Author Topic: Hatsan 125 transfer port, unusual for me. (Read 1897 times))

Atom · « **on:** September 26, 2023, 02:25:29 PM »

What is the diameter of the transfer port on the Hatsan 125 and has anyone seen one like the one in the attached photo?

Madd Hatter · « **Reply #1 on:** September 26, 2023, 07:39:08 PM »

Mine is just a round hole like the barrel. I wonder if there's a piece missing?

mikeyb · « **Reply #2 on:** September 26, 2023, 07:57:52 PM »

Simple round hole on unrestricted muzzle energy US rifles. Yours look like a threaded insert was added to restrict airflow/muzzle energy for your country or a restricted muzzle energy country near yours.

Edit: will try to measure one of mine snd post results.

splitbeing · « **Reply #3 on:** September 26, 2023, 08:02:23 PM »

What's the caliber?

Blowpipe Sam · « **Reply #4 on:** September 26, 2023, 08:55:46 PM »

Hatsan sells guns with a screw in restrictor in the transfer passage in places that require the guns meet a maximum power regulation.

mikeyb · « **Reply #5 on:** September 27, 2023, 06:38:41 AM »

Hatsan springers are IMHO good entry level bargain air rifles. They typically DON'T have the finest finishes and tolerances at their price point. However, the breech face on your rifle appears to be one of the roughest I've ever seen. Also, the transfer port insert appears to be damaged. While that damage should NOT significantly affect the performance it is disappointing to see such crude work on one of my favorite brand of air rifles.

H95Kidd · « **Reply #6 on:** September 27, 2023, 08:40:16 AM »

Wow... Crude doesn't even begin to describe the quality of the machining work (or lack thereof) on that 125 transfer port. In contrast, on my 95 Vortex, the port machining is very nicely done. The cutting tool used on that 125 port was probably dull or damaged, or BOTH. As mikeyb indicated, and as ugly as it is, probably little to no effect on velocity as long as breech seal is in good shape. But, that crappy machine work/finish would really bug me though....

Back_Roads · « **Reply #7 on:** September 27, 2023, 08:52:36 AM »

Yikes that is a bad one, I could do better with an angle grinder blindfolded

Atom · « **Reply #8 on:** September 27, 2023, 10:40:08 AM »

Quote from: splitbeing on September 26, 2023, 08:02:23 PM

What's the caliber?

Transfer port is about 3.5 mm, caliber 5.5 mm or .22

Atom · « **Reply #9 on:** September 27, 2023, 10:44:49 AM »

I already have negative experience with their weapons, not to mention everything. I'm tidying this one up a bit because the FAC came from the factory and on measurement it's about 24J, short spring 43 coils 41 active...

Atom · « **Reply #10 on:** September 27, 2023, 10:49:37 AM »

Quote from: mikeyb on September 27, 2023, 06:38:41 AM

Hatsan springers are IMHO good entry level bargain air rifles. They typically DON'T have the finest finishes and tolerances at their price point. However, the breech face on your rifle appears to be one of the roughest I've ever seen. Also, the transfer port insert appears to be damaged. While that damage should NOT significantly affect the performance it is disappointing to see such crude work on one of my favorite brand of air rifles.

You are right, the lower part is damaged probably when twisting the insert, the trigger has rough surfaces where it touches, I will try to take a photo

mikeyb · « **Reply #11 on:** September 30, 2023, 08:42:12 PM »

Quote from: mikeyb on September 26, 2023, 07:57:52 PM

Simple round hole on unrestricted muzzle energy US rifles. Yours look like a threaded insert was added to restrict airflow/muzzle energy for your country or a restricted muzzle energy country near yours.

Edit: will try to measure one of mine and post results.

Pulled my oldest Mod125 from storage. Coil spring version, NOT a Vortex air spring model.

Could not get my calipers positioned to measure transfer port directly. I was able to just barely fit a short piece of 0.159" rod into transfer port.

I'm pretty certain that all my Mod125 rifles (177,22,25) have the same diameter transfer port.

edit: The milling marks in my photo are visible but I cannot "feel" them. Like I posted earlier Hatsans are bargain air rifles not famous for superb machining and finishes.

Toxylon · « **Reply #12 on:** October 02, 2023, 05:42:44 AM »

It seems obvious to me the "lobed" TP on Antom's gun is not a machining fault but a different type of TP altogether. I've never seen a Hatsan where an ordinary-type TP wasn't completely ordinary. Ordinary TP's are drilled out with a single pass of the bit, and you can't drill lobes into the cross section that way.

Atom · « **Reply #13 on:** October 02, 2023, 02:12:45 PM »

I don't see the point of what Hatsan did, the insert in the transfer port is 4mm ID OD 7mm and the transfer port in the cylinder is about 3.5mm funny and unclear

Atom · « **Reply #14 on:** October 02, 2023, 02:18:20 PM »

Blowpipe Sam · « **Reply #15 on:** October 02, 2023, 04:09:44 PM »

I'll bet it's made out of that soft mild steel that Hatsan uses for their screws. Do you have a Chronograph? It would be nice to compare velocities with and without the insert. Possibly you could make a brass insert of smaller interior diameter and test that.

mikeyb · « **Reply #16 on:** October 02, 2023, 05:31:50 PM »

If someone wanted to experiment/document rifle performance with different transfer port diameters you have a nearly ideal test platform there. Buy a box of set screws or "grub screws" that fit your Hatsan and drill several different diameter holes in them. Document several different pellets for each drill size and publish the data.

Yeah, could be interesting but who has that kind of free time and desire to perform the detailed experiment? I"d like to but it would need to wait until I retire. Best case for me would be another decade at 72... if I'm lucky!

Atom · « **Reply #17 on:** October 03, 2023, 10:34:36 AM »

Correction of the incorrect statement, the transfer port is 3.9 mm in diameter, I measured with a drill bit, I tried 4 mm but it doesn't go through the hole!

Atom · « **Reply #18 on:** October 07, 2023, 06:55:36 PM »

mikeyb · « **Reply #19 on:** October 13, 2023, 01:43:48 AM »

I LIKE the FirePiston avatar! Probably very similar to what happens inside a springer if there is any trace lube present :-)

Quote from: Atom on October 12, 2023, 03:36:01 PM

I believe that this topic belongs in this part of the forum and if it is proven that they made a big mistake, it should be posted on the bulletin board!

I recently got a nearly new Hatsan 125 5.5mm to install an optic on, of course I did a velocity measurement first and found it to be around 22J. I also noticed that unusual transfer port that I hadn't seen before, but at first I thought it was a piston seal problem because the rifle was all full of factory grease and oil.

When I disassembled the rifle, I first noticed that the shorter spring 43 coil 41 was active and removed the piston, but the seal was not damaged from dieseling, but had minor damage during factory assembly. I was interested in that insert in the TP and I twisted it and it was stuck with something. The threads on it correspond to a standard M7 screw, and it is drilled with a 4mm drill bit, about 7 mm long, the transfer port on the cylinder is 3.9 mm and about 5 mm long, so the total length of the TP is 12-13 mm, that insert, when twisted, passes into the cylinder about 0.7 mm, the four slots are about 2x2 mm for the screw driver.

I put that insert back again and put Loctite 241 got a bigger original spring 48 coils carefully installed a new piston seal properly applied Feinwerkbau special grease and tried the speed and then I found that I didn't get any power, the speeds even fluctuated a lot for a spring gun. I contacted the Hatsan factory and got no answer, the supplier is totally ignorant and justifies that the warranty is lost because he did not service that classic rifle. My only fault is that when they made that insert, they didn't make it from M8 or M10 (M7 is hard to find) with an O-ring holder, then people would have made it easier with stainless steel screws and two holes so that it can be unscrewed and screwed in.

What do you think about this because I was thinking of making a 3.5 mm wide insert. Please join this discussion as all new Hatsans come with this insert*.
here are the pictures
https://www.gatewaytoairguns.org/GTA/index.php?topic=210458.0

* Possible but I'd expect this modification to the transfer port to be rare on rifles made for the unrestricted muzzle energy US market.

My Mod125 25cal (6.35mm) has a straight drilled (no insert) 4mm diameter transfer port. Not too different from your rifle if I read your description correctly. I doubt very much your low muzzle energy readings are caused by the transfer port design change you have shown.

Your rifle (22 J ~ 16.2 FPE)
My rifle (39.3 J ~ 29 FPE --> at 30' , higher FPE at muzzle)

Yes 7mm or M7 thread nuts/bolts/taps/dies are not that common over here either. However I found several M7 parts when I was looking for a cheap alternative to the Hatsan SAS bolt (M7).

My rifle has the factory supplied spring which is 44 coils (42 active) 0.142" diameter wire with an OD of ~0.840".

I don't know where you are getting your springs from but MORE COILS alone does NOT PROVIDE MORE POWER. The 2 springs in this photo are a good example.

The one with fewer coils is the factory spring for a US(China) air rifle that shoots around 16 FPE. I tried using the "more coils" spring in the same rifle and it just barely had enough energy to make the pellet leave the barrel (~4 FPE?).

My Mod125 here was sold as factory refurbished at a steep discount. I purchased it in ~2020. It has a 0315 manufacturing date code.

The rifle had terrible performance (large velocity variations) with a VERY HARSH shot cycle when I received it. Others would have returned it for refund but it was more than 50% discounted from $new$ and I KNEW how to repair these rifles. I performed a thorough cleaning, deburring, and re-lube with high quality lubricants. Replaced damaged piston seal with new OEM seal ($5) and same with breech seal($2). Made a custom steel snug-fit spring guide ($2 +labor) to replace the very loose (and way too short) plastic factory guide. Cleaned, lubricated, and adjusted the nice Quattro trigger group to where I LIKE my springers triggers set.

This rifle is still a MONSTER SPRINGER but it is now a JOY to shoot. It has a crisp trigger release around 2 lbs (right where I like it) and a FIRM THUMP shot cycle with "0" spring vibrations. Attached below is the chronograph data I just shot tonight along with the 30' group of 10 shots using the factory open sights.

Hatsan Vortex Strike pellets 24.7 grain