That's the BATF, the serial number designates that it can be in pistol configuration. It's essentially a short 40X. Look at the bolt it uses. Try a 40X one piece scope base. Fits perfect when you cut off the back hole. The way it's used, it's as much rifle as any other BR rifle.
S
steve b.
Guest
Great, now that we are all on some page, any photos or info with this barrel countour on a something other than an XP...?
Steve,
I don't think they were tried on anything but the XP. I could be wrong. Maybe I don't understand your question. Are you just wanting to see it on something like a Turbo in rifle configuration or are you wondering about performance? The reason I ask is performance probably won't be much different except most people have little experience shooting a Calfee XP and that would be a factor.
I don't think they were tried on anything but the XP. I could be wrong. Maybe I don't understand your question. Are you just wanting to see it on something like a Turbo in rifle configuration or are you wondering about performance? The reason I ask is performance probably won't be much different except most people have little experience shooting a Calfee XP and that would be a factor.
S
steve b.
Guest
Beau,
In terms of a Sporter or 10.5 lb rifle, I wanted to see if they helped in tuning a rifle without adding tons of weight to the tuner. It's my guess that this countor could help in allowing the tuner of a 10.5 rifle be more effective with less weight, and allow for the tuning of a Sporter via lathe and barrel OAL.
But, from some of the scores I have been seeing, I guess it's not done because the need has not presented itself.
s.
In terms of a Sporter or 10.5 lb rifle, I wanted to see if they helped in tuning a rifle without adding tons of weight to the tuner. It's my guess that this countor could help in allowing the tuner of a 10.5 rifle be more effective with less weight, and allow for the tuning of a Sporter via lathe and barrel OAL.
But, from some of the scores I have been seeing, I guess it's not done because the need has not presented itself.
s.
P
pacecil
Guest
Wow!!!
Let me see if I got this straight. If you reduce the barrel down as shown on the XP you will allow it to vibrate more. You can then add a tuner to reduce the vibrations back down to what they would have been if you didn't cut the barrel down. You make a better gun because you made it worse so you can make it better! Riiiiight!
Let me see if I got this straight. If you reduce the barrel down as shown on the XP you will allow it to vibrate more. You can then add a tuner to reduce the vibrations back down to what they would have been if you didn't cut the barrel down. You make a better gun because you made it worse so you can make it better! Riiiiight!
I believe BC had some barrels out that were lighter and smaller diameter a while back with the more to tune/more tunable mindset but it looked like a propasition that yielded diminishing returns. Anyway it seems like something around that .900" mark seems pretty common today.
No, you don't have it straight. If you have a barrel that needs a lot of lapping to get a tapered bore, you can lap the barrel, turn down the middle, which opens it up, blend the lap and you have a taper. Little less work for the same result. If it is easier to tune that's just a side benefit.
P
pacecil
Guest
Beau...
The relief of stresses in bore by machining off o. d. is a valid point. This makes sense to do this to get a proper taper into the bore.
What I don't see is the argument that tuning is made easier by using a smaller diameter barrel. I think you will understand the analogy using finance's. This would be like saying, you could get some one out of debt more easily if you can first get him into more debt.
I don't believe tuning is made easier by increasing vibration. Probably what has happened to Calfee and others is simply this: They don't find a light barrel shoots very well and they find by adding weight to the barrel they can improve it. They call this weight a tuner and declare that lighter weight barrels can be more easily tuned. The conclusion they should have reached is light barrels more often NEED tuning.
The relief of stresses in bore by machining off o. d. is a valid point. This makes sense to do this to get a proper taper into the bore.
What I don't see is the argument that tuning is made easier by using a smaller diameter barrel. I think you will understand the analogy using finance's. This would be like saying, you could get some one out of debt more easily if you can first get him into more debt.
I don't believe tuning is made easier by increasing vibration. Probably what has happened to Calfee and others is simply this: They don't find a light barrel shoots very well and they find by adding weight to the barrel they can improve it. They call this weight a tuner and declare that lighter weight barrels can be more easily tuned. The conclusion they should have reached is light barrels more often NEED tuning.
When bill first looked into the Barrel Device....he was using larger and heavier barrels. What he found...through a lot of trial and error...was a barrel diameter that the device worked best with and surpased the ability of the larger stiffer barrel in 22 rimfire. When I first looked into 22 rimfire shooting, everyone was pretty much following the same path at centerfire, short heavy barrels.
Hovis
Hovis
I think you have to follow the history of the whole tuner thing, and I know there were tuners back when cavemen didn't work for Geico, but I'm talking about the rimfire tuners that first showed up around 1995-96.
For one, I've never bought the theory that you can make a barrel shoot better by first making it worse, but from the time I've been shooting rimfire, I've never seen a heavy barrel do consistently well against a barrel that was between .850 and .900. In other words, ever since I've been doing this "light" barrels have shot well. Adding weight seems to improve them. But I think you have to say a lighter more flexible barrel is easier to tune simply because of the weight that would have to be added to a heavy, stiffer barrel. Common sense says the heavier stiffer barrel should shoot better, but they don't at least not consistently. All of Calfee's barrels that I've ever seen have been in .825 to .900 range and maybe some a little smaller. This was not initially done for tune; it was done for weight. BR-50 gave you a 1% increase in score for each pound you were under 12lbs, so you could often win with a pistol even though you didn't shoot the best agg. I hope we don't get into the fairness of that as BR-50 is long gone. As tuners became more popular and the weight advantage disappeared, barrels became longer. Some people say to make them more tunable; I think a longer barrel to a point shoots better anyway.
I've seen people shoot is gale force winds and then jump up and turn their tuner a few clicks and say "there it is". I never subscribed to that and still don't. I think the weight (or mass) of the tuner has more to do with increasing the accuracy than anything but I suppose there is a maximum weight. I said for years that adjustable tuners could not have a great effect because when you calculate the actual change in weight on one click it is insignificant. My opinion was that a tuner is simply a weight. I have modified that opinion to some degree over the years but still don't see it as a miracle device. I always thought a tuner without clicks but with stackable weights would be the best choice. I also always thought, and stil do, that tuners once set should probably never be reset. A lot of people disagree with that, but several of the movers and shakers in rimfire seem to be coming to basically the same conclusion.
To summarize, the light barrels shot very well, the weight improved them.
Finally, if there is any effect of being able to tune better due to the expansion barrel, it is a side effect. It's merely a way of mechanically inducing a taper
Finally, if you BELIEVE it works, it will.
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More on the expansion barrel
Here’s a picture of one of BC's expansion chamber barrels that was used for a test a couple years ago. He had an article of the results about finished when he decided to stop writing for Precision Shooting Magazine.
Anyway, this barrel is threaded for three actions, a 40-X, an XP-22 and a Turbo. The tenon length of the Turbo and the 40-X are shorter than the XP-22, so to headspace it to the Turbo or 40-X, BC machined two very precision spacers that fit between the barrel shoulder of the XP and the action face of either the 40-X or the Turbo.
The extractor slots are cut for the XP so to test on the 40-X or Turbo the empties had to be picked by fingernail. He also didn’t even use the extractors for the XP part of the test, that way the test would be consistent from action to action.
What he wanted to see is which action would make the barrel shoot the best, the 40-X, XP or the Turbo and he found out at least to his satisfaction.
Anybody care to guess.
Here’s a picture of one of BC's expansion chamber barrels that was used for a test a couple years ago. He had an article of the results about finished when he decided to stop writing for Precision Shooting Magazine.
Anyway, this barrel is threaded for three actions, a 40-X, an XP-22 and a Turbo. The tenon length of the Turbo and the 40-X are shorter than the XP-22, so to headspace it to the Turbo or 40-X, BC machined two very precision spacers that fit between the barrel shoulder of the XP and the action face of either the 40-X or the Turbo.
The extractor slots are cut for the XP so to test on the 40-X or Turbo the empties had to be picked by fingernail. He also didn’t even use the extractors for the XP part of the test, that way the test would be consistent from action to action.
What he wanted to see is which action would make the barrel shoot the best, the 40-X, XP or the Turbo and he found out at least to his satisfaction.
Anybody care to guess.
J
Jefferson
Guest
I will guess
XP22 of course
Jefferson
XP22 of course
Jefferson
J
J Pappas
Guest
Mossburg?
Probably a Turbo.
Probably a Turbo.
J
J Pappas
Guest
Beau
I think I am sharper, I did not guess the 40X or the XP. When Bill has to do a 40X or trigger work he should send it to Gene Davis. Gene doesn't have any problem making them shoot as good as a Turbo. Seems Like a 40x smithed by Gene won the ARA Nationals last year.
I think I am sharper, I did not guess the 40X or the XP. When Bill has to do a 40X or trigger work he should send it to Gene Davis. Gene doesn't have any problem making them shoot as good as a Turbo. Seems Like a 40x smithed by Gene won the ARA Nationals last year.
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Kent Owens
Well-known member
Looks like there would be quite a bit of space around the rear of the 3/4" barrel shank if it was threaded to a 40X. Wonder if that had any bearing on it. No way to tell on a test like that. Pretty work though.