Strange "Grooves" in the throat of my 1911 barrel, what are they from?

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Lavid2002

New member
I have a springfield mil spec 1911 that I have had for 2 years. I have shot about 7,000 rounds through it. Only about 100 of which have been factory ammo loads, the rest have been home grown 230 grain cast boolit loads sitting on 6 grains of Unique powder and a wolf large pistol primer. I size them all to .452" after lubing them with LLA. After sizing them I lube them again with some more LLA.

After I'm done seating the boolits they have a film left from the LLA. I toss them in the tumbler with a splash of mineral spirits and the corn cob media takes the LLA of the exposed portion of the boolit. I used to not do this and the rounds would pick up dirt and what not, so I quickly started cleaning them to keep from bringing foreign objects into my pistol. I have always been a pretty meticulous cleaner, and had some problems with lubes at first (I tried pan lubing these little .45s with several different lubes and extraction methods to no avail, I also had the gun lead up a few times at the range) After switching to LLA I have had no such problems, plus it's convenient and I can bang out a few hundred rounds in no time!


To get to the point, you don't have to read the story above....
I have these groves in the throat of my barrel, they somewhat follow the contour of the rifling at first, then start to follow the rifling. I have an idea what it's from, but would like to get some other opinions so I can hear some un biased opinions before I try calling it :)

Anyone ever see anything like this?

Thanks for the help everyone!

-Dave


The scratches or groves are most visible in the last two pix! It's hard to get a good barrel shot. :eek:

DSCF3181.jpg

DSCF3179.jpg

DSCF3178.jpg

DSCF3175.jpg
 
J

James K

Member In Memoriam
I am stupid this week - what is LLA?

That barrel looks like a very hard object, like a ball bearing, was fired through it, scoring the barrel as it followed a straight line, then starting to follow the rifling. Even steel jacket bullets won't cause that kind of thing, as bullet jacket steel is softer than barrel metal.

Jim
 
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Lavid2002

New member
Lead build up maybe?
Click to expand...
My first thought initially as well, but after running a brass screen on a rubber plug down the barrel (My usual method of de-leading a bbl) the scratches remained and no lead came out.



In regards to cleaning practices,

All my cleaning is done with brass brushes and cloth patches.

I'm sorry Lee Liquid Alox (LLA) I a type of lube used for cast bullets. It is a liquid applied to bullets by tumbling them and letting them dry. It can leave a sticky residue on the bullets.

I don't think it's from harsh cleaning methods as you would have to work really hard to get a brass brush to eat into steel like this. Also, it isn't uniform, only <1cm into the rifling lands.

Here's my guess. When I started using LLA contaminates would get onto my bullets, I would brush them off if I dropped them, but if they had sand or something on them that's going to be very hard on the bore. I now tumble all my bullets to clean the LLA off so contaminants wont find their way into my gun, but I think a little damage is already done. It doesn't effect accuracy so I don't mind. I'm just curious as to what caused this phenomenon. I figured some of the gurus over here may have seen something of the sort before, as I sure haven't.
 
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drail

Moderator
What you are seeing is the result of the carbide "button" used to cut the rifling. When new they cut smooth rifling. After some wear they get kind of ragged. The bullet going down the bore isn't really affected by this.
 
S

Sgt127

New member
Would I be wrong to say: "who cares"?

It may have come from a slightly rough rifling tool.
It may have come from a dirty batch of lube.
It may have come from aggressive cleaning.

But, if the guns accuracy is good, I would just not give it a second thought. However, every once in awhile, something like that gets under my skin and it bugs me to no end, and, I have to tell myself "It just doesn't really matter." So, I'm telling you what I have to tell myself.

.45 barrels are cheap. Shoot it until accuracy drops off and drop in another barrel.
 
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drail

Moderator
If you ever get the chance to look at the inside finish on a Wilson or Brown or Kart barrel you will see why they cost more. Looks like glass. But for the average shooter those grooves aren't going to hurt anything.
 
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rock185

New member
Lavid, after looking at the last photo, I have to agree with drail. I have also seen this effect with barrels used with ammo that had picked up some grit, like dropped on the ground, etc. prior to firing. I used that 230 grain cast/6 grains of Unique load for years myself. I found it exceeded the velocity of most factory 230 grain ball I chronographed. You don't reports any ill effects, but I have never been comfortable myself tumbling loaded ammo...

ps, as drail indicated, the more premium type barrels really do display a finer interior finish.
 
G

geetarman

New member
Lavid,

I think you are right about some contamination on your bullets causing the marks you see.

If the gun shoots good, I would consider it experience. You probably won't do that again.
 
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Lavid2002

New member
I don't understand why anyone would have a problem with tumbling live ammo. Clearly it has been done many, many times without issues.

I tumble the loaded ammo to get rid of the LLA on the boolits. Without it, surely they would pick up more contaminants.

Good to know what happened though.
 
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chris in va

New member
Ditch the LLA and get some Johnson's Paste Wax, mixed with 10% mineral spirits. Dries faster and just coats the bullet with a wax layer instead of that sticky LLA.

BTW you don't lube then size. Size first, then lube. No LLA needed for sizing.:cool:
 
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dwhite

New member
Drail's right. Just tool marks from the button broach used to cut the rifling.

Drail's right too about a high end barrel being almost a mirror finish.

Barrels pretty hard so it won't just "wear" out of it.

They're probably no more than 0.0001 to 0.0002 inch deep at most.

I wouldn't worry about them. But, that's just me.

All the Best,
D. White
 
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