keyholing and copper fouling

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ChefJeff1

ChefJeff1

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STILL keyholing and copper fouling updated

I'm having a problem with my Marlin 336 30-30. It's an early 60's model and is keyholing factory frderal 150's, 170's, and handloads. The crown looks good as far as I can tell. I've been scrubbung the bore for 3-4 days with Butch's bore shine and Hoppes. Wet patch, soak, wet patch again soak, bore brush, another wet brush----for days. My house stinks of this stuff! The patches still come out blue/green so it must be working.

So, this should help my keyholing problem, right?
How long does this take to get clean?
Any better ideas?
 
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What's the twist rate of the barrel?

What does the throat look like?

Have any pics of the keyholed targets?

BSW
 
I don't think you can get a gun dirty enough to make it keyhole.
Click to expand...
Yes, you can.

I worked on my dentists 7mm Mag BAR a couple years ago because he couldn't keep his shots on a 2' x 2' target at 50 yards.

After the first cleaning with Hoppe's #9, I looked through the bore and could not see any rifling!

About two days of copper solvent & JB Bore paste later, I finally stopped getting solid strips of copper out of the rifling grooves! Then another day before I stopped getting blue patches!

It shot clover-lief three shot 100 yard groups with mixed ammo when I got done.

rc
 
I have no idea what the throat looks like. What do I look for? My current Marlin catalog lists the twist rate as 1:10 RH. I don't know if it's changed since the 60's. Here is a pic, there are several on the cardboard target and the distance was about 25 yards. I could see this with handloads but the fact that factory ammo isn't working either worries me. I guess the twist is what it should be.
I"ll keep scrubbing:barf:

In the process, after soaking a while a blob of goo comes out.
 

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Look for rifling that's missing or severely damaged in the throat. I wouldn't expect that to be the case unless the rifle has seen many 1000's or hot rounds.

You can measure the twist by running your cleaning rod down the bore with a patch attached. Make a mark and count the number of inches until the rod makes a 360 revolution.

You are using the right ammo? Barrel isn't for a wildcat or anything? Has this rifle ever shot well?

BSW
 
It seems unlikely to me a 30-30 would jacket foul bad enough to cause that.
Muzzle damage is far more likely.
Is it a micro-groove or conventional rifled barrel?

I have owned old Winchester lever-actions with 100 years of cleaning rod wear at the muzzle that wore the rifling out to a funnel.
They key-holed just like that!

Have you always taken the bolt out & cleaned it from the rear end?
If always cleaned for the muzzle, you might check that.

Also take a Q-Tip and run it around the muzzle crown several times in both directions. Any burs or crown damage will pick up cotton fibers so you can see it.

PS: Throat erosion is also unlikely in a 30-30.
Anyway, it would not cause key-holing if the rest of the rifling was still good & sharp.

It is also very unlikely it is the wrong rifling twist. It should be 1/10, as that's what it came from Marlin with.

rc
 
I bought this rifle this summer for not very much and it did shoot well, like an inch or so, didn't really measure but it was a clean hole and reasonably accurate. I've always cleaned it from the rear the muzzle looks ok but I'll do the q-tip trick. yes, it's microgroove and it is indeed 30-30, nothing exotic. well, I'm going to go home and scrub some more, I think I'm getting addicted to Butch's Bore Shine, it smells so good.
 
cr,

Don't mean to hi-jack this guy's thread: Will JB's help get lead out of an old Rem MDL # 33 barrel, or other product? Patches still come out "BLACK" ! Even after 3 hrs of Hoppes and bore brush. Thanks
 
RC has the correct approach.

Find an aggressive copper solvent. I had lumps of fouling from firing Iraqi 303 Brit, the only copper solvent that worked worth a flip was Sweets. It took days but it dissolved the lumps.

The most thorough chemical clean would be one of those electro chemical kits that uses an anode and cathode. Forgot the name of the things.

Sparingly JB bore paste the bore. Might try it before the chemical clean and afterward. The stuff is an abrasive so don't round your lands and grooves.

A mechanical scrubbing is needed to knock out impacted carbon in the throat that copper solvents will not remove.

If that does not work then you have a barrel problem.
 
Ok, I think I'm making some progress. I read somewhere that using the brass brush can alter the results because the solvent is dissolving the brush. So I'm just doing patches and soaking and they're starting to come out cleaner, I think I'm almost there. I used almost 1/2 a 4 oz bottle of Butch's!! The electgric reomver looks cool but it costs amost as much as I paid for this rifle. Gotta go scrub some more.....
 
Fouling can cause bullets to key hole once the grooves get close to full of deposits at the throat area the bullet can fail to obturate properly and "slide' part way down the bore without ever getting enough spin to stabilize it.

try shooting into a backstop and recovering the bullet... bet it looks like somebody took sandpaper to it

Many guys think they're "cleaning" their rifles when all they're doing it getting a bit of powder fouling out... then adding layer upon layer of copper and carbon on top of each other.

The eventual cleaning required usually takes days of soaking and patching.

I bought a NICE rifle "cheap" at our range two years ago that was key holing something terrible... owner said he'd had nothing but trouble out of it since he bought it several years prior.

3 applications of wipe out, followed by 30 minutes of scrubbing and 2 more applications followed by more scrubbing and one last wipe out treatment and it was clean.

The rifle was a Remington 7 Mag CDL. I paid the guy 200 bucks for it sans the scope.

Fired it with factory ammo as I don't load for that cartridge and it put 3 shots into 7/8" on the first try. Pulled my scope off of it and sold it for 475.00 a week later.
 
I was ready to sell this just to get rid of it but I figured what the heck, let me try to clean it REALLY good and see what happens. I think it's working judging by the amount of goo that comes out.

The only backstop I could use is a 16" round of lodgepole pine. I love shooting rounds and splitting the wood to retrieve my bullets.

I saw that thread and will read the rest of it.

Thanks, Jeff
 
Update----

I braved the blizzard and howling winds and shot my Marlin 336 today. It seems to be shooting better but not quite right. It shot the first 3-4 shots fine and then a keyhole. I let it cool, which didn't take very long, brrrrrr.. Then 2 more good shots and then a keyhole. So what gives? I don't think 3 shots could cause enough copper fouling to cause keyholing again. Maybe I have a different problem. I did the q-tip around the crown test and there were no fuzzies or snage at all.

I'm going to get after it again with the butch's and tgry it again...

Or maybe I just to shoot it more to foul the barrel after such a strong cleaning.

By the way, my new 336ss shot a 1 hole 3 shot group with Fed factory 150's from only 25 yards or so in a gale wind. pretty cool.
 
RE: keyholing and fouling....

Cleaning it is a good idea and certainly can t hurt. Do you clean your rifle from the muzzle? I would have the crown checked and recut. That rifle should work with factory ammo and good reloads. Others have said check the crown and I say have it cut by a good gunsmith.
 
I suspect that you may have a badly pitted bore. Nothing has been said regarding pitting. Most "shot out" rifle bores I've seen were due to pitting.

Pitting results from the gun not being cleaned after shooting and allowed to sit up, and the bore aquires a coating of rust. When the gun is next fired, the bullet tears off the rusted areas like tearing off a scab, and the result is a pit in the metal surface. Shooting corrosive primed ammo and not cleaning properly is the main cause of pitting, followed by lack of cleaning and humid environment.

If the barrel is badly pitted, no amount of cleaning is likely to bring it back. If not too badly pitted and pits are mid-barrel or nearer the chamber, the rifle my be decently accurate for a few shots, then loose accuracy due to rapid fouling due to the roughness of the bore.

With the bolt removed, look through the barrel towards a brite light source. If the barrel has sharp shiney, well defined grooves, it's not pitted. If it has dark, irregular "splotches" in it, then its most likely pitted.

Good luck with your restoration project. Most likely, a trip to Marlin for a new barrel will be your best bet.
 
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