Haenel 303 disassembly and cleaning

Note: this article was originally posted to my Google Pages location back in 2010.  Now that Google has seen fit to retire Pages, and I was too lazy to convert my content in time, I have finally started this blog site.

 A friend of mine is the owner of an excellent condition Haenel 303, made in East Germany in the early 1980's.  I did a review on this rifle as a guest blogger for Pyramyd Air Air  here.  That article goes into detail about the features and performance of the gun and I don't want to repeat all of that here.

What I do want to cover is the disassembly process to be able to clean and lube the gun.  The Haenel was not terribly difficult to work on; no special tools were required.  It was the first springer that I have taken apart and it still only took about four hours one Sunday afternoon.  It is also interesting to examine a few of the features of the construction of the 303 with it apart.  I must apologize for the quality of some of the photos; the lighting was not good and I did not realize this until I was done.

The first step is to remove the action from the stock; this just involves removing the two screws near the front of the forearm and the two trigger guard screws.  The angled bolt at the front of the trigger guard adjusts the sear engagement and normally will not need to be touched.

Front of the action removed from the stock.  The button in the forearm

is spring loaded and prevents the cocking arm from rubbing on the wood.

Rear of the action showing the trigger and safety parts.

The flat metal safety bar that the trigger passes through sets the safety when the gun is cocked.  The rear of the cocking arm, just visible at the far left, pushes on the spring wound around the left end of the flat bar.  The spring can be removed and the safety will no longer automatically set since it is possible to depress the safety and pull the trigger with the barrel fully open to decock the gun.

Remove the large bolt in front of the trigger.  Use a punch to remove the rear cross pin.  This will allow you to rotate the safety button 90 degrees and withdraw it from the action.  The safety transfer bar can then be removed.  Push the end cap out; an allen wrench can be useful here as the cap is a bit snug.  Important: there is a small spring and ball in the end cap that are used to keep the safety from moving under its own weight; be careful to not lose these parts.  They are in a small hole above the safety rod.

Use a punch to remove the remaining pin at the rear of the action.  The trigger can now be removed.  The block through which the pin passed can be pushed out the rear of the tube.

Trigger block ready to come out of the receiver.

Trigger parts out of the gun.  The end cap and safety button are the 

only two plastic parts on the rifle.

The trigger body is folded sheet metal; a sear block is held within the upper trigger body to hold the piston.  Since the two parts are not solidly connected the gun has a two stage trigger.  I thought it was interesting that the safety bar has bluing of equal quality to the barrel and receiver and has smooth edges.  That is not necessary on a part contained within the stock and not normally visible.  The circular block on the left has chamfered edges that make it easy to insert into the receiver.  It is plain that even though this was not an expensive gun the internal parts were made with great care.

Barrel removed from the receiver.  On the 303 the locking wedge is in the front of the

receiver instead of the breech block.  No washers are used on the pivot bolt.

Due to the joint in the cocking arm it is not necessary to remove the barrel pivot bolt to disconnect the cocking shoe from the piston.  Remove the small lock screw and the pivot bolt and the breech block can be removed.  There are no breech block washers.  The pivot bolt was removed in this case so the joint could be lubricated.

The spring guide is retained by a locking plate.

The small flat plate forward of the trigger locks the rear spring guide in place and retains the spring.  The spring is under about three quarters of an inch compression.  I used a three foot wood clamp with a deep well socket as a spring compressor.  With a little forward pressure it is possible to slide the locking plate out.  Release the clamp pressure and the spring guide, spring, and piston can be removed.

Locking plate removed and spring guide starting to move rearward.  A three-foot wood clamp

and a deep well socket worked well as a spring compressor.

Spring, piston, and guide removed from the gun.  The spring was straight.  Photo is

prior to cleaning.

Leather seal was in perfect shape.

All machined slots had smooth edges.

The leather piston seal was in perfect shape and so was left alone.  All of the old grease (which had hardened) was removed from the spring, piston body, and other parts.  Moly grease was used on the piston and spring guide; Jim Maccari's black tar was used on the spring.  Assembly is the reverse of the disassembly.

Parts cleaned, lubricated, and ready for reassembly.

Velocity testing
Before I shot the Haenel the first time the piston seal was oiled and let it sit overnight.  After about a dozen shots the velocity leveled out.  After cleaning and lubing the velocity increased with most pellets and the variation dropped dramatically; some pellets varied by less than a third compared to before cleaning.  The "before" velocities are on the left and the "after" are on the right.

Pellet	Wt.	FPS	Hi-lo	FPS	Hi-lo
Beeman Bearcub	8.0			659	39
Beeman Coated HP	7.1	651	29	663	23
Beeman Coated WC	7.8	593	17	609	13
Beeman Crow Magnum	8.8	535	42	590	10
Beeman Kodiak	10.2	520	10	519	16
Beeman Ram Jet	9.8			547	8
Crosman Copperhead WC	7.8			616	20
Crosman Premier Light	7.9	595	42	627	14
Crosman Premier HP	7.8			635	34
Crosman Pointed	7.4			660	24
Eley Wasp	8.0			610	18
Gamo Pro Magnum	7.6			604	18
Gamo Rocket	9.4			544	22
H&N Match	7.9	586	8
Milbro Caledonian	7.6	591	47
Nickerson Magnum Point	8.1	562	54	583	27
RWS Hobby	6.9	625	56	657	17
RWS Super H-point	7.0			652	26
RWS Superdome	8.2	557	20	608	15
RWS Superpoint	8.2			604	16
RWS Meisterkugeln	8.2			605	17

The Haenel 303 is a fun gun to shoot.  Cocking effort is about 22 pounds; it can be accomplished with a single finger.  The 303 makes a nice plinker and is very accurate with the RWS Superdome and Crosman Premier Hollow Point pellets.  Unfortunately there is no way to mount a scope without modifying the gun, but some variants of the 303 do have 11mm grooves from the factory.