Cold hammer forged barrels

[rangur1]

Firstly, I know almost nothing in regards to barrel specifications and design. I do understand twist rates and their causal relationship with projectile weight. Now FX uses liners, so we’ll put them aside for this post as I’m curious about cold hammer forged barrels such as BSA and CZ , which I love. Do other barrel makers use different degrees of same procedure? If not, what are some of the other techniques? What are the advantages? I find cold hammer forged barrels generally agreeable with a fair range of different projectiles. So, barrel gurus educate me on differences/advantages of others. LW, TJ, alpha precision, polygonal and so forth. What other techniques used besides cold hammer forged? Many thanks.

 

[Bladesx]

Button rifled and cut rifled. Too much to as to details, easy to look up.

 

[jps2486]

Hammer forged barrels were developed as a reduced cost to make barrels. The older methods required drilling a deep hole in a bland, then rifling it with either a pull through button or cutting the grooves one by one. Other processes are required as well such as lapping and/or polishing. Which is better?? Dunno, but all custom barrels that I know of, made by guys like Lilja, Bartlein, Shilen, Krueger, etc, and not hammer forged. You pay your money and take your chances.

 

[nervoustrig]

Here’s a pretty good article that concisely describes the common rifling processes
https://www.bearcreekarsenal.com/blog/cold-hammer-forged-barrels-guide.html
I normally don’t like to just link to an article but it looks like a pretty good primer, and seems to do a good job of being objective.

Just a few comments to add:

1. For AG barrels, button rifling is far and away the most commonly used process. Cold hammer forging is probably second, but a distant second. If I had to guess, the distribution is probably in the ballpark of 90% button, 5% hammer forged, 3% pressed (FX), and 2% everything else.
2. Both button rifling and hammer forging are highly subject to a range of process controls that can produce results over the full range of abysmal to excellent. However due to the additional expense and complexity associated with hammer forging, I think it’s safe to say you’re less likely to find a terrible hammer-forged barrel than you are a terrible button-rifled barrel.
3. Hammer forging produces a surface with improved wear resistance to the heat and pressures associated with PB, but is irrelevant to our application.
4. Button rifling tends to leave a rougher surface finish than hammer forging. Meaning the barrel may require more frequent cleaning, or it may benefit from a lapping or polishing regimen.
5. Both button rifling and hammer forging impart stresses in the steel. We don’t see the elevated temperatures of a PB barrel so that aspect can be set aside but there are some machining operations that may be affected. For example, machining the OD of a barrel may cause the bore dimensions to change slightly.

 

[Headshots]

Hammer forged barrels have been on top end guns for a long time . They are NOT easier to make than a button cut rifling. Button cuts are for mass produce barrels .

Cut Rifling vs Button Rifling and Cold Hammer Forged Barrels

Looking to learn about barrel types and their rifling more? We get into all of it here! Read up on the different barrels that are on the market these days before you commit to buying one!

www.80percentarms.com

From the above article.

CHF barrels are known for the best longevity and durability. Cold hammer forged barrels have an advantage in that they can better withstand heat which inevitably leads to a longer service life. Other barrels may be just as accurate and far lighter, but they may not last as long comparatively under constant heat and stress. Symptoms of a barrel degrading or nearing the end of its service may include gas port erosion, throat erosion or loss of accuracy. The average shooter won’t see this happen with a CHF barrel unless they shoot over 20,000 rounds.

 

[delooper]

I think for airguns the machining process is far less important than the care they take in making the product. Hammer forging is the most expensive process to set up, but long-term its cheaper as you turn out high quality barrels for less cost, i.e. after the start-up cost producing individual high-quality barrels is easier. So if you are a company with a good amount of capital on hand it's usually the smarter thing to do.

You'd go with the other manufacturing processes if you produce small batches, or don't have the capital to set up hammer forging.

 

[Hunter25]

I have a tj stainless 28in 30 caliber barrel on my impact. I change barrels and liners alot depending on what I'm shooting. The tj barrel is a solid piece of work. It's accurate and not choosy what it'll shoot with accuracy. After polishing with 5000 grit,it does not foul up quickly either. I'm looking for another one cause I lost my spare sending it to a friend to test. Mail people lost it. That's my take,I had two,liked them both. 26in and 28iñ.

 

[Scotchmo]

As far as I know, TJ does not use stainless steel. Their 7/8” O.D. barrels are DOM carbon steel. Otherwise, they are all chrome molly steel. Though not stainless, they have some corrosion resistance.

 

[Jaxjax]

I find going to the barrel makers web sites usualy has some extremely interesting info on barrel making & why they do it a particular way . Alot of these companies were started by the Bench Rest enthusiast . I think Lilja has there own theories to why they do it a certain way & they all do. A button pulled/pushed barrel is not the same cross the board, far from it. Many things done before & after that make them different. Bartein has excellent data on why they do cut & the related processes. In air world I'm convinced it's about TIR spec to be very good from end to end. & think it all goes wrong from barrel to barrel in cutting thread at muzzle & breach work being different from mass produced airgun barrels. All these better blanks from Hart/ Bartlein, Lilja etc have a sh.. ton of hand work done to bore although I think Bartlein has went automated in that regard with same results. My Lilja internal look nothing like a factory blank Stainless LW barrel. Lilja is a mirror the other is not until you do it yourself. factory chokes just piss me off, it takes a barrel magician to get them right. Factory is pure luck IMO. Shelin select match grade barrels cannot vary from end to end by more then .0001 for bore uniformity.

 

[Hunter25]

As far as I know, TJ does not use stainless steel. Their 7/8” O.D. barrels are DOM carbon steel. Otherwise, they are all chrome molly steel. Though not stainless, they have some corrosion resistance.

Well,it's not regular steel. Cold roll. Probably chromo moly like you said. Sorry for misstatements what my barrels made of. It looks like stainless till I polished the outside also,now it's shinny like chrome. So I expect your right. I was told the blanks where stainless,so that what I thought they where. I shot a 235 this weekend with it on a practice target. My dad witnessed it. It shoots good. The target was an fx official like that shoot at the matches. I had three of them. First time I'd ever shoot any targets that big. My rifle differs from top target to the bottom target,just enough to put me off center. Learned that on a friday,shot a 235 on a Saturday morning. So,for sure,the chrome moly is accurate with 50 grain pellets at 100 yards.

 

[caliusoptimus]

As far as I know, TJ does not use stainless steel. Their 7/8” O.D. barrels are DOM carbon steel. Otherwise, they are all chrome molly steel. Though not stainless, they have some corrosion resistance.

Zero rust on my TJs. Oiled or not. My other steel barrels rust like it's a requirement of their continued existence.

 

[Hunter25]

Zero rust on my TJs. Oiled or not. My other steel barrels rust like it's a requirement of their continued existence.

Mine don't rust either,even after I polished outside to shinny finish. I have fx liners as accurate,but they'll not shoot both pellets and slugs as well. With the liner,it's one or the other real good. The tj has certain ones it likes extremely well,but those all good when you find the speed for that pellet or slug.