Saturday, April 16, 2011

Haenel 303-Super Tear Down Part 2

Finally back to the Haenel 303 after a brief hiatus.

Removed the pivot bolt locking screw.

The pivot bolt head has 4 cut outs around it's circumference. The pivot bolt is snugged up to the desired tension then the locking screw is installed. The head fills into one of the radii and locks the bolt in place.

The locking screw is really tiny. I believe it's an M3x 0.5mm.

Before I remove the barrel/breech block from the compression tube, I wanted to take a look at the barrel latch. On many guns, the barrel latch itself is spring loaded and fits into a precision recess. And on many guns, that latch is pulled forward toward the muzzle to unlock the action.

Not so on the 303.

The Haenel has a spring loaded chisel shaped detent.

The latch is pushed toward the rear where it bears directly against the detent. It's a bit awkward in practice, but you get used to it.

As you push the latch rearward, it shoves the detent into the compression tube and unlocks the action.

No pressure on the latch, the detent sticks out under force from a small spring, locking the barrel in place.

Latch pushed in, pushes the detent in.

Here's a better pic of the detent with the barrel opened.

Removed the main pivot bolt and the breech/barrel unit.

A small screw secures the detent mechanism.

The chisel and the spring.

And the latch itself. Polished then reblued the sides that fit against the breech block.

Thought that the trigger could use some help. It's supposed to be a target gun after all.

There are two adjustment screws in the trigger unit. The front screw sets the amount of first stage travel.

I removed the screw and polished the end that bears on the bottom of the sear.

The rearmost screw (not well shown here) adjusts the amount of sear contact. On a target trigger, less is helpful--it shortens the amount of trigger travel in the second stage to fire the gun. Too little contact though will make the gun fire unexpectedly--like when the barrel is opened for loading. That's bad. So, I'll err on the side of caution. When the gun gets reassembled, I'll cock the gun and give it a "bump" test to see if I can make the sear slip and fire. There's no shade of gray here--it's pass or fail. Increase sear contact until it's absolutely, positively safe--then add just a tiny bit more overlap.

Trigger at rest with a ton of first stage travel. (forward screw backed out)

About that much travel. Too much for my preference. I'll screw the front adjustment in a bit further and shorten this up.

Click on this pic (or any for that matter) to enlarge it and see the circled sear contact point. This is the one spot where the trigger really should be lubed.

I used a 60% moly grease and set the trigger unit aside.

The piston got a quick polish on the front and rear.

Can really see the colors from the hardening on the body. Deburred the slot in the piston body since I was working on it.

Here's the inside of the compression tube. The transfer port hole looks awfully large.

For a target gun, the 303 is quite harsh firing and I'll venture that the transfer port hole size is to blame. Too big means that the air rushes through too fast to cushion the piston at the forward end of it's travel. The piston, instead, slams into the front of the tube. It's almost like dry firing the gun.

The hole is approximately 0.169" in diameter. For a transfer port hole in a spring piston gun, that's really large.

More soon.

Thursday, April 14, 2011

Airgun Finds at the Toys that Shoot Show Findlay, Ohio.

Not quite ready to get back to the Haenel 303-Super just yet, so I thought I'd share some of my finds from the Toys that Shoot Airgun show held last Saturday.

Bought several items from Ted Summers. Among them were a couple diopter sights.

Didn't know what kind this was at the time, but the quality was obvious. Turns out it's a relatively recent one from Weihrauch. Guess it's about 20 years old.

The front stop pin was missing. The pin threads into the sight body and a post fits into one of the 2 (or 3) recoil stop holes in the top of the compression tube. I had a Weihrauch scope stop in my parts box and the pin fit the sight perfectly. Mounted this up on my HW35E.

The second diopter was missing the aperture. It's completely unmarked but also conveys a sense of high quality manufacture.
Update from reader Duskwight: This is from Russian manufacturer IZH. It's typically found on their model 7-4 biathlon rifle. Thanks for the info.

Anyway, the aperture thread is M9 x 1mm--not the typical M9.5 x 1mm. Wait, I don't mean to suggest that M9.5 is a "typical" size--it's certainly not--but many of the high end sight companies have adopted this oddball thread size as a standard for the apertures. On this sight, there's not enough metal in the sight block to tap the M9 hole to the "standard" size. Already checked. I'll probably just turn a replacement aperture. The M9 die is already on the bench.

Yet another Crosman 2240. I don't recall who I got this one from. It was too inexpensive to pass up and I always have something I want to try with one of these as a base gun.

This was sitting on Don Raitzer's table. It's a Crosman 116. It's filled from a separate CO2 tank. Given the cosmetic impression, I almost passed on it, but the grips are in almost perfect shape and the action functioned flawlessly. The price was so right, couldn't lose. I got it home, found a tank and it gassed right up. Been holding ever since. It also hits to point of aim at 35 feet.

A holster for a Predom Lucznik.

Ted Summers was responsible for this IZH-60, too. He had a pile of these at the end of his table at fire sale pricing. Unsure where he got them, but he warned that they all needed internal work. Finally, Ted's speaking our language! This gun was on Nick's hit list so I found the best looking one and bought it for him.

But Nick had to pay my finder's fee--the metal cocking handle is going on my IZH-61 to replace the plastic one.

No sights. I have a front tunnel from my IZH-61, but I don't think it'll fit. The muzzle is finished differently from my newer model. I'll send it along when I ship the gun.

Forend cover is missing. Nick'll have fun with this one.

This .177 cal IZH-SJ22 was the big score for Nick. John Groenwald had it in the rack.

I can see now why this was on his list. It's got great lines.

The set back on the trigger makes the gun very comfortable to shoot.

Like the IZH-60, this one also needs work. It won't push a pellet down the barrel. I'm guessing that the piston seal is toast.

Raitzer got me again with this Belgian Hy-Score in .22 cal. I'd look at the gun, walk away, walk a lap of the show, look at the gun...always hoping someone else would buy it. In the end, I was glad it was still there.

This scratch is about the worst of the stock damage. I'll do minimal repair to this gun.

The checkering is everywhere. Literally, every single place you touch the gun is checkered.

Ha! Checkered.

On the way home from Findlay, I stopped at the Medina County gun show to pick up this .22 cal TF79 target gun from Guy Guzzo. I posted his Walther LG55 a few weeks ago and he worked out one heck of a deal on this gun as a thank you.

Really a nice rifle. The action is based on the old Crosman 160.

This model runs on two 12g Co2 cartridges or it can be bulk-filled.

Still has the preservative on it. Really appreciate it, Guy. I can't thank you enough.

Now, if I can just get them to hold the airgun show closer to home and 6 times a year...