AR Sponsor
Posted: 11/10/2004 11:50:42 PM EDT
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Hi all, I've been working with ColonelKlink, looking to do a little bit of optimization with the AR. The goal is trying to compute/determine optimal buffer weights and spring strengths for smoothest, lowest-recoil operation. The findings will naturally be released here on ARFCOM. We need some help, though, and I'm trying to see if anyone has any technical data for the AR. I'm looking for a couple bits of info, with an emphasis on carbine systems. Data from any configuration would be helpful, though. -Buffer/Action velocity vs. time or displacement vs. time data -Action cycle time -"Official" action spring constant data. (Hooke's K-values; experimentally derived as k=286 newton/M) -Standard carbine buffer weight I know we do have a lot of engineers. if anyone has even a pointer to a data source, that'd be great. Thanks all! |
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And if someone's using different hammer and hammer springs? If someone's using M16 or non-shrouded carriers? If dirt gets in the action? Are you looking at rifle/mid/carbine length gas system? If gas holes aren't drilled/aligned pefectly? What if you switch ammo? What if mag springs have different weights? All those play into the operation of the bolt/carrier/buffer. It was already engineered specifically to make it reliable despite all of the variables mentioned above. A bolt cycling slower to the rear -could- cause extraction problems. The more likely scenario is feed problems as a slow bolt would have trouble stripping rounds out of the mag. IIRC from those mech eng classes so many years ago, energy is proportional to v^2. So you're loosing feeding energy by slowing the bolt and increasing spring weight. If I understand your goal, it's to make it so the buffer doesn't realy hit the receiver extension, but still operates? I doubt you'll calculate your way to your goal of perfection given all the variables, esp if you want it to be reliable in the slightest. Definately not if you want it to work in different firearms or w/ different ammo (not even getting into different configurations yet). If you want to lessen recoil on the mighty 5.56, get a comp, a pistol weight buffer, run it in a full-length stock on a 20" rifle, put some lead in the stock, and that's about as light as it gets. Just my $0.02. rvb ps. From one engineer to another, find another "problem" to be solved, one that'll make you $$$ :) rvb |
| I can't help you with most of your requests, but www.biggerhammer.net has some data on buffer weights. And I have a reasonably accurate scale so I could weigh my carbine buffer and try to experimentally determine the spring constant as per Matth3wdean's reply to ColonelKlink's post, if you think more experimental data points would help. |
The weights on biggerhammer corresponded to mine: H buffer to go with a M93 from Denny's guns 3.7719oz 1650.19grain RRA carbine from legal transfers 2.9653oz 1297.35 standard buffer that was in a wilson 5.1475 2252.06 VLTOR straight from the factory 2.9746 1301.40 odd ball stuff: YBD carbide weight 2.89xxoz assembled it is over 5.6oz (for ar10) SSS CWS (d tubb) carrier only 1.47xxoz carbide insert 2.51xxoz steel insert 1.37xxoz i can get in my safe later today and weigh some colt and armalite buffers. we can see that carbine buffers should be called "3.0oz" according to proper rounding procedures. not a lama and col klink- call jp and see if they can help you any with speed and time, they have an ultralight setup for minimal recoil in gaming/ competition use. rvb- i don't think they are out to make money on this experiment, there are already many products on the market that they would have to compete with- from DTubb to JP |
you should edit your "moderator of......" in your sig, it makes reading difficult because your posts are staggered from everyone else. |
| If your goal is to get the lightest recoil why not just get a adjustable gas tube? Sorry for the dumb question but it seems like a lot of work to get the light recoil by measuring/computing/building parts when the turn of a allen wrench will work just as well. |
If you could restate this question, in say.....English, I'll see what I can do. |
Almost recoilles you can get with effective brake and really heavy buffer. I´m using selfmade steel buffer and brake, selfmade as well, with good results on my Bushmaster M4. Brake has three ports on each side and buffer weighs 160.3 grams, 5.664 oz. This of course has its drawbacks. You can´t shoot soft loads, but who the hell wants? Combination works very well with MilSpec and pretty hot loaded reloads. MN |
Sure. Tell me these, please? -Buffer/Action velocity vs. time or displacement vs. time data -Action cycle time -"Official" action spring constant data. (Hooke's K-values; experimentally derived as k=286 newton/M) As stated, nobody's trying to make a buck here. This is just public research for ARFCOM. The most important data we're looking for is displacement vs. time data from which velocity vs. time can be derived. If we can't find anything, I'm going to sacrifice a buffer tube here for implantation with either a sonic ranger, a high speed macrocamera, or optical gates. I'd rather not, though, since that cuts into my ramen budget.  Thanks all.. |
Actually, extraction is IMPROVED by slower cycling. One of the reasons that shorter-barreled ARs have problems is because of extraction problems that result from the faster cyclic rate inherent in the shorter gas system. That's the reason for the heavier buffers to help compensate. -Troy |
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