I picked up a all-matching 1932 M91/30 today. I didn't check the bore before I bought it as the guy told me it was great, and found out its very rusty. Turns out he wasn't aware that surplus 7.62x54R is corrosive ammo. Anyways, I'm going to keep it & not make a fuss because I didn't check for myself.

So what is the best way to get it out?

Currently I'm using a bronze brush soaked with CLP, brush the bore about 8 times, and then wipe with 2 CLP-soaked patches. This is helping, but there is still a lot of rust in the grooves. I've gotten most of the rust off the lands, and there seems to be very little to no pitting. Is there a better way I'm not aware of?

http://www.lovemyguns.com/

I did the same thing when i bought my M48, didnt do a bore check.

Lots of solvent and scrub like hell man, mine was horrible and now it isn't too bad at all!

I cleaned for a few hours BTW.

I heard shooting will blow some shit out too, i am gunna try that with my Yugo.

Vigorous cleaning sessions with vigorous shooting sessions in between.

I don't believe shooting and cleaning it is going to get the rust out.

We spoke about lapping on here awhile back, unless there is another way to get the rust out I haven't heard of it. Even when you get it out the pitting is still there.

You're not going to get pitted rust out of a bore. The most you can do is clean it and keep it oiled so it doesn't get worse.

If you lap it enough to remove the pits your accuracy is going to go to hell from the increased bore size.

A lot of heinous looking bores shoot pretty well. You'd be surprised.

Slight Update

I was recommended to try PB Blaster to get the rust out. After letting it set most of the evening, I was able to make the bore look about 30% better, and it is actually shining under light. The lands look very good, but the grooves are either still filled with rust or very pitted. I can't tell with my LED lights due to the bluish tint. I pushed another patch soaked with PB Blaster to let it sit overnight. I should be able to tell with sunlight tomorrow.

Wait until you go shoot and take her home to clean. You are gonna go through so many patches. I remember when I got my first M44 with a rusted and pitted bore. After shooting it took me damn near a half a T-Shirt later using Sweets 7.62 and CLP. The patches just kept coming out dirty....dirty.....a little cleaner but still dirty.....dirty......wow does it end

Update 2

I tried the Electrolysis Bore Cleaning method as described here: http://thegunwiki.com/Gunwiki/ElectrolysisCleaningMethod

I had a bitch of a time trying to get a 9V AC adapter to work, so I just used 2 double headed alligator clips on a 6V Lantern Battery

Here is the first 30 mintue run time:



Here is the 2nd 1 hour run:



And I forgot to take pictures of the 3rd 1 hour run, but it was pretty much the same as the first two.

I honestly could not believe how fricking dirty the bore was. I went through at least 40 patches tonight, and they were all nearly pitch black. The good news is most of the shit in the grooves is coming out. The bore is easily 65% better after I just was using CLP & PB Blaster. I think 1 or 2 more runs should take the last of the rust out of the bore.

The only bad thing is I didn't have the the funnel taped too well on the first run, and the water/vinegar/ammonia mixture got on my stock. I now how a few places where the finish was removed.

"The only bad thing is I didn't have the the funnel taped too well on the first run, and the water/vinegar/ammonia mixture got on my stock. I now how a few places where the finish was removed"


Yep, I always remove the stock when doing maintenance like that, just a habit I got into that saves trouble down the line.

sweet work.

i was going to suggest shooting it until shes hot, then scrubbing. looks like thats not a concern anymore though

How about wiping it out with something line naval jelly?  I've used it to take rust off bigger pieces of flat metal, or knife blades.

Or plugging one end and filling it with coca cola?  They say that takes rust off (but I've never tried it).

Final Update

Yesterday I decided to go 1 more round of the electrolysis bore cleaning. The fluid came out much cleaner that the previous 3 cleaning cycles. After cleaning out the bore, I noticed there was still a fair amount of crud in the grooves. I decided to switch bore brushes, and it made a world of difference. The brush I had been using was pretty worn after cleaning so much this weekend. I was able to get nearly all of the crud out of the grooves. It only took nearly 100 patches & about 8 hours of time, but it was finally clean.

Amazingly there is hardly any pitting, and just a few scratches in the barrel. The rifling looks pretty damn good, and has plenty of service life left. There is still 1 spot of crud about an inch or so from the chamber. I decided to see if just shooting it would remove it, and if not I'll just chuck a bore brush into a power drill.

Thanks for all the suggestions, and I will highly recommend the Electrolysis bore cleaning.

Good job, a lot of what looks to be pitting is actually years of built up junk.

I've found that a .357 brass brush fits my mosins very well. (just an fyi for future use)








 

Interesting, I must try this.