Thanks for the input, just curious, my brain is still trying to wrap itself around the pcp Benchrest guns (BARRELS) and competition, I’m getting an EDUCATION that’s for sure. ( still makes me wonder why they offer stainless in a land and groove configuration when I would think this would be tougher to machine?, also aren’t t all LW barrels button rifled? Or are some cut Rifled? The reason I ask is I don’t see the process explained or described on their website, which is fine because whatever process they use seems to be working, most BR shooters are using them!
Let me try to help you with the confusion...
There are 3 processes for making barrels:
1. Cut Riling
2. Buttoning
3. Hammer Forging
WL uses BUTTONING since around the late 1920's + or - a few years and if I am not mistaken I believe that this company (In Germany) invented and patented the buttoning process...WL does it right and stress relieve all of its barrels, and if they don't meet their specs, those barrels are scraped.
There is a general misconception about which process is better..
.Is is a fact that all 3 processes can produce the VERY SAME level of accuracy if done right and if somebody wonders why a company uses this or that process, the answer is INVESTMENT in technology and equipment, and VOLUME of sales.
Cut rifling is mostly used by very small manufacturers and custom barrel makers that have a low volume of production/sales...This process requires the least investment but has been perceived as the BEST one...The reason behind it is that most of these barrels are as said: CUSTOM made to specific specs where the maker drills the bore to desired dimensions and then cuts (removes material) ...It is a very slow process of manufacturing, they usually cut anywhere from .00005 to .0001" on each pass...It is time consuming and time is $$$.
Button rifling requires much more investment in equipment, but the rifling is done in one pass...Nevertheless, this process requires stress relieving and stress relieving requires technology in how to achieve the desired internal dimensions AFTER the stress relieving...Walther Lothar discards barrels that don't meet their parameters as mentioned, but many other companies don't and have no scruples in selling these barrels to the market or they simply put them in cheap guns. This process is probably the most used by medium sized barrel and gun manufacturers and because the market has been flooded with barrels that should've been discarded, this process is considered by many people second to cut rifling.
Hammer Forging is the most complicated of the 3 processes...The investment is 15+ times more than button rifling and the technology is very sophisticated and the company requires large volume of sales to make money...Hammer forging is a mandrel inside a drilled blank where hammers pound the blank around the exterior...The secret is at what temperature is the hammering done and what is the cycle rate of hammering...then comes hammer synchronization and pounding energy control (not constant)...The key issue is to make the barrel grow in length homogeneously in order to achieve certain bore and length dimensions that will be the desired dimensions after stress relieving (same last stage as button rifling)...
This process is used by very few companies in the world because of investment, technology and volume of sales required to make the operation profitable....
Remington in the US is one of these companies and CZ in the Czech Republic are 2 companies using this process successfully...
Summarizing: Cutting involves drilling & lapping a blank to the exact dimensions and then cutting the groves (removing material) as explained above....
Buttoning requires drilling the blank to an estimated bore dimension such that after pulling the button and stress relieving the finished barrel it will come out with the exact dimensions wanted...Achieving this precision is VERY DIFFICULT (lots of technology and variables to control and it is very easy to ruin the entire lot.
Hammer forging involves the same parameters as buttoning and much more technology and variables to control as mentioned above. it is also very easy to ruin the entire lot if the variables in the stress relieving step are not done right and it fails.
Another fact to keep in mind is that many machinists and gun makers don't realize is that bore dimensions CHANGE when the barrel is machined on the exterior...You have a good barrel but decide to machine a groove for installing a rear open sight just above the end of the leade and suddenly the gun lost its precision....What happened? DIMENSIONS CHANGED!. But this is another topic...
CZ produces VERY GOOD quality airgun barrels, I've seen some excellent shooting ones in the FT circuit mainly in England...Brits and then Germans are usually ahead of the game when we speak air gun technology...If you ask me, my Remington 700's hammer forged barrels used for rough country hunting are more precise than my custom made rifles that cost many times more...
Regards,
AZ
