Early Impact .22 slug liner report

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I measured my pellet and slug barrels at 1 in 19 twist. I'm still quite surprised it's the same for pellets and slugs.

Out of curiosity, I did some searching for .22 cal rimfire rifle twist rates. It seems 1 in 16 is a very common twist, even for subsonic rounds. As I understand it, the general rule is that heavier bullets require faster twist rates. If 1 in 16 is good for a 40gr rimfire bullet, maybe the slower 1 in 19 is right for our generally lighter bullets (why do we call them slugs?). I have to believe FX knows what they're doing, but it would be nice to see some of the testing for various twist rates that I'm sure they've done. 

Cheers,

Rusty

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1 in 19 or 1 in 20? Not really sure I did a fast check. But Matt mentioned 1 in 20 on his video about the slugs. He also explained that as the pellet slows down it's spin rate increases.

It starts at the muzzle as 1 in 20 but 100 yrds out it may be 1 in 16 because the spin rate remains the same but the fps slows down.



So for a rim fire .22 to have a 1 in 16 twist isn't so bad considering that they launch their projectile at well over the speed of sound and because of their heavier grain will maintain their fps longer.

Not really sure? All this ballistics I'm still learning about. I don't have the pellets or the distance close by to do my own testing. So I'm very interested in seeing what you can come up with.

Besides the Nielsen slugs are rather expensive. I'd hate to buy the wrong ones. 

Have you had the chance to try Huben or H&N Piledriver slugs? (Just because they are a bit more affordable) 

I know these liners are designed around the Nielsen slugs, but I'm hoping other slugs might work well also.

Thanks for doing the these test! Good luck!
 
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Have you had the chance to try Huben or H&N Piledriver slugs? (Just because they are a bit more affordable) 

I know these liners are designed around the Nielsen slugs, but I'm hoping other slugs might work well also.

Thanks for doing the these test! Good luck!
Click to expand...



I took a quick look around, and I can't find anywhere to buy Huben or H&N slugs. Who sells them? Of course from that question, I'm sure you've figured out that I have not tried them :)

Just as we've had to be patient for slug liners, I think we're going to have to be patient for more competition in slug production as well. Hopefully demand and competition will drop the price on them. I'm also open to casting my own, but it's pretty slim pickins for molds and sizing dies for the odd .217 size we use for .22 cal. 

Rusty


 
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Krale has the Huben pellets but the shipping is pricy but you will 

have you slugs in around 4-5 days you need to order like 12 or more

to get a break on the price .

https://www.krale-schietsport.nl/en/airgun-pellets-huben-lrn-5-52-mm.html 

There are people out there making swage ammo here is one that a friend

of mine has used and mentioned it did very well From the FX slug barrel .

https://www.ebay.com/itm/253282310399?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649 

Sizing dies are are out there I use NOE and buy the .223 die and then

I polish them to the size I need for the Huben , there are several molds 

out there that will cast a slug for the Huben I know of 3 that will do this . 

Here is a look at one of them , an it's a hollow point too 36 grain .

1537079206_10400923545b9df7a6ad60d7.85664658_IMG_2012.jpg



 
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Thanks for the info. As you mentioned, the shipping from Kral would be painful, and those ebay slugs are as expensive as Nielsen's, so I can't see any real benefit to ordering those. 

It would be cool to have a swaging setup, but they seem pretty pricey. Given the choice, it would be better to avoid handling molten lead, and the results would be better I think. Fortunately, I don't shoot enough for this to be a problem for now, and prices should come down in the future.

Rusty


 
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Greetings,

I did some testing today with all the NSA slugs and some JSB pellets. There was a little wind, but just a few mph, and I tried to shoot between periods of wind as best I could.



-50 yds, max power, slug-A liner: NSA 19, 21, 23, 27, 28BT, 30, 32BT, and 33 slugs.



The 19, 21, and 23 were clearly the worst groups. The 27 and 33 were very good, with below 1/2" groups. The 30 was excellent at 3/8" group. I also tried the 27 and 28BT with power wheel settings of 1, 3, 5 to see if that made any difference, and in both cases they were better with max power.



-50 yds, max power, slug-A liner: JSB 15, 18 pellets.



These were both excellent. 7/16" and 9/16" groups. This is at least as good as anything I ever saw with the old ST barrel.



-100 yds, max power, slug-A liner: NSA 27, 28BT, 30, 32BT, and 33 slugs.



These were mostly just OK. The 30 was the best at 1-1/8" for 5 shots, and the 28BT would have been close but there was one flyer.



-100 yds, max power, slug-A liner: JSB 18, 25 pellets.



The 25gr pellets were pretty wild, but I've read that they only do well in the pellet-B liner. The 18 gr were 1-1/2" groups.



The takeaway for today is that JSB pellets shoot very well with the Slug-A liner. Pity you can't buy the barrels with the slug liner, since I'll never use the pellet liner now. The other big discovery is that the boat tail slugs do not shoot as well as the flat base slugs. As badly as I want them to, it's clear that for my current setup, I'm having better results with the flat base slugs, and in particular, the 30 gr.



Rusty
 
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Have you had the chance to try Huben or H&N Piledriver slugs? (Just because they are a bit more affordable) 

I know these liners are designed around the Nielsen slugs, but I'm hoping other slugs might work well also.

Thanks for doing the these test! Good luck!
Click to expand...



I took a quick look around, and I can't find anywhere to buy Huben or H&N slugs. Who sells them? Of course from that question, I'm sure you've figured out that I have not tried them :)

Just as we've had to be patient for slug liners, I think we're going to have to be patient for more competition in slug production as well. Hopefully demand and competition will drop the price on them. I'm also open to casting my own, but it's pretty slim pickins for molds and sizing dies for the odd .217 size we use for .22 cal. 

Rusty

Click to expand...

https://www.ebay.com/itm/H-N-PILEDRIVER-22-5-50mm-Airgun-Pellets-4-tins-x150pcs-FAC-HUNTING-SUPER-HEAVY/132381236529?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
 
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I tried varying the speed of a couple slugs (27 and 28BT), and faster was always better for me. In my mind, one of the main reasons to go to slugs is to be able to push them faster without worrying about diabolo effects. On the other hand Ernest said JSB 18 pellets are accurate and stable at 1085 fps from the slug liner, which does have a slight choke. Sometimes I wonder how much of what we "know" about air gunning is really true :) 

Rusty (I need more power)


 
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I tried to figure that out as well, but didn't come up with a definitive max pressure. Best I can tell, the manual still says 150 bar. I have a pre-X Impact, and have one of the new Huma extra high pressure regs on the way. It's supposed to be good to 190 bar I think. I'll likely end up doing some other high power mods as well, since I'd like to test the slugs at the highest speed possible, ideally just below supersonic. 

Rusty


 
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I asked AOA about that statement when I was deciding whether to buy the STX upgrade for my original 500mm barrel, or get the new 600mm barrel. They said they just copied it directly from FX. Seems like it could mean either of the following:

- If you have a 500mm barrel, you'll be better off shooting lighter slugs.

- Lighter slugs will shoot better from a 500mm barrel than longer barrels. 

Of course it doesn't matter now, since I have the 600mm :)

Rusty


 
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That's a fair statement. I wonder how hard we can run the new regulator in our X's. 150 bar was the understood limit for the older regulator. Matt has blown through that ceiling with the new one. Has anyone seen any statement from FX stating what the new limit is?
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Thats the thing. I don't think there is much of a limit anymore. Here is my regulator setting at one point in time. The only thing that is preventing us from breaking the 100 FPE area is the hammer spring. It is not strong enough to smack the valve open to utilize the higher regulator pressure past 165 bar. And if you think about it the .25cal 44 grain slugs are the same weight as the .30 cal JSBs so you can get high energy with superior BC right? My highest FPS i've gotten is 920 with JSB 44 grains. 

Anyone know where we can get stronger springs? I feel it might be necessary for some of us who want high velocity/energy high bc combo. Just becareful going past 165 bar. You can cause damage to your regulator. As far as I can tell though ES is the same for me even after hitting 195 bar in my picture.



1538020859_5782587785bac55fb448b85.16484006_REGULAtor pressure.jpg

 
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When I was searching, I saw some references to springs that were 10% stronger, but I could never find anywhere to buy them. It was also suggested that you could preload the spring as a test as long as you didn't turn the power wheel while it's under tension. That will be an interesting test when I get the higher pressure reg installed, assuming it ever gets here. Huma shipped it fast, and it cleared customs days ago, but there's been no sign of movement since. 

I've thought about how caliber relates to velocity. On one hand, you have more force acting on the projectile if we assume the same pressure, and more surface area. Unfortunately you also have to consider the larger amount of friction in surface area touching the barrel, and the larger mass of the projectile. My Impact has always been on the low side of normal with regard to velocity using .22. At one point I bought the .30 cal barrel to see if that would be any better. Sadly, it was also lower than normal, and by a wider margin than .22 was. Maybe .25 is the sweet spot, or maybe it doesn't make much difference.

My reasoning for starting with .22 for slugs is the potential for higher BC, and the fact that the rifle should have enough power to push the smaller slugs faster. The trick seems to be finding a way to transfer enough of the power to the slug. From what I've read, one of the factors in BC is length vs diameter, where longer bullets tend to have higher BCs. Since the .22 slugs are already too long for the mag, a larger diameter with the same length to diameter will be even worse. At some point you will have to compromise the bullet length just to make it fit when single loading. I may be completely wrong about all that, but that was my thought process.

BTW, I just ordered a LabRadar unit to try to measure downrange velocities and calculate BC. I will be really interested to compare the 30 gr NSA, and the 30 gr PileDriver at the first official test of the unit. My eyeball estimation of BC has the NSA out front by a long shot (sorry). Now I'll be able to actually find out if the velocity agrees.

Rusty


 
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