optimator Posted July 22, 2016 Share Posted July 22, 2016 (edited) Yeah, it's me again My current 3 gun upper is a RRA R3. I'm building a Lightweight 16" upper now for no real reason other than I grabbed one of the LaRue PredatAR sale barrels. I've decided to go with a SLR gas block and a yet undecided adjustable gas key. I've never yet messed with low mass BCG's or lightened buffers. I've been researching them and it's a real mix of what the common opinions are. With a lightened buffer and and adjustable gas, is a standard BCG good enough? I do know "good enough" is subjective. With the above AND a low mass BCG, is it that much better? If I have to throw money that direction, I will. But if I'm not going to notice a $300 difference, I'd rather add the BCG money to the optics fund. Thanks in advance guys. Edited July 22, 2016 by optimator Link to comment Share on other sites More sharing options...
GringoBandito Posted July 22, 2016 Share Posted July 22, 2016 I am sure there are many people on this forum with much more experience than me that will chime in...Here is what i have concluded to help reduce the felt recoil and muzzle movement. 18 inch barrel with a mid length or longer gas system, jp low mass bolt, jp silent capture spring, adjustable gas block and I use a surefire procomp brake. Having shot a similar upper to what you have with xm193, I can say that the reduction in recoil and muzzle movement is massive. Link to comment Share on other sites More sharing options...
IntenseImage Posted July 23, 2016 Share Posted July 23, 2016 You mention an SLR block AND an adjustable key ... You need one, not both Sent from my SM-N920V using Tapatalk Link to comment Share on other sites More sharing options...
optimator Posted July 23, 2016 Author Share Posted July 23, 2016 You mention an SLR block AND an adjustable key ... You need one, not both Sent from my SM-N920V using Tapatalk The SLR Micro, not the adjustable. It's one of the few that have .450 spacing to match the LaRue barrel. Link to comment Share on other sites More sharing options...
BOOM Posted July 23, 2016 Share Posted July 23, 2016 OP I'm with you on NOT being sure a low mass bolt carrier would really CHANGE the felt recoil that noticeable. Some have said that for the money it really did NOT. . JP enterprises has done ALL the development, and has a semantic plan / formula that works,and with years of experience behind them. The 3 parts of recoil to deal with, bullet leaving, buffer hitting the back of tube, and bolt locking back. AIM'S make a L.W. bolt carrier which for 1/2 the price can give you a sense or confidence. I'd like to here more from those who have experience in this Link to comment Share on other sites More sharing options...
BigBamBoo Posted July 23, 2016 Share Posted July 23, 2016 All my AR's...both large and small frame...have JP low mass BCG's and SCS's. I shot my buddies new 18" AR with standard gas block and full mass BCG. I had forgotten what shooting a standard AR was like. I would NEVER go back to a standard configured AR. So yes....IMHO the low mass system is the way to go and money well spent. Link to comment Share on other sites More sharing options...
biglou13 Posted July 23, 2016 Share Posted July 23, 2016 BOOM.... i'd add to you 3 part list .... bolt forward movement... it is often missed tune. (with rifle pointed in safe direction) hold stock rifle in good un-supported position have a friend release bolt , strip round from full magazine and lock forward..... what happens to sight picture???? to tune utilize minimum buffer spring force to strip cartridge chamber, and lock bolt..... A. i think of the rearward motion as one part both hitting the back of tube and locking back since both of these items are tuned via tuning gas block or gas key. B. I have tuned forward movement of bolt with http://www.taccom3g.com/223-adjustable-recoil-system.html along with enhanced light weight spring, minimum forward energy and deceleration via tuned buffer spring . not to mention also dampening the forward movement C. bullet leaving with good muzzle brake In response to OP looking at A. the reward motion is tuned / controlled/dampened already, i think adding the light weight BCG will add only minimal improvement. I will eventually test a low mass BCG. but i feel that current efforts are sufficient without light weight BCG. newtons 2nd law force equal mass x acceleration.... gas key tunes the acceleration , mass is tuned via buffer, and BCG but i think the tuning process is about deceleration vs acceleration i recently completed a build and testing these systems by shooting with stock/ mil spec components 1st, then tuning forward movement B. and shooting a few rounds, followed by A. shooting a few rounds... then finally adding B. shooting..... (i believe this is running the ragged edge of performance, these mods are not what stoner engineered, reliability will decrease with these mods.... but that's another discussion) Link to comment Share on other sites More sharing options...
BOOM Posted July 23, 2016 Share Posted July 23, 2016 This is getting Very interesting Bigou13; I like how your going about this dealing with one issue at a time. Please explain ( your link is not working... SPRINGS; Do you use a 10% light buffer spring, cut a factory spring, or ?. BUFFERS taccom buffer=6oz., or empty carbine 1.15 oz. or? Having Bolt bounce, or NOT having enough energy for it to lock up constantly would be a concern = reliability. Link to comment Share on other sites More sharing options...
biglou13 Posted July 24, 2016 Share Posted July 24, 2016 (edited) I can't get link to work Google taccom .223 recoil. Carbine system is a bit different. Buffer spring is light weight I believe 10%. Then spacers are used in steps to provide reliable strip and lock up. ( could do this cutting spring a home made spacers) I'm usin taccom buffer. The rifle length I haven't weighed yet but carbine is .06 ounce for moving part I don't imagine rifle legnth is significantly more. I'm pretty sure this is the lightest weight buffer available. I always thought bolt bounce was an full auto issue .... I haven't experienced it..... You have recall the stoner design was for military / full auto,...... I imagine stoner is rolling his eyes at the mods being made now Another minor issue is trigger.... And of course the major issue... The nut behind the trigger. Edited July 24, 2016 by biglou13 Link to comment Share on other sites More sharing options...
Dr Mitch Posted July 24, 2016 Share Posted July 24, 2016 Low mass and adjustable gas is the way to go. Adjustable gas and full mass is, to a degree, an exercise in futility. It helps some, but does not an awesome gun make. Link to comment Share on other sites More sharing options...
biglou13 Posted July 24, 2016 Share Posted July 24, 2016 I've been thinking about this low mass BCG question. ( my job requires driving) Ultimately the true test will be build 2 equal rifles, all same components and tuned.... With the exception of low mass bcg. ( I think this would be a great test for a shooting TV/ web... I'd be glad to produce it) My theory is that Tuning the BCG reciprocating action is all about controlling the deceleration. I'm no physics wizard ( I dropped that class) but a lot of what we are discussing is about force, and decreasing the force. F= m x a. Alter mass and/or acceleration you affect the force. My theory or thoughts on this is as long as you alter the acceleration appropriately the mass becomes secondary.. F=m x a So consider the moving parts ( bolt, BCG, buffer) ( if you want to get really technical spring,cartridge weight) as Mass or m. The adjustable gas system, buffer spring system as a or acceleration. F equals the force of moving parts influencing muzzle rise, recoil, perceived recoil. In the case of heavier bcg as long as you adjust the a or acelleration. You can maintain same reusult in force!! I'd still test a low mass BCG eventually, but for now my $200 plus dollars is better spent bourbon and bullets..... Ps. I can't believe I just used algebra today!!! My science and algebra teachers would be proud!!!! PPS.... If you want to really get deep throw friction into the mix, trigger resistance, bolt and trigger interaction.(something I'm working on).But the biggest thing you can do to affect muzzle rise is to tune the nut behind the trigger but that's a different conversation. Link to comment Share on other sites More sharing options...
dogtired Posted August 3, 2016 Share Posted August 3, 2016 I played with a LMBCG and could never get it to run reliably. I am using a standard bolt with adjustable gas on a lightweight rifle with a comp of course, and it is a pussycat. I actually retired the LMBCG to a suppressed 300 blk upper and that gun has never run so well. Go figure. Link to comment Share on other sites More sharing options...
biglou13 Posted August 3, 2016 Share Posted August 3, 2016 I played with a LMBCG and could never get it to run reliably. I am using a standard bolt with adjustable gas on a lightweight rifle with a comp of course, and it is a pussycat. I actually retired the LMBCG to a suppressed 300 blk upper and that gun has never run so well. Go figure. Were you getting failures? What kind of failures? Link to comment Share on other sites More sharing options...
ano Posted August 3, 2016 Share Posted August 3, 2016 18-20 barrel. and rifle gas. Link to comment Share on other sites More sharing options...
dogtired Posted August 4, 2016 Share Posted August 4, 2016 My problems were hashed out on another thread. Happy with the guns performance as is and happy the BCG is working elsewhere. Link to comment Share on other sites More sharing options...
ccoker Posted August 4, 2016 Share Posted August 4, 2016 JP LMOS and their silent captured spring with an 18" rifle gas and adjustable GB with brake of your choice is a thing of beauty. Link to comment Share on other sites More sharing options...
Vespid_Wasp Posted August 11, 2016 Share Posted August 11, 2016 JP LMOS and their silent captured spring with an 18" rifle gas and adjustable GB with brake of your choice is a thing of beauty. This is my setup. I have let many shooters who have never shot a tuned AR try it out. They usually say, 'Wow." Link to comment Share on other sites More sharing options...
biglou13 Posted August 12, 2016 Share Posted August 12, 2016 I had set up Low mass buffer system with adjustable gas key. ( taccom, rubber city) Was waiting to test/ buy a light weight BCG...... A deal came by I could'n't pass on... Bought it Installed the low mass/weight BCG Re tuned ... Functions 100%....... I bought a d.wilson BCG. Used my own bolt. This unit is slightly heavier than AIM. My BCG retains forward assist notches. So my opinion is.... With tuned low mass buffer and adj gas system..... I have NOT appreciated a noticeable difference adding the low mass BCG Link to comment Share on other sites More sharing options...
BOOM Posted August 12, 2016 Share Posted August 12, 2016 Biglou13; So in your opinion the test between a standard vs. a light weight bolt carrier there was NO change in the perceived felt recoil. 1st. were you able to reduce more of the gas using the light weight bolt carrier, 2nd. when running multiple shots (5) did your sights seem to stay on target better than before. I'd think adding a low mass carrier should creat less muzzle dipping, due to bolt carrier weighing less = less force slamming back into the barrel extension This is pretty much the JP formula. Link to comment Share on other sites More sharing options...
optimator Posted August 12, 2016 Author Share Posted August 12, 2016 I had set up Low mass buffer system with adjustable gas key. ( taccom, rubber city) Was waiting to test/ buy a light weight BCG...... A deal came by I could'n't pass on... Bought it Installed the low mass/weight BCG Re tuned ... Functions 100%....... I bought a d.wilson BCG. Used my own bolt. This unit is slightly heavier than AIM. My BCG retains forward assist notches. So my opinion is.... With tuned low mass buffer and adj gas system..... I have NOT appreciated a noticeable difference adding the low mass BCG What are you using for a buffer and spring? Link to comment Share on other sites More sharing options...
biglou13 Posted August 12, 2016 Share Posted August 12, 2016 On rifle length system. Tac com ALW 223 system enhanced buffer spring rubber city armory adjustable gas key D. Wilson bolt carrier Mil spec bolt Schuller brake Boom ...... With The taccom ALW system/ rifle length. The forward BCG is dampened and tuned with enhanced buffer spring, and spacers. So basically with 30 round mag loaded, I tuned buffer spring with spacers for minimal amount of forward motion/energy.... Minimal amount of energy to strip round from loaded magazine and lock bolt forward..... Minimizing dip from forward reciprocation action/ movement I can't confirm "No" change. If any it was very minimal either way... No noticeable difference by adding lt wt bolt carrier. the muzzle motion I noticed is a slight lateral move to the right. I'm going to study th JP formula.....but I retuned system for each additional part/ modification. 1. Buffer/ sprig/spacer. For forward motion 2. Adjustable gas system. For minimal bolt lock back... ( found out I needed to open gas a bit more to function for multiple shots) 3. Light weight bolt carrier (4.). Brake. does not really affect reciprocating weight/ movement. Link to comment Share on other sites More sharing options...
BOOM Posted August 12, 2016 Share Posted August 12, 2016 With very minimal improvement; Not sure why every top shooter runs some type of LW bolt carrier, or where this idea ever started..Any way you covered all the bases Link to comment Share on other sites More sharing options...
biglou13 Posted August 12, 2016 Share Posted August 12, 2016 I did have to make adjustments with adjustable gas with addition of light weight bolt carrier....... I did NOT have to make adjustments fo buffer spring spacers / Increase or decrease spring weight/ with addition of light weight bolt carrier... If that helps. ...... Link to comment Share on other sites More sharing options...
BOOM Posted August 12, 2016 Share Posted August 12, 2016 Thanks for your insights; It might be time to reload and see if you can squeeeeeeezes>> more out of it Link to comment Share on other sites More sharing options...
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