bullet you can it will be the longest one which will help stabilize the bullet better. The rifling in these old Mausers is different than modern rifles and don't shoot lighter bullets as well as heaver ones. I know you most likely already know this but for the benefit of others that may read this thread wanted to point this out.