Mungo ... hammer forging produces barrels with an extremely good internal finish and structure and have the reputation of lasting many rounds, however, the machines used are costly, complex and very BIG. I will go out on a limb here an suggest that there is probably a stigma attached to the hammer forged barrels due to the process alone & this alone dissuades competition shooters from using them. I would suggest that it would only take an elite shooter to start using one and winning to start a trend toward their use. I will stand corrected but I don't think there are any hammer forged barrels available "off the rack" as it were, down here.
regards
Mike.
No, there is far more too it than just fashion. Find a video of how a hammer forged barrel is made and you'll see the forces involved are staggering. (A short, fat 'blank' is bored through and has a mandrel forced into it, the mandrel having the rifling on it as a 'negative', and in many cases, the chamber too. The blank plus mandrel are fed into a machine which pummels the outside with opposed hammers literally squeezing it onto the mandrel, reducing the O/D by a half or so and increasing the length also by around a half. The mandrel is then pulled out of the near finished barrel.)
The problem is that enormous stresses are fed into the blank in the process. Even with substantial post hammering destressing, it is very difficult to make the barrel stress free. These are often released as the barrel heats and the POI shifts, sometimes as a gradual process, sometimes abruptly after x number of shots and the barrel achieving y-deg temperature. Conversely, match barrel makers destress their blanks first and do everything possible to reduce subsequent stresses. Cut rifling inflicts virtually no stress in a match barrel shop as the rifling machine only takes a tiny cut from a groove at one time. Button rifling injects more as the 'button' pulled through the bore swaging the rilfing into a previously smooth surface. The most likely problem from button rifling is in skinny barrels which taper to a small diameter at the muzzle. The tendency of the barrel metal after the button has gone through is to expand. This is resisted successfully in fat match barrels, but often causes lightweight examples to expand at the muzzle so they are marginally oversize there which rarely does much good for accuracy.
The main benefit of hammer forging is high output and low per barrel cost, so it is high output producers who invest in them. They have been used in match and precision rifle barrels, Parker-Hale making all of its barrels by this method. Some of the P-H TR and police / military sniper rifles shot brilliantly, but some performed very badly. In the latter case, P-H was very good at taking the rifle back and rebarrelling it without quibble. P-H's machinery is owned by Armalon Limited which completely refurbished it, replaced all the electronic and control bits with modern digital systems and makes very attractively priced barrels that look very good and which perform more than adequately for sporting rifles, sniper rifles and some competition disciplines. Many CSR competitors use Armalon barrels on their straight-pull .223 Rem AR-15s. Peter Sarony, Armalon's owner claims they will match the best of the limited output cut or button barrels, but I for one won't accept that they'll
consistently provide the ultimate precision that is the norm from Krieger, Broughton, Bartlein, Benchmark etc products. Another issue is that match quality blanks are invariably supplied as just that - rifled blanks - and the gunsmith uses a finishing chamber reamer and throating reamer that suits the customer's needs or specifications to a 'T'. Likewise rifling pitch and barrel finished length / weight. Hammered barrels nornmally come with the rifling pitch and the chamber / throat the barrelmaker specified. As mandrels are incredibly expensive items, the cost of a drawer full of reamers, the barrelmaker is unlikely to have more than one design. Most gunsmiths will not attempt to alter a hammered barrel, for instance by reaming the throat longer, as the hammered steel is so hard that it is difficult to cut with the required degree of precision and may wear the reamer out prematurely or damage both it and the barrel.