My .22 Impact slug shooting journey begins!

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Doug-T

Doug-T

Member
Feb 19, 2019
286
17
Orygun, United States
I got my new .22 Impact shooting JSB 18.1g at 1020 fps. They really zing and I can feel the recoil difference from 860fps in my AlumiRod.

It was a nice, overcast day today so I took the afternoon off to start testing slugs. I've picked up 17 different types from four makers (ASV, NSA, Griffin & Varmint Knocker) in weights between 19g & 27g. One problem, I have a limited supply of each. Some 15 or so, some 25, some 35 and some 100. 

After watching Bob O's and Matt Dubber's videos on Impact slug tuning, as well as reading as much as I could, I decided to use Bob's plan. Shoot a 3 shot group at 30 yards. If the group isn't great change the velocity and try again. If it was great then shoo t a 3 shot group at 100 yards. It it's great then you know you have an accurate slug for your gun and you can tweak on it some more. I also decided that if the first 2 shots aren't touching to not shoot the 3rd as it won't be a good group anyway. That way I can conserve slugs to try more velocities.

Today I tried 9 of the 17 types before running out of light. I have the 600mm slug liner A with the regulator set a bit below 150 BAR. Most of them were marginal or OK with velocities between 990 & 880fps. They would be accurate enough to grease a pigeon at 50 yards. I would start on MAX settings then work my way down in velocity. Only a couple were very good shooting in the 900-940 fps range. So far the ASV 22 grain 0.217" shot the best with a 4 shot (I ran out) 100 yard group measuring 0.78" CTC. I noticed that I'm only holding about 3 mil-dots high at 100 yards with this slug when a JSB 18.1g requires about 7 mil-dots.

I can't wait to continue this testing. If I end up with 3-4 types that shoot well and have to buy more to test Oh Well! My next two evenings are tied up coaching and refereeing. Dang!

Here's the testing pages.

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Here's the ASV 0.217" 22 grain 100 yard group. 1" target stamp.

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Much of my air rifle shooting is pest elimination: pigeons, starlings and ground squirrels. Where I live trees are few and far between so ranges can be whatever you want. It's not uncommon to see hundreds of ground squirrels at all sorts of ranges, even out of powder burner range. Air rifles are so great because you don't scare everything away when you shoot, many times getting a follow up shot that a powder burner would allow. Having the much flatter trajectory of a slug with much more terminal energy is a huge benefit over a diablo shaped pellet.
 
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Good luck with your slug testing. I’m working with a 25 cal trying to accomplish the same . 

This can be very frustrating. My problems have been that three shot groups or even five shot groups are not telling me much. The frustration comes from when you get three touching with the forth or fifth shot going pretty far out of the group. Seems to happen a lot. 

My approach has been to buy 300 of the slugs that have worked for others and then test at 100 yards while striving for consisted velocities at or near the velocity that has worked well for others and seeing if I can get the gun tuned in .

So far it’s not going all that well. I’m just not getting good groups that are repeatable.

The learning curve seems rather steep to me 

I’ll be interested in hearing how it goes for you . 

The impact seems to me to be a hard gun to master. A slight change in valve adjustment can have a large affect down range and it would seem finding something exceptional and repeatable difficult 

keep us informed and I’ll do the same.
 
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Gents , 

I've been shooting cast bullets for the last couple years and I feel your pain on finding an accurate bullet . I have gone through literally tens of thousands of bullets in different calibers to find only a few that give great performance . My advise if this , one bullet at a time and work with it until it either performs or it doesn’t . Let me explain . 

I start at 15 yards , tune both the gun and bullet ( by sizing , trial and error) until the groups are one ragged hole . Move out to 30 yards , if the groups stay acceptable move out further , if not fine tune until the groups shrink . If not , I call it right there and move on to the next bullet . 

Now its not necessarily common knowledge but , bullets tend to need a bit more range before going to “sleep” when compared to pellets . Meaning you might shoot a group at 30 yards that is borderline acceptable say 3/4” , when you move it out to 50,75,and 100 the group size remains almost the same . I have two bullets now that do exactly that , one is an NOE 225-39 FNGC and the other is another NOE 260-63 FNGC . 

One last thing , eliminate the shooter from the equation as best as possible . Use a solid rest , and the least amount of input to the rifle as possible . I try not to even touch the rifle with other than my trigger finger . Good luck 
 
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The question that I have is ,

do you need the extra plenum In order to shoot slugs ?

I have been trying to get NSA and VK slugs in different weights ( 22-28g ) and shooting different speeds ( 850- 960fps) to group well with not much luck. Maybe 2.5 inch @ 100

wondering if you must have the extra air to make it happen ?

FX Impact X , 700mm slug liner , second one

shoot 28g slugs at 960
 
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@Doug-T

Thanks for this thread Doug - I just ordered a .22/700mm Impact as a slug gun and will be following your journey with great interest.

Don't know if I will get setup before the Canadian winter arrives but I plan to spend 8 - 10 tins of pellets to break in the rifle and get me used to the feel of the Impact as it is my first "tactical" style gun.

Hopefully, JSB and H&N will be producing slugs by next spring!

Good luck with your testing!

Hank
 
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The larger/wider hollow point, flatter instead of pointed, creates a "pillow" of air at the tip that reduces the acceleration of airflow around it. One of the results is more stability.
Click to expand...

Ah ok. I had noticed the same shape with the VK slugs you shoot Bob. More stable and I’ll bet they open up on impact well. I saw Voelf had a picture of a slug they were designing on his instagram. It had the simulated airflow and what your saying seems to be illustrated in that diagram. Thanks 👍

 
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I took today off to just test slugs. 6:00 basketball, shower, nap, burned a bunch of weeds, then I started in. The weather started out ideal but just as I started burning the wind picked up to 10-15 mph straight from behind. I moved the shooting bench to right in front of the garage doors and used the house as a wind block, which seemed to work pretty well. The wind didn't seem to affect things with the speed and shape of these slugs plus the very short range (30 yards). I tested 1-9 of 17 slugs last week in my first post. Today was 10-17 of 17 slugs. I forgot to mention that I'm using a 600mm slug liner A and the regulator is just under 150 BAR.

Here's my setup.

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Here are my record sheets for all slugs, settings, velocities, thoughts, etc. After doing this for a while I developed a settings order that would slowly decrease velocity by 10-15fps between groups.

#1: MAX hammer, valve adjuster all the way out.

#2: MAX hammer, valve adjuster in 1 3/8 turn.

#3: MAX hammer, valve adjuster in 1 1/2 turns.

#4: MAX hammer, valve adjuster in 1 5/8 turns.

#5: 3 hammer, valve adjuster all the way out.

#6: 3 hammer, valve adjuster in 1 1/2 turns.

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Here are the eight target pages from today. I will test six of the 17 slug types at 100 yards to see how they group. Five of the six are 0.217" diameter but the one that shows the best groupings are the Griffin 24g 0.218" dish based slugs. I've circled the groups in yellow in the picture below. The NSA 27g 0.217 did pretty well but my Impact doesn't push them very fast averaging 892fps with all MAX settings. Not sure if I want to try that heavy of a projectile.

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If the wind lets up before dark I'll test them out at 100 yards using the settings on my records. If they show promise I'll have to order larger quantities of each. Too bad the Varmint Knockers didn't shoot great because I have 100 packs of each type and only used 18-20 of each.

Just for fun I shot some groups with the JSB 18.1g at all the slug settings I used today. The were moving at 1025fps on MAX settings and 936fps in MIN hammer setting. They were more accurate than I thought they'd be, easily tighter than many of the slugs.

Here's the poor, old cardboard box that has seen better days.

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HI just wondering who makes asv and griffin slugs aire the sage or casted ? can you cast them ?

I can say with me and all my slug setups it was time consuming to find a good slug and tune it for best accuracy and efficiency , I make about 30 different types now but I use like 5 mostly for hunting and target shooting , I have tried the light hollow point slugs and I like the heavier casted ones for hunting . good luck finding your best slug

LOU
 
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