There was a thread somewhere on this site that discusses compensators and had links to what the port/ baffle angle should be along w distance from muzzle for the leading edge of the baffle. The idea being to scrub the gases before imbalance could induce yaw. Did you happen to read that thread? I'd like to revisit it but have had no luck in searching.
- Thread starter Goofster
- Start date
No, I never saw that one...
I should've said that I just shot the 1st match since putting the tuner on that V-22 - I built it in Sept. of '17, and have shot it in every PRS-type 22RF match I've shot since then.
Haven’t said much in while here, so here’s a small update. I’ve been continuing testing the 10tw, have made hits out to 500 with it on switchy wind days. Unfortunately haven’t gotten a chance to play in the calm. Have placed decent in prs regional matches with it. I don’t think I can reach 600 with my current setup, but I’ll try next fairly calm range day.
This thread is fascinating. I have a fast twist rimfire. 1:8 PacNor .172. barrel. Chambers 22lr. and swages the bustles down to .172 upon firing. The barrel will stabilize bullets up to 36gr. IT IS NOT A MATCH ACCURATE RIFLE. It is a hunting/varminting gun built before the 17HMR was a thing. However, it has occasionally shot 1-inch groups at 100 yards with yellowjackets (33gr) and Federal 724 (31gr). It seems to shoot any 36gr hv truncated cone hp bullet just over MOA at 50 yards. Armscor Precision is an example. The barrel started life at 24 inches but after 19yrs of lugging that heavy beast around I had it shorted to 16.5. It shoots the same as it did when 24 inches long.
The photo shows some recovered 33gr yellowjackets, some recovered 20gr CB short bullets and one 20gr bullet recovered from firing out of a .22rf. barrel. The choke is just ahead of the chamber and short. Randy at Connecticut Precision Chambering cut the chamber. If decent hunting accuracy can be had from a choked barrel shooting hyper velocity ammo, then I think that match ammo from a match chamber spin a bit faster can be very accurate. Folks with money keep pushing, please!
P.S. in October 2001 I wrote this rifle up in the now defunct Precision Shooting magazine. Some of you may have copies.
The photo shows some recovered 33gr yellowjackets, some recovered 20gr CB short bullets and one 20gr bullet recovered from firing out of a .22rf. barrel. The choke is just ahead of the chamber and short. Randy at Connecticut Precision Chambering cut the chamber. If decent hunting accuracy can be had from a choked barrel shooting hyper velocity ammo, then I think that match ammo from a match chamber spin a bit faster can be very accurate. Folks with money keep pushing, please!
P.S. in October 2001 I wrote this rifle up in the now defunct Precision Shooting magazine. Some of you may have copies.
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Thanks. It is fun. I have not shot it past 100 yards, at least not that I recall. This thread has inspired me to do so. It is being restocked at the moment. It is receiving a laminated stock with adjustments and enough meat for the barreled action. this skinny sporter stock is ridiculous on the rifle! When I get it back I will put a 25MOA DIP cz527 rail on it and start testing out to 300 meters. The action is from a Brno model 1. Basically cz452 but with the wider cz527 receiver dovetail, and a two stage trigger.
Hard numbers for those interested. My 5.75” twist barrel on the bottom of first pic. Then my buddies 16” twist on the next. 
Minus my fast first round, which was shot after 10 rounds of copper solids. Our Es was identical at 28fps. Of course, same barrel lengths and chambers would have made more direct comparison. This is pretty typical of what I’ve seen before. AB is supposed to be getting a bunch of 22 barrels in different twists to test this very thing.
Ix
The bad lands are decent for BC variation.
I'm glad to hear AB is going to test it as they wont be biased.
The bad lands are decent for BC variation.
Shot at 300 today, it was calm compared to the last try.
Vudoo 360 10 Twist.
The setup.
Noticed an insect on the flower
The results. Of course I got excited and opened it up on the last shot.
Vudoo 360 10 Twist.
The setup.
Noticed an insect on the flower
The results. Of course I got excited and opened it up on the last shot.
I expect if you sent another 5-10 the 2.43" vertical would look "normal" and that would not be a "flier".
Good group by the way!
Nah I’m not gonna tell myself that
Try it....Nah I’m not gonna tell myself that
dare you.... I would have shot more but only had one box of what I had gone out to try.
Shot 5 to confirm zero at 50
35 for a 6x5 at 100
and the last 10 to try out 300.
I dialed .5 left so I could see the group vs the black bull where I would have no idea what’s going on wind wise.
Now to find more of that ammo.
Shot 5 to confirm zero at 50
35 for a 6x5 at 100
and the last 10 to try out 300.
I dialed .5 left so I could see the group vs the black bull where I would have no idea what’s going on wind wise.
Now to find more of that ammo.
What ammo were you using?
I also use a regular match reamer.
Thanks guys, good to know.
I am very seriously contemplating ordering a 1/12 twist barrel in the very near future. Can anyone with experience tell me if 20" is too short with this twist rate or is 22" a safer bet?
Everything I've read says that you need 22" to stabilize the faster twist.
I have read the same regarding 1/9 twist. I just spoke with someone at IBI barrels and he mentioned that with 1/12 twist the 20” had better overall accuracy based on their testing but was barely noticeable difference compared to 22”.
I had the same conversation with Ryan at IBI. If I remember right, he said there was some velocity loss at 22” vs 20”. Considering what I had read about 22” being better in faster twists, and wanting my barrel to stick out past my ACC forend, I ordered a 22”.
Do you have it yet and/or how does it shoot?
I’m hoping to have it in a month or so. If it tightens up the vertical spread for 10 rnds+ at 200+ I’ll be happy. If it puts 10 rnds of SK RM in 1/2” at 50 and 10 in 1 1/4” at 100 consistently I’ll be real happy.
My 1-12 from IBI just arrived. Once I have some solid data I'll share. I currently have a 1-16 from them as well.
What action(s) are you running your 1/12 and 1/16 IBI barrels on?
1-12 on a Ultimatum Deuce 1-16 on a RimX
I shoot almost exclusively suppressed
Anyone doing a test cycle 1:16vs1:12?
Yes. 16 twist until 200 then 12t better. It's close before 200 but the 16t slightly out edges it.
I’ve seen some chat on another forum, but didn’t want to steal any thunder.
I gave up on my 9 twist. Too many crazy fliers. Lapua test center results were not great. I shot thousands of rounds through it trying to convince myself it shot and that maybe the fliers were me. Swapped stocks, triggers, scopes. It wasn’t until i shot the fast twist side by side with my 1:16 on the same day I saw it wasn’t me.
Were you running a 22" barrel?
24
24”
I just got a 22 inch 12 twist and am thinking of doing some tests against my 16.5 inch 16 twist but I have a feeling that is an apples to oranges comparison due to the different barrel lengths
Wont matter. Test a bunch of ammo compare the ones that group simular at 200 at 300 it will be obvious.
The barrels best will likely be with different ammo. To say one twist rate shoots better just because you get smaller groups with it using ammo X doesnt mean that its better. It only means out of the ammo you tested it shot best. It has to be averaged out over a bunch of ammo types. You also have to eliminate the ammo each barrel hates as it can skew results. If a ammo doesnt suit one of the barrels take it out of the test. I results show 30% smaller groups at 300 yard with 12 vs 16 with ammo that shoots simular at 200.
Because the best in each relies to much on harmonics and various other factors that approach will not work.
Example all of my testing would indicate that Eley is better at long range then lapua multiple rifles and lot#s so if the 16 twist prefers lapua (it does at 50,100) it would skew the results if I use Eley in the 12 twist. Then check long range performance. I already know the Eley is going to win. We also have to use the same lots in both. One of the reasons for this is I had a lot of Eley match that I was regularly shooting 1 moa groups at 200 (20 shot) this same lot didnt shoot well in the 16 at all. I also have not had any lot since then that would do that. So if looking only at best data would be pointless.
When looking at statistics it is very important to not get hung up on the extremes. I could really go off track here but when you compare woman and man charitaristics our woke left is infatuated with the extremes giving very skewed "data". The reality is the difference between genders personalities on average is extremely small if you include all data.
We have to use a selection of ammo and lots that shoot simular in both so we can have a average across different brands and bullet types. Then we can look at the rate of group growth to see if the additional spin is helping.
Now if someone had enough money that they could test 1000s of different ammo this would take care of itself. I simple dont have the funds or the time for such a exercise.
I say average because we can end up with really bad data if we only use one ammo type. A example that comes to mind for me is bullet BC. If I would only test BC increase going from a 16 to 12 with SK, lapua I would be all excited because of the 8% increase in BC. Well if I test that with Eleys 42 gr bullet its 2%.
We need to run averages.
Lapua shoots the best in both rifles at 50 with 16 and 12. Groups are the same size. At 200 the 12 has half the group size.
Same is true with Eley Tenex shoots the same at 50 but at 200 the 12 is maybe 1/3 the size of the 16. Maybe thats more along the lines of how some people think.
Example all of my testing would indicate that Eley is better at long range then lapua multiple rifles and lot#s so if the 16 twist prefers lapua (it does at 50,100) it would skew the results if I use Eley in the 12 twist. Then check long range performance. I already know the Eley is going to win. We also have to use the same lots in both. One of the reasons for this is I had a lot of Eley match that I was regularly shooting 1 moa groups at 200 (20 shot) this same lot didnt shoot well in the 16 at all. I also have not had any lot since then that would do that. So if looking only at best data would be pointless.
When looking at statistics it is very important to not get hung up on the extremes. I could really go off track here but when you compare woman and man charitaristics our woke left is infatuated with the extremes giving very skewed "data". The reality is the difference between genders personalities on average is extremely small if you include all data.
We have to use a selection of ammo and lots that shoot simular in both so we can have a average across different brands and bullet types. Then we can look at the rate of group growth to see if the additional spin is helping.
Now if someone had enough money that they could test 1000s of different ammo this would take care of itself. I simple dont have the funds or the time for such a exercise.
I say average because we can end up with really bad data if we only use one ammo type. A example that comes to mind for me is bullet BC. If I would only test BC increase going from a 16 to 12 with SK, lapua I would be all excited because of the 8% increase in BC. Well if I test that with Eleys 42 gr bullet its 2%.
We need to run averages.
Lapua shoots the best in both rifles at 50 with 16 and 12. Groups are the same size. At 200 the 12 has half the group size.
Same is true with Eley Tenex shoots the same at 50 but at 200 the 12 is maybe 1/3 the size of the 16. Maybe thats more along the lines of how some people think.
Test the best ammo in each rifle/barrel to determine if one outperforms another.
If the best performing ammo is not tested in different rifles/barrels, what is the purpose of the test? If a shooter wishes to compare how two rifles/barrels shoot, there's no reason to compare how they shoot ammo that doesn't perform well. If it's believed that different ammo perform differently at various distances, test with the ammos that perform best in each rifle/distance at the distance in question.
Is there any identifiable reason to expect that as a rule Eley ammo performs better at distance than Lapua?
If the best performing ammo is not tested in different rifles/barrels, what is the purpose of the test? If a shooter wishes to compare how two rifles/barrels shoot, there's no reason to compare how they shoot ammo that doesn't perform well. If it's believed that different ammo perform differently at various distances, test with the ammos that perform best in each rifle/distance at the distance in question.
Is there any identifiable reason to expect that as a rule Eley ammo performs better at distance than Lapua?
I had 6 lots of Center-X that came from Lapua test center for various rifles, and although I didn't send my new 16t and 12t for testing yet, they each found a lot of Center-X that worked the best for it and then a few hundred rounds between 50-200y. So while it's not as many rounds as CRPS did, it was enough to see that the clumps at 200y were much smaller, even though the groups at 50/100 were about the same as my 16T.
To be upfront, my 16T is also a more expensive rifle as a Vudoo 360 with a Benchmark Barrel. And my 12T is a Deuce with an IBI barrel. So it is possible that if I wanted to do more apples to apples, like a Vudoo 360, Benchmark 12T put together by Vudoo, maybe a 12T would perform even better...
But the fact that my 16T outperforms it, and the 12T takes over at 200y, and that CRPS is seeing gains > 200y and more out to 400y has a good amount of evidence.
I don't shoot matches regularly out past 200y so I run my 16T all the time as it is more consistent at ranges < 200y. At the longer distances, the targets are generous enough that honestly if I'm not shooting f-class at 300y, the wind call is what is going to get you, not the vertical dispersion. NRL/PRS targets are always large enough so it's not a pure gear challenge. So while it is really cool to shoot a 3" group at 300y, the targets are always going to be rather generous.
To be upfront, my 16T is also a more expensive rifle as a Vudoo 360 with a Benchmark Barrel. And my 12T is a Deuce with an IBI barrel. So it is possible that if I wanted to do more apples to apples, like a Vudoo 360, Benchmark 12T put together by Vudoo, maybe a 12T would perform even better...
But the fact that my 16T outperforms it, and the 12T takes over at 200y, and that CRPS is seeing gains > 200y and more out to 400y has a good amount of evidence.
I don't shoot matches regularly out past 200y so I run my 16T all the time as it is more consistent at ranges < 200y. At the longer distances, the targets are generous enough that honestly if I'm not shooting f-class at 300y, the wind call is what is going to get you, not the vertical dispersion. NRL/PRS targets are always large enough so it's not a pure gear challenge. So while it is really cool to shoot a 3" group at 300y, the targets are always going to be rather generous.
The smaller cone of error really does help cover other mistakes, rather than multiply them though. Especially considering how 22 rounds get squirrelly out at 300, compared to CF. 300M with 22 RF is the same as 1300M+ elevation wise with a 6.5.
Agree on the cone of error. Usually my errors are left and right and not up and down so that's why I'm not so concerned.
On lapua vs Eley I dont have a answer. Both have the same velocity ES on large sample sizes. Both have the same BC.
On average my best groups at close range are with lapua.
My best guess is it just harmonics? Maybe? Its a question that is interesting to me. Your rifles with different brand barrels and chambers might be different?
Both brands shoot well hot to cold. Both are not velocity sensitive as in I can shoot slow and fast lots with simular results.
When my rest has fore/aft wobble is the only time vertical is really an issue outside of velocity variation.
(Edited as I mistyped the twist rate)
Incredible thread.
It opens to many questions though:
1. Is the “Goldilocks” barrel length to twist rate a constant? (9T/22”)
2. Does such a combo have a “Goldilocks” range where it will excel above all others with conventional 40gr .22LR?
3. Does that imply that 16T has it’s own “Goldilocks” zone of barrel length and range?
4. Would this apply to other twists such as 12T, 14T, etc?
5. Is the “secret” to the 22” barrel/9T combo a perfect storm of reduction in bullet upset from muzzle blast/powder burn and pressure curve?
In the same vein of long distance rimfire accuracy testing, are there “benchmarks” in range that would
give the most useful, shareable results (such as 200, 300, 400yds?)
RAVAGE88
On your own test rifles, are you using your newer adjustable bolts in your action (pin strike depth/power)?
Incredible thread.
It opens to many questions though:
1. Is the “Goldilocks” barrel length to twist rate a constant? (9T/22”)
2. Does such a combo have a “Goldilocks” range where it will excel above all others with conventional 40gr .22LR?
3. Does that imply that 16T has it’s own “Goldilocks” zone of barrel length and range?
4. Would this apply to other twists such as 12T, 14T, etc?
5. Is the “secret” to the 22” barrel/9T combo a perfect storm of reduction in bullet upset from muzzle blast/powder burn and pressure curve?
In the same vein of long distance rimfire accuracy testing, are there “benchmarks” in range that would
give the most useful, shareable results (such as 200, 300, 400yds?)
RAVAGE88
On your own test rifles, are you using your newer adjustable bolts in your action (pin strike depth/power)?
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