The bolt cam pin channel has a fair bit of straight forward/rearward movement when in battery. Matter of fact I have a AR BCG in my hands right this very moment and can tell you that there is easily 1/4 an inch of movement. The "bolt bounce" in the video was not 1/4 of an inch, much less over that amount.
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?
So, how many guns have you had exhibit the issues that you claim, including having debris enter the action during "bolt bounce"?
I'd venture none.
And i'll fully admit that the only time I ever had airborne debris enter the action of amy rifle I owned was either at a training session when we were doing stress fire courses of fire (including having other students throw stuff at the shooter in an attempt to distract them) or while shooting prone next to people with muzzle brakes that were throwing debris to the rear of the line.
So, once again, how many failures have YOU had that you could scientifically attribute to "bolt bounce"? I've had NONE. Hell, i've had mud in the internals of my M4 AND a Beretta 92Fs and neither one malfucntioned during one particular training session where the weather was "non-compliant". Still have pics taken afterwards. After rain had washed most of the mud off as well.
My proof is personal experience of shooting under adverse conditions and close to 17 years of experience with the type of weapons platforms being discussed, and not a single time during that timeframe has "bolt bounce" ever been an issue in a properly built rifle using unmodified parts.
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?
So it appears that you are arguing a point that you just admitted to not knowing anything about based on your incorrect assumptions and interpretations of the laws of physics in relation to the topic at hand. Why?
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.
If you honestly believed your last statement, 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.
Last edited by Grumpy; 03-15-2012 at 08:29 AM.
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
Also, when you are talking about the hammer engaging the "disconnector" during fully automatic fire, you are actually talking about the full auto sear, right? Because it is physically impossible for the hammer to engage the disconnector during full automatic fire. When the selector is put on full automatic fire, a cam on the selector axle lowers the rear of the disconnector, pushing it out of the way of the disconnector notch on the hammer. If the hammer engages the disconnector, there is something wrong with the triger mechanism, not bolt bounce. As far as bolt bounce causing the hammer to be caught by the sear on the hammer notch.....not plausible, as there would have to be a lot of movement. Actually, it is not possible as long as the trigger is depressed with the selector on fully automatic fire. The hammer notch will not engage the sear.
ETA: With the selector on full auto, there is a 2 cm gap in the ejection port before the hammer engages the sear when I pull the charging handle to the rear. The gap is even bigger, maybe 3,5-4 cm, before the disconnect engages the hammer, with the selector on semi auto.
Last edited by AGR416; 03-15-2012 at 05:16 PM.
I think i'm going to leave things to AGR to explain for the most part from now on.
Things that I see as "common sense" and expect people to understand (which some obviously don't), he actually explains better then I can.
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.
Here's the skinny, no BS, bottom line.
Any extra wear you would experience on account of bolt bounce, would NOT cause an issue in the weapon until long after the barrel has already been shot out several times over and then some. In that time, the bolt will probably have been replaced at least once, and all springs, extractors, ejectors, etc. will have been replaced several times over.
Meaning that the throat and bore will have been worn to the point that it would have been replaced and the whole wear cycle would have started over.
This is why bolt bounce is absolutly meaningless in all aspects to every group that owns firearms, regardless of their reason for owning them. There is no way to measure the effects of bolt bounce because it has that little effect on anything.
You're trying to approach this from an engineering point of view, which strangly enough, I understand. But you're not viewing it from a real world use aspect, nor are you viewing it from the proper life cycle wear aspect of the machine in question.
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.
Last edited by Grumpy; 03-19-2012 at 01:16 PM.
For FA, we have already determined that the issue arises when the hammer drops when carrier is moving rearward, striking the carrier instead of the firing pin and riding it home causing light primer strikes, as Grumpy already mentioned.
And if you experience bolt bounce, just switch to a heavier buffer.
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.
But there is another way to think of it that is even more simple, if the effects bolt bounce in a semiauto were "virtually meaningless" money would not be spent to prevent it.
As for your earlier question, my main concern is not with the bolt bounce it's rather the bouncing around the cartridge does as it leaves the feedlips on the mag.
Its clear the MR762 is feeding much more smoothly than the other two. That aside, I don't like the bolt bounce for the reasons I mentioned earlier, but what I really wonder is if the MR762 can maintain that no bounce condition over the full range of ammo types.
In that regard, I'm not sure though if it worth the extra $2k to buy a MR762- that is in essence what I am trying to figure out. There is not enough info in the video to determine if there is a bolt bounce difference between the Sig and the HK over the full range of ammo types and gas settings, but it does appear that there is enough info to indicated the feeding on the MR762 is superior.
But if we want to focus on the bounce, and assuming there is some difference between the HK and Sig over a range of ammo, I prefer the one with less bounce.
The areas that I would focus on would be increased opportunity for FOD to enter/jam the action. I actually had walnut media jam a USP9 tight once, was not to happy about that one. Other issues: (1) two impacts on every cycle. On an AR type lockup I'm not totally sure where that impact is -brass, bolt, bolt carrier, etc. (2) additional cycles on any springs involved, and wear on key components. Looking at the first video you posted it would appear that the highest wear point common to bolt bounce in an AR style lockup involves the bolt cam pin; on a Kalashnikov it would probably be on the locking lugs.