View Full Version : Pitted outside SS barrel
August 7, 2005, 11:31 AM
Recently I was given a Remington 7MM Mag rifle by a relative. He had let it set in his gun cabinet for aproximately 20+ years and claimed that he only shot about 9 rounds. When I recieved this gun the exterior of the barrel was corroded pretty badly most of the corrosion came from the stock (it appears) under the barrel. The barrel is Stainless and it had a blued finish the top of the barrel had color splotches where the bluing appeared to be gone and a whiteish color was left underneath. My Father inlaw claimed that in those days gun stocks were cured in salt to help the wood dry out faster. The gun came with a nice Redfield scope and was deadly accurate at 200 YDS it shoots great!! I would like to refinish the barrel and repair some of the pitting can this be done? I've heard that bluing is not recommended for Stainless Steel.
August 7, 2005, 12:03 PM
Are you sure of it being SS? SS can and will rust if it is not kept dry. I would suspect the stock was put up wet. The salt cured wood is a new one on me. I wasn't doing much wood work back then, but I have read many of books from before and after and none of them have ever mentioned using salt to cure wood, meat maybe, but not wood. You said the finish of the gun was blued, most of the time SS isn't colored since the process of blackening it is corrosive. If the inside of the barrel gets any of the chemical in it, it will erode the rifling away. If it is blue as you say, it may very well be the process that caused the pitting. could you show us a pic, I would really like to see this gun. I would take it to a smith and let him see if he can remove the pits for you and then bead blast it for you. Does the gun barrel say it is stainless? There wasn't a lot of stainless rifle barrels around at that time. I think I bought my first one around 1993 or 1994. but they were a round for a few years or so before that time.
August 7, 2005, 02:16 PM
My wife gets home with the digital camera tommorrow so i will post pics.
i'm pretty sure its stainless it says it on the barrel. i'll get the pics as soon as i can
August 7, 2005, 02:39 PM
Salt cured wood - at one point in time Browning was running out of stocks.To dry stock wood quickly they treated it with salt which absorbs moisture.Unfortunately there is residual salt in the wood which in time corrodes the steel. That occured years ago and I haven't heard of any other maker doing it......Since it was blued I also question whether your rifle was stainless steel.
August 7, 2005, 04:27 PM
What kind of receiver does it have?
I would have thought Browning would have known better than to put salt of the wood. I understand the principle about it removing moisture, but salt has always led to rust. You will never find anythig to remove the salt once it soaks in.
You may in deed have a SS barrel. The pits could be from the process of coloring the metal and if they are, I would advise you to have a smith remove the pits and then beadblast it if there is enough metal there to begin with. You said it shot well, but if you could have a look with a borescope, I would be interested in knowing if the pits have entered the barrel as well. If there are any inside and you want to keep the gun shooting, I might see about doing a rebarrel job depending on how bad they are.
August 8, 2005, 07:35 PM
Sorry it took so long. Here are the pics. First you can see the barrell bluing has deteriorated and left a splotchy white in the background 2cnd you can note that the
barrel Say's stainless steel, however a Cow magnet sticks to it with a pretty good grip. It must be a very weak composition of Stainless. Perhaps that is why the bluing managed to stay on for a while?? Finally you can start to see the pitting. The worst of it is hidden under the stock that is why you would tend to think the deterioration emanated from the stock.
The worst is yet to come. :eek:
August 8, 2005, 07:53 PM
Finally This is the part i really don't like. Underneath the 7MM engraving, hidden by the stock is some very severe pitting.
Now the Questions :D
Is it possible to restore this Barrels appeal?
Can pitts this deep be repaired and if so how would this be accomplished?
After bead blasting what kind of finish could be re-applied?
Can any one tell this guns age?
Finally I really enjoyed Shooting this Like I said when I got it. I snapped the scope on to the mount and at 200 YDs first shot we plugged a 14" industrial Sawblade off it's branch in the desert. (You can find weird things out in the desert). It would be too bad to have to throw this one away.
August 8, 2005, 09:11 PM
I would pull the barrel myself and put on a Douglas prechambered barrel or a Pac-Nor barrel myself, but if you check out The Sportsmen Guide, I have seen decent looking take off barrels for the 7mmRem mag for less than $100. I would hate to be shooting a hot round from the 7MM mag and find out the pits went all the way through to the inside. I would think the coating would end up being something other than bluing, but without looking at it close, I couldn't be sure what it is. I would thank the man for the nice receiver and go from there myself and replace the stock and barrel. Good luck with it William, let me know I can help you.
August 8, 2005, 09:18 PM
That is some butt-ugly pitting. Did you remove the original corrosion that caused it? The only ways to remove pitting that I am aware of are to re-contour the barrel to cut through the pitting, or fill the pits with welding, then restore the original contour, or build up a very heavy hard chrome plate, then re-contour to original specs with a toolpost grinder. The first option leaves the barrel lighter and may compromise its accuracy if the added “whippiness” doesn’t vibrate agreeably. The second option is used by restorers, and is slow and labor intensive and may ruin accuracy by imposing axi-asymmetric stresses where the welding is applied. The last method is least likely to affect accuracy adversely, but you will have to want a hard chrome finish and it won’t match the original.
The original finish looks chipped to me. Bluing usually either blends as it wears, fading out as you go away from the wear point, or it is gone only where corrosion has hit, but remains between the pits. The chips tell me this was some kind of painted finish applied to get around the fact they didn’t have a good bluing formula for stainless at the time (they exist now); probably a baking lacquer, like Brownells’ Aluma-Hyde (sp?). If you can find out exactly what it was, you can probably get it re-done to near-original appearance.
I am going to guess this gun was “cared for” with a hygroscopic oil of some kind (saddle soap, for example) that someone thought would be good for it. The moisture was gradually absorbed by the lacquer, causing it to hold the moisture against the steel before ultimately flaking off the next time someone rubbed against it. The stainless steel had never been passivated, and indeed may actually have been pickled to remove surface chromium oxide and to activate it so the finish would adhere better. Thus it was vulnerable to any free iron in it rusting.
Ask Mete, but I believe the non-magnet quality only applies to the austenitic stainless (i.e., 316) used in surgical implants and the like. A tool maker told me once there was only one “True” stainless (probably referring to 316) that really wouldn’t corrode, and that it wasn’t heat-treatable or tough enough for modern gun barrel pressures; this was 35 years ago and may no longer be true, but maybe. . . In any case, your gun barrel is just a corrosion resistant stainless, like most stainless guns and tools are made from.
If the gun shoots well, I would take it to a gunsmith to remove the rest of the original finish and buff it and re-paint it to gloss over the exterior pits (or else bead blast it for a matte white finish) and ignore the pitting that the stock covers. Why go to a lot of expense to potentially ruin its accuracy? If you think it has collector value, you’re better off to sell it as-is, since any messing with the original finish will detract from its collecting value.
If you clean it up, I would also look at removing all traces of whatever-it-was from the stock before putting it all back together.
August 8, 2005, 10:04 PM
Butt ugly is right!!
I had thought about the welding option and the only method I could contemplate was the Tig welding method. It is one method that I Am fortunate to be skilled with.
Still I decided against this because I don't have the experience to tell what i might do to the barrels temper. I was also thinking of getting creative and suspending a capped off barrel in some Water and making a low temp high freq. heli-arc weld by exposing the weld surface just above water (or a non flashable oil). Still it would be a lot of trouble. I didn't know I guess I didn't really look at how much a replacement barrel would cost if it is that cheap Then I think I might go with the new barrel route. May i'll experiment with the old barrel and the welding thing afterwords who knows.
As for the stock it has a clear resin coating and there is no bare wood showing. I'm going to try to neutrilize it. From here on i'll just take good care of it. I wasn't really thinking of the gun as a collector gun instead I just wanted it to look better cared for!
August 9, 2005, 05:34 AM
Do not attempt to weld up the pits , you'll just create more problems.There must have been moisture in the stock to get that corrosion .Stainless barrels are usually made from 416 stainless which is a heat treatable and free machining grade of stainless. It is magnetic .With that corrosion it has no collectors value .The best thing to do [assuming there is no pitting so deep as to create a danger] is to polish it up a bit ,no necessarily removing all the pits,and leave it with a brushed finish. Then you have a shooter and you won't have to worry about getting it scratched ! I would attempt to find why the stock caused the corrosion, if it was wet that can be dried .BTW while the barrel and receiver channel of rifles sometimes are not finished moisture will get into the stock there.Always finish the inside to prevent warping or worse.
August 9, 2005, 10:01 AM
WOW! That finish sure looks like paint to me. It also reminds me of the blue dye that machinists use for marking layouts. I would say that your barrel is ruined. I would replace the barrel. It would be a great learning project with the proper guidance. Or, just take it to a reliable gunsmith...
August 9, 2005, 11:09 AM
Looks more like a galvanic reaction...Whats channel of stock look like??
August 9, 2005, 11:37 AM
If the photo [.020] is the worst part that's not enough corrosion to make the barrel unsafe....Galvanic corrosion requires two metals of difference electric potential and a conductive liquid such as water with salt. Here there is only one metal. Actually it's fairly typical of pitting corrosion. I also think the barrel has been painted. That's what they did with stainless barrels at that time.
August 9, 2005, 01:15 PM
That's why I asked about the stock channel. I have seen some
unwise materials used in home float jobs of that era... Just a thought.
August 9, 2005, 02:07 PM
If the inside looks decent, I'd get rid of the rest of the black paint and then shoot it.
August 9, 2005, 03:26 PM
If the inside looks decent, I'd get rid of the rest of the black paint and then shoot it.
Now you have a nice shooter that you can take out in any weather and not worry about. Nothing wrong with that.
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