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Are A2 stock spacers supposed to be loose and rattly? (Page 2 of 2)
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Originally Posted By 556Cliff: It has me wondering about the A1 stock and if there is any space between the inside of it's butt plate and the end of the buffer tube... I just don't have any A1 stocks lying around to check it out.  Nope, no space that I can make out on an A1. There nothing there to move around anyway since there is no spacer |
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Originally Posted By mcantu: Nope, no space that I can make out on an A1. There nothing there to move around anyway since there is no spacer Originally Posted By mcantu: Originally Posted By 556Cliff: It has me wondering about the A1 stock and if there is any space between the inside of it's butt plate and the end of the buffer tube... I just don't have any A1 stocks lying around to check it out. Nope, no space that I can make out on an A1. There nothing there to move around anyway since there is no spacer Hmmm, that's interesting. I guess I just have to deal with the loose spacer issue and use shims like I had planned. |
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Originally Posted By Dangus: This thread has me mesmerized. For the life of me, I've never experienced or heard of a loose A2 spacer. Can't you just put some muscle behind the screwdriver to cinch it up? Negative, it just won't compress that much. I'm assuming at best it might compress about 0.01" of free space with the screw tightened. Depending on which butt plate I use I have between 0.01" and 0.08" of free space. I usually stick to using the NOS surplus A2 butt plates and those are between 0.03" and 0.04" of free space. I go 30 inch pounds on the stock screws and that's a bit more than what feels tight enough when doing it by feel alone... It's tight, at 30 inch pounds the drive slots in the screws start to deform using a proper fitting hollow ground screwdriver bit. Edit: Regarding what I said highlighted in red. Apparently I was wrong on that... Though if the free space between the spacer and the butt plate's spacer pocket is 0.04" like it is on my NOS surplus A2 butt plates, then I can say for certain that just turning the screw until the spacer stops rattling will damage the butt plate (see pictures below in post 7). If there's any more than between 0.01" and 0.02" of free space it's a bad idea to just keep turning the screw until the spacer stops rattling. |
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Got my 0.03" Nylon shims and the 3/8" inside diameter is perfect. Not sure if I'll go the easy route of just putting them in the spacer, or the slightly more effort route of putting them in the butt plate. Though I think I'll likely end up putting them in the butt plate, because if I have to use any of the stainless shims I'd rather have them against the back of the A2 spacer than against the back of the buffer tube (probably overthinking things here). Need to get my work bench in the garage cleaned up and I'll test this out first with the loose A2 stock on my brother’s Aero .308 lower.    
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Alright, happy to report that the 0.03” Nylon shim worked. I put the shim in the spacer pocket of the butt plate. The butt plate on my brother’s Aero .308 is one of the NOS surplus A2 butt plates that I buy from AR15Sport and Fulton Armory. So it has about 0.04” of free space between the spacer and the butt plate. Filling that space with a 0.03” shim seems to be what was needed. No spacer rattle and the stock is tight to the receiver. We will see if anything loosens up over the year as he continues to work up loads for that rifle. Other butt plates will be different as I’ve noted in previous posts, but I think you should always leave between 0.01” and 0.02” of free space for compression when including shims… That is if you end up running into the loose spacer issue at all… I seem to be one of the very few that has run into this. Lucky me! Lol… 
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Finally got all my A2 stock spacers properly shimmed today!  I only have 5 rifles with A2 stocks so it wasn't a huge hassle, but just trying to find some time to do it is always the problem for me.All the buttplates were the NOS surplus type, so they all got the 0.03" nylon shims placed in the spacer pocket of the buttplate. I did do some destructive testing on one of the NOS surplus buttplates (these have 0.04" of free space to take up) and I tightened it up without any shim just to see if I could stop the spacer from rattling and I did manage to (and to my surprise I didn't have to go beyond 25 inch pounds), but beyond a certain point it just felt very wrong and it took way too many turns to get to the point where it would tighten up. I then removed the buttplate to inspect it for damage... I didn't notice any cracks, but there were spots in the plastic that were turning a shade of white due to the polymer stressing/stretching beyond it's limits. Pics below with red arrows indicating the stressing in the polymer (I won't be reusing that buttplate)... So the shims are definitely a must in my opinion.    
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Are A2 stock spacers supposed to be loose and rattly? (Page 2 of 2)
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