Canadian Airgun Forum

Today I finally got a chance to adjust my Hatsan air stripper and measure the effect on group size.
I found that the size of the gap has a significant effect, so here are the results.
About the rifle: Hatsan AT441022W, non-PAL shooting CPHP 14.3gr @ 470fps @200 bar peaking at 495 fps at 170 bar.
Stripper came from Sniper with a 10.76mm gap, where it has remained until today (about 15 months) now set at 4mm gap.

I read about the gap adjustment on the UK Turkish forum, but hadn’t experimented with it myself, although I did recommend others do it.
Here is my 44 after charging:

This is my rest, it is a bit wobbly but more stable than offhand. (Can anybody guess what the screwdriver stabbed into the top of the box is for?)

This is my 14 yd indoor range.

Now the results:

As you can see the groups were terrible with the stripper set at 10.76 mm, and also without the stripper. But the stripper correctly set produces a ragged hole at 14 yds. I have it now at 4mm. It’s as good as I need it for my wobbly set up and shaky arms. I got 80 shots between 200 and 150 bar (pretty good), I often shoot it down to 70 bar before refilling. But in this experiment, I wondered if the crappy groups for the first 20 shots was due to the 200 bar fill, so I recharged it to 200 bar then shot the final 9th group shown. The group was single ragged hole, and would have been better except I was shaking double time after putting 50 pumps into the rifle. I should have rested for 15 minutes. Anyhow, there is enough evidence there for me to conclude that adjusting the gap is a good thing. Of course, the optimum gap will be pellet sensitive, and power level sensitive, and maybe even range sensitive so your optimum gap will likely be different.
“Let there be some more test made of my metal, before so noble and so great a figure be stamp'd upon it.”…
There ya have it.

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Iacio, ergo sum

The Crossman Premier Hollow Points are very accurate in my Bam51 as well- much better than the Predators, unfortunately.

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Best Wishes
Daryl

Judging by the first groups and what I saw Gord's Hatsan .22 shoot (PAL version), perhaps your rifle needs crowning or something? His AT44 shoots amazingly well with a variety of pellets at 20 yards, with no stripper. That it seems to work for yours over no-stripper is great, but I think your rifle will do better than it is doing, perhaps? Yes, I can see your 'rest' leaves a LOT to be desired and the shooting is pretty good, considering - just thinking out loud.

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Best Wishes
Daryl

Nice shooting and great information. I must test mine. Beautiful stock on that gun of yours. My guess for the screwdriver is to hang your lens covers on.

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If I had only one wish, it would be to be able to "unsay" things.

That is a good looking piece of wood.

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Best Wishes
Daryl

Well!! Just have time to use my desktop (Couldn't open the link while using the Tapatalk App ) to open the forum and follow the link to this 8+ years old post regarding the Hatsan Air Stripper! It's a pity the pictures are out-dated and couldn't able to enlarge them to see it clearly... But I got the very important number 4mm as a reference to setup mine in the coming future!

Gave a try on my 25cal stripper on the 22cal PP700 long barrel... Yes! the result is very signaficant as I can drift the POI about 3/4 inch sideways in just 9 yards in my basement range! And in best result I got (not seriously tuning at all) was a tight group like without the stripper... That should be caused by the bigger stripper size on a smaller caliber barrel. Looking forward my 25cal barrel....

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~Plinkers~
FX-M3-22 Compact#PP700-Carbine#Diana48-177#XS28M-25@26fpe#HW45 Beast#AW-Custom Z-Killer DE
~Competitors~
FWB300SU#Tau-7#IZH-46M#FWB-65#CP88-C
~Target~
HW 30s/35e/97k/40+Extender/P3+Scope/70#CZ200s Laminated@10fpe#AA ProSport-177@12fpe

How time flies! Yes Photobucket stared out as a good site to store and host pictures but over the years it degenerated to a POS. I just logged in and got a telling off that I am hosting photos without a paid subscription. This is BS because when I uploaded and hosted these photos it was free and legal so..
Anyhow, I couldn't even find my original photos on Photobucket for this thread, Suffice it to say you can see I had a wobbly bench rest and the groups got tighter as I reduced the stripper gap. I think you always have to experiment with the stripper adjustment and it may or may not improve groups from a no stripper condition, but if you do put one on the muzzle you have to adjust it. And just like pellet testing, it takes time and patience. I have to have the stripper for bling factor, so it's there only for that reason. Just adding mass to the muzzle may affect poi, so pay more attention to the groups as you test the adjustment.

BTW, the screwdriver was used to hang a bag that housed my HPA tank for shooting my QB78s tethered. But it would also be a great place to hand scope covers

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Iacio, ergo sum

R Sterne had a good article on the same subject.I think he is from your neck of the woods. He also told how to line it up from scratch. Very informative.

Indeed, actually I dug up this old post for YepYep and pointed him towards Bob's post on alignment and adjustment.
For the benefit of those interested, here is Bob's post:
topic74104.html

Bob is in Coalmont, BC...very far drive for me and YepYep but only minutes away by Forum.

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Iacio, ergo sum

[emoji38] read the last reply from Joe too and thinking this air stripper is seriously an ' anti-human ' or ' very interesting ' design that you might need much more time on adjusting it rather than practicing artillery hold on shooting springers ~

If you hate somebody, give an air stripper to him to put on his favor rifle and tell him this will greatly tighten up the group after a little work to finish well...

Looking forward on my new barrel again to start the journey on mine~

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~Plinkers~
FX-M3-22 Compact#PP700-Carbine#Diana48-177#XS28M-25@26fpe#HW45 Beast#AW-Custom Z-Killer DE
~Competitors~
FWB300SU#Tau-7#IZH-46M#FWB-65#CP88-C
~Target~
HW 30s/35e/97k/40+Extender/P3+Scope/70#CZ200s Laminated@10fpe#AA ProSport-177@12fpe