N/A .177 for slugs (primarily at least)?!

Utah. STX 177 700mm Heavy.. Got 2 of them. :)
I thought they were all 1:18? Just a slightly different 1:18
My P35-177 definitely does not like 10 grain knockouts but seems to shoot 12 grain Nielsen slugs pretty well. They do not expand hardly at all at 35 yards into wet magazines. Penetration of the Nielsens is fine so I wouldn't be worried about them on squirrels. I need to increase the speed, they are only going about 850 fps.
Those NSA won't expand unless you hollow out the HP or stanp a jewelers Phillips screw on top of it, regardless of speed.

You could shoot the 12.5gr at 1000fps and they will hardly expand if anything all as they are.
 
I thought they were all 1:18? Just a slightly different 1:18

Those NSA won't expand unless you hollow out the HP or stanp a jewelers Phillips screw on top of it, regardless of speed.

You could shoot the 12.5gr at 1000fps and they will hardly expand if anything all as they are.
Kinda sad… I still have to figure what’s going on with the 15gr .178… dumped a few in aceton the other day to see whether it’s any type of coating/lube causing the bouncing back and forth of the fps. Shot them at current tune for the 10gr aaaaand… what can I say… shot two at 750fps and the third WOULDNT LEAVE THE BARREL! Needed two more shots the get it out of the barrel… now I’m really wondering what’s going on there. Maybe the .178 are just too big for the barrel (didn’t slug it yet since I don’t have a .177 cleaning rod…). Well, gotta wait until I’m through a couple more of the 10gr and then bump power for 15 and 16gr, probably a little more than initially and see what happens.
 
Kinda sad… I still have to figure what’s going on with the 15gr .178… dumped a few in aceton the other day to see whether it’s any type of coating/lube causing the bouncing back and forth of the fps. Shot them at current tune for the 10gr aaaaand… what can I say… shot two at 750fps and the third WOULDNT LEAVE THE BARREL! Needed two more shots the get it out of the barrel… now I’m really wondering what’s going on there. Maybe the .178 are just too big for the barrel (didn’t slug it yet since I don’t have a .177 cleaning rod…). Well, gotta wait until I’m through a couple more of the 10gr and then bump power for 15 and 16gr, probably a little more than initially and see what happens.
Once you are out of the 10gr, adjust the reg back to stock. Then turn it about 100⁰ CC. You'll be around the same range as I.

I've been shooting the NSA 15gr, and although the speed jumps around, they are still super freaking accurate. I'm also having the issue of the speed jumping around the lot with longer slugs, no matter how I tune the hammer spring. This is with 20gr Griffin, 16gr griffins, 15gr nsa, 16.5gr vk
 
  • Like
Reactions: greenbeans
Once you are out of the 10gr, adjust the reg back to stock. Then turn it about 100⁰ CC. You'll be around the same range as I.

I've been shooting the NSA 15gr, and although the speed jumps around, they are still super freaking accurate. I'm also having the issue of the speed jumping around the lot with longer slugs, no matter how I tune the hammer spring. This is with 20gr Griffin, 16gr griffins, 15gr nsa, 16.5gr vk
I’m kind of temped to adjust sooner… damn wind these days blowing the 10gr around like nothing :)
 
  • Like
Reactions: JaceSpace1369
although the speed jumps around, they are still super freaking accurate
I too have seen pretty darn good consistency, with a chrono barking out anything but consistent speeds, mind you not wildly different speeds, but fluctuations of 10 - 20 FPS between slowest and fastest no problem, well some times at least.

I have also seen a slow shot, but the damn lead land higher on the target, and reverse a faster shot but it dipping below the other shots.
This up / down thing confuse me like on a quantum level.

These freak shots, some time like 1-2 inches off, i just shrug my shoulders and tell myself i put that slug backwards in the gun, CUZ the following shot are often dead on.
 
  • Like
Reactions: JaceSpace1369
Also some times shooting far, and with really low winds, i notice a drifting bias to one side, often one i can not blame on wind.
This is always sideways and hammering a paper i see the shots drift slowly to one side, not necessary shot after shot, of course also with a little up / down spice in the mix, so at some time i will have to add a click, and it is like a reset button, but only for a while then the process repeat.
Not for ever t hough at some time it will stop or start to move to the other side, which freak me CUZ often that would be up against the wind.

I swear i will never get this hobby, but fortunately i am not here for the science in it.

A 100 yard paper i shot today i soon noticed a LEFT bias and so was holding a little high and to the Right, but still some shots wanted to drift left, and also a little low.
Okay there is also a bias for my shots sort of landing where i was aiming or only drifting a very little.
Contemplating if this can be scope / eye alignment issues, i do after all go off the scope and back on for every shot i make using a single shot tray.

10-at-100-png.545107
 
Also some times shooting far, and with really low winds, i notice a drifting bias to one side, often one i can not blame on wind.
This is always sideways and hammering a paper i see the shots drift slowly to one side, not necessary shot after shot, of course also with a little up / down spice in the mix, so at some time i will have to add a click, and it is like a reset button, but only for a while then the process repeat.
Not for ever t hough at some time it will stop or start to move to the other side, which freak me CUZ often that would be up against the wind.

I swear i will never get this hobby, but fortunately i am not here for the science in it.

A 100 yard paper i shot today i soon noticed a LEFT bias and so was holding a little high and to the Right, but still some shots wanted to drift left, and also a little low.
Okay there is also a bias for my shots sort of landing where i was aiming or only drifting a very little.
Contemplating if this can be scope / eye alignment issues, i do after all go off the scope and back on for every shot i make using a single shot tray.

10-at-100-png.545107
Isn't that usually due to spin drift? I know for long distance this is something one should account for, I don't know about it enough to account for it, but I know some do.
 
It's not a problem for me, I already ordered it and paid for it. I will let you guys know when it gets here!

Where did you manage to find a 1:16 twist FX liner for .177?

I need to make a correction. The FX barrels are not 1 in 16 they are 1 in 18.. I asked Utah twice specifically are these 1 in 16 barrels and they affirmed. Well the 22 barrels are 1 in 16. Anyway according to Utah Air this was the best combination for slugs. We have one on an Avenger that shows a lot of promise in accuracy that is making 40 ft lbs with 15 gr NSA's. I did ask what twist the normal 177 barrels had and he said 1 in 24. So the 1 in 18 is a big improvement.
 
That doesn't sound right either @Sicumj
Fx stopped making 1:24 .177 barrels in 2021, or supposedly they did. And all STX superior barrels are supposed to be 1:18 twist. With the stx superior heavy being what I assume is unchoked, making the biggest difference. Either way, best of luck! Glad you got a power house of an airgun!
 
  • Like
Reactions: RabbitofCaerbannog
That doesn't sound right either @Sicumj
Fx stopped making 1:24 .177 barrels in 2021, or supposedly they did. And all STX superior barrels are supposed to be 1:18 twist. With the stx superior heavy being what I assume is unchoked, making the biggest difference. Either way, best of luck! Glad you got a power house of an airgun!

Hes right .. I thought the exact same

FX superior .177 is 1:18 with a heavier choke,
FX superior heavy is 1:18 with more significant grooving and different choke specs
 
Utah add states 1 in 24 twist for the 22 in standard STX and 1 in 16 on the heavy. No listing at all for the 177. My 177 heavy has 1 in 18 lasered on the barrel. When i was firing NSA 20.5 SLUGS I notised they were keyholing. Disappointed in the twist rate. 15 is as big as I can get in my Akela magazines, which this barrel is goung in.


20250309_193954.jpg
 
Utah add states 1 in 24 twist for the 22 in standard STX and 1 in 16 on the heavy. No listing at all for the 177. My 177 heavy has 1 in 18 lasered on the barrel. When i was firing NSA 20.5 SLUGS I notised they were keyholing. Disappointed in the twist rate. 15 is as big as I can get in my Akela magazines, which this barrel is goung in.


View attachment 545630
Yeah .22 has 1:24, and 1:16, but you said they told you .177 has 1:24, I'm just saying that's old news as of 2021.
 
Well that is what Thadius told me Saturday on the phone, from Utah Air. He is also the one that confirmed twice 3 weeks ago the heavy was 1 in 16. Supposedly Utah is the main distributor now for FX. You would think they would get their product info straight. The STX Heavy in 700 mm will not stabilize a 20 grain slug. When asked about this Thadius said the barrel is designed for 13 to 15 grain slugs. Not exactly what we were after when I initially purchased the barrels. Here is 20.5 NSA slugs at 50 yards.

20250304_151450.jpg
 
Last edited:
Our goal was to shoot 17 to 20 grain slugs. We initially decided to try Redman barrel liners in .172 that have a 1- 9twist. WE just could not get the accuracy out of this barrel. Using NOE's sizing dies they did a good job at resizing but accuracy just didn't get much better that 1" at 50 yds. The liners are buttoned rifled and you could see chatter marks where the button appears to start and stop.

This was a bit of a challenge since we had to make the chamber and throat. Chamber being 177 part way to allow the bolt entry, then down to .172 for the resized slugs. Though accuracy was poor it did stabilize 20 gr slugs. Hind sight I wish we would have went with Lothar now.

I'm still debating on keeping the other STX liner. It seems to shoot 15 gr slugs well and that is max for what will fit in my Akela magazines, where this barrel was going. I haven't tried Zan's 16 gr slugs to see if they fit. That would be a better slug for hunting. NSA's slugs do not open well and modifying each slug is not an interest for me.
 
Last edited:
  • Like
Reactions: JaceSpace1369
Our goal was to shoot 17 to 20 grain slugs. We initially decided to try Redman barrel liners in .172 that have a 1-16 twist. WE just could not get the accuracy out of this barrel. Using NOE's sizing dies they did a good job at resizing but accuracy just didn't get much better that 1" at 50 yds. The liners are buttoned rifled and you could see chatter marks where the button appears to start and stop.

This was a bit of a challenge since we had to make the chamber and throat. Chamber being 177 part way to allow the bolt entry, then down to .172 for the resized slugs. Though accuracy was poor it did stabilize 20 gr slugs. Hind sight I wish we would have went with Lothar now.

I'm still debating on keeping the other STX liner. It seems to shoot 15 gr slugs well and that is max for what will fit in my Akela magazines, where this barrel was going. I haven't tried Zan's 16 gr slugs to see if they fit. That would be a better slug for hunting. NSA's slugs do not open well and modifying each slug is not an interest for me.
Get some Varmint knocker slugs from Dale on ebay. You can order 50ct samples from him, and he makes both .1771 and .178 from 13.5gr, to 19.5gr. Also griffin slugs are fantastic he makes 13, 14, 16, 20, 23gr which 16gr and 29gr shoot great out of my U2 177 600mm 1:17.7" twist