.22 to .25 conversion

[tickfawriver]

Hello everyone, I am new to the forum and looking for some insight into the possibilities of a caliber conversion.

I own a Kalibrgun Cricket carbine in .22 cal and I am bitten by the .25 bug. Instead of buying another gun I was wandering about the possibilities of converting my existing gun to .25 caliber. I would like to hear some opinione maybe soem pro's and con's.

Thanks,
Randy

 

[DeutschKSK]

You can do it, need a barrel and probe.. magazine too.. Will need to turn the reg pressure up as well.. 

 

[guod123]

Not familiar with the dimensions of the carbine, the difference in bullpups is an 11" to a 16.5" shroud. The .22 has a 17" barrel, and the .25 is almost 24". The airtube is 21" on the .22 and better than 3" more on the .25 The regulators appear the same, as is the OD and the air port along with the barrell indexing. Years back Ernest did a compact .25. The velocity was some what less than the average 900+ fps the Crickets were usually tuned to at that time. I don't know if the baffles have different hole sizes in addition to their lengths? 

 

[Dairyboy]

I think I'd talk to Charlie at Georgia Airguns as I believe he could help in this area

 

[DeutschKSK]

+1 above, he’s a cool dude. 

 

[tickfawriver]

Many thanks, I will give Charlie a call.

 

[rwsmike]

I would contact Ernest Rowe on this one 

 

[SMH77]

I know it's not the same gun, but I do the same thing with my RAW. I had it built for .25 caliber with a LW polygon barrel (setup to shoot JSB Heavies at 60 fpe). The regulator setting stays the same when set to shoot .30 caliber, so I have a .30 caliber probe and barrel setup. I switched from my .25 caliber polygon to the .30 caliber setup tonight to shoot some groups with the .30 caliber for someone asking about the H&N .30 cal Baracudas. The entire swap over (includes removing the scope, removing the barrel, removing the probe, installing the new probe, installing the new barrel, reinstalling the scope) took me a total of 6 minutes, 22 seconds to complete-and about 2 minutes of that time was dismounting / remounting my scope. It's a pretty easy procedure, and I've written a guide on how to do it so others can follow suit.

Anyway, just chiming in to say it's a very cost effective way to own multi calibers-I think its worth doing...


Sean

 

[tickfawriver]

Does anyone have Ernest Rowe's email?

It would be great to get opions from both Ernest and Charlie.

Thanks Sean, your experience is what I am hoping for.

Randy

 

[EliteAirgunr]

www.ernestrowe.com

 

[zx10wall]

Looks to me that the .22 Kalibrgun carbine (rifle) to a .25 would be easy. The tough part would be to acquire a .25 barrel for the carbine. Charlie might have one. A .25 probe probably won’t be difficult to find. You may also need to switch the hammer spring out for the .25 spring. 

I’ve converted a .25 Cricket pup to a .30. Switched the barrel (acquired from LW) and probe (acquired from Ernest). This is the easy part. Ernest has a video on swapping the probe. 

The more technical part is now to tune. The reg will need to be bumped up. You will probably need a .25 hammer spring also. 

I just acquired a .22 Cricket pup that I will do the exact same on. I already have the .25 hammer spring, barrel (Kalibrgun CZ original) & probe. I’m leaning toward buying a Huma for the .25 setup and tune to shoot the 25 gr to 880 fps. With this, I swap barrel, probe, hammer spring and reg each time. Probably a 20 minute swap but not bad. 

With Sean’s RAW, he has it a bit easier as the 34 gr .25 and the 44 gr .30 are using the same reg setting. 

 

[SMH77]

Now that the forum has a 'upload document' feature, I'm uploading a copy of the RAW conversion procedure in case anyone wants to download a copy of it for their use. I realize this isn't the right guide for the Kalibrgun, but it will give you some insight into the process, and what a 'probe' looks like.

I'll start a new thread to pull this one out to the top level for easier access for better visibility as this topic comes up fairly regularly. Hope it's useful for you guys-if so, just leave me a '+' on my profile (if you want, no pressure). More importantly: if you find errors, need clarification, or want something added: PLEASE let me know and I'll include/update, etc for you.

Here it is:

 View attachment 1524077856_13076287715ad79520d63e56.94903022_RAW Caliber Change Guide, Rev 2c.pdf ​

Sean

 

[tickfawriver]

I watched all of Ernest's videos and I am thinking that I will give it a try. It may take it a while to get it done (I have a lot of irons in the fire) but I will provide an update when I do.

Thanks

 

[zx10wall]

I’ve done the coversion now to my .22 Cricket pup. I tranferred the .25 caliber, barrel & probe then tuned for 875 with the 25.4 Kings. It takes a bit of time to get that probe in there. Tidious. 

To my surprise, when coverted back to .22, without any tinkering or tuning the HST or reg, the 18.13 gr JSBs were shooting at 880 fps. This is awesome!!

 

[tickfawriver]

Beautiful gun, so how was the accuracy at .25?

Where did you get the parts and what was the cost?

Did you adjust the reg yourself?

I emailed Charlie and he does not do the conversions for several reasons but he did not elaborate.

 

[zx10wall]

I had the parts after converting a .25 Cricket to a .30 LW. Like I mention previously in the post, I got the .30 probe from Ernest. That was a few years ago.

So I had the .25 CZ barrel and .25 probe here. I aquired the .22 Cricket with the thought of this conversion. Accuracy is awesome with both. As I mentioned, the gun is tuned; hammer spring tension and reg are in hormony. I also adjusted the valve spring tension a bit and secured adjuster. I don’t have to touch the HST or reg when swapping. Shoots the .22 at 880 fps and the .25 at 875 fps. 

Why would Mr. Frear not do this work? Probably because he’d rather sell you two guns. If he sells you a .25 barrel (get the moderator also) and probe I’ll tune it for you. BTW, I also use the same hammer spring so no need for two.

 

[tickfawriver]

Thanks for the response. I think I will get a price on a barrel, moderator and probe and go from there.

 

[COSTAS4597]

I had the same problem. Having the .25 just wanted a .22 also!
It’s difficult to find any parts here so………
I took the easy path!.......Just bought a second one…

Here side by side. Both with Athlon Helos (8X34 for the .25 and 6X24 for the .22) scopes.

Both shoot exceptionally well. The .25 likes the MKII at 830 fps and the heavies a little faster (840-850 fps). If no wind is involved, the 25’s at 100fps more also group well. The .22 likes the 18’s at 880-890 fps but also shoots the 16’s very well at the same speed (or a little lower at 860-870 fps). Regulator pressure on both seems to be around 110 bar.
The .25 barrel has a 14X1 thread for the silencer. The .22 hasn’t.
I hadn’t had a chance to open them for differences. But one should also consider transfer port size, regulator plenum size, valve setting etc… Good luck.

 

[zx10wall]

"COSTAS4597"I had the same problem. Having the .25 just wanted a .22 also!
It’s difficult to find any parts here so………
I took the easy path!.......Just bought a second one…

Here side by side. Both with Athlon Helos (8X34 for the .25 and 6X24 for the .22) scopes.
Both shoot exceptionally well. The .25 likes the MKII at 830 fps and the heavies a little faster (840-850 fps). If no wind is involved, the 25’s at 100fps more also group well. The .22 likes the 18’s at 880-890 fps but also shoots the 16’s very well at the same speed (or a little lower at 860-870 fps). Regulator pressure on both seems to be around 110 bar.
The .25 barrel has a 14X1 thread for the silencer. The .22 hasn’t.
I hadn’t had a chance to open them for differences. But one should also consider transfer port size, regulator plenum size, valve setting etc… Good luck.

Nice Crickets. With my coversion, the pup is a .22. I converted to .25. All I did was swap barrel, shroud, probe, resealed all and tuned the gun to shoot the 25 gr Kings at 875 fps. I didn’t mess with porting, the plenum is the same on factory .22 and .25. I did adjust valve return spring tension slightly and secured adjuster.

With this said, again, when I converted back to .22, swapping barrel, shroud and probe, to my delight, the gun shot the 18 gr at 880 fps with no adjustments at all.