• *The discussion of the creation, fabrication, or modification of airgun moderators is prohibited. The discussion of any "adapters" used to convert an airgun moderator to a firearm silencer will result in immediate termination of the account.*

"HIGH" quality aftermarket barrels in their pcp's?

For some of the winners at EBR and RMAC the trend for the last few years are slower twists for pellets, like 30 or 40. Some of these barrels typically shoot the lighter slugs ok but at some point in weight and length the precision begins to fail.

Then many of the guys that are dedicated to shooting slugs are leaning towards faster twists to shoot the longer and higher BC slugs.

Here's my match 22rf which is a Anschutz 1827F biathlon. It averaged .26" in the Jbells 50Y 6x5 when I first got the gun a decade ago. It has occasional POI shifts though which I haven't been able to figure out totally yet despite bedding, having a steel pic mount made, etc.

And I'd still like to get a Vudoo at some point!
View attachment 325890
Nice rig for sure! Love the Annies but a Vudoo is my wet dream
 
  • Like
Reactions: steve123
Karl,

For long range I'm kinda tapped out on the 22rf thing because of the poor-ish ES of the better ammo's as well as the cost of them. I still do it some but that hindrance is something I can't see ever being overcome.

I made up a light load for my 5mmFBI, its like a 20 Vartarg AI. I got the SD down around 8 with 10 grains of powder and its a .6" gun at 100Y. Around 2300 fps and .21 BC which I enjoy for its benefits out to 420Y.

I have a few pcp's I use for slugs now that do ok at long range but I'd like nearly twice the power and want to use 50-65gr slugs. Around 900 fps is fine. From what I read here on AGN about what a ballistic expert wrote, there is no wind benefit in the 1050 fps range compared to 900 fps for slugs so I might as well save the air than go there.
 
(Pardon the thread creep)
Can't explain why, but the Vudoo just shoots. I've had both a Bartlein and Ace barrel - they both shoot in the .2s at 50.

My Safari with 25.4 RDs stays in the .2s at 25

vudoo.jpg
 
Karl,

For long range I'm kinda tapped out on the 22rf thing because of the poor-ish ES of the better ammo's as well as the cost of them. I still do it some but that hindrance is something I can't see ever being overcome.

I made up a light load for my 5mmFBI, its like a 20 Vartarg AI. I got the SD down around 8 with 10 grains of powder and its a .6" gun at 100Y. Around 2300 fps and .21 BC which I enjoy for its benefits out to 420Y.

I have a few pcp's I use for slugs now that do ok at long range but I'd like nearly twice the power and want to use 50-65gr slugs. Around 900 fps is fine. From what I read here on AGN about what a ballistic expert wrote, there is no wind benefit in the 1050 fps range compared to 900 fps for slugs so I might as well save the air than go there.
I'm guessing you meant me:) I hear you on ES of rimfire ammo. That old lot from the 80's of cci standard velocity may just have been the best lot they made ever, even better than most current high dollar match ammo. ES over hundreds that went through a chrono was right about 30 fps, and 48-49 out of 50 would be closer to 20-23 fps ES. I bet if I had 100k of them right now some well healed competitors would pay me dearly for that ammo. It was sub moa, barely including the small fliers, in no wind at 100 yards all the time in my normal rimfires, not high end competition stuff.

Wind drift for the same bullet/slug is greater the higher in transonic range you get, starting around 880 or so fps is where it starts to get measurable instead of lost in the noise for a reasonably accurate weapon. You can run any ballistic calculator and vary the muzzle velocity from 880 to 1000 and see how much more the wind affects drift at 100 yards, it is science, that I don't pretend to understand. At the same time, twist rate needed to stabilize increases dramatically.

Vudoo is the company working on the 1-9 twist 22" barrels, they have done lots of doppler radar work with it and other twist rates, the 1-9 twist improves long range BC by a lot, but not with shorter than 22" barrels. Has something to do with the angular acceleration of bullet in barrel and something doesn't settle down until 22", shorter barrels in 1-9 do worse than standard twist.
 
  • Like
Reactions: steve123
When you tell a airgun machining guy ..that you have a barrel that he has to work from 1-1/4 .. or 1-1/2 at 32 " long..to 5/8" that is simply not happening..🙃

The point of using a Krieger or a Lilja as far as what I want to end up with, is to NOT turn it down but to use it at the largest OD that will fit on your airgun without a shroud over it. Obviously that isn't going to work on something like an FX, but it sure could on an RTI Prophet 2 from what I can see.
 
  • Like
Reactions: mercado
The point of using a Krieger or a Lilja as far as what I want to end up with, is to NOT turn it down but to use it at the largest OD that will fit on your airgun without a shroud over it. Obviously that isn't going to work on something like an FX, but it sure could on an RTI Prophet 2 from what I can see.
In my case I wanted to use it in a texan that needed to be reduced to 1" in order to fit the frame..that was like 2 or 3 years ago..but at that moment couldn't find someone to doit..but right now.. Donny is coming out with a line of gun that use a bull barrel, so I'm really looking forward for its release..
 
It should be understood that turning down the OD of a button rifled barrel will open up the ID. Taking a 1” barrel and turning the first 4” down to 16mm to fit in an airgun action will create 4” of loose barrel and it will feel like running into a wall when you reach the full diameter pushing a pellet or slug through. By doing so, you will have seriously compromised the barrel performance right from the start. You would be better off to turn the entire length…but then you are back where you started.

Mike
 
  • Wow
Reactions: JungleShooter
It should be understood that turning down the OD of a button rifled barrel will open up the ID. Taking a 1” barrel and turning the first 4” down to 16mm to fit in an airgun action will create 4” of loose barrel and it will feel like running into a wall when you reach the full diameter pushing a pellet or slug through. By doing so, you will have seriously compromised the barrel performance right from the start. You would be better off to turn the entire length…but then you are back where you started.

Mike
What will be the effect of reducing OD of a cold hammer forged barrel?
 
What will be the effect of reducing OD of a cold hammer forged barrel?
For what it’s worth, the industry data is unequivocal about hammer forging introducing stresses into the material. For example, barrels for powderburners need a secondary operation after hammer forging to relieve stresses, otherwise the barrel and its POI will move as it heats up. However it’s not obvious to me how that would translate to potential changes to the bore resulting from removing material from the OD, except that on an intuitive level it doesn’t seem favorable.
 
  • Like
Reactions: mubhaur