What'cha doing air gun related today?

[Pumacarl]

Worked on the trigger (again) of my Uragan 2 this morning. The U2 has the worst trigger of any air rifle I have ever owned! I mean..., if light weight-of-pull is all ya care about then you might love the U2 trigger. But, if you like a trigger with 'feel', you won't get it with the U2 trigger!

Currently, I have the trigger setup as single stage and with a pull weight of 12ozs. The safety still works and now the trigger at least has a 'soft' wall that I can feel. Best compromise I can get out of it.

Fired 15-slugs with the U2 at 50yds just to check trigger and zero.

Fired about 30-shots through the 250z at 50yds with all but 2-shots staying in the ragged-hole groups. Feeling pretty good about the performance of the 250z this morning.

With my 250z and my Paradigm, I did a lot of sporadic one shots, to see how the first shot would be after a day or a week and even a month, for several months, and both guns were, and are, first shot accurate. I really cherish that trait in an airgun. Actually most of my airguns can do this, but those two got really checked and rechecked right off the bat. I also did cold weather checks on them, and my Airforce TalonP, all good. I have high confidence in the guns as a result and that is an ingredient in good shooting too. I keep forgetting to rto with my scopes so I have less confidence in me lately though.

 

[Murfdurf82]

Some 9 and 10 mm springs arrived from AliExpress, from a link a fella posted on here in a thread I can't find. I'd like to thank him, and will if I find the post again. I installed a 9mm spring after trimming it to what I thought was correct for my project rifle. Well power wise with the regulator set at 2000 psi it shot jsb exact heavy 33.95gr at a 1019 fps for 5 shot spread. Deviation was 1032 high, 1014 low. I added a evolve 3d band as the barrel sagged. It still sagged a bit so I ordered 1/16" silicone pad, filed the bottom of the barrel band so I had more room to fit the pad on the top side. I fitted a 1" by 3/4" piece in that area at the crown of the bottle portion of the band. I used a dab of silicone on the bottle to silicone pad so it would slide on. It's tight, a thinner pad would have worked. It's straight, very secure. The gun was slammed around during transportation, it was a package that went missing in Kansas for 5 days and I assume this caused it.

Tomorrow I may have time to shoot it and see if the barrel is accurate. The way the barrel sat before I moved it straight makes me a bit worried. It has every possible upgrade Internally and ported. I have taken the main rail and everything down to the trigger 3 times to adjust it to cock after a different side lever was installed. It feels much more smooth and the rifle has unreal potential. 800mm slug barrel. Another round of used rifle rullet lol. 79 ft lbs, I'll be bringing slugs. The max 1 will accompany the Zelos tomorrow.

 

[Murfdurf82]

Went to the 4 acre plot my old man has. Did my yard maintenance cleanup and set up to shoot. I Have Never seen so many sweat bees before this year. All over my truck and the rifles. I threw on my mosquito hat from clean-up to shooting and that was annoying. Wind was 7-15 roughly with random gusts. Even with the wind and a few portable fans it was a pain to shoot but I did it.

My sk-19 did not like zan 56 grain at 890 fps, jsb heavy 50.15gr were better in the 980-960 range. I took my hat off after warmup shooting and got bit a few times. I jammed 2 38 gr slugs after a few shots on the Zelos, double loaded when I was swatting at them. So I never really shot it. I ended up shooting Bills shooting challenge with the SK-19, prone as I don't have a bench set up and didn't do great but I'll post it later. I need to download the scoring app and all that accompanies it.

Shot a few magazines out of the buster and notos. I planned on shooting more but was out of time. Even with all the malarkey it was fun!!

Of course before I left I had to hit the fun switch and empty all 17 shots!

 

[BBGunn]

Went to the 4 acre plot my old man has. Did my yard maintenance cleanup and set up to shoot. I Have Never seen so many sweat bees before this year. All over my truck and the rifles. I threw on my mosquito hat from clean-up to shooting and that was annoying. Wind was 7-15 roughly with random gusts. Even with the wind and a few portable fans it was a pain to shoot but I did it.

My sk-19 did not like zan 56 grain at 890 fps, jsb heavy 50.15gr were better in the 980-960 range. I took my hat off after warmup shooting and got bit a few times. I jammed 2 38 gr slugs after a few shots on the Zelos, double loaded when I was swatting at them. So I never really shot it. I ended up shooting Bills shooting challenge with the SK-19, prone as I don't have a bench set up and didn't do great but I'll post it later. I need to download the scoring app and all that accompanies it.

Shot a few magazines out of the buster and notos. I planned on shooting more but was out of time. Even with all the malarkey it was fun!!

Of course before I left I had to hit the fun switch and empty all 17 shots!

Bug splatter on the target! Gotta love that!

 

[Murfdurf82]

Yes sir that's another evil sweat bee! They are all over at our lay down yard at work, my dad's Nebraska house and Iowa plot I shot today.

 

[BBGunn]

This afternoon I cleaned the bore in my 250z in preparation for testing JSB KO 20.83gr .216" slugs. I wasn't going to shoot them until tomorrow morning when the wind is still but decided to go ahead and 'season' the clean bore with the new ammo.

The wind is blowing hard and switching so I took that into account while shooting-in the bore. I fired 40-shots and did not see any change in the accuracy as the bore leaded-in. Accuracy was not very good with 5-shot groups hanging around 1" at 50yds. Shot-to-shot consistency was pretty uniform with all shots in a group forming their own hole and equally dispersed, but not forming a ragged hole.

When chambering the .216" KOs there is no feel of the slugs engaging the lands in the bore. There is no feel of any resistance at all while chambering the KOs.

It's completely overcast so my optical Chrony would give me accurate readings. I put 10-shots over the screens. Average velocity was 945fps. I know from reading that Pumacarl was having his best results with KO 20.83gr up around 980fps with his 250z. Tomorrow I'll turn up the regulator and see what we get from the KOs.

 

[Playingdead]

Finally back from traveling and it was time to set up the new gun! I have been wanting a .177 PCP bullpup. I found a deal on a Beeman underlever regulated. While I was gone I ordered everything. 24 hours of travel on Saturday, up at 4am with nothing to do today (I mean besides laundry and cleaning).

Tore the Beeman all the way apart clean and polish everything. Barrel polished up nicely and the hammer and parts are all done. Trigger done. All back together and ready for pellet testing. I want to do a sub 20 tune and a sub 12 tune. Any suggestions? Maybe a H&N FTT 8.64 at 780-800?

I also have a box of parts for the Pinty Striker for this week (C88, Regulator, and will print some others)

 

[Grunt64]

This afternoon I cleaned the bore in my 250z in preparation for testing JSB KO 20.83gr .216" slugs. I wasn't going to shoot them until tomorrow morning when the wind is still but decided to go ahead and 'season' the clean bore with the new ammo.

The wind is blowing hard and switching so I took that into account while shooting-in the bore. I fired 40-shots and did not see any change in the accuracy as the bore leaded-in. Accuracy was not very good with 5-shot groups hanging around 1" at 50yds. Shot-to-shot consistency was pretty uniform with all shots in a group forming their own hole and equally dispersed, but not forming a ragged hole.

When chambering the .216" KOs there is no feel of the slugs engaging the lands in the bore. There is no feel of any resistance at all while chambering the KOs.

It's completely overcast so my optical Chrony would give me accurate readings. I put 10-shots over the screens. Average velocity was 945fps. I know from reading that Pumacarl was having his best results with KO 20.83gr up around 980fps with his 250z. Tomorrow I'll turn up the regulator and see what we get from the KOs.

BBGunn, your results with the KO 20.83gr .216s tell a very clear story.
When a slug chambers with zero feel of the lands, that almost always means the slug is undersized for the bore. And when the fit is too loose, you get exactly what you described:
every shot makes its own clean hole
groups stay “uniform”
but they never stack into a ragged hole
seasoning the bore doesn’t change anything
velocity adjustments don’t fix it
That’s classic behavior of a slug that isn’t engaging the rifling.
If the slug doesn’t engrave, you lose consistent start pressure, rotational start, bore friction, and harmonic timing. The gun can still shoot consistent, but it won’t shoot precise. That’s why your 1" groups at 50 yards stayed 1" no matter how many shots you put through the clean bore.

Chasing Pumacarl’s 980 fps won’t solve it either. Velocity can tighten vertical a little, but it can’t overcome a poor fit. If the slug isn’t touching the lands, the tune can’t pull it into accuracy.

Your 250z clearly wants a slightly larger diameter. Most shooters who run KOs in .22 find:

.217 is the sweet spot
.216 is often too loose
.218 can be too tight depending on the barrel
If you want to continue testing KOs, I’d go straight to .217.Other slugs that tend to match bores like yours:
NSA 20.2gr .217
Griffin 21–23gr .217
H&N .2175
Zan .217
Anything that gives you that smooth, positive “kiss” of the lands when chambering.

Bottom line:If you don’t feel the slug engage the rifling, you’re starting from a disadvantage. Your rifle is telling you the KO .216s simply aren’t the right fit. please let me know how you make out?

 

[BBGunn]

BBGunn, your results with the KO 20.83gr .216s tell a very clear story.
When a slug chambers with zero feel of the lands, that almost always means the slug is undersized for the bore. And when the fit is too loose, you get exactly what you described:
every shot makes its own clean hole
groups stay “uniform”
but they never stack into a ragged hole
seasoning the bore doesn’t change anything
velocity adjustments don’t fix it
That’s classic behavior of a slug that isn’t engaging the rifling.
If the slug doesn’t engrave, you lose consistent start pressure, rotational start, bore friction, and harmonic timing. The gun can still shoot consistent, but it won’t shoot precise. That’s why your 1" groups at 50 yards stayed 1" no matter how many shots you put through the clean bore.

Chasing Pumacarl’s 980 fps won’t solve it either. Velocity can tighten vertical a little, but it can’t overcome a poor fit. If the slug isn’t touching the lands, the tune can’t pull it into accuracy.

Your 250z clearly wants a slightly larger diameter. Most shooters who run KOs in .22 find:

.217 is the sweet spot
.216 is often too loose
.218 can be too tight depending on the barrel
If you want to continue testing KOs, I’d go straight to .217.Other slugs that tend to match bores like yours:
NSA 20.2gr .217
Griffin 21–23gr .217
H&N .2175
Zan .217
Anything that gives you that smooth, positive “kiss” of the lands when chambering.

Bottom line:If you don’t feel the slug engage the rifling, you’re starting from a disadvantage. Your rifle is telling you the KO .216s simply aren’t the right fit. please let me know how you make out?

Thank you for your advice and reasoning. That all sounds very logical and If I hadn't already tested many other slugs in diameters from .217" to .2193" and weights from about 20gr to 30gr I would feel hopeful from what you wrote. But, to be honest, these .216" have actually been the most accurate of any or the many I have already tested.

If you have any interest you can read about my history with the 250z in the thread below.

B

250Z I'm in the club boyz!

Jan 8, 2026

Midway got a new shipment of 250Z in stock yesterday. Only FDE color but that's fine by me.

In a couple weeks I'll have a Gen2 250Z in .22 with new optic, grip, etc.

First will be to check the rifle holds air. Next will be to patch bore and check with bore scope. If bore/leade,/crown looks dimensionally good then I'll pull the barrel and polish the bore. After that we'll adjust the trigger to a light, crisp, single stage setting.

Then the fun part starts!

I love getting a new rifle for a Winter project. The snow stays long here in the mountains.

• BBGunn
• Replies: 73
• Forum: Barra Airguns

• 
• 

 

[Pumacarl]

Thank you for your advice and reasoning. That all sounds very logical and If I hadn't already tested many other slugs in diameters from .217" to .2193" and weights from about 20gr to 30gr I would feel hopeful from what you wrote. But, to be honest, these .216" have actually been the most accurate of any or the many I have already tested.

If you have any interest you can read about my history with the 250z in the thread below.

B

250Z I'm in the club boyz!

Jan 8, 2026

Midway got a new shipment of 250Z in stock yesterday. Only FDE color but that's fine by me.

In a couple weeks I'll have a Gen2 250Z in .22 with new optic, grip, etc.

First will be to check the rifle holds air. Next will be to patch bore and check with bore scope. If bore/leade,/crown looks dimensionally good then I'll pull the barrel and polish the bore. After that we'll adjust the trigger to a light, crisp, single stage setting.

Then the fun part starts!

I love getting a new rifle for a Winter project. The snow stays long here in the mountains.

• BBGunn
• Replies: 73
• Forum: Barra Airguns

• 
• 

The .216 don't feel tight in my breech either because I reamed my breech to .218 but on the advice of @Dairyboy, I tried them anyway and they shoot great for me. Try them fast because I think what is happening is that the base of these slugs have such thin walls that between the hit of air and that they seal against the bore, which you won't see by simply pushing one through. The increased speed ups the spin for more stability too.

 

[md_shooter_rick]

Unboxing my GX CS2 and the GX filter. WOO HOOO. (i know simple things for simple minds)

 

[Grunt64]

Thank you for your advice and reasoning. That all sounds very logical and If I hadn't already tested many other slugs in diameters from .217" to .2193" and weights from about 20gr to 30gr I would feel hopeful from what you wrote. But, to be honest, these .216" have actually been the most accurate of any or the many I have already tested.

If you have any interest you can read about my history with the 250z in the thread below.

B

250Z I'm in the club boyz!

Jan 8, 2026

Midway got a new shipment of 250Z in stock yesterday. Only FDE color but that's fine by me.

In a couple weeks I'll have a Gen2 250Z in .22 with new optic, grip, etc.

First will be to check the rifle holds air. Next will be to patch bore and check with bore scope. If bore/leade,/crown looks dimensionally good then I'll pull the barrel and polish the bore. After that we'll adjust the trigger to a light, crisp, single stage setting.

Then the fun part starts!

I love getting a new rifle for a Winter project. The snow stays long here in the mountains.

• BBGunn
• Replies: 73
• Forum: Barra Airguns

• 
• 

If the .216s are already your best performer across all the diameters you’ve tried, then stick with them and tune around them. Your barrel has spoken — now it’s just a matter of finding the right pressure/harmonic window.
I’d bump the reg a bit and see how the groups behave at:
960 fps
975 fps
985 fps
One of those will usually snap the groups shut with KOs.

 

[BBGunn]

Yesterday I posted about testing JSB KO 20.83gr .216" at 945fps in my 250z. Results were not what I hoped for.

This morning I turned up the regulator and tested the KOs at 965fps and again at 978fps. Neither velocity produced accuracy that is good enough for my hunting use. The best accuracy came at 978fps but those 5-shot groups were running 3/4"-7/8". I even fired my AEA 21.9gr pellets at 978fps (yes, they fired exact same speed as the KOs) and the 50yd groups were much better that the KO groups.

I turned the regulator back down to give me 933fps with the AEA 21.9gr pellets and fired the two 5-shot groups at 50yds seen in the pic below. I'm done with trying to find a slug that will shoot with the pellets from my 250z.

Also, there was some conversation yesterday about whether the .216" diameter KOs were even making contact with the lands in the bore. This morning I pulled a JSB KO 20.83gr .216" through the 250z bore. As you can see in the pic below, the .216" slug does just lightly make contact with the bore's lands.