If the play from the upper/lower bugs ya, cut a thin strip of electrical tape the width of the receiver wall and apply it to the either side of the lower just above the take-down pin. Some trimming or moving of the tape may be required but it'll stop that play.
M&P 15 movement between upper and lower
- Thread starter josh1976
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GunsNotPuns
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No less than Eugene Stoner thought the FA was pointless and was annoyed at the US Army's insistence that it be tacked onto the AR-15/M-16.
At any rate, Accuwedge is what I refer to as a capitalist version of wealth redistribution, except it reverses the process.
I was holding a colt today at CDN gunworx in Oshawa (awesome store btw). I'll tell you, there is a difference in the tolerance and fit between a $700 AR and a $3000 AR. That said, i would never buy one. That's crazy money for me, and the M&P is everything I need it to be. Much respect to the high end rifles though.
I can't find design specs, so we can't comment on this. However I found in the manual that there's an acceptable gap.
This second question was not about if gap was withing spec. Question is out of two guns, one with no gap and another one without - which one would be better protected?
Do you have a link where I can read about extensive testing? I mean proper scientific testing performed by armorers, not some forum posts? Because physics says opposite. I can understand that slight wobbling could affect very insignificant, however any stabilized system would ALWAYS perform better.
Are you saying that stress ends at the upper? How come you feel the recoil and why would we need a buffer spring as part of the stock connected to lower? And again I would refer to physics with remark that I understand that stress could be insignificant. And again I know for sure that stabilized system due to lack of gap creates no additions stress that could contribute to the gap increase. And army manual describes the situation when replacement is required after gap is too big. So issue DOES exist.
True that we have these day better processes and materials. However it does not mean we use them. Technological and economical considerations are very important in the firearm manufacturing. And nobody will be using "best", they use "sufficient". As example modern can openesr are mostly made from powder metal, as opposed to old ones made from steel. As for firearms I was referring to the quality of fitting and finish of old semi firearms and no doubt it is much better. We could do better these days buy we don't, that's my point.
Good "quality of manufacturing" is ability to manufacture something up to the highest standards possible with available technologies, materials and knowledge. See what I mean?
I can't find design specs, so we can't comment on this. However I found in the manual that there's an acceptable gap.
You likely won't find the specs as they're part of the TDP which is a protected(secret) document controlled by the US military and the contracted parties(Colt and FN) who supply their rifles. Just an FYI, there's more to the TDP/milspec than just dimensions. The TDP includes material specs as well as manufacturing processes.
This second question was not about if gap was withing spec. Question is out of two guns, one with no gap and another one without - which one would be better protected?
Again, if you have a milspec rifle then it makes no difference if the gap is there or not. You would be hard pressed to find a very tight fit AR that was built to spec.
Do you have a link where I can read about extensive testing? I mean proper scientific testing performed by armorers, not some forum posts? Because physics says opposite. I can understand that slight wobbling could affect very insignificant, however any stabilized system would ALWAYS perform better.
Working on information links. This topic has been discussed by respected shooters(both mil and civilian) as well as armorers and the answer is the same, the effect is near zero and nothing to worry about. Keep in mind that the sighting system and barrel are fixed to the upper and thus remain connected to one another at all times. Any wobble will be removed when you shoulder the rifle and apply proper rearward pressure before firing.
Are you saying that stress ends at the upper? How come you feel the recoil and why would we need a buffer spring as part of the stock connected to lower? And again I would refer to physics with remark that I understand that stress could be insignificant. And again I know for sure that stabilized system due to lack of gap creates no additions stress that could contribute to the gap increase. And army manual describes the situation when replacement is required after gap is too big. So issue DOES exist.
The transfer of energy during firing(recoil) and the stresses applied to the rifle are not mutually exclusive. You will wear out an upper reciever or its components long before you see any significant wear to the lower. An increase in gap between upper and lower receiver is caused by more than just firing,
rough use/abuse and hanging grenade launchers off the bottom are a couple examples.
True that we have these day better processes and materials. However it does not mean we use them. Technological and economical considerations are very important in the firearm manufacturing. And nobody will be using "best", they use "sufficient". As example modern can openesr are mostly made from powder metal, as opposed to old ones made from steel. As for firearms I was referring to the quality of fitting and finish of old semi firearms and no doubt it is much better. We could do better these days buy we don't, that's my point.
If you buy from a reputable quality manufacturer who follows the TDP(or as much of it as they can access) and builds guns to milspec then no,
they don't build "sufficient" products they build products to spec. For products outside a milspec there are still companies who take pride in their work and spend the time and cost to do things right. Quality goods come at a price and it isn't near the bottom of the scale. You get what you pay for..
Good "quality of manufacturing" is ability to manufacture something up to the highest standards possible with available technologies, materials and knowledge. See what I mean?
You said it, "highest standards possible" and the only standard for the AR family of weapons is milspec. Every other "Standard" is proprietary to the source/individual companies applying them. And again, the only standard for materials is the milspec standard. The M&P15 sport fails to follow the basic milspec requirements as it does not use the proper steel for the barrel is missing the forward assist and the dust cover. One could argue that the FA is not necessary and has zero effect on the rifle, same could be said for the dust cover although it does a pretty decent job of keeping debris out of the action when not in use. The barrel(and chamber) is also not chrome lined which is also a milspec requirement. The guts are not milspec and appear to be MIM parts. The receiver extension nut is not properly staked. The RE is likely not 7075 aluminum as per milspec either as no one seems willing to comment on it from S&W(as per video reviews). Bolt carrier is civilian style semi auto not a milspec full auto. The bolt is MPI'd but likely not HP tested, as per milspec. These are just some of the known non milspec parts/processes that are used in the M&P15. Now I'm not saying this rifle is the worst option nor am I saying that S&W are the only ones offering non milspec guns. There are plenty of non milspec guns being offered, in fact most brands are not milspec. Some are better than others but without adhering to a spec of any sort leaves a lot of room for corner cutting.
In the RED. Below is a list of milspec requirements that BCM does to their rifles. A lot of them are either completely irrelevant or can be argued as having no negative effect on performance or reliability of the rifle. Nevertheless BCM spends the time and money to do it right.
• M4 Feed Ramp Barrel Extension
• M4 Feed Ramp Flat Top Receiver
• T-Marked Upper Receivers
• USGI 5.56mm NATO Chambers
• Independently Certified Mil-Spec 11595E Barrel Steel
• Chrome Lined Bore and Chamber
• Manganese Phosphate Barrel Finish on entire barrel
• Mil-Spec F-Marked Forged Front Sights
• Taper Pinned Front Sight Base
• USGI Government Profile Barrels
• HPT (High Pressure Test, per Milspec) Barrels
• MPI (Magnetic Particle Inspected, per Milspec) Barrels
• Bolt machined from Mil-Spec Carpenter No. 158® steel
• HPT Bolt (High Pressure Tested/ Proof)
• MPI Bolt (Magnetic Particle Inspected)
• Shot Peened Bolt
• Chrome Lined Carrier (AUTO)
• Chrome Lined Gas Key
• Gas Key Hardened to USGI Specifications
• Grade 8 Hardened Fasteners Key
• Staked Per Mil-Spec
• Tool Steel Extractor
• BCM® Extractor Spring
• Black Extractor Insert
• Receivers Machined from Aluminum Forgings 7075-T6
• Receivers Hardcoat Anodize per MIL-A-8625F, Type III, Class 2
• BCM® Milspec 7075-T6 Receiver Extension
• USGI Mold M4 Stock Staked M4 Lock Nut
• USGI H Buffer (1 USGI Tungsten, 2 Steel)
• Magpul MOE Enhanced Trigger Guard
• Low Shelf for RDIAS installation
• Low Shelf for Accuwedge use
• Un-notched Hammer compatible with 9mm use
• Fire Controls marked SAFE and SEMI
In fact follow the link and read the whole thread, some really minute details are covered..
http://www.m4carbine.net/showthread.php?55930-BCM-Stuff
I found some info for you if you want to do some real digging. The book is called "The competitive AR" by Glen Zediker. On page 56 there is a comment from Bill Wylde, yes that Bill Wylde who makes a comment about upper to lower fit.
You can get them too tight, but you can't get them too loose to shoot well", Bill Wylde. Source: The Competitive AR15, Glen Zediker, Page 56. Bill Wylde is an expert on Service Rifles, barrel design, etc. He's fired some incredibly small groups with the AR15.
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Hahaha! Enjoy the rifle!
Thank you, you provided a lot of references and I will enjoy dipping into them.
LeadMonkey
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Still alive
CGN Ultra frequent flyer
- Location
- Rainy mosquito infested part of BC
Yes they are fine for range use. The ammo will be the pricey part compared to an SKS. The AR is restricted, unlike your SKS, so only for range use.
Or, you could buy a .22 conversion kit, and shoot .22's all day for a few bucks !!
