80% lowers ?

[msinc]

Yes I understand you have to tear them down for cleaning(obviously) but I didn't think you meant take down pins as much as the two trigger group pins. But what you are saying does make. And yes I know after awhile you should strip them down to clean the trigger group. You said you could send them out to be hardened, what does it cost? And I wonder about going to over sized pins as the originals ware out. I guess I am just used to doing things myself and am really big on doing one because of that and someone told me it was to hard to do unless you were a good machinist with all the tooling needed! But like I said I see what you are saying and can see it happening.

Yeah, I mean, go ahead and do one...I get it. I did and it works fine. Although I am a machinist by trade, you certainly do not have to be a machinist by no means to do this, let alone "good" machinist. There is something to knowing that you can make your own part without being interfered with by anyone and have it work okay. As others have said, you don't necessarily need to try and shoot hundreds of rounds thru the thing. I think for most people it is a thing where they build it to see if they can and when it works put it away for another time, such as when needed. I seriously doubt that too many guys are using home finished lowers on their main target/hunting/calling/all around fun gun/home defense rifle.
You have to watch which one you buy...some do not require any milling machine, but some others require the tap to cut the thread for the buffer tube. If that is the case you will need a $75.00-$100.00 tap!!! The ones that just need all the holes drilled can be laid out and drilled by hand and they will work fine, but they are easier done with the drilling jig which costs more. I guess my point when you asked about people being down on them is that for the money vs. effort and finished product it just don't make sense to finish one unless you are a convicted felon and need a gun that goes bang.
The accu wedge works and it will tighten up the slop until it wears out more. They are only like $4.00 or so to buy. I guess the bottom line is that you could do one and have it nice and tight, the rifle could shoot really well for quite a while. But I wouldn't count on that and there's a better chance that if what you want is a nice shooting AR you would be better off to buy a good lower.

 

[hunter243sgk]

I see what you are saying and I agree it might not be the best route to go. But I do think I will do one thanks for the info especially on what to look for when getting one as I didn't know they were that different. Also I saw one jig kit that had a milling bit that was to be used with a router. Does that sound like a good idea to you. You being a machinist would know way more than I. But me being a carpenter and drywall man I am used to using a router. If the bit can be used in a router I can see it working better than me using my drill press and cordless. And if I remember correctly you can get the ones at Midway anodized or in the white for not much price difference. Thanks again!

 

[msinc]

I have never tried to cut aluminum with a router. That said I have cut many metric schitt tons of it with other wood cutting type tools and machines...tablesaw, bandsaw, etc. It might work, I cant imagine someone selling you something that wont do it or worse, be dangerous.
As far as buying an 80% lower already anodized, well, it's better than in the white. But, the critical areas that need it wont have it as you will be drilling them out and having holes that are bare unhardened or otherwise "treated" aluminum. The other drawback to already having a finish is that it might {most likely} will get scratched up in the milling/drilling process.
The worse ones are the ones that do not have the magazine well cut out...that is about impossible to do and get to look right at home. Next in line would be the ones that don't have the top line where it curves up in the back for the buffer tube cut to spec. That is also pretty tough to do without some pretty decent equipment. The ones that just need all the holes drilled and the trigger/hammer well milled out are about the easiest/best. Again, make sure the buffer tube hole is threaded already...that big tap is not cheap...it's not exactly something you run over to Lowe's and grab up on either.

 

[carlsbad]

This being a gunsmithing forum, I would expect lowers to be made with a milling machine. the templates are for amateurs and result in a product that most here would be ashamed of. The cast lowers (often sold as forged) should be avoided. The billet lowers machined from 7075 are generally very very good. The amount of work for the experienced machinist isn't much. The strength of the 7075 is good but if you're planning on putting a gazillion rounds through it, then anodizing is readily available.

You won't save a lot of money but if you prefer to make your own, you can create a top quality product.

--Jerry

 

[Larryh128]

I have looked at them when parts were scarce but I've never seen 1 that was cheaper than I could buy a stripped lower for. Any day of the week I can buy an Anderson stripped lower for under $50. They aren't a billet but they work very well for their intended purposes. One of the companies that was selling 80% lowers had their records seized by the ATF, so it kinda makes that point pretty mute.

 

[SheepDog]

If the pin holes are a major concern then you can make bushings from aluminum bronze or stainless steel sweated in place and use pins of an appropriate length to compensate for the bushings. It's not rocket science but it is adaptable.

I wondered why the lowers were not made in steel until I got my first AR. They are heavy enough with aluminum. The problem that I see is that aluminum and its alloys will eventually fail. There is no process or finish that will keep fatigue from affecting it.

Fitting new, larger diameter, pins to restore the fit is what was done on rolling block actions to compensate for wear and it would work with uppers and lowers in the AR platform too. I think fitted bushings that spread the load over a larger area is probably the ideal repair.

 

[carlsbad]

Designed for military field use, it is considered a consumable.

 

[mr45man]

Designed for military field use, it is considered a consumable.

As were the poor souls that had to rely on them.
God bless them.

 

[Fast14riot]

I have done 6 so far, my service rifle is built on one, a couple "lead hose" builds have been done on them, varmint lower and still have a few sitting around. Getting good fit between fcg pins and the holes is important, or just use drop in triggers with KNS pins.

I've done in the white and anodised. I do mine usually like a colt lower and leave the bridge in. It doesn't save any money, but when I can buy multiple at a time and ship to my door, have a couple done and built in an afternoon without the hassle of 10 day wait, DROS records, and other associated BS that PRK likes to issue, it's worth it to me.