dahun 0 Posted February 11, 2004 Report Share Posted February 11, 2004 I've designed a true bolt-hold open device for the AK rifles. Currently offered for 7.62 Cal, rifles with double stack magazines. Please visit the site for more info. AK bolt catch.... Leave feedback in any case... Thanks, Dahun Link to post Share on other sites
dahun 0 Posted February 11, 2004 Author Report Share Posted February 11, 2004 Rock47, Thanks for the input! Actually, this is the third and final prototype and I'm getting ready to send samples to a few magazines for their review. The one that's installed on my rifle has worked beautifully. Your note regarding the magazine mod. is well taken. My only problem has been the ability of sensing the bump, tab, etc. on the mag. follower. As you know, most bolt catch mechanisms are operated from a notch, recess, or hole in the mag. housing, and not through the magazine opening. Also, the AK magazines are pretty tight in that area. Another consideration was the proximity of the back of the magazine, the receiver cross rivet, and the bolt as it rides over both. The bolt is about 1/16" from the cross rivet and the magazine housing. Also, the amount of travel of the follower from last round to empty is also about .070" which makes actuation tricki. So, my only option was to change the follower, and provide a place for it to protrude. Modifying the magazine is really not as scary as it sounds, just need a slot where the tab can protrude... plastic mags are even easier. And I needed two levers (and thus a second pivot) to multiply the small motion of the follower 3X-5X at the catch end. Yet another consideration was to anchor the bolt catch on a strudy part of the receiver. As far as drilling the receiver, if they use the provided tool, they can't go wrong. I have thought of a drop-in where the lever and such are in one assembly, but that added quite a bit to fabrication costs, and therefore selling it for under a $100 became unrealistic. Like with all things I had to make compromises and this is the result. That is not to say I won't investigate possible improvements. And quite honestly, the more and more time I spend fine tuning, I'll never get it done, and I might even loose interest. As an engineer, overthinking things has always has been my problem. I'll have better installation pictures, and have started working on a DVD. Thanks, Dahun Link to post Share on other sites
rock47 1 Posted February 12, 2004 Report Share Posted February 12, 2004 (edited) I got it! The answer is simple! Edited February 16, 2004 by rock47 Link to post Share on other sites
rock47 1 Posted February 12, 2004 Report Share Posted February 12, 2004 ALSO, if a guy wants to sell his AK he can uninstall the device and won't have to give it away with the rifle when he sells his AK. Or it can be put on a line of USA made AK's like, AK-USA rifles to give the selling edge against other competitors like Kreb's Custom, it might be the difference to the consumer to buy one AK over the other AK JUST because one company is producing an AK with auto Bolt-hold ! These devices can be massed produced and made for all calibers with out any modification to the receiver to speak of. Also it does not require removal of the side rail scope mount. The best part of the idea is that it can be switched from AK to AK in under 20 minutes and both rifles ready to fire again. Installation will be no harder than popping out the old trigger group and attaching the new device, securing to sets of springs, replacing the trigger group and pins, "WALLA!" A NEW US 922R PART TOO! THE WHOLE IDEA IS GETTING BETTER BY THE MINUTE! yOUR GOING TO HAVE TO SHOOT ME TO STOP!!!!!!!!!! Link to post Share on other sites
dahun 0 Posted February 17, 2004 Author Report Share Posted February 17, 2004 Good ideas... and I have been considering them. I have thought of the drop in feature, but again money and space were at a premium. There is not much room inside next/between the trigger and hammer with springs and wires and such. ALso, the catch hat do be anchored somewhere where the receiver would be able to take the punishment. THis also dictated the geometry. Again, the magazine only moves about .07" from last round to empty, so that too had to be a big factor and had to multiply that by about 3x-4x to actuate the catch. Trust me, it took a big leap of faith (in myself) to strart drilling the receiver, etc. But after a year of design and prototyping, I bit the bullet. As far as removing the side raill, It was a bit of work, but I replaced it with screws and nuts, and suffered no ill affects. Riveting it back on is still an option. Actually, I did start the design on the right side of the receiver for just this reason, but couldn't work it out, and besides, I wanted the thumb release on the side where the mag. is replaced, sanp mag. in, and use thumb to release slide.... As soon as I receive the patent, I will approach some of the American manufacturers with the proposal you mentioned. Pheewwhh... I just relived my last year on this... Link to post Share on other sites
rock47 1 Posted February 23, 2004 Report Share Posted February 23, 2004 I'm calling my Bolt Catch the "AK-SUPER-CATCH" " Link to post Share on other sites
dahun 0 Posted February 25, 2004 Author Report Share Posted February 25, 2004 I'm calling my Bolt Catch the "AK-SUPER-CATCH" " I'd like to see pics. Post them, 'cause I'm curious! Good luck, Dahun Link to post Share on other sites
rock47 1 Posted February 25, 2004 Report Share Posted February 25, 2004 The only pics' will be a 30sec. video of it in operation, no sneak peaks, sorry! This thing works so good and is so special that I will not dare to reveal! Link to post Share on other sites
JesusCow 1 Posted February 25, 2004 Report Share Posted February 25, 2004 rock47 - would this work in saiga shotguns? - how "drop-in" is it? Link to post Share on other sites
dahun 0 Posted February 25, 2004 Author Report Share Posted February 25, 2004 The only pics' will be a 30sec. video of it in operation, no sneak peaks, sorry! This thing works so good and is so special that I will not dare to reveal! Excellent! Maybe you've solved an age old problem... Hope it works! Dahun Link to post Share on other sites
rock47 1 Posted February 28, 2004 Report Share Posted February 28, 2004 My current prototype will definately not work in a Saiga shotgun, but I am working on a model that will, but i am afraid that it will require some internal mods to the receiver cross brase, really no biggies there but it won't be a true drop-in, more like a drop-in with minor fitting. I got to tell you that I am on something big here and I will not be abel to meet anybodys expectations for a few months, but when I do have them available for market, you'll be wanting one for every Kalashnikov you own, garunteed! Rock47 Link to post Share on other sites
dahun 0 Posted March 5, 2004 Author Report Share Posted March 5, 2004 My current prototype will definately not work in a Saiga shotgun, but I am working on a model that will, but i am afraid that it will require some internal mods to the receiver cross brase, really no biggies there but it won't be a true drop-in, more like a drop-in with minor fitting. I got to tell you that I am on something big here and I will not be abel to meet anybodys expectations for a few months, but when I do have them available for market, you'll be wanting one for every Kalashnikov you own, garunteed! Rock47 When will you have the video of the prototype in action? Dahun Link to post Share on other sites
shotgun_lobotomy 0 Posted March 7, 2004 Report Share Posted March 7, 2004 Here's the deal- Anybody wanting a bolt-hold device is either a AR-15 junky or a try-er-outer. i beg to differ, ive been to many clubs that MADE you have a poen bolt while not in the prosess of shooting, and in the case of the saiga-12 it would make mag changes quick and clean, awsome design , Link to post Share on other sites
dahun 0 Posted April 12, 2004 Author Report Share Posted April 12, 2004 The only pics' will be a 30sec. video of it in operation, no sneak peaks, sorry! This thing works so good and is so special that I will not dare to reveal! Got anything that you could share with us? I'm curious about the features if not the mechanism. Later, Dahun Link to post Share on other sites
Tengu 0 Posted April 12, 2004 Report Share Posted April 12, 2004 The Device is way too complicated. Link to post Share on other sites
dahun 0 Posted April 15, 2004 Author Report Share Posted April 15, 2004 The Device is way too complicated. Well, it is not "simple" but in order to achieve my goal, this is the simplest I know how. Goal was to provide: a last round bolt hold-open, with external thumb release, not interfere with the normal operation of the rifle, if it were to fail it should not interfere with the operation of the rifle, easy installation by most anyone, good quality materials (and durability) low cost. I think I achieved all my goals. As to the individual solutions, those are in most cases are subjective, relative to what you think is easy, simple, etc... Also, some compromises had to be made so that not one goal has the optimum solution. To some people the cup is half empty, to others it's half full, the engineer thinks that the cup is twice as big as it needs to be... I think the cup can be designed better. Link to post Share on other sites
dahun 0 Posted September 7, 2004 Author Report Share Posted September 7, 2004 My current prototype will definately not work in a Saiga shotgun, but I am working on a model that will, but i am afraid that it will require some internal mods to the receiver cross brase, really no biggies there but it won't be a true drop-in, more like a drop-in with minor fitting. I got to tell you that I am on something big here and I will not be abel to meet anybodys expectations for a few months, but when I do have them available for market, you'll be wanting one for every Kalashnikov you own, garunteed! Rock47 How is the work on this going? Have a movie clip yet? I'm anctious to see one, maybe your solution is the ticket. Dahun Link to post Share on other sites
dahun 0 Posted October 28, 2004 Author Report Share Posted October 28, 2004 My current prototype will definately not work in a Saiga shotgun, but I am working on a model that will, but i am afraid that it will require some internal mods to the receiver cross brase, really no biggies there but it won't be a true drop-in, more like a drop-in with minor fitting. I got to tell you that I am on something big here and I will not be abel to meet anybodys expectations for a few months, but when I do have them available for market, you'll be wanting one for every Kalashnikov you own, garunteed! Rock47 Hey Rock, Any progress on that bolt hold open? It's been a while... I know it takes long, it took me 2 years to come to the final design. Keep us posted. Dahun Link to post Share on other sites
SOPMOD 254 Posted October 8, 2005 Report Share Posted October 8, 2005 I've designed a true bolt-hold open device for the AK rifles. Currently offered for 7.62 Cal, rifles with double stack magazines. Please visit the site for more info. AK bolt catch.... Leave feedback in any case... Thanks, Dahun <{POST_SNAPBACK}> Has anyone bought oneof these yet?It looks great. Too bad he hasn't developed for Saiga 12 shotgun Link to post Share on other sites
mopeman 0 Posted October 8, 2005 Report Share Posted October 8, 2005 Looks good, but can the scope mount be reinstalled, or better yet not removed at all? I might have to put one on the wasr-10, it's my test bed for all my mods, and one hell of a bump-fire machine! Link to post Share on other sites
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