+1. It is my understanding that HK went with the heavier recoil spring on the HK416 to increase service life due to the increased energy delivered by a piston system. As a result, they expereinced bolt-bounce and had to tungsten fill the buffer. The MR556 retains these features.The MR762 displays typical "light gas" operation with slower bolt speed and rechambering. This of course can be mimicked by several factors such as a possible stronger action spring and heavier buffer. I know the 416/MR556 come with those, so i'd venture a guess that the MR762 does as well. In all, not a bad thing, but it *can* (not will) make the rifle have reliability issues with lighter loaded ammunition, crappy surplus, etc., manifesting as failure to extract/failure to eject or even failure to feed issues as the system might not get enough gas to properly cycle thebolt.
The neat thing about "bolt bounce" (really it should be "carrier bounce) is that it only really effects FA fire. In a semi-auto gun, it's virtually meaniningless.
And your proof of this is?Its far from meaningless in semiauto; it does add additional wear and tear, especially if the bounce is hard enough that the ejector is moving the cartridge in the chamber. It also opens another venue for debris to jam things up during that split second.
Res ipsa loquitur,And your proof of this is?
So you have no proof, only what you "suspect" without empirical data.Res ipsa loquitur,
additional load cycle on the extractor
additional wear on the chamber from sliding brass
additionally, if the bounce is big enough to have an affect on the disconnector (such as is the problem with full auto fire), then the gap is large enough to allow debris to do the same. A good reason for a forward assist.
as I said, Res ipsa loquitur,
Enough "experience" to qualify the initial statement with the following " if the bounce is hard enough that the ejector is moving the cartridge in the chamber" But just to be absolutely clear, YOU are saying there is no breach face movement from bounce in that Sig?So you have no proof, only what you "suspect" without empirical data.
Clue #1= Bolt bounce in "normal"* working systems doesn't move the carrier far enough to cause the bolt itself to move at all. Thusly throwing your guessing about extractor wear, and "chamber wear", etc. right out the window...... ESPECIALLY the part about "sliding brass"......do you realize just how far a bolt would have to bounce to unlock the bolt and cause the brass to "slide" in and out of the chamber again????? I mean seriously, how much experience do you have with firarms to think that this would even remotely be an issue?
I will hold you to your own standard and quote you: "And your proof of this is? "As to your contention that bolt bounce "allows" forign debris to enter the system and thusly cause malfunctions, once again, this is merely the product of a fertile imagination. Do you realize exactly how fast this process takes place? Do you not understand that if there was that much debris airborn and able to enter the ejection port during the cycle of the firearm that the amount that would enter duing "bolt bounce" is insignificant compared to the debris that would enter during the cycle of the bolt? Crap! Can't fire the gun at all now....stuff might fall inside while it's cycling!!!!
I apologize if my sentence structure is somehow interfering with your reading comprehension, but I did qualify the statement with an "if"- "IF the bounce is big enough to have an affect on the disconnector" But just to be clear, I don't claim expertise with any of the three weapons above. I would also point out that it would be more courteous and helpful to politely point out that based on your experience that the above weapons are incapable of experience that level of bounce during full auto fire -ie something like "even considering the harmonics, such level of bounce is extremely unlikely in these actions" and maybe quantifying your qualitative analysis. But just to be clear, are you saying that full auto weapons never have enough bolt bounce to engage a disconnector?The part that REALLY gets me is your idea that the disconnector is somehow involved in this.
As it were, the issue with FA fire and "bolt bounce" is the hammer dropping when the carrier is at the apex of the "bounce" and the hammer is hitting the carrier instead of the firing pin and riding it forward thus causing a light primer strike and not igniting the round.
*by "normal" I mean that in order to make "bolt bounce" bad enough that it causes the actual bolt to move, one would need to modify the buffer substantially outside of the specifications of the weapon.
Funny, I didn't know there was a competition; heck, I'm even more surprised you have a league. Are your league shirts brown, or just black and tan?Sigh....Seriously dude, you're way out of your league.
Yup.Enough "experience" to qualify the initial statement with the following " if the bounce is hard enough that the ejector is moving the cartridge in the chamber" But just to be absolutely clear, YOU are saying there is no breach face movement from bounce in that Sig?
Ah....I love it when people argue like my ex wife. All fluff and no substance.I will hold you to your own standard and quote you: "And your proof of this is? "
But it does seem a little strange that you will acknowledge that a spent case can fly back into an over gassed gun, but some how you cannot envision debris entering during a bounce? Did you consider that the bounce itself might be enough to loosen debris on the bolt, or do you only shoot safe queen clean guns?
Yup. That's what i'm saying. That unmodified AR15/M16 type weapons do not EVER experience enough "bolt bounce" to push the hammer far enough back to engage the dissconnector. Either in full auto or semi-auto. Do you even know how far that would be?I apologize if my sentence structure is somehow interfering with your reading comprehension, but I did qualify the statement with an "if"- "IF the bounce is big enough to have an affect on the disconnector" But just to be clear, I don't claim expertise with any of the three weapons above. I would also point out that it would be more courteous and helpful to politely point out that based on your experience that the above weapons are incapable of experience that level of bounce during full auto fire -ie something like "even considering the harmonics, such level of bounce is extremely unlikely in these actions" and maybe quantifying your qualitative analysis. But just to be clear, are you saying that full auto weapons never have enough bolt bounce to engage a disconnector?
Typical fallback response when you have willfully wandered out of your lane of knowledge.Funny, I didn't know there was a competition; heck, I'm even more surprised you have a league. Are your league shirts brown, or just black and tan?
I guess I have learned something, were not all here with the primary priority to help each other out.
I take it you are talking about your original claim that bolt bounce is "virtually meaniningless" in a semi-auto. In light of our current discussion, what you are saying is that the extra impacts from bolt bounces cause NO additional damage or wear, and that bolt bounces do NOT allow ANY additional opportunity for debris ingress/jamming. That is what you are claiming, right?You would have entered into this topic by asking questions, not by making incorrect statements and trying to justify them as fact when you don't have any experience or even a base knowledge of the system being discussed to even understand what it is you are talking about.
As it were, you are correct, at least as far as i'm concerned, that the point of such sites is to gain or pass on knowledge. Factual knowledge, not supposition or assumption. Remember that and these conversations will be easier for you.
Highly unlikely, and negligible compared to what happens during a normal cycle of operations:the extra impacts from bolt bounces cause NO additional damage or wear
Compared to when the ejection port is fully open during the cocking phase, it is negligible. If debris entering the weapon during the cycle of operations, or because of bolt bounce, caused the weapon to malfunction (not jam), I would imagine that weapons maufacturers would have developed a different design by now.....most of the debris that gets in to the upper, gets there during reloading. Either through dirty magazines or through debris inside the magazine that sticks on the ammunition.bolt bounces do NOT allow ANY additional opportunity for debris ingress/jamming
What possible issues, in regards to wear and malfunctions, do you see arising from bolt bounce and why do they arise? If you could articulate these concerns, rather than "just" a theory that bolt bounce must cause additional wear or increase the likelyhood of malfunctions, it would be easier to address the issue.AGR416,
Thanks for the insight.
I took it for granted that the issues were obvious. I could have been more precise in what I wrote; Unfortunately the lack of precision opened up an opportunity to muddy things up. I'll give it another shot
Basically the question is: is bolt bounce "virtually meaniningless" in a semi-auto. From a quantitative standpoint "virtually meaningingless" means that there is ZERO variance in MTBF (mean time between failure) between a weapon with no bolt bounce vs one with bolt bounce. I don't think it is possible to argue that an unnecessary bolt bounce on every cycle doesn't cause unneeded movement, openings, and impact within the firearm, and that those actions MUST cause additional wear and potential for jamming.
Of course, if one does not care that a gun has any additional chance of jamming, or reduced service life then the question is moot because 'virtually meaningless' becomes a personal subjective assessment. People tend spend big money on HK's because those issues are NOT meaningless to them. On the other hand, some people do buy HK's for a perceived snob appeal. From that perspective, the best one can do is claim that such wear,tear and jamming effects are minimal, such as saying the worst case maybe one less round fired over the weapon's life cycle. In that case the question is: what is the value of having that one extra round when you need it? If it is enough to spend $2k more on a MR762 than a Sig716, it ain't so meaningless.
You are correct experience is helpful, in this case what we are talking about R&M experience. Using the "proper terms" is only helpful if they provide useful meaning to the reader, it wouldn't do much good to start throwing around FMECA terminology, nor would it do much good to use the "proper" German failure mode terms for failures in germanic weapons. But you may find this helpful, what is important in not any individual experience, but rather the population experience; typically a Mean Time Between Failure and a distribution curve describing that population. Its almost the same mistake as thinking firing one shot through a weapon means that it is reliable.Here's the skinny, no BS, bottom line.
..p.s. for what it's worth, your reference to possible issues created by bolt bounce as "jamming" instead of the proper term, prompts me to believe that you're trying to apply your understanding of machinery in some other aspect to firearms without the necessary experience to back it up. Theoretical vs. real world. Being anal has it's place, just know when to judiciously apply it. Hint: this isn't it.
Thanks for the vids.Vid of cutaway AR-15 firing:
Cutaway AR-15 - High Speed Video - Preview - YouTube
Extrem bolt bounce, with weights removed from buffer:
AR-15 Extreme Bolt Bounce - High Speed Video - YouTube
Now, if you have bolt bounce like on the bottom vid I can see where you would experience issues.