How many of you actually prooftest your barrels?

[flehto]

I only "function" fire my builds w/ a stout hunting load......Fred

[Bob Roller]

Hi,
I have not proofed a barrel since I started using only swamped barrels with pretty large breech dimensions.  However, it might be a good routine practice.  I did proof some barrels years ago that were straight octagons and had thinner barrel walls than I use today.  I used a double load of ball and powder.  I also measured the outside diameters around all flats at 6 locations from the breech to about halfway up the barrel.  I compared before and after measurements of those locations as well as visually inspecting the bore and outside.  I am curious how those of you who proof barrels inspect them beyond just detecting an obvious failure.

dave

Dave, you have a good point, it is really hard to determine if a unseen failure exists either before proofing or after.
After the second proof with a 1/2 proof load I carefully clean the bore and run a clean lightly oiled patch through the bore and try to feel any irregularities that may exist especially tight/loose spots and do a careful inspection of the breech and drum if a cap gun. If it seems OK I go with it. Failures generally occur in breech/drum area rather than barrels. I believe that most barrel makers use 12L14 steel because it machines smoother and cuts cleaner because of the lead in the alloy. I don't think 12L14 is classed as Gun Barrel Steel especially in smokeless applications. GM uses a much better steel, they use A.I.S.I. 1137 modified, stress relieved, annealed, certified rifle barrel quality steel. Having said that I seldom use GM barrels, not that they are bad, I just prefer barrels from Getz-Colerain-Rice. Check this post for more information on makers and steel used http://americanlongrifles.org/forum/index.php?topic=21944.0

Superior material offered and rejected.The trade mark of latter day muzzle loading for decades.

Bob Roller

[Dphariss]

Part of the reason low quality steels are used in ML barrels is that they are easy to get in small lots. Next its far easier to cut. Next few ML shooters will pay 400-450 bucks for a good barrel. Too cheap.  Switching from 1137 to 4140 will cause a lot of bitching from the people machining it and greatly increased tool wear and more and better sharpening is required for cutter heads etc. Of course Krieger and Bartlein and a number of others make very high quality cut rifled barrels from 4150 (its the mil spec) so it must be possible.  With a little knowledge and skill....
Then we have the handloader defense. Everyone automatically assumes its a loading error when a ML barrel fails. I contend that if the proper steel were used that its not possible to fracture the barrel with BP regardless it will simply bulge at worst.
But of course this is contrary to contemporary thought on the matter. They think that any modern steel is better than iron. I would ask why the Rifle Muskets of the American CW had IRON BARRELS. SKELP WELDED IRON at that. This was because low grade steel makes a poor barrel, it has all sorts of "issues". I think that the reason barrels became heavier in the percussion era was the increased use of "cast steel" barrels (all steel is cast to this day so please don't think its cast iron). Its far more likely to fail than a "best iron" barrel in a ML. I have read that the Rifle Musket barrels were proved with something over 200+ gr of powder and a minie spaced 2" off the powder.
But people will tell us that barrels will blow with an airspace. Then we have 1850s period arms like the percussion Sharps that cannot be shot without SOME air space due to design. They did not blow either.
For years Douglas used cold rolled 12L14 and some split. So they apparently started annealing the bars. Something a metallurgist (you know, a trained expert in metals?) tells me is a no-no for steels with high levels of lead. That's what the "L" stands for.. Anyway they stopped making ML barrels all together because of failures. Had they changed alloys and continued they would have admitted liability.
TC had a rash of strange and not so strange blowups early on. Then the blowups stopped. They claimed they added an xray process. Everyone figured they switched to better steel. But could not admit this because of the "L" word. Given who supplied the early ones they were surely cold rolled leaded screw stock.
I could retell the tale of seeing cold rolled 1144 being button rifled and the failure rate compared to GB quality 1137 or 41xx steels. But who would care.
A long time friend of mine had a face to face with one of the big names in modern match grade barrels. He said that anyone that watched steel being made would never use a cheap steel in any gun barrel. He also said that given the choice he would shoot an iron barrel over a 12L14.  Iron is not brittle but is remarkably ductile and for BP ML barrels its strong enough. As the Gov'ts use of iron for the Civil War Springfield barrels shows.
So while a any better quality carbon steel, even 1010/1018 can and has been used for a great many barrels such as  1911 Colt barrels in 45 ACP, another steel with a higher tensile strength will be unsuitable for safety reasons. Because free machining steels are supposedly very strong they are also BRITTLE and this is bad.
If MLs shot factory loaded ammunition there would be no 12L14 barrels. But they don't and since ANY steel will stand BP pressures and gross overloads they can "prove" its safe. In reality the FLAWS present in the bars (these steels are mill run and are not checked for flaws in any way that I know of) will give the stuff a failure rate. Improper steels and steel manufacturing processes are the reason some re-enactor guns have failed with blanks where there is not projectile at all. But of course they are "safe". Well at least according the people that make them and the buy the cheapest no matter what "shooters" that buy this "stuff".

Dan

[oldarcher]

Thank you Dan, I read these posts to learn and always do. Good post! I believe that the reason that I prefer Getz-Colerain-Rice barrels even though I know that 12L14 is not the best quality alloy for gun barrels is that I feel that it is more than adequate for BP loads and the weakness is almost always the breech/drum part of the system. That is why I ALWAYS proof the system as it is going to be used.
The real reason is that I enjoy the uniqueness of using a "custom hand made barrel with the makers name on it" even though I know that GM barrels are using better quality steel.

I search out old barrels made by GRRW and Sharon as well as Large to build rifles. I just completed a Vincent with a NOS GRRW barrel, and the rifle previous to that was a Hawken with a Sharon barrel.  Why?? because I like the provenance of the famous old names that were legendary from the time I started shooting BP, not because they are better.

In response to Bob's comment: I think that we are a small community of folks who shoot traditional BP rifles and that the rifle stockers are an even smaller sub-group of people who are motivated to actually build what they shoot and as such are very resistant to change of any type. The very nature of what we do is to recreate the old so....we don't like to change it even though we may realize that there are better products out there.

[Captchee]

 Im with a couple of the others in that I don’t generally do a so called  “Proof”  . I do however fire every gun prior  to it leaving my shop .
 From what I have read , it wasn’t  the steel that caused the issue with Douglas as much as it was the process  in which that steel was made . IE extruded vs. drawn

As to the barrels  and their make up .   Every time this subject comes up , I think back to  the time Don Getz came right , proclaimed what steel he used ,. The gave a rather short but to the point  experienced opinion on the subject  . Then just let it go as nothing more really needed said
 When someone mentions quality control  and barrel steels , I cant help but wonder, when where and how this takes place ?
GM appears to  have laps in the QC   of that there is no doubt
 What barrel steel is Savage using  , 
 How about Remington and the current issue with SS barrels failing in cold weather  or for that mater standard barrels as well as spec barrels ?
 Granted these are smokless barrels , but still  IMO either QC is there or its not .
Either the metallurgist new what they were talking about or they didn’t

 When I see and read of the modern barrel failures , I cant help but ask myself . Where is the QC, surly these companies have  high paid metallurgist working for them or at least consult one prior to  implementing a new barrel steel into the production .

As to cost being an issue   of not using a higher grade of steel . I just purchased a new 2 new barrels  from GM . 1 for my Cetme  chambered in 308  and another for an AK that im rebuilding . They were each  50.00 less in cost then a muzzle loading barrel  and they had far more milling work  at far closer tolerances.

[Pennsylvania Dutchman]

I plan on proof testing my .62 cal. oct to round smooth rifle barrel when I get the touch hole drilled. I did do a proof test on a piece of the material that I made the barrel out of. I drilled and reamed a .625 hole in a piece about 8" long. I used a standard chucking reamer so it is not as smooth inside as the barrel, I used a square reamer on it. I tapped both ends and drilled a #7, .201 dia touch hole. I filled the blank with between 800 and 900 grains of 2F and set it off with a piece of cannon fuse. I proofed it twice, the second time I turned the OD down so it was smaller than the breech of my barrel across the flats. I measured it carefully after each proof and did not find any bulging or damage. I will still proof my barrel, but this does prove, to me at least, that the steel is capable of a lot more pressure than it would ever be subjected to in normal firing.
Mark

[Dphariss]

Im with a couple of the others in that I don’t generally do a so called  “Proof”  . I do however fire every gun prior  to it leaving my shop .
 From what I have read , it wasn’t  the steel that caused the issue with Douglas as much as it was the process  in which that steel was made . IE extruded vs. drawn

As to the barrels  and their make up .   Every time this subject comes up , I think back to  the time Don Getz came right , proclaimed what steel he used ,. The gave a rather short but to the point  experienced opinion on the subject  . Then just let it go as nothing more really needed said
 When someone mentions quality control  and barrel steels , I cant help but wonder, when where and how this takes place ?
GM appears to  have laps in the QC   of that there is no doubt
 What barrel steel is Savage using  , 
 How about Remington and the current issue with SS barrels failing in cold weather  or for that mater standard barrels as well as spec barrels ?
 Granted these are smokless barrels , but still  IMO either QC is there or its not .
Either the metallurgist new what they were talking about or they didn’t

 When I see and read of the modern barrel failures , I cant help but ask myself . Where is the QC, surly these companies have  high paid metallurgist working for them or at least consult one prior to  implementing a new barrel steel into the production .

As to cost being an issue   of not using a higher grade of steel . I just purchased a new 2 new barrels  from GM . 1 for my Cetme  chambered in 308  and another for an AK that im rebuilding . They were each  50.00 less in cost then a muzzle loading barrel  and they had far more milling work  at far closer tolerances.

Cold drawn 12L14 is cold drawn 12L14 the shape is not relevant. Nor does the shape change the fact that the high levels of lead, sulfur and phosphorous cause dangerous inclusions and embrittlement of the steel along with the cold rolling process along with the cracks often seen in mill run bars. This fairly tale about the shape is simply a way of people deluding themselves. People that think the barrels made of ROUND bars of 12L14 have not failed simply have not been paying attention of have not looked or asked the right questions.
If you cannot see the difference in the cost of a CUT RIFLED and lapped 44" swamped octagonal barrel (lathe contoured and then machined octagonal) and a BUTTON RIFLED AK lathe tuned barrel then perhaps you need to do a little more research. We have to remember that the post WW-II military barrels, other than perhaps the m-14, are generally just lathe turned tubes, the Centme and AK fall into this description as you well know. Some like the AR15/M16 have extentions for locking lugs. Price? You get what you pay for.
For example a 20" CUT rifled Krieger AR15  CMP/NRA match contour barrel chambered and headspaced is $420. A GM A@ barrel (issue contour) is 168. Since both start from the same blank it has to do with the machine time and labor. A Krieger Garand barrel is 370 and requires final fitting and headspacing. Fitted to an action and headspaced? $580 plus shipping.  Part of the difference is that single point cut barrels require MULTIPLE passes to form ONE GROOVE. A button rifled barrel takes about 10 seconds to rifle, I have watched this many, many times. Green Mountain makes a great production grade barrel for military style rifles and they have had military contracts so they are set up the do high volume modern mass production once the machines are programmed for a contour  they can make a barrel simply by telling the machine what program to run. But they are not in the class with a Krieger or Bartlein or a number of other high end match grade barrel makers.
Modern barrel failures come from maybe four issues, underloads, overloads, bore obstructions and poor choice of materials.  The point is that BP will not make anywhere near the pressure levels of smokeless when a projectile is used so over pressure of modern steel with BP is inpossible. Nor will it detonate so underloads are not an issue either.

Dan