Heckler & Koch HK4 Pistol
General Information The HK 4 (P11 in German military issue) pistol is from the German firm of Heckler and Koch, GmBH. Introduced in 1967, and now out of production (as of 1984 according to the Blue book of Gun Values 13th ed.), it is a large sized pocket pistol, designed to interchange between .22 LR, .25 ACP (6.35mm), .32 ACP (7.65mm) and .380 ACP (9mm Kurz), (8 rounds each except .380 for which the mag capacity is 7) by replacing only the barrel and magazine.
Much of the markings are the same as for the P7 guns -- look here.
H&R catalog from 1971 (page 37)
H&R Commemorative Pistol Set
H&R is pleased to introduce a Commemorative Pistol
Set in honor of its 100th anniversary. Only a limited
number of these semi-automatic pistol sets have been
produced in serial number sequence from HR 1 to HR 2000.
The set consists of a double action pistol with
interchangeable matched barrels and magazines in .380
caliber and .22 caliber long rifle. A distinctive gold name
plate and gold trigger accent each pistol. Matched
barrels are identified with the pistol's serial number. Each
pistol set is packaged in a custom fitted, velvet lined,
wooden presentation kit with lock and key and will be a
welcome addition to any sportsman's collection of
limited production sporting arms.FEATURES AND SPECIFICATIONS
Calibers: .380 auto. (9mm short) and .22 long rifle.
Capacities: .380 auto. 8 shots. .22 long rifle 10 shots.
Grips: Black checkered grips.
Barrel Length: 3 1/2".
Overall Length: 6".
Weight: 24 oz.
Action: Single and double. Semi-automatic.
Sights: Fixed front site. Rear sight adjustable for windage.
Finish: Blue/black with gold name plate and gold trigger.Commemorative Pistol Set $160.00
Manual & Library
Proof HousesHK enthusiasts and books will tell you that HK only uses one Proof House, the Ulm, Germany. Here are images of two .7.65mm barrels, one proofed at Ulm (with stag horn on left) -- the other not! Early HK4 barrels were not proofed at Ulm.
ExtractorsOne area of complication and confusion for the otherwise simple HK4 are its extractors. There are either two, three, or four different styles depending on who you believe. I don't know who is correct, so until I do I can only offer this information without explanations. This is under construction.
The Bardwell article (above) says "The manual speaks of having to change extractors between calibers, but my pistol has a "universal extractor" and requires no changing, so I will assume that was a very early feature, and not cover it. If yours came with multiple extractors you will need to interchange them or get a universal one."
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This is from gun #4210X that was made in 9/70. Note the orange fill on the barrel, but the magazine was all black.
This extractor is labeled, and I would guess is the "old" style
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e-gunparts.com offers four different types -- .22 & centerfire, both in "old" and "new" styles. These are the two "new" style, don't know which is which.
Parts
1 Slide (Note #1 Below) 2 Extractor (Note #1 Below) 3 Set Bolt 4 Compression Spring 5 Rear Sight 6 Safety 7 Recoil Spring (Note #1 Below) 8 Barrel (Note #1 Below) 9 Cylinder Head Screw (Note #1 Below) 10 Face Plate 11 Firing Pin Spring (Note #1 Below) 12 Firing Pin (Note #1 Below) 13 Plunger Spring (Note #1 Below) 14 Plunger 15 Stop Pin 16 Barrel Clamp 17 Barrel Clamp Cylindrical Pin (Note #1 Below) 18 Ejector (Note #1 Below) 19 Ejector Spring (Note #1 Below) 20 Sear (Note #1 Below) 21 Spring Support 22 Drag Spring 23 Disconnector Spring 24 Disconnector 25 Hammer 26 Buffer Plate (Note #2 Below) 27 Buffer (Note #2 Below) 28 Elbow Spring (Note #1 Below) 29 Trigger (Note #1 Below) 30 Trigger Cylindrical Pin 31 Trigger Bar 32 Ejector Cylindrical Pin 33 Hammer Pin (Note #1 Below) 34 Receiver 35 Magazine Catch Cylindrical Pin 36 Spring Rod 37 Mainspring (Note #1 Below) 38 Magazine Catch 39 Grip 40 Grip Screw, Countersunk, Lens Head (Note #1 Below) 41 Magazine Assembly 42 Magazine Bottom (Note #1 Below) 43 Follower 44 Follower Spring 45 Locking Plate Assembly Some of these parts are still available at e-gunparts.com
If they have them, they will be cheaper than from me.Note 1: As this is written (JAN-2004), I have these parts available
Note 2: Part 27 the Buffer is was not available for a while, but now can be bought at Gun Parts Corp.