Hammer Forging Firearms Barrels

[Danny M2ZParticipant @dannym2z]

Wile cleaning one of my favourite .22 rifles (a Russian Izhmash Biathlon Basic Review ) I noticed that it has hammer forged barrel with a pattern like spiral wound carbon fibre, It is deadly accurate both at the range and in a paddock,

Due to lock down boredon I asked Mrs. Google and found some interesting stuff about the machinery that can produce a rifled barrel bore to an accuracy of 0.0001".

The video referred to in the link below (U.S. Army Watervliet Arsenal) is also fascinating as it shows field gun and tank barrels being forged into shape at 2000 deg C How Hammer Forged Barrels are made

* Danny M *

[Danny M2ZParticipant @dannym2z]

[not done it yetParticipant @notdoneityet]

Interesting, but I don’t think any hobbyist making rifle barrels in the UK would be looked on positively by the authorities🙂🙂🙂.

Can’t remember how long the prison sentences were for the gang that was manufacturing firearms, illegally, in the back of a ‘front’ business on an industrial estate. They only got found out due to testing them (after normal business hours) and the reports being heard and reported.

[Danny M2ZParticipant @dannym2z]

LoL ndiy.

I was not suggesting that somebody would want to use this process to make their own backyard barrels.

The engineering aspects of making a long accurate hole are of interest to me and maybe a few other people so this was posted in regard to the engineering techniques. It is interesting that the accurate bores formed are also work hardened due to the manufacturing process.

I doubt if a 'gang' could afford one of these machines.

Anyway, I am in Australia and permitted to own a firearm for legitimate reasons after a police background check and new licencees are also required to attend an approved training course.

* Danny M *

[Bob StevensonParticipant @bobstevenson13909]

Hammer forging was devisd by the Germans as an emergency production method during WWII and, like sevreal of their wartime devices, has made it into modern firearms production. It was originally devised in 1941 by Rheinmetal Borsigg fir the M42 machine gun.

Much more interesting for members here are the homespun methods for hand rifling the flintlock rifles used by the early American settlers….many of the barrels were very accurate and much of the rifling was carried out by the wives and daughters using very basic, but very clever methods. Obviously, all of the kit including the the barrel cutters had to be made up 'in house' before the work could begin.

amazingly, there are quite a few people still making these 'long rifles' in the American deep south using traditional methods and some of these 'primitive' gunsmiths are well known…….some have passed into folklore themselves or are in the proicess of so doing such as Hershel House…see here;

Rifling method see here;

[Brian HParticipant @brianh50089]

Is this the same technique used to make 'Damascus' gun barrels?

Brian

[Bob StevensonParticipant @bobstevenson13909]

the Damascus process was originally a method of making the barrel tube by winding strips of iron around a former and then welding the joins. This gives a distinctive 'look' which has been much duplicated in moden times, for obvious marketing reasons…..

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Danny M2Z on 28/04/2020 08:09:39:

[…]

The engineering aspects of making a long accurate hole are of interest to me and maybe a few other people so this was posted in regard to the engineering techniques. It is interesting that the accurate bores formed are also work hardened due to the manufacturing process.

[…]

.

Thanks for the link, Danny

I was ‘aware’ of the process, but it’s great to see some video of these machines in action.

MichaelG.

[Mick B1Participant @mickb1]

Attitudes to Damascus barrels have varied with time. I can remember them being dissed in gun magazine articles in the 60s with assertions there was a risk of the welds springing open and the barrels unwinding on firing. If it wasn't just a marketing ploy to sell more new guns, this probably happened mainly with barrels of low original quality, and/or firing unsympathetic varieties of modern ammunition. Of course, the process more usually employed during the black powder era up to roughly the last decade of the 19th century – and I think they were most usually made for relatively low-pressure guns like shotguns and some of the double-barreled big-game express rifles.

As Bob said, hammer-forging is a technique developed to speed production but as Danny said the resulting product is in some important ways superior. I believe that at least the L1A1 7,62 SLR barrel used by British forces up to the 80s was made this way at Enfield Lock. I'm not sure, but I had the impression that in that instance it was done cold. Many volume barrel makers will use this method, whilst companies making smaller but still significant quantities may use button-rifling, which shares some of the advantages but is slower.

 

Edited By Mick B1 on 28/04/2020 09:20:16

[vintage engineerParticipant @vintageengineer]

By forging the barrels, the steel becomes much stronger and denser. Also by forging there is no chance of any drill wander.

[JohnFParticipant @johnf59703]

Posted by Bob Stevenson on 28/04/2020 08:12:06:

Hammer forging was devisd by the Germans as an emergency production method during WWII and, like sevreal of their wartime devices, has made it into modern firearms production. It was originally devised in 1941 by Rheinmetal Borsigg fir the M42 machine gun.

Bob not sure where you found the information relating to 1941 ? When visiting the Beretta factory many years ago I saw this process working and manufacturing both rifle and shotgun barrels, however we were told the process was developed long before WW2 to circumnavigate the WW1 armistice treaty which did not allow Germany to posses any rifle drilling machines or rifling machines thus theoretically preventing them form re-arming ??? the hammer forging process was developed whereby they needed neither of the prohibited machines.

It is indeed an amazing process and barrel production time is reduced dramatically, another interesting fact is Beretta were at that time producing barrels by hammer forging and traditional methods, all barrels were crack tested before being assembled and sent to proof. From the traditional method a small [very] percentage would be rejected but on a later visit I noticed the crack testing had been abandoned the production manager said since they went 100% to hammer forging over a 1 year period there were nil rejects from the crack test !

[SillyOldDufferModerator @sillyoldduffer]

Posted by Mick B1 on 28/04/2020 09:11:37:

Attitudes to Damascus barrels have varied with time. …

The original Damascus steel was made in the Near East between AD300 up until about 1750. The raw-material was Wootz Steel from India. Wootz and Damascus both have mythic qualities because in their time they were high-quality, and because we don't know exactly how they were made. Modern steel makers can easily get and hold high temperatures and pure materials, but how the ancients did it is unknown.

Damascus is made by repeated folding and forge welding a mix of different steel billets – the operation has to be done correctly several times, and is downright difficult in a primitive forge. Anyway, for about a thousand years, Damascus Steel was better than anything made in Europe. But it was rare, expensive, and much faked!

By the seventeenth century European steel-making had improved, mainly with the intent of producing good quality steel cheaply, rather than the best possible metal. The latter still depended much on the application of skill, expensive (pure) materials, and a lot of hard work. Steel made for the best sword blades was far more expensive than steel used to make working tools.

Technology moved on slowly, and for a long time steel was slowly made in furnaces producing up to a ton of steel per day, with lots of wasted heat. Then Mr Bessemer arrived with his converter, blasting out very good mild-steel hundreds of tons at a time, and using far less heat that traditional processes. Bessemer steel was far from perfect, but it could be used directly for structural purposes, and also as a pure raw-material for making tool and other quality steels. Most modern steel is made by an improved Bessemer-like technique, with some furnaces producing 13,000 tons of steel per day.

Damascus steel has an attractive characteristic pattern, which can be naively associated with 'quality'. Possibly a true sign of quality today, but far more likely it's cosmetic, done because it looks good, not for a technical reason.

Hammer forging gun barrels is another example of a modern technique developed to reduce cost that also produces a superior product. Traditional rifle barrels went through several processes that inevitably left them with imperfections. Much inspecting and rejecting done! The final step with Lee-Enfield barrels was to hold them to the light and check internal reflections to see which way the barrel was bent. Any error was corrected by hitting the barrel with a mallet. Sounds crude, but it's an optical test that skilled men could use to correct unacceptable barrels to 'good' or 'excellent'. Sniper and competition barrels were selected from the best of the best.

Kaiser Wilhelm's Germany cheated by using machines to straighten their barrels!

And this method appeals to some:

Hammer forging removes the need for this and other labour intensive processes; the machine churns out consistently straight barrels, and they're stronger than the ordinary type. It's also possible to make them even tougher by forging from alloys that don't machine easily.

Dave

 

 

 

 

Edited By SillyOldDuffer on 28/04/2020 11:16:28

[Brian HParticipant @brianh50089]

Many thanks for the explanations Dave, very interesting.

Brian

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