User Panel
[#1]
Here are a couple newbies to the BumpSAW. The first is a Marine from my old unit and second is another Marines girlfriend. As you can see, both of them pick it up pretty quick.
First time BumpSAW users https://youtu.be/bxJbbx1GoSw |
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[#2]
What is the collective thought on using a piston upper? Might have an LWRC M6 not doing much. Thinking the piston might make more sense. Not looking for mag dumps, but more realistic bursts.
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[#3]
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[#5]
Quoted:
@pezboytate A little update on this. I've found a custom cut M16 carrier reduces the echo activation weight by about 4lb. I highly recommend cutting your own carrier. Here are two I've done. https://www.AR15.Com/media/mediaFiles/57761/20170119-214738-129674.jpg https://www.AR15.Com/media/mediaFiles/57761/20170202-224302-139128.jpg View Quote I went ahead and ordered a Franklin Armory BFSIII. I know hammer follow is possible but it will also work with my dedicated 22 upper for cheaper practice. I like that it is a standard hammer and the trigger is more like a standard trigger. I figured it was worth a try. I'll update in 8-12 weeks |
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[#6]
It's nice being able to get the BFS triggers so much faster. I've found that adding an ALG ACT hammer to my BFS III cut about 1.5lb off the pull weight.
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[#7]
Quoted:
It's nice being able to get the BFS triggers so much faster. I've found that adding an ALG ACT hammer to my BFS III cut about 1.5lb off the pull weight. View Quote I am curious as to how the ALG ACT hammer reduced the pull weight. Did you use the hammer alone or a different spring as well? |
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[#8]
Quoted:
I am curious as to how the ALG ACT hammer reduced the pull weight. Did you use the hammer alone or a different spring as well? View Quote I'm tempted to order a PSA NIB coated trigger and see if it provides the dame benefit. |
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[#9]
Quoted:
Hammer alone. The weight also varies based upon which hammer spring I use. The pull is consistently lighter with the ACT hammer by over a pound. I think it's just ground smoother than the provided BFS III hammer. I'm tempted to order a PSA NIB coated trigger and see if it provides the dame benefit. View Quote View All Quotes View All Quotes Quoted:
Quoted:
I am curious as to how the ALG ACT hammer reduced the pull weight. Did you use the hammer alone or a different spring as well? I'm tempted to order a PSA NIB coated trigger and see if it provides the dame benefit. Makes sense, thanks. A smoother hammer would do this. I wonder if polishing the original BFS trigger might have a similar effect. Would not mind trying your idea. Did not see hammers sold alone on the ALG website. Did you pull one from a set or did I perhaps miss seeing where to get a hammer alone? |
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[#10]
I had a spare ACT set sitting in my parts bin that I pulled it from.
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[#13]
It's a light weight carrier from AP Precision. Unfortunately they went out of business last year. If it starts causing issues I'll put my AIM light weight carrier in.
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[#15]
Quoted:
@SkilletsUSMC I had an idea today. I think I'm going to turn down the left side of this selector and build a trigger block that rotates on it. The trigger block will be actuated by the carrier closing. Should make for perfect timing control, the trigger can reset under recoil, but once reset it can't be pulled until the carrier closes. https://www.AR15.Com/media/mediaFiles/57761/20170216-222611-148168.jpg https://www.AR15.Com/media/mediaFiles/57761/20170216-222655-148169.jpg View Quote I think I'd need to see how the trigger blocks work on the other models to see exactly what you mean. But if you can pull that off, I think you've got the winning formula. That should run FAST if I'm understanding you correctly. |
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[#17]
I should also point out that if you are pulling the trigger but it's being blocked by my trigger block - you will instantly pull the trigger when the carrier closes - kind of how the tracking point works. With the tracking point you pull the trigger but it won't let it move until the marked target is lined up perfectly in your sights.
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[#18]
Quoted:
I should also point out that if you are pulling the trigger but it's being blocked by my trigger block - you will instantly pull the trigger when the carrier closes - kind of how the tracking point works. With the tracking point you pull the trigger but it won't let it move until the marked target is lined up perfectly in your sights. View Quote Yeah that will work basically exactly like everyone THOUGHT the 3MR would. |
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[#20]
The block sounds a lot like the the old Vietnam trick of finger hard on the trigger, and firing by moving off safe. (don't try at the computer with a loaded AR LOL)
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[#21]
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[#25]
Short video describing how the echo functions for those of you wanting a binary type trigger in your build. I should also point out that this trigger in a BumpSAW will solve 100% of hammer follow problems when put in semi.
https://youtu.be/u4Q404KWGUM Fostech Echo - cycle of operations shown in a jig. |
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[#26]
I have a trigger jig enroute. Sadly, for non-BumpSAW purposes.
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[#27]
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[#28]
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[#29]
I just finished drawing out my trigger lockout device. Now I need a machine shop to cut it.
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[#30]
I dropped my drawings off at a local machine shop a few minutes ago. Should be fun having automatic timing control.
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[#32]
Quoted:
Need. Let me know what you want for it. View Quote My current design is set up to be hand fitted. I'll have to cut the back left side of the trigger for sure. Then cut the locking device until I'm happy with how it fits/locks/disengages. I'm also expecting to trim the carrier interface. It will have to have an M16 type carrier, light weight carriers without the trip face won't have anything to disengage the lock. If you want one, pick out a selector you want to use. You need one that can have the selector lever removed from the left side. I have to get that side turned down for the trigger block to rotate on. Hopefully in a week or two I'll have a working prototype and an idea of how much its going to cost me. We didn't discuss cost, lol. |
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[#33]
Hammer follow question for the experienced
Trying an LWRC piston A1 upper with KE arms DMR single stage trigger, GGG bipod and Fostech DefendAR stock. I've tried both blue (Sprinco moderate extra power buffer spring) and red (Sprinco extra power spring). Because the local ranges frowns on anything over 3-4 at a time I haven't tried anything more. I did, however, have a few instances of what appeared to be hammer follow. Closed bolt and hammer forward requiring chambering of new round. Any thoughts/suggestions? I've read that "too much" forward pressure can cause this, but there are also other factors as well. It'll be awhile before I can get to a place to let loose a bit more and am trying to work out bugs ahead of time. Thanks. |
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[#34]
Which buffer?
Is the gas adjustable? Do you have an extended firing pin? Can you adjust your reset out slightly. |
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[#35]
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[#36]
Quoted:
Which buffer? Is the gas adjustable? Do you have an extended firing pin? Can you adjust your reset out slightly. View Quote Thanks for responding! Here is what I have: Which buffer? H2 buffer with red springco spring Is the gas adjustable? No. LWRC is a piston design Do you have an extended firing pin? I do not. Did not know such existed. How does it help and which are "good" ones? Can you adjust your reset out slightly I'm so new to this I think you are talking about how I hold the rifle, but am not 100% sure what you mean (my ignorance). I highly suspect my technique is an issue and practice will help. Unfortunately, where I can is quite far away and does' happen very often. That's why I am trying to reduce the "no my own damned fault" errors ahead of time. Thank you. |
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[#37]
Quoted:
I would put this in. http://shop.redxarms.com/ENHANCED-FIRING-PIN-FOR-762-X-39-AND-545-X-39-BCGS-EFIRINGPIN.htm View Quote Ah, now I see this. Will try it too. Thanks. |
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[#38]
Quoted:
Thanks for responding! Here is what I have: Which buffer? H2 buffer with red springco spring Is the gas adjustable? No. LWRC is a piston design Do you have an extended firing pin? I do not. Did not know such existed. How does it help and which are "good" ones? Can you adjust your reset out slightly I'm so new to this I think you are talking about how I hold the rifle, but am not 100% sure what you mean (my ignorance). I highly suspect my technique is an issue and practice will help. Unfortunately, where I can is quite far away and does' happen very often. That's why I am trying to reduce the "no my own damned fault" errors ahead of time. Thank you. View Quote The extended firing pin will allow the hammer to still ignite the primer even if the carrier has bounced slightly open. By adjusting the reset of the trigger out it should force a longer period of time before the trigger can be tripped again. It might not make much difference but it shouldn't hurt. I think it's more likely to stop your string of fire but less likely to cause a dead hammer failure. |
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[#39]
Not a bump rifle but I thought you might be interested.
I got my BFS III. I'm not sure if it function tested 100%. I was using it with a CMMG 22 upper. On semi it won't reset sometimes and I have to push the trigger forward. I was having it not fire on release a few times but that may have been the hammer not going fast/far enough back. There were a couple duds which didn't help. The last two mags were flawless however. I've been trying to go slow to get the hang of it before pushing the ROF limit. |
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[#40]
Quoted:
I would swap to a standard or H buffer. That will speed your action up which should help avoid hammer follow. The extended firing pin will allow the hammer to still ignite the primer even if the carrier has bounced slightly open. By adjusting the reset of the trigger out it should force a longer period of time before the trigger can be tripped again. It might not make much difference but it shouldn't hurt. I think it's more likely to stop your string of fire but less likely to cause a dead hammer failure. View Quote Makes sense. I erroneously equated a heavier spring AND heavier buffer as being good. Apparently the spring being heavy is good and buffer less so. |
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[#41]
Right, extra buffer mass slows down your cycle speed which increases the liklihood of the hammer striking the carrier (while it's still open) instead of the firing pin.
Extra spring closes the gun faster. The problem with removing too much buffer weight is you can then run into bolt bounce. This happens when the internal reciprocating weight of the buffer isn't high enough and the carrier bounces off the barrel extension. Generally a heavier barrel needs more buffer weight and a lighter carrier needs less buffer weight. My heavy 16" rifle gas barrel would nominally need an H3 buffer in a traditional machine gun, but with my lightweight carrier and extended firing pin I haven't experienced bolt bounce yet. |
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[#42]
Quoted:
Right, extra buffer mass slows down your cycle speed which increases the liklihood of the hammer striking the carrier (while it's still open) instead of the firing pin. Extra spring closes the gun faster. The problem with removing too much buffer weight is you can then run into bolt bounce. This happens when the internal reciprocating weight of the buffer isn't high enough and the carrier bounces off the barrel extension. Generally a heavier barrel needs more buffer weight and a lighter carrier needs less buffer weight. My heavy 16" rifle gas barrel would nominally need an H3 buffer in a traditional machine gun, but with my lightweight carrier and extended firing pin I haven't experienced bolt bounce yet. View Quote Again, thanks for your time and insight. Any tips on the best way to actually start/stop bumping? Seems there is a line between too much and too little forward pressure. I am beginning to wonder how much of a factor my rifle itself it. As a piston gun, the LWRC has a rather heavy bolt carrier. From the factory they come with an H2. In fact, some bolt carriers have "H2" stamped right on it. Aftermarket carriers are non existent. What I'll have to do it wait till I get to the one range where I can test a it more. Still can't do too much even there (not the kind of attention one wants to draw except in SHTF), but if I take a few different springs and buffers at least I'll know more. In the interim, I've found my BFS II can do a damned good job of being about as fast. A bipod does wonders for controllability . Next on the project list will be seeing what an old, unused HBAR can do. Still like the LWRC due to its much cooler running bolt carrier, but the longer 20" Hbar has its own benefits. |
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[#43]
Quoted:
Again, thanks for your time and insight. Any tips on the best way to actually start/stop bumping? Seems there is a line between too much and too little forward pressure. I am beginning to wonder how much of a factor my rifle itself it. As a piston gun, the LWRC has a rather heavy bolt carrier. From the factory they come with an H2. In fact, some bolt carriers have "H2" stamped right on it. Aftermarket carriers are non existent. What I'll have to do it wait till I get to the one range where I can test a it more. Still can't do too much even there (not the kind of attention one wants to draw except in SHTF), but if I take a few different springs and buffers at least I'll know more. In the interim, I've found my BFS II can do a damned good job of being about as fast. A bipod does wonders for controllability . Next on the project list will be seeing what an old, unused HBAR can do. Still like the LWRC due to its much cooler running bolt carrier, but the longer 20" Hbar has its own benefits. View Quote I have yet to have any real heat issues, and I have ripped off hundreds of rounds at the rapid rate. I'm not saying you "shouldn't" use your piston gun, but I am saying it isn't critical. That's sort of the appeal of using the cheap carbine gas uppers IMHO. |
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[#44]
Quoted:
I have yet to have any real heat issues, and I have ripped off hundreds of rounds at the rapid rate. I'm not saying you "shouldn't" use your piston gun, but I am saying it isn't critical. That's sort of the appeal of using the cheap carbine gas uppers IMHO. View Quote Makes sense, thanks. BTW, it was your videos that got my interested! I find them very well done and informative. I used the LWRC M6 A1 upper as I more or less had it sitting around after I got an IC-SPR, which is in addition to an M6 A2 I also have with a dedicated NF scope on it. I find their products well made and SO easy to clean! Talked to LWRC today as the A1 one was throwing brass at 2 o'clock-the others are 3:30 and 4. Found some odd tiny silver metal slivers on the bolt. 3 hours after my call an entire new BCG was on the way for delivery tomorrow. Not bad! They also suggested I swap out the piston spring as the tech's opinion matched mine--overgassing. Hadn't really thought of that as it has maybe 600-700 rounds through it. Can't hurt to try. You've given my an idea. I also have sitting around a pretty much never used old mash up of brands A2 HBAR with a Colt barrel and old style AR15 (not M16) lighter bolt carrier. Add a rail (torn between 12.5" which allows me to keep the A1 sight) and perhaps better for balance 15" rail), an unused Rock River 4.5lb trigger, sitting around Slide Fire SSAR mod stock and I'm almost good to go. Just add a bipod and red dot and I've got version #2. I imagine the 20" HBAR barrel would do quite well. |
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[#45]
This thread is going to make me build one of these
I see some running dissipator uppers. Is the gas system carbine length, mid length, or rifle length? I ask because this barrel is on sale. 16" dissy but has rifle length gas. Would this gas system with this barrel run? |
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[#46]
I use a rifle gas dissy. I opened the gas port way up for reliability with tulammo. I think I'm at .125, maybe a 64th under.
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[#47]
Do you think an 18" or 20" barrel w/ rifle gas would work with Tula w/o opening the gas port? Apologies if this has been covered. I am still reading through all the info.
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[#48]
I would still open the gas for tulammo with a longer barrel, it just wouldn't be as much.
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[#49]
AR15 (not M16) Bolt Carrier
From what I've had here a lighter bolt carrier, heavier spring and lighter buffer seem to be decent combinations. Now playing with an old 20: Hbar upper. What is the group's take on using its equally old AR15 style bolt carrier in place of the newer (and heavier) M16 carriers? Lighter should be good, yes? Any thoughts? |
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