Don't know where else to post this so here it is. 10+ years ago my newly re-barreled (Criterion replacement) M1 Garand was fired around 25 shots with what I now know to be corrosive ammo. It sat uncleaned for years in the safe. I cleaned it up this past weekend and here is a picture of the barrel end? I can't tell if that is pitting in the grooves or something else. Is the barrel messed up?

https://i.imgur.com/JhKSp9E.jpg

If you cleaned it fairly well - yes - I would say it is "messed up".

micro pitting for sure..BUT it may still shoot just fine. i have a Mauser barrel that looks like a sewer pipe and it shoots moa. another barrel on a springfield looks like yours and with the right size lead bullets it doesn't lead up if i clean it right.
shoot it and find out. you might get a lapping setup and see if it will polish up some.

Looks like corrosion making the steel "blister". I don't know the technical term, but you see old rusty things where the rust build up a rough surface. How well did you clean it? Stainless brush, bronze, really good goop of some kind. Have you tried lapping it with something? Or if you reload, try some reduced loads to see what it does, both accuracy, and maybe taking some of whatever is in there out. What of the chamber, gas port, bolt face, and other stuff?

You do realize that no one else on the fire has ever put a gun away without cleaning it. We always have the time and correct equipment all arranged in our spotless mancave.

Lapping sounds like a good idea. Ammo was "KA72" korean corrosive stuff. I am reading really bad things about it, probably just throw it away.

I cleaned it "OK" at best. Brass brush, Hoppes #9, then Hoppes copper solvent. The gas port, bolt face, op rod all look brand new, no damage. Here is a picture of the chamber.

https://i.imgur.com/nrr5Klu.jpg

Never let one of my guns go for more than a day w/o cleaning.

Was issued one owned by the taxpayers that I cleaned about a year later. Cleaned right up after a bath in JP4. No pitting in the barrel at all. No rifling in the first 8" or so either. Oh well.

How does it shoot?

Have you inspected the gas cylinder and the piston on the op-rod?

I agree with Kennyd that it looks " blistered" with rust... when the "blistering" is removed then you'll probably have pitting. It still needs to have a good scrubbing... I would wrap a patch around a worn-out brush and scrub the heck out of it with JB compound after a 2-3 day soak with ATF or Kroil applied liberally via patch.

i have some of that korean ammo. a few years were bad, other years no issue.

Looks like corrosive ammo and poor cleaning.

Get this:

https://www.midwayusa.com/product/1006412014/wheeler-engineering-bore-lapping-kit

Done many military bbls, works great.

Get some .30 caliber cast bullets. Fill the lube grooves with fine lapping compound. Load 'em to about 1100 fps. (a few grains of H4227) They won't cycle the action, obviously, so you'll have to single load them. shoot about 25 rounds through it, then give the bore a good scrubbing by wrapping some 0000 steel wool around a bronze bore brush saturated with Mother's Mag Polish.

,....polish it right up.

https://www.google.com/search?q=fin...566j0j8&sourceid=chrome&ie=UTF-8

http://www.mothers.com/02_products/05100-05101.html#MJFYgHj6tla0xzhj.97&slider1=20

you will wear your guns out from cleaning then rather than shooting... have to have at least 500 rounds in most of my guns before cleaning, mags a bit less obviously as that would be half their barrel life.

Cleaning is over rated as long as its not corrosive issues...

Well at least you saved those 30 minutes 10 yrs ago by not cleaning the gun and putting it away long term .Now you are sitting by the tree of woe wishing that 30 minutes back from 10 yrs ago. Plenty of good suggestions on polishing out and or lapping the bore. Might cost ya about 60 minutes now to maintain or improve the condition. 13 dollar boresnake with solvent and oil ran through the barrel 6 or 7 times might have helped ya out somewhat back then, did things like that exist 10 yrs ago . How many times within a week,a month, 6 months , a yr or 3- 5 yrs after firing those 25 rds did ya think to yourself Gee maybe i oughta punch the barrel on my garand after firing surplus buckethead ammo from korea made in 72 in my nice new replacement barrel.... gawd.....

This. I know what each of my rifles is capable of. Barrels don't get cleaned until accuracy starts to degrade. Exterior, of course, gets a wipe down more frequently.

I wouldn't be too concerned about it...

Underneath the corrosion, the rifling looks sharp, as one would expect a new barrel to look like.

I definitely wouldn't lap it, as that will tend more to damage the throat and round the sharp edges of the lands and prematurely wear the barrel.

I would apply about 2 dozen strokes with JB, being careful to avoid the last inch near the muzzle, then keep the bore wet with Kroil and let it sit around like that until you shoot it... then clean it with solvent followed by denatured alcohol and final dry patches and shoot it.

When you take it to the range for the first time, do a barrel break in process...shoot a few rounds then clean with copper solvent, then repeat that a few times over the first 20 rounds. This is just an experiment and may not make a big difference, but it won't hurt and it may help.

The other option, which might be just as good, is just to do nothing at this point and just shoot it as normal. It may tend to copper up faster than normal...or it may not.

If it does you will have to deal with that, but keep in mind that many barrels won't shoot their best when totally clean, until they become stabilized with fouling.

I'd definitely use the Kroil though.

While it's not pretty, I think it will shoot normally.

i have a national match garand built near ft bragg in the 50's for a nationally ranked shooter at the time.
he told me he had never had the wood off the gun.
when i bought it after his death i was wondering about what happened inside on the cyclinder and pisto.
the piston nut was cross threded which may of had somehting to do with it.
one wipe with brakefree, clean as a whistle.

I can not believe that steel wool has not been mentioned.

Wrap some 0000 steel wool around a 30 cal bronze brush, add some solvent or JB paste, and stroke the corrosion right out of that Garand. It will not put the wear on a barrel like fire lapping will.

I appreciate all the advice on this. I spent the evening loading up some rounds to shoot through it. I did't clean it tonight as it was just too hot and humid in the garage. Tomorrow will be much cooler. I olan on using some steel wool, an old brush and some JB paste. I will take some "after" photos and target pics.

Well, interesting day. I went to range today with some of my reloads from last night. Sierra 150 grain SPBT Gameking over 46.5 grains of IMR 4895, CCI 200 primer, Federal brass. Shot 24 rounds, average velocity right around 2650 fps. A little faster than I thought it would be, was going for 2600 fps. Will probably back off a 1/2 grain. Rifle cycled perfectly, no signs of pressure on the brass. But the Garand is really tough on the brass when ejecting, beat up the case rims pretty good. Interesting part was looking in the barrel when I got home. It looked really smooth! I then cleaned it thoroughly, scrubbed it with JB bore paste, cleaned again, and oiled it. Barrel went to looking crappy again! I think this one will just get seasoned and stay "dirty". Accuracy was good, better than my eyes are at 100 yards, photos attached.