250Z I'm in the club boyz!

[BBGunn]

Fired this group at about 1:30pm today. Wind was swirling a little as per my wind flags. A light rain, but the highest chance reason for the high shots in the group are my own mental incapacity to stay 'in' proper shooting form on the bench. I'm just not as good of a 'shot' as I was when I was younger. I believe I was applying some inconsistent shoulder on the stock. Such is getting old.

Still, I want to post groups like this because they are honest and others who are in the market for a 250z can see that the rifle's potential is solid!

EDIT: I see after posting that I got the pellet weight wrong on the pic. Should be 21.9gr. Just another 'old guy' thing.

 

[Freddy J]

I have yet to see a barrel for the 250Z get anywhere close to that. Three barrels and they all have damaged lands that deform the pellets and slugs. Waiting on another one.

 

[BBGunn]

I have yet to see a barrel for the 250Z get anywhere close to that. Three barrels and they all have damaged lands that deform the pellets and slugs. Waiting on another one.

I am sorry to read about your bad luck with the barrels. I was skeptical when I bought my rifle as several people reported bad barrels like you described.

I scoped my barrel when I first got the rifle. Bore was perfect all but the spot just ahead of the leade where the pilot on the cutter rubbed the lands. However, it didn't smash the lands like some reported, just marked the lands on the surface.

I polished the bore and the rifle shoots pellets as well as any air rifle I have ever owned. So far, I haven't had luck with slug testing.

If Barra doesn't have this issue sorted-out with SPA they will not sell many more rifles going forward!

 

[BBGunn]

Fired one more 20-shot group this morning to add onto this thread. This will be the last 'pellet' group I post here as I think I've shown enough that prospective 250z buyers can see that if they buy a 250z (or coming 270z) and the rifle has a good barrel that it will be an excellent pellet shooter!

Was 8:00am and any wind movement was minimal as seen at my wind flags. I tried to the best of my senior years ability to shoot each shot as precisely as I could. As you can see from the target pic, the group was very much similar size overall to the other two 20-shots groups I have posted. Today's group was a little more precise as the group was more uniform vertically and horizontally than yesterday's group.

Shot-to-shot precision has been excellent and POI remains the same from day-to-day on target. Accuracy average is right in there with about any similar air rifle, at any price.

Any further posting added to this thread will be my efforts with slug shooting, or if problems develop with the rifle.

Hope someone finds some value from reading this thread.

 

[BBGunn]

I said above that I wasn't going to post any more pellet groups from my 250z, so I won't. But, this morning the 250z put down some 50yd 5-shot groups that were just OMG small!

Still have some slugs coming from Griffin to try. It's 3-weeks from order to delivery from Griffin as his slugs are popular and he can only produce so fast. I should have them here for shooting maybe next Tuesday???

 

[BBGunn]

Drove into town and picked-up my next test slugs at the P.O. early this morning. The slugs are Griffin 21gr. TC Hollow Base, 218".

I already had the bore cleaned on the 250z and the rifle ready to go. I prepped the slugs and setup the Chrony. I fired 40-shots total so as to make sure the barrel was fouled and the rifle's bore was shooting the slugs as well as it could. The 21gr Griffins were shooting 10fps faster than the AEA 21.9gr pellets. Velocity was 955fps-960fps. That's a regulator pressure of 2050psi.

These new slugs grouped with no better accuracy than any of the other 1/2 dozen various slugs I have tried. All the various slugs I have tried grouped 5-shots from 3MOA to 6MOA at 50yds. That's roughly, 1.5" to 3.0" average. These Griffins were hanging about 1.75" 5-shot groups at 50yds.

If I try another slug in this rifle it will be what PumaCarl has had success with. That's the JSB KO 20.83gr. For now, I'll stay with the AEA 21.9gr pellets that are shooting 5/8" average 5-shot groups at 50yds. Velocity 945fps to 955fps (depending on ambient temperature).

I wish it would shoot slugs just for the better terminal performance on rock chucks. However, the pellets will perform just fine on the chucks with brain shots. And, the pellet accuracy is so good and so consistent that hits will be almost guaranteed!

So, that's probably the last I'll post on this thread. Hope folks that are researching the .22 250z find the info. in this thread helpful.

 

[Cantona256]

Fired this group at about 1:30pm today. Wind was swirling a little as per my wind flags. A light rain, but the highest chance reason for the high shots in the group are my own mental incapacity to stay 'in' proper shooting form on the bench. I'm just not as good of a 'shot' as I was when I was younger. I believe I was applying some inconsistent shoulder on the stock. Such is getting old.

Still, I want to post groups like this because they are honest and others who are in the market for a 250z can see that the rifle's potential is solid!

EDIT: I see after posting that I got the pellet weight wrong on the pic. Should be 21.9gr. Just another 'old guy' thing.

That’s outstanding

 

[Cantona256]

Drove into town and picked-up my next test slugs at the P.O. early this morning. The slugs are Griffin 21gr. TC Hollow Base, 218".

I already had the bore cleaned on the 250z and the rifle ready to go. I prepped the slugs and setup the Chrony. I fired 40-shots total so as to make sure the barrel was fouled and the rifle's bore was shooting the slugs as well as it could. The 21gr Griffins were shooting 10fps faster than the AEA 21.9gr pellets. Velocity was 955fps-960fps. That's a regulator pressure of 2050psi.

These new slugs grouped with no better accuracy than any of the other 1/2 dozen various slugs I have tried. All the various slugs I have tried grouped 5-shots from 3MOA to 6MOA at 50yds. That's roughly, 1.5" to 3.0" average. These Griffins were hanging about 1.75" 5-shot groups at 50yds.

If I try another slug in this rifle it will be what PumaCarl has had success with. That's the JSB KO 20.83gr. For now, I'll stay with the AEA 21.9gr pellets that are shooting 5/8" average 5-shot groups at 50yds. Velocity 945fps to 955fps (depending on ambient temperature).

I wish it would shoot slugs just for the better terminal performance on rock chucks. However, the pellets will perform just fine on the chucks with brain shots. And, the pellet accuracy is so good and so consistent that hits will be almost guaranteed!

So, that's probably the last I'll post on this thread. Hope folks that are researching the .22 250z find the info. in this thread helpful.

How much hammer spring are you using at the moment? What do the groups look like? Are they just totally scattered or is there a pattern to it? Looking at the shape of the holes does it look like the slug are tumbling?

You’re getting fantastic speed for that reg pressure. The fact that the slugs are going faster than the pellets gives me pause though… I’m thinking that .218 might be too small (lack of thread engagement) or you have a lot of hammer spring (more dwell) which means the valve is being held open too long.

 

[BBGunn]

How much hammer spring are you using at the moment? What do the groups look like? Are they just totally scattered or is there a pattern to it? Looking at the shape of the holes does it look like the slug are tumbling?

You’re getting fantastic speed for that reg pressure. The fact that the slugs are going faster than the pellets gives me pause though… I’m thinking that .218 might be too small (lack of thread engagement) or you have a lot of hammer spring (more dwell) which means the valve is being held open too long.

When I first got the rifle I realized the hammer spring was overly stout for the valve. At the factory reg. setting of 2050psi the velocity would decrease when tensioning the spring , but would increase velocity when releasing spring tension. There was no way to get a proper balance with the stock spring. So I shortened the spring (pic) and got the proper adjustment range to take advantage of the valve. Even after shortening the spring I still have to run the spring tension 1/2-turn loosened from flush with the block to achieve the proper setting.

The groups have been 'groups'..., no real outliers. The groups are mostly roundish with the slugs evenly distributed within the group. In fact, I fired a full mag (10-shots) into one group yesterday where not one single shot touched another. The group was about 1.75" CTC but yet all slugs made their own clean hole. That sort of group doesn't happen very often.

None of the half dozen slugs I have tested key-holed at all. Not even close. Just perfectly clean smaller than a pellet, slug holes. So, shot-to shot precision is consistent, but accuracy is bad. All the slugs performed pretty much the same with a couple slightly better than others but not a lot of accuracy difference between the whole lot.

I believe you are correct with your thought about the slugs diameters. The largest slugs I used were .2193" and those were the best of the lot. But still..., just not accurate enough to hunt with.

Personally, I feel the twist rate (1:18) is too slow for best slug performance. But that's just my gut feeling..., I can't prove it.

If you have any ideas I would love to read them. Thanks for your interest.


I cut the spring just enough that after re-finishing the end of the spring, the spring is now exactly .500" shorter than stock. I chose that length based on what hammer spring adjustments were showing me from the Chrony readings.

 

[Cantona256]

Drove into town and picked-up my next test slugs at the P.O. early this morning. The slugs are Griffin 21gr. TC Hollow Base, 218".

I already had the bore cleaned on the 250z and the rifle ready to go. I prepped the slugs and setup the Chrony. I fired 40-shots total so as to make sure the barrel was fouled and the rifle's bore was shooting the slugs as well as it could. The 21gr Griffins were shooting 10fps faster than the AEA 21.9gr pellets. Velocity was 955fps-960fps. That's a regulator pressure of 2050psi.

These new slugs grouped with no better accuracy than any of the other 1/2 dozen various slugs I have tried. All the various slugs I have tried grouped 5-shots from 3MOA to 6MOA at 50yds. That's roughly, 1.5" to 3.0" average. These Griffins were hanging about 1.75" 5-shot groups at 50yds.

If I try another slug in this rifle it will be what PumaCarl has had success with. That's the JSB KO 20.83gr. For now, I'll stay with the AEA 21.9gr pellets that are shooting 5/8" average 5-shot groups at 50yds. Velocity 945fps to 955fps (depending on ambient temperature).

I wish it would shoot slugs just for the better terminal performance on rock chucks. However, the pellets will perform just fine on the chucks with brain shots. And, the pellet accuracy is so good and so consistent that hits will be almost guaranteed!

So, that's probably the last I'll post on this thread. Hope folks that are researching the .22 250z find the info. in this thread helpful.

Last thing I’ll say is that I’ve only ever shot one rock chuck and it was last summer with my 250z in .25 cal…. At 81y the whack was spectacular and instant death so I didn’t have to worry about it scurrying down into its hole to die.

It was a pregnant female too so she was massive, 8-10lbs easily… I’m already planning on a trip up the mountain the end of this month to hopefully hit some 150y+ shots with my EQ

I say this only to encourage you to keep trying on the slugs. I promise it’s worth it. Not at the expense of tearing your hair out so if it doesn’t work no big deal of course. But for game the size of rock chucks I would really push for slugs. Pellets will kill them just fine but I think you’ll have more fun with slugs.

Idk what it is about the 250z but when you got it tuned nicely with slugs it’s a shooting experience that’s hard to beat.

 

[BBGunn]

Last thing I’ll say is that I’ve only ever shot one rock chuck and it was last summer with my 250z in .25 cal…. At 81y the whack was spectacular and instant death so I didn’t have to worry about it scurrying down into its hole to die.

It was a pregnant female too so she was massive, 8-10lbs easily… I’m already planning on a trip up the mountain the end of this month to hopefully hit some 150y+ shots with my EQ

I say this only to encourage you to keep trying on the slugs. I promise it’s worth it. Not at the expense of tearing your hair out so if it doesn’t work no big deal of course. But for game the size of rock chucks I would really push for slugs. Pellets will kill them just fine but I think you’ll have more fun with slugs.

Idk what it is about the 250z but when you got it tuned nicely with slugs it’s a shooting experience that’s hard to beat.

We use to go on 2-week long (I had 6-weeks paid vacation per year) air rifle chuck hunts to Idaho and Nevada. We met some local Indians that lived up high where we were hunting. They actually ate rock chucks! When they learned we were hunting them with air rifles and the chucks wouldn't be all blown-up, they ask us to bring a few back down to their place and drop them off, which we did. I was not inspired to eat a rock chuck, or any other ground squirrel even though those folks spoke highly of their eating quality.

 

[Cantona256]

When I first got the rifle I realized the hammer spring was overly stout for the valve. At the factory reg. setting of 2050psi the velocity would decrease when tensioning the spring , but would increase velocity when releasing spring tension. There was no way to get a proper balance with the stock spring. So I shortened the spring (pic) and got the proper adjustment range to take advantage of the valve. Even after shortening the spring I still have to run the spring tension 1/2-turn loosened from flush with the block to achieve the proper setting.

The groups have been 'groups'..., no real outliers. The groups are mostly roundish with the slugs evenly distributed within the group. In fact, I fired a full mag (10-shots) into one group yesterday where not one single shot touched another. The group was about 1.75" CTC but yet all slugs made their own clean hole. That sort of group doesn't happen very often.

None of the half dozen slugs I have tested key-holed at all. Not even close. Just perfectly clean smaller than a pellet, slug holes. So, shot-to shot precision is consistent, but accuracy is bad. All the slugs performed pretty much the same with a couple slightly better than others but not a lot of accuracy difference between the whole lot.

I believe you are correct with your thought about the slugs diameters. The largest slugs I used were .2193" and those were the best of the lot. But still..., just not accurate enough to hunt with.

Personally, I feel the twist rate (1:18) is too slow for best slug performance. But that's just my gut feeling..., I can't prove it.

If you have any ideas I would love to read them. Thanks for your interest.


I cut the spring just enough that after re-finishing the end of the spring, the spring is now exactly .500" shorter than stock. I chose that length based on what hammer spring adjustments were showing me from the Chrony readings.

Nahh 1:18 twist ratio is more than enough for slugs in this caliber. I shot about 5-6 thousands slugs and only one can of pellets through mine. It’s not the twist rate.

Humor me a little and throw the reg pressure up to about 2500psi and see if you can’t get those slugs going about 950fps… the only slug I ever shot out of the Z slower than 950fps was maybe 920-930fps on the 37gr Franco’s.

To be fair the .22 cal has always been harder to tune for slugs than the .25 cal is. Not sure why (besides barrels).

 

[BBGunn]

Nahh 1:18 twist ratio is more than enough for slugs in this caliber. I shot about 5-6 thousands slugs and only one can of pellets through mine. It’s not the twist rate.

Humor me a little and throw the reg pressure up to about 2500psi and see if you can’t get those slugs going about 950fps… the only slug I ever shot out of the Z slower than 950fps was maybe 920-930fps on the 37gr Franco’s.

To be fair the .22 cal has always been harder to tune for slugs than the .25 cal is. Not sure why (besides barrels).

Friend, I appreciate your ideas, thanks for your help. However, I already have experimented (further up in this thread) as you suggested with no better results.

B

250Z Post in thread 'I'm in the club boyz!'

Feb 15, 2026

This morning I tested the latest AVS .2193" slugs I received this past week. Both versions of the AVS slugs are 22gr, and both have dish base. One slug is the 'ELR' version and the other the 'Std' version (see pic).

Started with a clean bore like I always do when testing new projectiles.

As you might guess, the .2193" slugs are snug going into the leade. The 'ELR' version has more contact against the bore's lands than does the 'Std' version. Thus, the ELRs have a little more resistance pushing into the lands. While the .2193" slugs fit into the bore with resistance, it's not overly...

• BBGunn

• 

It's getting close (a few weeks) to chuck hunting time so I think I'll just focus on using my pellet tune for now. I'll be shooting my distances for my drop-chart this next week so I can confirm my dial-ups. It's all good..., I have confidence in the rifle shooting the 22gr pellets.

Perhaps I'll have another go at slug testing with the .22 250z again next Winter when I am not hunting (except coyotes) or fishing much.

 

[Cantona256]

Friend, I appreciate your ideas, thanks for your help. However, I already have experimented (further up in this thread) as you suggested with no better results.

B

250Z Post in thread 'I'm in the club boyz!'

Feb 15, 2026

This morning I tested the latest AVS .2193" slugs I received this past week. Both versions of the AVS slugs are 22gr, and both have dish base. One slug is the 'ELR' version and the other the 'Std' version (see pic).

Started with a clean bore like I always do when testing new projectiles.

As you might guess, the .2193" slugs are snug going into the leade. The 'ELR' version has more contact against the bore's lands than does the 'Std' version. Thus, the ELRs have a little more resistance pushing into the lands. While the .2193" slugs fit into the bore with resistance, it's not overly...

• BBGunn

• 

It's getting close (a few weeks) to chuck hunting time so I think I'll just focus on using my pellet tune for now. I'll be shooting my distances for my drop-chart this next week so I can confirm my dial-ups. It's all good..., I have confidence in the rifle shooting the 22gr pellets.

Perhaps I'll have another go at slug testing with the .22 250z again next Winter when I am not hunting (except coyotes) or fishing much.

Yeah sorry I’ve read the rest of the thread before but it’s been a minute haha.

But I totally get it. If it was the .25 cal I’d be very confident in being able to help you figure it out but the .22 has always been tricky for some reason.

I wish I had the money to just buy a .22 just to fiddle with it and see if I could figure it out. Alas, I have to keep my powder dry for other projects. Plus I can’t let my 2 baby mommas find out I’m having too much fun or I’ll be in trouble

But as a hunter I completely understand your desire to not fiddle with it. I hunt coyotes all year long.. well I call them all year long .. but I’m really excited for some Chucks haha… it’s especially fun around here because we only see them way up on cedar mountain and at 8,000-10,000ft of elevation the slugs really sail. My goal for this summer is to get a 250y+ shot on one.