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.