hobbyshooter 59 Posted April 6, 2011 Report Share Posted April 6, 2011 Thanks for your work on this. Quote Link to post Share on other sites
dgyver 13 Posted April 6, 2011 Report Share Posted April 6, 2011 Thanks for your work on this. My pleasure. Always up for a challenge. Might need to start calling my gun my "mistress". Quote Link to post Share on other sites
Bridis 319 Posted April 6, 2011 Author Report Share Posted April 6, 2011 I like how your's has more meat at the neck then mine. I'am guessing you bent your's up before filing the underside of the HB? I filed the underside of mine before bending the HB side up.And that's how much had to come off to clear the mag and move up and down and it still hit the mag untill bending. I wish it said in the instruction's that the HB side would need bent up first before grinding/filing. I think they all will need the HB side bent up . I haven't seen where Tom has advocated bending the LRBHO. Though I think that's my next step. Are you guys just grabbing the HB and bending it upward? Or is there a specific place to grab and heating involved? Quote Link to post Share on other sites
dgyver 13 Posted April 6, 2011 Report Share Posted April 6, 2011 I clamp it at the HB and its neck. Then twist it at the S bend. No heat, seems soft enough for slight bending. Trace your profile on paper first to check your progress. Quote Link to post Share on other sites
Bridis 319 Posted April 7, 2011 Author Report Share Posted April 7, 2011 I spent some more time screwing around with my LRBHO tonight and made considerable progress. I now have my gun hand cycling MD-20 drums and the factory 5 rounder. How you ask? Well I started by doing the bending described above by dgyver. That bend allowed the HB to clear the mag without having to notch it and the shells to rise high enough for the bolt to pick them up. However, with that bend alone the tip of the HB would catch on the edge of the shell before it could be ejected. To solve the hang up, I marked the HB where it sat over the edge of the mag. I put the LRBHO in the vice right at that point I marked the HB and bent the HB downward enough to where it would clear the shell when it was being ejected. Now if you've already ground down your HB you should be able to perform the bend. Otherwise you could simply shape the HB of a new LRBHO to match the profile. I hope to do some live testing this weekend. If everything goes well I'll post some video of the test and pictures of my LRBHO. GL all. Quote Link to post Share on other sites
havok 21 Posted April 7, 2011 Report Share Posted April 7, 2011 (edited) Well I'am happy to report that mine is running about 98% today. Had 2 rounds out of about 200 rounds miss feed in the same drum that had mixed rem/fed 7 1/2 bulk. But before that and after that it was running 100%. Now I'am out of cheap bulk ammo. Mine always close when drums are inserted and stick mag's are slammed in real hard. If I just click in the stick mag's the bolt stay's open. As of now I think I'am out of test mode and can now just shoot it. Edited April 7, 2011 by havok Quote Link to post Share on other sites
Bridis 319 Posted April 7, 2011 Author Report Share Posted April 7, 2011 My gun will also load on an empty mag without releasing the bolt. But I notched the back of the LRBHO to help retain the bolt while inserting a loaded mag. I just found it too much of a pain in the ass trying to slam the drums in without the bolt getting jammed on a round. Quote Link to post Share on other sites
datubie 21 Posted April 7, 2011 Report Share Posted April 7, 2011 Has anybody with a aftermarket magwell try the LRBHO? Quote Link to post Share on other sites
dgyver 13 Posted April 7, 2011 Report Share Posted April 7, 2011 Has anybody with a aftermarket magwell try the LRBHO? I have JTE magwell. So far it manually cycles perfectly. Hopefully I will live fire it tomorrow. Quote Link to post Share on other sites
datubie 21 Posted April 7, 2011 Report Share Posted April 7, 2011 Cool! So have I. Let us know what happens. Has anybody with a aftermarket magwell try the LRBHO? I have JTE magwell. So far it manually cycles perfectly. Hopefully I will live fire it tomorrow. Quote Link to post Share on other sites
Crusader 64 Posted April 8, 2011 Report Share Posted April 8, 2011 Has anybody with a aftermarket magwell try the LRBHO? Yes. Works so far, but I still need to live fire. Quote Link to post Share on other sites
Bridis 319 Posted April 8, 2011 Author Report Share Posted April 8, 2011 (edited) Here's mine after yet another trip through the CSS store. (Man, someone needs to block my I.P. address) I added a Tromix charging handle, rail mount sling swivel, sling and probably the most desired part for anyone attempting the LRBHO installation, a retention plate. Though I've received all my parts it doesn't look like I'm going to be able to make it out to do some test firing this weekend. Most likely next weekend. EDIT: BTW, the 12 round Pro Mag is very loosely fit from the factory. It wobbles around quite a bit. The SGM 12 round mag is pretty solid. Edited April 8, 2011 by Bridis Quote Link to post Share on other sites
amityn 0 Posted April 8, 2011 Report Share Posted April 8, 2011 Has anybody with a aftermarket magwell try the LRBHO? Yes. Works so far, but I still need to live fire. I have one of the original JT agp magwells on mine and my LRBHO does not like it at all..I think it has to do with the way my mags are modified to use in the magwell and it has me scratching my head. It looks like my mag is at a different angle then using a un modified mag with no magwell. Keeps nose diving the round. Take the magwell off, use a regular mag, no problems..go figure..... Matt Quote Link to post Share on other sites
Crusader 64 Posted April 9, 2011 Report Share Posted April 9, 2011 Has anybody with a aftermarket magwell try the LRBHO? Yes. Works so far, but I still need to live fire. I have one of the original JT agp magwells on mine and my LRBHO does not like it at all..I think it has to do with the way my mags are modified to use in the magwell and it has me scratching my head. It looks like my mag is at a different angle then using a un modified mag with no magwell. Keeps nose diving the round. Take the magwell off, use a regular mag, no problems..go figure..... Matt It is the way you modded your mags for the magwell. The mags must be seated straight. Put some JB weld on the front, let dry, file down until the mag seats in without the front dipping down. Quote Link to post Share on other sites
dgyver 13 Posted April 9, 2011 Report Share Posted April 9, 2011 I fired mine today no hitches extra for low brass not cycling on 2 of 12 rounds. Shooting high brass at the 3-gun tomorrow, so I should not have any cycling issues. Quote Link to post Share on other sites
Bridis 319 Posted April 9, 2011 Author Report Share Posted April 9, 2011 (edited) I did some more tweaking and hand cycling tonight. I was trying out the new 12 round stick and drum mags. I've got my set-up to perfectly hand cycle the factory 5 rounder and the MD-20. The SGM 12 seems to be functioning ok. I'll know more after a live fire. The Pro Mag 12 round drum seems to have the most issues. I believe it has to be because of how sloppy it fits. If the shit drum ends up being my only issue I'll prolly end up shooting it or donating the sale to this site. Edited April 9, 2011 by Bridis Quote Link to post Share on other sites
hobbyshooter 59 Posted April 9, 2011 Report Share Posted April 9, 2011 Dibs on that promag! As for the SGM 12, there are documented threads here of the loose followers causing feed issues. Search for "tnek surefire follower" and you should find his fix which worked great for me and RRice. Quote Link to post Share on other sites
topmaul 42 Posted April 9, 2011 Report Share Posted April 9, 2011 can you cut a notch in the back of your mags? Quote Link to post Share on other sites
Bridis 319 Posted April 9, 2011 Author Report Share Posted April 9, 2011 can you cut a notch in the back of your mags? You can cut it all you want I suppose. It's yours. But I've got my LRBHO shaped to where I don't need to notch the mag. Quote Link to post Share on other sites
Bridis 319 Posted April 9, 2011 Author Report Share Posted April 9, 2011 Dibs on that promag! As for the SGM 12, there are documented threads here of the loose followers causing feed issues. Search for "tnek surefire follower" and you should find his fix which worked great for me and RRice. No luck with the search. The thread you've linked to in the past seems to be dead. Quote Link to post Share on other sites
Crusader 64 Posted April 9, 2011 Report Share Posted April 9, 2011 Is there any danger in cutting the notch in the bolthead too large? Quote Link to post Share on other sites
hobbyshooter 59 Posted April 9, 2011 Report Share Posted April 9, 2011 Dibs on that promag! As for the SGM 12, there are documented threads here of the loose followers causing feed issues. Search for "tnek surefire follower" and you should find his fix which worked great for me and RRice. No luck with the search. The thread you've linked to in the past seems to be dead. You're right. Why would that thread get deleted? Anyhow, the jist of it is to glue a shim on the front of the follower that is just a tad more narrow than the follower, to fill the gap between the follower & the front of the mag body. I'll have to dig through my junk box to see if I can find the left over piece of shim so I can give you the thickness. It was just plexiglass purchased at lowes/home depot. Quote Link to post Share on other sites
Bridis 319 Posted April 9, 2011 Author Report Share Posted April 9, 2011 Is there any danger in cutting the notch in the bolthead too large? Cutting the notch too deep may be why I had to bend my Hawk's Beak downward... If the notch is too deep in the bolt it could allow the Hawk's Beak to rise too high and catch on the rim of the shell casing as it is being ejected. This will cause the gun to lock up with the spent round still in the extractor. At this point you may have to bend the HB downward to miss the shell casing rim as it passes. Quote Link to post Share on other sites
Crusader 64 Posted April 9, 2011 Report Share Posted April 9, 2011 Is there any danger in cutting the notch in the bolthead too large? Cutting the notch too deep may be why I had to bend my Hawk's Beak downward... If the notch is too deep in the bolt it could allow the Hawk's Beak to rise too high and catch on the rim of the shell casing as it is being ejected. This will cause the gun to lock up with the spent round still in the extractor. At this point you may have to bend the HB downward to miss the shell casing rim as it passes. Could too deep of cut be dangerous to shoot? Quote Link to post Share on other sites
Bridis 319 Posted April 9, 2011 Author Report Share Posted April 9, 2011 Could too deep of cut be dangerous to shoot? I don't think so. If you over notched the bolt, it would still chamber the round properly. The only problem that I see would be if you were completely reckless and ground the bolt until you affected it's integrity. But you'd have to be somewhat retarded to do that. Quote Link to post Share on other sites
havok 21 Posted April 9, 2011 Report Share Posted April 9, 2011 (edited) Is there any danger in cutting the notch in the bolthead too large? Cutting the notch too deep may be why I had to bend my Hawk's Beak downward... If the notch is too deep in the bolt it could allow the Hawk's Beak to rise too high and catch on the rim of the shell casing as it is being ejected. This will cause the gun to lock up with the spent round still in the extractor. At this point you may have to bend the HB downward to miss the shell casing rim as it passes. I'am pretty sure the depth of the slot in the bolt has no effect on ejecting. The only way I found to keep the HB down low enough so the HB would not kiss the ejecting round is to file the back top of the LRBHO and a little more spring tension. The step up on the back of my LRBHO is almost all gone. At first I only took about 1/16 off, now mine step up is gone and now my LRBHO can swing down alot more and it just work after that. During testing mine would hand cycle in my office,but as soon as I test fired, it would kiss the rim and fte. The slot in my bolt is deeper and longer then the one in Tom's pic he posted. My HB is bent up to allow fast easy feeding with drums and goes to the almost to the top of the slot when a round is chambering. And when ejecting the HB is down and off the top of the slot. The pic of the shell have the kiss from the LRBHO the one on the left is just under the 12ga. Edited April 9, 2011 by havok Quote Link to post Share on other sites
Bridis 319 Posted April 9, 2011 Author Report Share Posted April 9, 2011 (edited) The bolt holds down the HB when it passes over and on its way back. If the bolt is notched too much the HB could rise high enough to catch the ejecting shell. Again, this thing has to be fitted to each individual gun. Havok, your pics are of the initial round sitting high enough to be loaded and not from the underside of the gun when the round is being ejected. Does your HB clear the spent casing during the ejection? Edited April 9, 2011 by Bridis Quote Link to post Share on other sites
havok 21 Posted April 9, 2011 Report Share Posted April 9, 2011 (edited) Yes The spring need's to have a tight hold on the LRBHO so the LRBHO stay's tight up under the carrier when ejecting and does not bounce up and down during recoil .The bottom of the carrier sliding across the back top of the LRBHO is what set's the HB position during ejection in my S-12. Edited April 9, 2011 by havok Quote Link to post Share on other sites
oceanrover 1 Posted April 10, 2011 Report Share Posted April 10, 2011 I am and thanks for the good info in this thread. I hope this will be the main thread for this subject as it gets confusing trying to get reliable install information...... Just started it yesterday afternoon, used a mill file for the Ejector Notch and worked well in achieving a straight cut at apx .135" also notched the Bolt and opened up the receiver a bit to accommodate the wider metal. I then started on the ABHO or LRBHO I like the term Auto Bolt Hold open, less letters Also had to take a little off the right side of the hammer to get it to install due to the thicker ABHO. At this point the ABHO is in and fit is tight and I'm ready to start on the process of trimming to fit My S12. Will update with pics. I am confused on one of the instructions namely STEP 5 "Drill into the Ejector Block Pin That Was Cut in Half Etc?? I really can't see clear pic on this and don't see it on others. Quote Link to post Share on other sites
Bridis 319 Posted April 10, 2011 Author Report Share Posted April 10, 2011 Yeah, I didn't quite get that either. I also haven't needed to do it. Quote Link to post Share on other sites
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