This post is copied from gunboard forums. Thought it might be of use to you and the other Star BM owners. Credit for the original info is found in the topic below: (I’ve cleaned it up a bit…some of the punctuation and other info got garbled)
My brother, WillRuss wrote these up before he so kindly gave his BM a new home (mine), so I thought I post them.
Disassembly and Reassembly of the Star BM Pistol By William Russ, June 2005
The following describes both minor and major disassembly / reassembly of the Star model BM 9mm pistol.
Disclaimer: The author assumes no responsibility for any damages that may result from attempted duplication of the actions described herein. It merely documents how the author successfully performed the actions on his own personal firearm. Any attempts to duplicate these actions are done so at the readers own risk.
Remove the magazine. Point the pistol in a safe direction, move the slide to the rear, and push the slide stop upward to lock it in the open position. Visually inspect the chamber to insure that it is empty. Grasp the grip with the right hand, placing the index finger on the pin from the slide stop lever that protrudes from the right side. Press the slide stop lever pin inward while pushing the slide rearward with the left hand until the slide stop lever moves away from the frame. Hold the slide and frame with the left hand and remove the slide stop lever from the frame. Turn the pistol upside down, move the frame rearward and off of the slide. Grasp the rear of the guide rod / spring assembly, then remove it by pulling it up and rearward. Rotate the barrel bushing on the front of the muzzle area1/8 turn counterclockwise, then pull it away from the slide. Lift up the rear of the barrel slightly, then move it forward through the front of the slide.
Re-insert barrel through the slide muzzle opening. Replace barrel bushing. It must be inserted 1/8 turn to the left then rotated to the 12 o’clock position. Replace the guide rod / spring assembly. The blunt end should rest in the barrel bushing, and the U-shaped side of the other end against the barrel. Note: It may need to be compressed slightly in order to fit flush against the barrel. Mount the slide onto the frame. Look through the slide stop pin hole to line up the pivot link hole, then insert the slide stop pin. (It won’t go all the way in yet.) Move the slide all the way to the rear, then snap the slide stop pin all the way in against the frame. Note: If the slide will not move rearward, it is most likely that the guide rod / spring assembly is not flush against the barrel. Remove the slide, reposition the assembly, and then retry. This is sometimes more easily done by mounting the slide to the frame with the slide upside down. Reinsert magazine.
Since complete detail disassembly is rarely required, perhaps never for some owners, this topic will be covered in sections that may be helpful for occasional cleaning and/or repairs. Should complete detail disassembly be required (e.g.: for refinishing or post-purchase inspection), simply complete the steps in all of the applicable sections.
The following tools are recommended (and in some cases absolutely necessary) to perform a complete detail disassembly:
A good set of small and large brass punches A metal hammer (for the punches) A padded vise or ratchet-type bar clamp A small flat-head screwdriver (for magazine release removal) A large brass or copper bar (optional, but it definitely eases rear sight drifting) Masking tape (optional for preventing firing pin loss)
Remove all ammunition from the magazine. Locate the small “button” in the middle of the floor plate. Depress the button with a brass punch while sliding the floor plate slowly to the rear. Note: It is handy to place a thumb over the bottom of the magazine as the floor plate is moved to prevent the spring and button plate from being ejected. Remove the floor plate. Remove the button plate, spring, and follower. Note the orientation of the spring in the follower as it is removed. The angle of the top of the spring will match the angle of the follower in the magazine.
Replace the follower and spring into the magazine in the correct orientation. Turn the magazine upside down and hold the button plate on what is now the top of the spring and press it downward into the magazine. Slide the floor plate onto the magazine and over the button plate. The button should snap through the hole in the floor plate.
Firing Pin Removal
Field strip the pistol as described above. Note the registration marks on the rear sight and the slide as the rear sight must be returned to the same position at the end of this procedure. (These consist of two small lines in front of the rear sight.) Secure the slide in a padded vise or ratchet bar clamp to a padded tabletop with the left side down. Use a large brass punch (or brass bar) and hammer to drift the rear sight approximately halfway across the width of the slide. Make sure to strike the sight ONLY with the brass to avoid marring the surface of the slide, and only on the base of the rear sight. Also, avoid removing the sight entirely. Continue drifting the sight until a large retaining pin is completely exposed. Locate the corresponding small side of the retaining pin underneath the sight, on the inside of the slide. (Optional) Place a piece of masking tape over the rear of the slide to prevent the firing pin from ejecting out of the slide when the retaining pin is removed. Tap the retaining pin upward from underneath until the firing pin is ejected. If present, remove the masking tape and remove the firing pin. If the firing pin spring did not come out with the firing pin, it should fall out by tapping the rear of the slide on a tabletop. (Be sure not to lose the spring!)
Firing Pin Replacement
Secure the slide with a padded vise or ratchet bar clamp. Place the spring directly into the firing pin canal or onto the firing pin itself. Insert the firing pin into the firing pin canal. Make sure that it is oriented with the side indentation facing the retaining pin. Hold the firing pin inward with a finger or brass punch, then press the firing pin retaining pin into the slide. It should go far enough to hold prevent the firing pin from backing out. Tap the firing pin retaining pin the remainder of the way into the slide with a brass punch. Secure the slide again and drift the rear sight back into its previous position with a large brass punch (or bar). Note: Be sure to realign the registration marks. Reassemble as described above in “Field Reassembly”
Guide Rod / Spring Disassembly
Field strip the pistol as described above. The spring must now be fully compressed toward the U-shaped end of the guide rod and held in place. This can be done with something like padded needle-nose vise-grip pliers, or perhaps a small ratchet bar clamp. Unscrew the round guide rod cap. Note: This is usually very tight and may be loosened by applying penetrating oil. Release the clamp holding the spring. Remove the spring from the guide rod assembly.
Guide Rod / Spring Reassembly Replace the spring onto the guide rod assembly. Compress the spring and lock in place with some type of clamp. Screw the round cap onto the end of the guide rod. Release the clamp holding the spring. Reassemble as described above in “Field Reassembly”
Hammer Group Disassembly
Field strip the pistol as described above. Remove grips. Note: Be aware that a detent spring / plunger is located beneath the safety and it can (and will) be expelled from the frame when the safety lever is rotated. Cover the safety lever with one hand while rotating it with the other toward the hammer. Carefully remove the detent spring / plunger. Slowly rotate the safety lever while pressing the pin from the other side of the frame. The lever will move freely out of the frame at approximately the one o’clock position. Remove sear by tapping out the sear pin with a brass punch. Once the sear is removed, tilt the frame forward so that the sear spring (along the rear of the grip) falls forward. Lift it up an out. Use a large brass punch to tap out the hammer pivot pin. Remove the hammer, spring and plunger.
Hammer Group Reassembly
Partially reinsert the hammer pivot pin into the left side of the frame. Replace the hammer spring and plunger. Replace the hammer, making sure to place the pin that hangs from the lower rear portion of the hammer into the socket at the top of the hammer spring plunger. Press the hammer downward to align the pin holes, then tap the hammer pivot pin back into place with a brass punch. Note: A large ratchet bar clamp makes this very easy. Replace the sear spring making sure that the “hump” goes behind the pin in the lower rear area of the grip. Partially insert the sear pin. Hold the sear spring toward the rear of the grip. Note: This is made easier with a small ratchet bar clamp with a small rod placed between it and the spring. This will press the spring in far enough to allow easy placement and alignment of the sear. Align the sear pin hole with the frame holes and tap in the sear pin with a brass punch. Note: Make sure that the sear spring is between the frame and the sear. Test hammer for correct movement and sear release. Fully cock the hammer, then hold it back as far as possible. Insert the safety lever. It will just drop in at about the one o’clock position. Release the hammer. Replace the safety spring / plunger. Use a brass punch to push the plunger into the frame far enough so that the safety lever can be rotated over it. Rotate the safety lever downward to the fire position. Replace grips. Reassemble as described above in “Field Reassembly”
Trigger Group Disassembly
Field strip the pistol as described above. Remove grips. Depress and hold the magazine release button as far as possible into the frame. Using a small flathead screwdriver, turn the retaining screw on the other side of the magazine release button counterclockwise until it stops. This will lock the magazine release assembly together, allowing it to fall free of the frame. Tap the magazine safety out of the frame by pushing the retaining pin in from the lower portion of the left grip panel. Use a small brass punch to remove the pin at the top of the trigger. Squeeze trigger as if it were being fired and it should fall into the magazine area. Remove interrupter / disconnector by sliding it down and out of its channel.
Trigger Group Reassembly
Replace interrupter / disconnector. Replace trigger into the trigger slot and align the trigger and frame pin holes. Reinsert trigger pivot pin and tap in with a brass punch. Test trigger for functionality. Replace magazine release assembly. Hold in the magazine release button on the left side to where the checkered area is slightly inside the frame. Turn the screw clockwise with a small flathead screwdriver. The spring tension should be felt again and the assembly locked into the frame. Replace the grips. Reassemble as described above in “Field Reassembly”
Field strip the pistol as described above. Use a padded vise or ratchet bar clamp to secure the extractor to the slide. (A strong spring is located beneath the extractor, which will cause the unit to fly off when the pin is removed if it is not secured.) Locate the retaining pin inside the slide beneath the extractor area. Use a small brass punch to tap the pin toward the top of the slide. Note: It is not recommended to completely remove the pin from the slide. It is only necessary for the pin to clear the extractor. Carefully release the pressure on the extractor. Remove the extractor and spring from the slide.
Place the spring into its seat in the extractor well on the slide. Place the extractor into the extractor well, compressing the spring. Secure the extractor into the slide with a vise or ratchet bar clamp. Note: A small brass punch can be used to align the extractor pin hole with the retaining pin hole in the slide. Tap the retaining pin back into place with a brass punch. Note: Be sure to check inside the slide to insure that the pin does not protrude past the surface as this could cause slide malfunctions. It can be made flush with the surface by intentionally making it protrude, then tapping it back with an oversized brass punch. Reassemble as described above in “Field Reassembly”