Silencerco Lowers - Out of Spec?

ReluctantDecoy

NES Member
Joined
Oct 17, 2017
Messages
7,103
Likes
9,218
Location
Cambridge, MA
Feedback: 1 / 0 / 0
Bought a Silencerco lower to build out. Seemed to have all the features I wanted. Abmi bolt release. Beveled magwell. 7075-T6 billet construction. Seemed great on paper, and looked really nice in person. So I buy it and proceed to try to install a FCG. Drop in trigger and milspec LPK. To my surprise, the trigger pins and ambi safety were both sticking out like a MM too long. I take out my calipers and measure this lower's body at the trigger and another lower I already built, and sure enough this one is definitely thinner.

Having only made one previous build, I've never experienced this before. Is this common? What are the work-arounds? I suppose the trigger pins don't really matter as long as they stay in place, but the play on the safety is concerning. Once I put the safety selector detent in, it balances in the middle somewhere, but seems to have like a half MM space on each side before the lower body. My concern is that if it were impacted right there with enough force to defeat the selector detent, I could lose proper functionality of the selector. Maybe a rubber gasket or washer? Also noticed the Magpul MOE+ factory grip screw wasn't catching threads even when tightly pressed up into the lower. Even did a test run without the detent springs just to see. Nope. Had to buy a longer grip screw. Is this lower completely out of milspec?

Anyway, disappointing (through no fault of the seller though).
 
What mike said but yes. It’s a common theme with them. I’ve actually failed four of them and had to send them back. Whether being out of spec or excessive machine chattering/bad finish. Now if these were $40-50 each it would be more acceptable, but not when the street price is $250 each for a stripped lower.
As a result and for the price I no longer deal in their lowers.
 
I cannot locate all the measurements on the blueprint to get the mil-spec width of a lower in that area. But, the largest deviation on the plans are +/- .010" (~.25mm).

I just measured three lowers (all billet) and they are either .910" or .920" (keeping with +/- 0.010" found on the plans). I agree that since your lower appears to be thinner than this, it needs to get returned. With what Pathfinder said, I'd suggest a full refund and buy a lower from a company that makes them closer to actual spec. If you can't locate one since you're in the PRM, well...
 
I cannot locate all the measurements on the blueprint to get the mil-spec width of a lower in that area. But, the largest deviation on the plans are +/- .010" (~.25mm).

I just measured three lowers (all billet) and they are either .910" or .920" (keeping with +/- 0.010" found on the plans). I agree that since your lower appears to be thinner than this, it needs to get returned. With what Pathfinder said, I'd suggest a full refund and buy a lower from a company that makes them closer to actual spec. If you can't locate one since you're in the PRM, well...
Yeah, was out and about and didn't realize that I was posting on my other account. To be a little more specific:
Well considering one of them outright failed what would be considered a no-go gauge for trigger pins in the realm of 5 thousands is outrageous and another had the same issue you describe with the pistol grip.
Again if this was a $30-40 garbage bin special, sure I'd let it slide, but the fact that it is supposed to cost more than the MSRP of a stripped KAC (not that those are in production anymore as stripped ones) BCM, or SOLGW? Hard pass. It's not even actually full ambi either is why I compare it to those.
Because MSRP on a true ambi LMT MARS-L is right there as well for that asking price. Or for slightly more street price there's the Radian AX556 which while costing more is again fully ambi and also includes basically all the parts you need minus a trigger. All the parts it includes are that of their making too like their radian safety.

What is of concern is that these lowers had a terrible rating on brownells and now those ratings are gone, that being said the lower was reposted as a new #sku, this review even talks about the other reviews that were there. Hard pass.

SilencerCo.png
 
IMO, 5 thousandths (.005") is within spec for most of the dimensions listed on the blueprints. Since 10 thousands is the +/- factor. What you measured is 0.020" on either side (0.040" total) which is FAR outside of spec. I'd accept a 0.005" per side, or .010" total, but not what you measured. I would also wonder how bad their process is if they machined that much off of the lower. Or they're using the lowers that other makers tossed into the 'reject' bucket, getting them for even less. If they're then selling them for more than you can get most of the quality lowers for, that's unacceptable (IMO). If I'm going to pay a premium for a part, it better be worth the cost. Since virtually all forged lowers are identical, I can't see spending all that much more for one over another. Some billet lowers are worth more due to either design differences (ie visual differences, but no functional differences) or some other aspect that makes them worth it. Then again, NOT living in the PRM means I can get reasonably priced lowers/parts/etc and am not subject to the moronic regulations/laws inside the PRM.
 
What mike said but yes. It’s a common theme with them. I’ve actually failed four of them and had to send them back. Whether being out of spec or excessive machine chattering/bad finish. Now if these were $40-50 each it would be more acceptable, but not when the street price is $250 each for a stripped lower.
As a result and for the price I no longer deal in their lowers.

Do you think this is just bad QC? I mean, this is terrible if so. My drop in trigger came with threaded pins. I honestly didn't really care to have them over regular pins, but I thought I'd try it out just for S&G. That's when I first noticed the issue. With both side screws firmly tightened, the pin has nearly a mm of slop and can just rattle in the lower. I ended up shaving off the excess on the pins and now have a tight fit, but makes me wonder about how out of spec the rest of it is. Oddly, the drop in trigger fits fine and an upper mates tighter than my other build, so at least some of it is in spec.
 
Do you think this is just bad QC? I mean, this is terrible if so. My drop in trigger came with threaded pins. I honestly didn't really care to have them over regular pins, but I thought I'd try it out just for S&G. That's when I first noticed the issue. With both side screws firmly tightened, the pin has nearly a mm of slop and can just rattle in the lower. I ended up shaving off the excess on the pins and now have a tight fit, but makes me wonder about how out of spec the rest of it is. Oddly, the drop in trigger fits fine and an upper mates tighter than my other build, so at least some of it is in spec.
Responding from my personal account - I do have concerns, but they mostly are going to be pertaining towards longevity of the product. Even out of spec (As long as the nominal dimensions are close enough) will run and often run safely for periods of time. But this situations make things prone to failures or unsafe situations down the road.
Something like a trigger pin being large isn't guaranteed to have an immediate bad issue, but if it has even a moderate shooting schedule it will. Having large pin holes creates two issues, pin walking and egging out of the trigger pin holes. There are many methods to fix mildly oversized pin holes such as KNS pins, though the gun still needs to be monitored long term for egging out. Egregiously large pin holes will prematurely egg the trigger & hammer holes out and create situations where the trigger might move enough to slip the hammer or the safety and go full auto which items like what you used will not resolve. I'm not sure if you're saying they're just sitting proud at this point and can be forced back and forth or if they actually rattle within the slot.

Personally before I go forward I'd just send it back.
 
Hahahahahaha.....never had that problem with an Anderson or PSA.......even with a BLEM.

Send it back with a picture of the calipers measuring it.
 
Hahahahahaha.....never had that problem with an Anderson or PSA.......even with a BLEM.

Send it back with a picture of the calipers measuring it.

Thanks. Kick a brother when he's down. lol. I mean, this can't be my fault, even for buying a relatively unknown (for lowers) brand. Who get's basic milspec wrong to the point you need to bring calipers when shopping for lowers? This just shouldn't happen. Like buying tires in the correct size and finding out they're an inch off from your rim size.
 
I cannot locate all the measurements on the blueprint to get the mil-spec width of a lower in that area. But, the largest deviation on the plans are +/- .010" (~.25mm).

I just measured three lowers (all billet) and they are either .910" or .920" (keeping with +/- 0.010" found on the plans). I agree that since your lower appears to be thinner than this, it needs to get returned. With what Pathfinder said, I'd suggest a full refund and buy a lower from a company that makes them closer to actual spec. If you can't locate one since you're in the PRM, well...
The fun part is s quick look at silencerco web site does not claim to be “mil spec”
So in a nut shell if it functions its gtg.
Right

not happy send it back
 
coincidental that SiCo is now running promotion for free lowers? They’re probably unloading their lowers to avoid selling them. I don’t own any of their products…not that their cans are junk but i have zero experience w their goods.
 
Back
Top Bottom