I have been holding my comments on this for some time simply because i wanted to see what these barrels were doing once in the hands of real shooters and not selected builders or shooters. The hype machines are always in full swing these days with everything in this industry.
My first comment, i do not mind proof barrels for hunting rifles. Everyone i have used for customer builds has met my 1/2 moa at long range accuracy standards. That said, every one had has POI walking as barrels warm up to some degree. Some minor some rather significant. This is generally hardly noticeable shooting groups at 100 yards but i never shoot groups at 100 yards. Testing at 600, 800 and 1000 yards, its very easy to see. Generally starts on shots 3-4 and will get progressively more noticable with more firings and barrel heat. To be fair, this is not a proof problem, its more generally a carbon wrapped barrel issue. Some are much worse then Proof, some much better. For a big game rifle, this is of little concern. You take 3-5 shots in the field at a big game animal, things have likely gone pretty western…..
As far as this design, have a lot of experience with gain twist barrels and while i know this design has some differences, it also will have some of the same issues. Its been stated that these barrels are not hard on bullet jackets, that my be when new and smooth but as the barrels wear, there will be more stress imposed on the jacket.
When a conventional rifling cuts into a bullet, it will leave a consistent groove that will never change on the bullet jacket as the bullet travels down the bore. As long as the bullet is seated near or to the lands and starts rotating as soon as it starts down the bore, the actual stress on the bullet jacket is not that great.
With this design and with gain twist, that groove cut into or pressed into, however you want to discribe it, the rifling groove pitch on the bullet jacket will continually be changing, which means there WILL BE a unique stress placed on the bullet jacket. The engraving on the bullet baring surface will be continually changing. Something that certainly caused issues with gain twist barrels. It will be an issue here as well, no way it can not be, at least with conventional cup jacketed bullets. Solids, another story as they have no jacket to worry about.
Using bullets with rear drive band designs such as CE will be interesting to see what happens…..
Another concern, from what i can tell from the information i have gotten, the rifling starts out very shallow and gradually gets taller as you get farther down the bore making the engraving of the jacket very gradual. This is similar in design to my Hybrid throat design and DE +P throat designs. The two are extremely similar in design and function and performance results.
I will only mention why i no longer offer my Hybrid throat design to customers and not what others claim. In my testing, with my wildcats in 6.5mm, 7mm, 308 and 337 calibers, this shallow throat rifling concept certainly boosts performance numbers by flattening the pressure curve. No question there. A flattened pressure curve allows us to use faster burn rate powders to gain significant performance, or allow MORE powder to be used compared to conventional rifled barrels.
However, in every test I performed, barrel accuracy life was reduced 20-40% compared to a conventional throat design. Unlike a conventional throat design, you can not simply do a routine barrel set back to clean up the throat. As such i could not recommend this design to my customers. I prefer long accuracy life throat and just use a bigger displacement engine to get the speed.
Once a throat wears to a certain point in a barrel with a shallow rifling design, its done. And a shallow rifling will erode to that point of no return MUCH more quickly then full depth rifling design.
Proof has stated they are using special alloys that will stand up to erosion much better then conventional stainless. Similar claims that Bartlein states about their 400BB steel. That alloy does offer some extended barrel life but not dramatic, at least not in my wildcat chamberings. In smaller capacity chamberings, the results are better.
Finally cost….. $1020 for a barrel. Considering one can buy two all steel barrels for less then this, thats hard for some to justify. If it will offer 50% longer barrel life….. but will it, i suspect no.
An all steel barrels of much smaller contour and fluted will be only marginally heavier, stiffer and more rigid then most of these carbon barrels, especially if they get out to that 26" or longer length. Have physically tested this and proven carbon barrels flex more then all steel barrels when same amount of weight is hung off the end of each. I may seem old school but steel is just stiffer and more rigid in a rifle barrel. Pound for pound, carbon is stiffer but a 4 lb cylinder of steel makes for a usable rifle barrel, a 4 lb cylinder of carbon is far to large to be useful for anything resembling a barrel…. That has always been the case.
If i had to GUESS, these NEW barrels with this NEW tech will not deliver fully the claims that have been made. Been at this a while, seem many new tech ideas come and most go. All had merit in advancing our industry but all also brought their own issues. Some remain, most have dropped off in popularity.
Like Alex, i will not buy one of these barrels and donate the time and labor and cost just to test one. If a customer wants one, by all means i will give one a go. I have no interest in having one for a personal barrel, at least not enough interest to drop +$1k to find out. Time will tell plenty
Again, i suspect accuracy life will be dramatically less then advertised, at least with serious performance chamberings
I suspect these will have the same issues as gain twist barrels do with jacket integrity as they get some wear on them.
Cost will be a serious issue with many shooters, especially if it is proven barrel life is not increased 50-80%…… which i predict will not happen.
I may be proven wrong on all counts, if i am i will be surprised from what has come and gone in the past few decades. I believe this is mostly marketing hype. That is rampant in this industry as we all know. I truly hope this is not just another case of that same hype but i suspect it is.
Time will tell, will prove itself or it will not. Once in the hands of unbiased shooters, we will learn a lot as these barrels get in the field with a decent number of rounds down the barrel. They will either work or they will be lime the King telling everyone to look at his beautiful clothes while standing there naked…. Hooefully it lives up to the marketing hype better then the 204 ruger, 6.5 creedmoor, 257 rpm or 7mm BC……
My first comment, i do not mind proof barrels for hunting rifles. Everyone i have used for customer builds has met my 1/2 moa at long range accuracy standards. That said, every one had has POI walking as barrels warm up to some degree. Some minor some rather significant. This is generally hardly noticeable shooting groups at 100 yards but i never shoot groups at 100 yards. Testing at 600, 800 and 1000 yards, its very easy to see. Generally starts on shots 3-4 and will get progressively more noticable with more firings and barrel heat. To be fair, this is not a proof problem, its more generally a carbon wrapped barrel issue. Some are much worse then Proof, some much better. For a big game rifle, this is of little concern. You take 3-5 shots in the field at a big game animal, things have likely gone pretty western…..
As far as this design, have a lot of experience with gain twist barrels and while i know this design has some differences, it also will have some of the same issues. Its been stated that these barrels are not hard on bullet jackets, that my be when new and smooth but as the barrels wear, there will be more stress imposed on the jacket.
When a conventional rifling cuts into a bullet, it will leave a consistent groove that will never change on the bullet jacket as the bullet travels down the bore. As long as the bullet is seated near or to the lands and starts rotating as soon as it starts down the bore, the actual stress on the bullet jacket is not that great.
With this design and with gain twist, that groove cut into or pressed into, however you want to discribe it, the rifling groove pitch on the bullet jacket will continually be changing, which means there WILL BE a unique stress placed on the bullet jacket. The engraving on the bullet baring surface will be continually changing. Something that certainly caused issues with gain twist barrels. It will be an issue here as well, no way it can not be, at least with conventional cup jacketed bullets. Solids, another story as they have no jacket to worry about.
Using bullets with rear drive band designs such as CE will be interesting to see what happens…..
Another concern, from what i can tell from the information i have gotten, the rifling starts out very shallow and gradually gets taller as you get farther down the bore making the engraving of the jacket very gradual. This is similar in design to my Hybrid throat design and DE +P throat designs. The two are extremely similar in design and function and performance results.
I will only mention why i no longer offer my Hybrid throat design to customers and not what others claim. In my testing, with my wildcats in 6.5mm, 7mm, 308 and 337 calibers, this shallow throat rifling concept certainly boosts performance numbers by flattening the pressure curve. No question there. A flattened pressure curve allows us to use faster burn rate powders to gain significant performance, or allow MORE powder to be used compared to conventional rifled barrels.
However, in every test I performed, barrel accuracy life was reduced 20-40% compared to a conventional throat design. Unlike a conventional throat design, you can not simply do a routine barrel set back to clean up the throat. As such i could not recommend this design to my customers. I prefer long accuracy life throat and just use a bigger displacement engine to get the speed.
Once a throat wears to a certain point in a barrel with a shallow rifling design, its done. And a shallow rifling will erode to that point of no return MUCH more quickly then full depth rifling design.
Proof has stated they are using special alloys that will stand up to erosion much better then conventional stainless. Similar claims that Bartlein states about their 400BB steel. That alloy does offer some extended barrel life but not dramatic, at least not in my wildcat chamberings. In smaller capacity chamberings, the results are better.
Finally cost….. $1020 for a barrel. Considering one can buy two all steel barrels for less then this, thats hard for some to justify. If it will offer 50% longer barrel life….. but will it, i suspect no.
An all steel barrels of much smaller contour and fluted will be only marginally heavier, stiffer and more rigid then most of these carbon barrels, especially if they get out to that 26" or longer length. Have physically tested this and proven carbon barrels flex more then all steel barrels when same amount of weight is hung off the end of each. I may seem old school but steel is just stiffer and more rigid in a rifle barrel. Pound for pound, carbon is stiffer but a 4 lb cylinder of steel makes for a usable rifle barrel, a 4 lb cylinder of carbon is far to large to be useful for anything resembling a barrel…. That has always been the case.
If i had to GUESS, these NEW barrels with this NEW tech will not deliver fully the claims that have been made. Been at this a while, seem many new tech ideas come and most go. All had merit in advancing our industry but all also brought their own issues. Some remain, most have dropped off in popularity.
Like Alex, i will not buy one of these barrels and donate the time and labor and cost just to test one. If a customer wants one, by all means i will give one a go. I have no interest in having one for a personal barrel, at least not enough interest to drop +$1k to find out. Time will tell plenty
Again, i suspect accuracy life will be dramatically less then advertised, at least with serious performance chamberings
I suspect these will have the same issues as gain twist barrels do with jacket integrity as they get some wear on them.
Cost will be a serious issue with many shooters, especially if it is proven barrel life is not increased 50-80%…… which i predict will not happen.
I may be proven wrong on all counts, if i am i will be surprised from what has come and gone in the past few decades. I believe this is mostly marketing hype. That is rampant in this industry as we all know. I truly hope this is not just another case of that same hype but i suspect it is.
Time will tell, will prove itself or it will not. Once in the hands of unbiased shooters, we will learn a lot as these barrels get in the field with a decent number of rounds down the barrel. They will either work or they will be lime the King telling everyone to look at his beautiful clothes while standing there naked…. Hooefully it lives up to the marketing hype better then the 204 ruger, 6.5 creedmoor, 257 rpm or 7mm BC……
slowly chipping away at it. That build will not be a PXT lol
