GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Rallyshark on January 31, 2021, 11:45:50 PM
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I just got 2 new blanks in to test in my .177 slug gun all the way from Russia! They are Alfa Precision hammer forged blanks that I got via relay, thanks to Brian at Edgun West. I was going to order them straight from AP, but the cost of paying them along with questions on them actually making it here, made me give Brian at EW a call. He was more than happy to help me out, since Maxim at AP told me he could throw them in with the next shipment of Leshiy barrels :D Here's the link to them on Alfa Precision's site:
http://alfa-precision.net/airgun (http://alfa-precision.net/airgun)
What makes them interesting(besides being hammer forged) is the twist rates and length. They are 650mm blanks for MO POWER. One barrel is a polygon 15mm OD with a 16.5" twist, and the other is a standard rifling 16mm OD with a 14.6" twist! Both are a faster twist than anything we can readily order here in the states, so that should equate to some good slug barrels. That's assuming the bore diameter works out. I think it should work out perfectly. I pushed an NSA 15 grain .178 through, and the rifling engages better than any other barrel I've tested. The grooves on these barrels are supposed to be .179, and that looks to be spot on. On a side note, the steel on these appears to be a little harder than LW blanks. The 14.6" twist barrel also has a different color to it. It almost looks copper colored. Any of you metal gurus got a guess on what kind of steel it is? I'm pretty sure that color comes from the heat of the hammer forging process on that particular steel. I noticed the shavings from the barrel are also that color(got hot), but the machined part of the barrel is a more "regular" steel color.
I just finished machining the 14.6" twist barrel for a quick power test. The final length ended up being about 25.25" end to end, or about 25" from the barrel port. We'll just call it a 25" barrel. I only tested it for power, since I just finished, and have some other stuff to do, before I start target testing. I took the barrel port as far as I could as well, since this is a slug barrel. Anyway, power peaked at 1094 fps with an NSA 21 grain slug, for about 56 fpe!! It will do a full magazine(14 shots) over 1050 fps no problem, which will make a very good hunting tune for larger critters. Go here if you curious about what I mean, when I say larger critters:
https://www.gatewaytoairguns.org/GTA/index.php?topic=181799.msg156069322#msg156069322 (https://www.gatewaytoairguns.org/GTA/index.php?topic=181799.msg156069322#msg156069322)
I'm also hoping one of these barrels will like the 15 grain NSA slugs for high shot count target/pesting duties. I have a good feeling about that :) Hopefully, I don't end up with two big paper weights... I'll be glad when NSA gets the heavier .177 slugs up on their site, so I can do some more testing with those. In the mean time, I'll be getting Mike at griffin slugs to send me some 24 grain slugs to play with. As soon as I get some more heavier slugs to play with, I'll report back on the results! Below are some pictures showing a pushed through 15 grain .178 slug, the two blanks side by side, and the one I just finished on the gun(minus a few parts). Note the different color of one of the barrels..
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This awesome to here. I was just looking at LW for a barrel. Your pig thread got me wanting a .177. I’ll keep an eye on this to see the out come!!
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This awesome to here. I was just looking at LW for a barrel. Your pig thread got me wanting a .177. I’ll keep an eye on this to see the out come!!
I'd say definitely wait and see the outcome, before you get a .177 blank. The LW polygon unchoked does great, but at very specific HIGH speeds. I haven't tested the standard rifling LW unchoked at high power, so I can't speak to how it will do. I'm hoping these Alfa Precision barrels will be a little less fussy with faster twists and a slightly tighter bore. I forgot to mention, the Alfa barrels are unchoked, of course ;) I'll also note that Brian at Edgun West said he would get blanks for other people, if asked. He'll also be able to get AP barrels for some guns already machined! You won't get it as quickly as you would, if you called up LW and ordered a blank, but... Just giving full disclosure here :)
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I would have thought in this small caliber and purpose shooting slugs at high power / speed a tad SLOWER twist rate would be more useful ???
Will be watching and waiting to see & hear what the accuracy will be.
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I would have thought in this small caliber and purpose shooting slugs at high power / speed a tad SLOWER twist rate would be more useful ???
Will be watching and waiting to see & hear what the accuracy will be.
You could certainly be correct, and I'll be the first one to admit it, haha. Time will tell, and I won't know until I try. All I know is, all of the slower twist barrel blanks from the different manufacturers that I've seen don't do the job, so this was my next logical step to try. Especially for slugs in the 20+ grain weights. It could be a matter of bore diameter as well, but I don't know for sure. I just want to be able to get solid accuracy from the heavy slugs, without having to push them at blistering speeds just below the sound barrier ;)
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Scott, do you have any theories about the kind of steel that is with the odd color? It definitely isn't a coating.
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Scott, TJ's found the i in 9 twist to work best in the .172 barrels. and it is very close to the .179. so-----
Donny, the color is simply a result of heat. In heat treating of tool steels it is called Straw land indicates a heat range between 400 and 425 deg. More than likely, it was a stabilizing, or stress relief cycle given the barrel after rifling. This is a normal practice. Carried a little further, to say 475 and the steel takes on a beautiful golden color. 525 and pail blue, 575 to 600 a deep to royal blue, higher and they become first rainbow, then pale then grey.
This color scheme is typical of all carbon steels. Including lower carbon steels such as in gun barrels.
Now, where's mine! Just kidd'n, id have a 1-9 twist Tj's here now. Just no way to fit it or a mold for it. GRRRRR!!! ;D
Mike
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Mike ... noted on twist & we shall see what Donny gets for accuracy.
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Mike ... noted on twist & we shall see what Donny gets for accuracy.
Looking forward to Donny's results! Very much so. Interested!!!
Mike
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Subscribed.
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I’d like to know what the weight is on those heavy walled barrels. I’m also on the waiting list for NOE to make some more of the .172 molds as I’ve got a TJ’s waiting for a mold. I hope the AP barrel works well for you.
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Following. BSA uses 15.5mm barrels so these are not extremely thick ones. I can see a .177 or .172 bullet shooter in my future.
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Hobbyman2007, love those open sights!
Hunter
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On Ebay a coupe sellers from Russia sell .177 (and other calibers) "Compressor Tube" or "Hydraulic Tube" for air guns
https://www.ebay.com/sch/masterdornscom/m.html?item=274306245251&hash=item3fdded2283%3Ag%3AVS4AAOSwsMZdRsgh&rt=nc&_trksid=p2047675.l2562 (https://www.ebay.com/sch/masterdornscom/m.html?item=274306245251&hash=item3fdded2283%3Ag%3AVS4AAOSwsMZdRsgh&rt=nc&_trksid=p2047675.l2562)
https://www.ebay.com/sch/theriflingbuttonsgmailcom/m.html?item=264760323665&hash=item3da4f1ee51%3Ag%3AwioAAOSwbzpc-ZJr&rt=nc&_trksid=p2047675.l2562 (https://www.ebay.com/sch/theriflingbuttonsgmailcom/m.html?item=264760323665&hash=item3da4f1ee51%3Ag%3AwioAAOSwbzpc-ZJr&rt=nc&_trksid=p2047675.l2562)
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Looking forward to seeing your further reporting... Power, CHECK!
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Beautiful barrels Donny! So glad Brian of EW was able to get them in for you! I sure hope they work....would like to see you take down more giant pigs with .177! Incredible!
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well I have a gut feeling that the 14.5 twist may do well with 15g up to about 22-24g flat base rounds... the 1:9 twist was so the longer nose/ boat tail 25g-30g rounds would stabilize...
The 16 twist barrel may work well with 20g ish blunter nosed rounds...and should be fine with about 15g-17g... just my gut feeling again but had to see what the Kolbe drag calc said... probably the better compromise pellet/slug barrel... jmo... but well each rifle/barrel does what it does in the end...
http://www.geoffrey-kolbe.com/cgi-bin/drag_working.cgi?unit_length=inches&weight_unit=grains&bullet_name=.338+air&re_calculate=yes&boundary_layer=L%2FT&diameter=.179&length=.3&nose=.18&meplat=.06&drive_band=.179&base_diameter=.179&angle=0&boat_tail=0&secant_radius=&weight=14.4&density=11.4 (http://www.geoffrey-kolbe.com/cgi-bin/drag_working.cgi?unit_length=inches&weight_unit=grains&bullet_name=.338+air&re_calculate=yes&boundary_layer=L%2FT&diameter=.179&length=.3&nose=.18&meplat=.06&drive_band=.179&base_diameter=.179&angle=0&boat_tail=0&secant_radius=&weight=14.4&density=11.4)
http://www.geoffrey-kolbe.com/cgi-bin/drag_working.cgi?unit_length=inches&weight_unit=grains&bullet_name=.338+air&re_calculate=yes&boundary_layer=L%2FT&diameter=.179&length=.33&nose=.12&meplat=.06&drive_band=.179&base_diameter=.179&angle=0&boat_tail=0&secant_radius=&weight=18.9&density=11.4 (http://www.geoffrey-kolbe.com/cgi-bin/drag_working.cgi?unit_length=inches&weight_unit=grains&bullet_name=.338+air&re_calculate=yes&boundary_layer=L%2FT&diameter=.179&length=.33&nose=.12&meplat=.06&drive_band=.179&base_diameter=.179&angle=0&boat_tail=0&secant_radius=&weight=18.9&density=11.4)
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Hobbyman2007, love those open sights!
Hunter
They have them for sale on aliexpress. Novelty gun sights I think. Now back to the barrels
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Scott, TJ's found the i in 9 twist to work best in the .172 barrels. and it is very close to the .179. so-----
Donny, the color is simply a result of heat. In heat treating of tool steels it is called Straw land indicates a heat range between 400 and 425 deg. More than likely, it was a stabilizing, or stress relief cycle given the barrel after rifling. This is a normal practice. Carried a little further, to say 475 and the steel takes on a beautiful golden color. 525 and pail blue, 575 to 600 a deep to royal blue, higher and they become first rainbow, then pale then grey.
This color scheme is typical of all carbon steels. Including lower carbon steels such as in gun barrels.
Now, where's mine! Just kidd'n, id have a 1-9 twist Tj's here now. Just no way to fit it or a mold for it. GRRRRR!!! ;D
Mike
That's the info I was looking for! I emailed Maxim at Alfa Precision and he said they use 40X steel in their air gun barrels, fwiw. I guess it's safe to say this steel was taken to 475, given that golden color it has. I kinda like the way it looks, but it will be covered up under some CF just the same ;) Mike ... noted on twist & we shall see what Donny gets for accuracy.
Looking forward to Donny's results! Very much so. Interested!!!
Mike
It will be a few days, before I can get some testing done, since I have to finish up with the CF sleeving, and attend to a few small things on the gun first. I also have to get some heavier lead in too. I've already spoken to Mike at Griffin Slugs, and he's gonna make me some 24 grain flat base slugs to play with. Besides, the weather isn't that great right now. It's cold and windy. I will have to change out hammer springs, when I test the 15 grain slugs, because the hammer spring I have in there right now won't let me get the power down low enough, haha.
I’d like to know what the weight is on those heavy walled barrels. I’m also on the waiting list for NOE to make some more of the .172 molds as I’ve got a TJ’s waiting for a mold. I hope the AP barrel works well for you.
I don't have a small enough scale to weigh them, but they do have a little weight to them being 650mm long. Fortunately, they're going on a pup, so I won't notice the weight much at all.
Beautiful barrels Donny! So glad Brian of EW was able to get them in for you! I sure hope they work....would like to see you take down more giant pigs with .177! Incredible!
I'd like to see more of that myself!
well I have a gut feeling that the 14.5 twist may do well with 15g up to about 22-24g flat base rounds... the 1:9 twist was so the longer nose/ boat tail 25g-30g rounds would stabilize...
The 16 twist barrel may work well with 20g ish blunter nosed rounds...and should be fine with about 15g-17g... just my gut feeling again but had to see what the Kolbe drag calc said... probably the better compromise pellet/slug barrel... jmo... but well each rifle/barrel does what it does in the end...
http://www.geoffrey-kolbe.com/cgi-bin/drag_working.cgi?unit_length=inches&weight_unit=grains&bullet_name=.338+air&re_calculate=yes&boundary_layer=L%2FT&diameter=.179&length=.3&nose=.18&meplat=.06&drive_band=.179&base_diameter=.179&angle=0&boat_tail=0&secant_radius=&weight=14.4&density=11.4 (http://www.geoffrey-kolbe.com/cgi-bin/drag_working.cgi?unit_length=inches&weight_unit=grains&bullet_name=.338+air&re_calculate=yes&boundary_layer=L%2FT&diameter=.179&length=.3&nose=.18&meplat=.06&drive_band=.179&base_diameter=.179&angle=0&boat_tail=0&secant_radius=&weight=14.4&density=11.4)
http://www.geoffrey-kolbe.com/cgi-bin/drag_working.cgi?unit_length=inches&weight_unit=grains&bullet_name=.338+air&re_calculate=yes&boundary_layer=L%2FT&diameter=.179&length=.33&nose=.12&meplat=.06&drive_band=.179&base_diameter=.179&angle=0&boat_tail=0&secant_radius=&weight=18.9&density=11.4 (http://www.geoffrey-kolbe.com/cgi-bin/drag_working.cgi?unit_length=inches&weight_unit=grains&bullet_name=.338+air&re_calculate=yes&boundary_layer=L%2FT&diameter=.179&length=.33&nose=.12&meplat=.06&drive_band=.179&base_diameter=.179&angle=0&boat_tail=0&secant_radius=&weight=18.9&density=11.4)
Thanks for the info! That's pretty much the conclusion I've come to. I've also got some 20.5 grain "test" slugs from NSA that I think should work quite well in this barrel. As most of us have figured out, we can't always go by the twist calculators. I just gotta sling some lead to find out what the real results will be. Time will tell!
Hobbyman2007, love those open sights!
Hunter
They have them for sale on aliexpress. Novelty gun sights I think. Now back to the barrels
I too, think those sights are hilarious!
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lot of rifling buttons for sale by those guys, are they pushed through the barrel from the breech ?
dont see any attachment on the buttons.
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lot of rifling buttons for sale by those guys, are they pushed through the barrel from the breech ?
dont see any attachment on the buttons.
I saw that too. I've no idea on how those particular ones are meant to be used. I think I'll stick to barrels made by proper barrel manufacturers myself :)
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I got the barrel sleeved now, and everything should be ready for sight in! Now I just need my ammo to show up, better weather, and some daylight to see what she's gonna do... If the barrel is a winner, then it will get it's camo to go with the rest of the gun ;) Here's a couple of pictures. One without the big 'ol LDC, and one with it. The phone distorts things, but it will actually fit in the case with the LDC attached.
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Buttons are brazed or silver soldered onto a steel rod. Either pulled or pushed thru the bbl. Small cal.. require pull thru due to flex id pushed.
Knife
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I got to do a little testing yesterday with the new 14.6" twist barrel, and the results are pretty good! I wasn't having a good shooting day, so I'm not going to post any groups at the moment. I did know when I pulled a shot though, and the barrel did consistently well with the Griffin 23 and 24 grain slugs. Most groups were a little under 1/2" with them at 30 yards, and the NSA 20.5 grain. I think with a little more time to find their happiest speeds they would work very well. This barrel shot all of those heavy slugs better than any barrel I've tried. I need to do some testing at a longer distance too. I think I'm going to regulate it, and change out the hammer spring, so I can do some testing with the 15 grain slugs next. That is the tune it will live at most of the time anyway.
On a side note, I managed a peak power of 58 fpe with the 24 grain .177 slugs!
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This is great!! Was gonna ask today to see if any updates.
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Looks promising. 58fpe in .177 is amazing.
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This is great!! Was gonna ask today to see if any updates.
I think there's a lot of promise with this barrel. I just need more time to play with the speeds a bit. I'm also going to try it without the front barrel band on there, because I think that has me chasing my tail a little. I finally figured out today that it had shifted some. I hope to have some definitive results in the next week or two, when I can get some more time to play with it. Here's a 5 shot group I did earlier today with the 23 grain slugs. I choked and yanked the last shot,lol.
Looks promising. 58fpe in .177 is amazing.
It is pretty awesome, but it can't hold that power for long. The highest power realistic power tune is around 53-55 fpe for one magazine. This is a case where a bottle gun would open up a whole lot of possibilities, as would the ability to do a higher fill pressure.
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Forgot the group...
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Forgot the group...
Oh wow!! Definitely looks promising. I’m considering one for my Origin, cause I really like the feel of the gun but just not sure if i could get enough power out it Or I could just get me a Flash & have you machine the barrel for me. 😉😉😉
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Forgot the group...
Oh wow!! Definitely looks promising. I’m considering one for my Origin, cause I really like the feel of the gun but just not sure if i could get enough power out it Or I could just get me a Flash & have you machine the barrel for me. 😉😉😉
I would think the Origin could be ported and tuned for more power, but I don't know anything about those. Those Airforce guns would be good slug candidates! I mean, they have power to spare. I'll be the first to say, I don't know if the Flash is the gun for everyone. They take A LOT of work to get up to those power levels. There are many other guns that would probably be easier to make that power with. I don't machine barrels for other people. It's one thing to mess up my own stuff, but I'd feel horrible if I got someone else's barrel wrong! My machining skills are just enough to get me in trouble ;)
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Forgot the group...
Oh wow!! Definitely looks promising. I’m considering one for my Origin, cause I really like the feel of the gun but just not sure if i could get enough power out it Or I could just get me a Flash & have you machine the barrel for me. 😉😉😉
I would think the Origin could be ported and tuned for more power, but I don't know anything about those. Those Airforce guns would be good slug candidates! I mean, they have power to spare. I'll be the first to say, I don't know if the Flash is the gun for everyone. They take A LOT of work to get up to those power levels. There are many other guns that would probably be easier to make that power with. I don't machine barrels for other people. It's one thing to mess up my own stuff, but I'd feel horrible if I got someone else's barrel wrong! My machining skills are just enough to get me in trouble ;)
Yeah I had my Origin apart & seen some stuff that needed attention but I really wasn’t worried about power till I thought about this barrel for it. I did drill the barrel port out but that was it. I know the transfer port through the receiver needs attention it’s kinda small & it’s threaded which would cause turbulence. Right now with the hammer spring turned in 4 turns it’s getting 885 with 22.5hr VK’s. So I’ll be tearing back into it to see what I could do it to get it a little more power out of it.
I was messing around about the barrel, my cousin builds custom PB’s so he could do the barrel for me.
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The jury is still out on the 14.6" twist Alfa Precision barrel. I'm having a hard time nailing down what works with the lighter slugs at the moment, but I'm also thinking it is time for a regulator rebuild. I'll get back to the light weight testing in a week or two. I have some other stuff I have to take care of first. At the moment, I can only say it works with heavier 20.5 grain slugs and up for sure in .177. I was also shooting those without the regulator installed, so... I need to remove some variables and try it again, so give me a few days and bear with me :D
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I have a small update. I machined the 16.5" twist Alfa Precision barrel, and it's a laser with the 15 grain NSAs!! This barrel is shooting those better than any barrel I've tried. I honestly couldn't expect anything better. It appears to be the perfect match. I got to do some proper long range testing Sunday. At 30 yards, they were one ragged hole. They shot very well at long range too. I watched them in flight well past 100 yards, and there was zero wobble, and they were dead on. I was popping pieces of gravel off a gate at 110 yards, and they were not missing at all! I even managed to pop an egg at 150 yards :D Cans at that distance weren't even a challenge. I'm speaking specifically about the newer 15 grain from the high speed machine. I was shooting them at 1000 fps on the dot. That was regulated, and it yielded a very good shot count for me too.
I've tested them previously in LW polygon choked, LW polygon unchoked, LW standard chocked, LW standard unchoked, and Hatsan. I had good results with the unchoked polygon LW with the older 15.5 grain, but haven't been able to get the newer .178 15 grain to do quite as well. The short version is, if you want to shoot the NSA 15 grain in .177, the Alfa Precision polygon barrel is the most certainly the barrel I would use, if possible. The LW standard rifling barrels in choked and unchoked do well too, but not as well as this AP barrel is doing. Not in my testing at least.
I haven't tested the other weight slugs in the 16.5" twist barrel yet. I was having too much fun with the 15 grain, haha. I hope to do some more testing in the coming weeks with the 12.5, and some heavier Griffin slugs in 23/24 grain. I just wanted to give a quick update, since I know the 15 grain slugs are the ones most people will be shooting. If you got a .177 slug build on your mind, give Brian at Edgun West a ring, or even email Maxim at Alfa Precision, and see about getting that polygon on the way!
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I have a small update. I machined the 16.5" twist Alfa Precision barrel, and it's a laser with the 15 grain NSAs!! This barrel is shooting those better than any barrel I've tried. I honestly couldn't expect anything better. It appears to be the perfect match. I got to do some proper long range testing Sunday. At 30 yards, they were one ragged hole. They shot very well at long range too. I watched them in flight well past 100 yards, and there was zero wobble, and they were dead on. I was popping pieces of gravel off a gate at 110 yards, and they were not missing at all! I even managed to pop an egg at 150 yards :D Cans at that distance weren't even a challenge. I'm speaking specifically about the newer 15 grain from the high speed machine. I was shooting them at 1000 fps on the dot. That was regulated, and it yielded a very good shot count for me too.
I've tested them previously in LW polygon choked, LW polygon unchoked, LW standard chocked, LW standard unchoked, and Hatsan. I had good results with the unchoked polygon LW with the older 15.5 grain, but haven't been able to get the newer .178 15 grain to do quite as well. The short version is, if you want to shoot the NSA 15 grain in .177, the Alfa Precision polygon barrel is the most certainly the barrel I would use, if possible. The LW standard rifling barrels in choked and unchoked do well too, but not as well as this AP barrel is doing. Not in my testing at least.
I haven't tested the other weight slugs in the 16.5" twist barrel yet. I was having too much fun with the 15 grain, haha. I hope to do some more testing in the coming weeks with the 12.5, and some heavier Griffin slugs in 23/24 grain. I just wanted to give a quick update, since I know the 15 grain slugs are the ones most people will be shooting. If you got a .177 slug build on your mind, give Brian at Edgun West a ring, or even email Maxim at Alfa Precision, and see about getting that polygon on the way!
WAY TO GO DONNY! Good news man...
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Thanks! I'm super happy about this one :D I've been trying to nail down the new .178 slugs for a while now, and I could only get them to do "pretty good", so I'm stoked that AP barrel is shooting real good! Their 14.6" twist barrel does great with the heavy stuff, but too much twist it seems for the light ones...