80% problems

[Cummins_Powered]

my 80% lower. (I milled it to 100% already)

There are a number of problems, all due to things that were already completed on the 80%. I am trying to figure out if these are problems people have heard of.

First off, Has ANYONE had any problems with any aspect of the lower parts kits installed in their (or have firsthand experience) 80% lowers?

Problem 1: Magpul moe grip left a big gap between the front of the grip and rear of the trigger guard. Used a different grip and it seems fine now...

Problem 2: fire selector switch is slightly off, meaning it doesn't travel from vertical to horizontal but rather slightly past vertical to slightly less than horizontal. My guess is the detent hole is not drilled 90* to the selector hole but at a slight angle. Poor machining?

Problem 3: The biggest issue. The bolt catch doesnt move at all. as in once i pinned it into the lower, it is pinned so tightly against the lower that it is jammed in place. basically it would not function at all once the final round is shot. Again i think the hole for the roll pin was not drilled in the proper location.

Problem 4: front takedown pin. again we have an issue with the dentent hole being off center. It should be drilled in the "center" and at a 90* angle to the takedown pin hole. but it is slightly off, causing the pin to sit at an angle. which in turn does not allow it to fully pin the upper and lower together.


So did i just get the biggest POS 80% lower ever? are manufacturing problems like this common? The quality compared to my spikes lower is absolutely horrendous.

[Germz]

my 80% lower. (I milled it to 100% already)

There are a number of problems, all due to things that were already completed on the 80%. I am trying to figure out if these are problems people have heard of.

First off, Has ANYONE had any problems with any aspect of the lower parts kits installed in their (or have firsthand experience) 80% lowers?

Be more specific please Personally I had some problems. I bought a lower that did not have the rear takedown pin drilled out, so when i got it done at AS&T it wouldn't fit gabe's jig. . he fixed that like a boss and that was the only real problem I've had.
Oh on another 80% I think the hole for my magazine release was drilled off center as my mag release cants when depressed. and the well where the mag release bar sits is a little too long so the mag release bar doesn't sit flush/snug in its hole. In any case they are physical imperfections that don't affect performance.

Problem 1: Magpul moe grip left a big gap between the front of the grip and rear of the trigger guard. Used a different grip and it seems fine now...

elbow grease. Mine did the same thing. put some lube on the polymer and wiggle it in!

Problem 2: fire selector switch is slightly off, meaning it doesn't travel from vertical to horizontal but rather slightly past vertical to slightly less than horizontal. My guess is the detent hole is not drilled 90* to the selector hole but at a slight angle. Poor machining?

if perfection is your game keep in mind this is a home built firearm. not sure of a fix but if in fact it isn't fixable, love it like a red-headed step child.

Problem 3: The biggest issue. The bolt catch doesnt move at all. as in once i pinned it into the lower, it is pinned so tightly against the lower that it is jammed in place. basically it would not function at all once the final round is shot. Again i think the hole for the roll pin was not drilled in the proper location.

is your lower anodized? this may be an issue. run small drillbit (by hand, not powered) through the bolt catch roll pin hole. this usually fixes that issue.

Problem 4: front takedown pin. again we have an issue with the dentent hole being off center. It should be drilled in the "center" and at a 90* angle to the takedown pin hole. but it is slightly off, causing the pin to sit at an angle. which in turn does not allow it to fully pin the upper and lower together.

need pics for this one please

So did i just get the biggest POS 80% lower ever? are manufacturing problems like this common? The quality compared to my spikes lower is absolutely horrendous.

its good to buy an 80 and know who did the machining. did you ahve that information prior to purchasing it? what reviews did they have? a lot of 2013 mid/late year 80%ers suffered from poor machining due to increased demand it seems. you may have bit an unfortunate bullet. good thing they are cheap!

[baih777]

what brand did you buy ?
I never had a problem with Tactical Machining 80% lowers.

[m16]

what brand did you buy ?
I never had a problem with Tactical Machining 80% lowers.

Yep.

I've assembled several TM lowers for myself and others and the only issues I've had are the takedown pin lugs on the uppers being a tight fit.

Did your forging come from Rohg?

[Cummins_Powered]

These two photos show the front takedown...hopefully what i was saying makes more sense now.





Here is the bolt catch/release. The problem now is that i pinned it in place. and it cannot be tapped completely through to remove it. I guess it would have to be drilled out.




As you can see the lower was cerakoted. which is rather thick. i filed down the areas where the fire control pins and take down pins sit. i didnt touch the bolt realease hole. which may have been a huge mistake.

[Germz]

Yep.

I've assembled several TM lowers for myself and others and the only issues I've had are the takedown pin lugs on the uppers being a tight fit.

people pay extra for gadgets that do this! consider it a blessing!

[Cummins_Powered]

I *think* its made my CPC machine in Sacramento? It looks exactly like the lowers sold by sac black rifle...(not where i got it)

[ElvenSoul]

All these problems are common!

Hear it all the time.

How I avoid them is get some blue prints and overlay the 80% lower.

[Germz]

oh I didn't realize this isn't a milspec form lower. thats the risk you run when people change the dimensions. sorry op. who did that cerakote job??

how much did you pay?

[electric7]

Two options for you, which you should do both. First, try again with another brand. Second, bust out the files, dremel, and drill to try and fix all the little issues that are present.

[Cummins_Powered]

oh I didn't realize this isn't a milspec form lower. thats the risk you run when people change the dimensions. sorry op. who did that cerakote job??

how much did you pay?

done by a member here. $50

Two options for you, which you should do both. First, try again with another brand. Second, bust out the files, dremels, and dril to try and fix all the little issues that are present.

Pretty sure that is the plan now. pretty bummed about this actually.

[m16]

people pay extra for gadgets that do this! consider it a blessing!

Yeah, but when you need a mallet to close the receivers it might be a little too tight haha

I can't believe someone thought it was a good idea to make a blind hole for the bolt catch roll pin.

How the f are you supposed to get that pin out?

[Cummins_Powered]

Yeah, but when you need a mallet to close the receivers it might be a little too tight haha

I can't believe someone thought it was a good idea to make a blind hole for the bolt catch roll pin.

How the f are you supposed to get that pin out?

THANK you. As soon as i tapped it in i realized it was only going in and not out. Immediate regret on my part. and a few choice words...

[appagohm]

I saw the front take down pin and laughed my ***** off, sorry, just looked so wrong. what I would do is dermal down the takedown pin it's self so it sits flush with the lower, the bolt catch should be abled to be hammered out and redrilled as well. Good luck

[Niviticus]

I'm wondering if it was the cerakote that added a small layer of material to make everything fit too tight. Most 80% lowers I've worked with needed a little persuasion to work right. Not quite as bad as you have it but small issues.