Parts Compatibility for the DPMS 308

[slugger43]

I'm not gonna second guess the motivation.  I've done the 80% thing three times, and have another lower on hand to do.  Not the same as a "weld-up", obviously, but a few folks here made the point that 80% doesn't really save any money, and "why would ya?".  Best reason is, because I can, and I want to, and I get to gently poke a finger in the eye of the "regulate-you" bureaucrat freaks.

I'm all about egging on any gun nut.  Buy a finished 308AR, build one from parts, 80%, 90%, 100% or if you are really talented, grab a chunk of aluminum (or a bunch of steel plates) and have at it.  Just show me the pix..........and the targets.  And/or the carcasses.  

Jeez, lighten up!  Just my two rounds downrange........

[archangel2003]

A A appears to want a cheapskate way to build a functioning LR308/7.62X51 gas operating semi-automatic rifle using a $28 plate steel lower receiver weld-together kit.  Probably in order to make a Utube video to show off his home garage building skills just as he appears to have done with a AK 47 receiver.

Any recommendations for using modern method like a $59 1-13/16 taper tap or a  $1K MIG or TIG welder will shoot down his Cheapskate project goal..

Did any of you regulars see the Utube of the guy that did the video of the guy building a  a working .410 shot gun from black pipe with a hacksaw and a crackerbox ac welder?

This appears to me, to be in the same order of a deal, that is my 2¢ worth.

 

Cheapskate, or frugal?

Cheap is less expense with no regard as to quality, frugal is less expense while having as high a level of quality as you can attain.

And I am not at the point yet where the $59 1-13/16 taper tap purchase needs to be made, so it could still make it into the budget, however, if I can find someone who has one to rent locally, even better.

And the $1000 TIG welder will have to remain a dream for now.

But the intent is not to show off my home garage creations, BTW, if you watched any of my crap videos, you would note they were shot in the basement.

And I am in no way going to build anything like that black pipe monstrosity you mentioned, I am only fabricating the lower frame, all the internals and everything above the lower will be quality components, not high dollar custom flash, but of reasonable quality.

Instead of an 80% lower build, mine is more like a 10% lower build, and it will look reasonably decent and in no way an embarrassment

I'd highly recommend a long string for the testfire...........

I'll never underestimate what a good metalworker can pull off. I've seen some antique tools welded back together and finished off so well the naked eye would never know. The hours the used to do this were extensive though so it's a matter of what is your time worth when you assign the cheap label to a project like this. No doubt it can be done but WHY is the word that comes to my mind.

The upper, barrel and bolt carrier group will be standard items properly head spaced so why the long string?

Do you recommend the long string theory to those who build one with an 80% lower?

I hear ya, there's no "cheap" way to really do this - even "bottom of the barrel" parts are gonna cost several hundred $ to obtain

unless someone he known donates an upper and other misc parts. If he cuts too many corners I'm afraid someone will likely get hurt

firing this thing - if he hasn't already put some rounds through a 308AR he probably should so he will know what kind of forces his

project will have to contain - the thought of a BCG, buffer and tube getting launched into ones shoulder sends a chill up my back.

 

The AR-15  upper I got from RGUNS was deeply discounted as it had a blemish on it, otherwise a quality part, so $40 saved right there, granted it was not a color I wanted, but it will function as intended.

The 308 lowers go from $150ish to well over $200, so $125 or more savings there as well.

The stripped upper I got after a few week of looking was on sale for $121, but then a day after I ordered it I found one with the forward assist and dust cover for $89!

$30 I could have saved had I waited one more day.

I do not need top of the line free floating quad rails or any of that custom kitchy crap, I just want a "durable expedited lead delivery system" that wont break the bank.

.

[mrmackc]

Yep,  "If we see the pics we are believers,  otherwise it never happened,"

That is a quote from one of our oldtimers, on another thread,  by the way.

[archangel2003]

This plate steel version does look a lot better than some of the previous versions I've seen. Unfortunately, my welding skills look like Michael J. Fox trying to thread a needle. I look forward to seeing a finished product.... I reserve the right to talk shiit if you weld anything like i do. Lol. Chances are you don't if you're taking up this project.

That AK receiver I did looked like all hell after I was done welding it, but it cleaned up fairly good.

It still has some splatter pitting in the welded spots though so I'm hoping the parkerizing will help hide some of it.

[archangel2003]

Yep,  "If we see the pics we are believers,  otherwise it never happened,"

That is a quote from one of our oldtimers, on another thread,  by the way.

There will be pictures a plenty,with closeups of anything non-typical like the buffer tube welded and the retainer with a threaded hole going out the bottom for removal.

There is a possibly a couple of minutes of video with me fumbling with the welder here and there too if I feel like "showing off my basement creation".

[archangel2003]

It may not necessarily get to the point of a firing test in order to accomplish the primary goal of making a Utube video.

I do agree that an ingenious person can do creditable work with what appears to be antiquated tools. Just look at the accomplishment that "Carbine" Williams did while in prison in Texas before WWII without either the internet or Utube or a M2 Carbine forum web site. 

Took a quick look and will look further, Thanks for the interesting read lead.

[mrmackc]

I saw the one on Utube of the spot welds on the AK receiver. Is that a flux core wire welder or a Mig? I have a Lincoln Wire welder with Mig in my shop, I have used it with Flux-core and also Mig steel and also aluminum, I found that Flux-core is very nasty , more smoke than using a stick welder, it is hard on an old codger's lungs. for me wire fed welding, t is easier to weld with than a stick welder by far. Have you ever used a Dillon Henrod 2000 torch?

[survivalshop]

        Wonder what the weight of the completed rifle would be , we get regular complaints of a 12# rifle being too heavy & thats with normal Aluminum Receiver . 

      What do you plan on using for an Upper Receiver, Barrel , BCG  ?   

[jtallen83]

The upper, barrel and bolt carrier group will be standard items properly head spaced so why the long string?

Do you recommend the long string theory to those who build one with an 80% lower?

.

I have to question competence when one dives into welding a receiver for a weapon that they have not researched enough to know the difference in charging handles, and no all 308AR charging handles are not the same but the vast majority would be compatible with your "DPMS" version.

Back to my question, Why? Is it just to see if you can make it work or are funds that tight? The answer to this question could have bearing on future questions. 

[survivalshop]

 I am waiting for the end results , talk about a true Franken gun, this would be it , body parts formed to make it alive ! ?

[EasyEJL]

And the $1000 TIG welder will have to remain a dream for now.

But the intent is not to show off my home garage creations, BTW, if you watched any of my crap videos, you would note they were shot in the basement.

And I am in no way going to build anything like that black pipe monstrosity you mentioned, I am only fabricating the lower frame, all the internals and everything above the lower will be quality components, not high dollar custom flash, but of reasonable quality.

Instead of an 80% lower build, mine is more like a 10% lower build, and it will look reasonably decent and in no way an embarrassment

The upper, barrel and bolt carrier group will be standard items properly head spaced so why the long string?

 

.

you should be fine. plenty of other people have used those lowers. it is a pity you're doing it with the flux core, but it will still work. just be cautious if you are grinding it down to clean up after that you don't grind to the point of weakening the welds. At least with these, the primary angle of force isn't along where the welds would pop. Really not that much force on a lower anywhere except at the buffer tube attachment. I would recommend welding the castle nut in vs threading too

[archangel2003]

        Wonder what the weight of the completed rifle would be , we get regular complaints of a 12# rifle being too heavy & thats with normal Aluminum Receiver . 

      What do you plan on using for an Upper Receiver, Barrel , BCG  ?   

The only part not standard is going to be the lower, and yeah, it will be a little heavier than an aluminum one, but I have no intent to be hiking the back country with it.

I have a Sears Model 53 (Winchester model 70) in 30-06 if I want to hunt.

When I get them together, I'll weigh them with nothing attached so we will know the difference.

[archangel2003]

I have to question competence when one dives into welding a receiver for a weapon that they have not researched enough to know the difference in charging handles, and no all 308AR charging handles are not the same but the vast majority would be compatible with your "DPMS" version.

Back to my question, Why? Is it just to see if you can make it work or are funds that tight? The answer to this question could have bearing on future questions. 

I had assumed they were different as the size is different, but I also read where a lot of the AR-15 parts are supposed to fit in the DPMS 308, so wanted to see if anyone knew.

Funds are tight, but it's also to see if it will work.

I now have everything for the AR-15 except the BCG and the barrel so will be welding it soon.

I have a couple of dusty poly AR-15 lowers so if I screw it up, I can still use the parts ordered to build the gun.

The higher cost of a completed 308 AR is an issue and I enjoy fabricating.

 

[archangel2003]

I saw the one on Utube of the spot welds on the AK receiver. Is that a flux core wire welder or a Mig? I have a Lincoln Wire welder with Mig in my shop, I have used it with Flux-core and also Mig steel and also aluminum, I found that Flux-core is very nasty , more smoke than using a stick welder, it is hard on an old codger's lungs. for me wire fed welding, t is easier to weld with than a stick welder by far. Have you ever used a Dillon Henrod 2000 torch?

Those Henrob torches are super nice.

A friend loaned me one that had a little water damage and after cleaning it, I completely destroyed my first AK receiver weld attempt with it.

It was so bad I cut it up for practice and patching.

I guess once I used a MIG, I've not bothered to improve my skills with any other type of welding equipment.

Yeah, F.C.A.W splatters like crazy unless you get the adjustment just right,(and still splatters) but I use splatter guard and often have to grind down the excess weld buildup anyway.

In the summer I weld just inside the open garage door and the winter it's the basement window well.

The first MIG I used was a Millermatic 250 and was what made me get one of my own

I welded everything from throttle and wiper linkage to frame rails.

However, when away from the shop, the thought of lugging a bottle around and having issues with the wind blowing away the gas was too much.

I found that the smaller wire works better.

I also use short pulses (1/2 to 3/4 second) every 1/2" or so at a higher power level than used for running a straight bead on that gauge of metal works well without overheating the work piece.

For the AR lowers, the metal is so much thicker I'll probably turn the power up much higher than I used on the AK.

The short pulsing almost needs the flux core as the gas would not give steady coverage for so short a time on the trigger.

 

[EasyEJL]

 

I had assumed they were different as the size is different, but I also read where a lot of the AR-15 parts are supposed to fit in the DPMS 308, so wanted to see if anyone knew.

 

 

there's only a few lower parts that are different, the trigger/pins, safety, detents, buffer tube, castle nut are identical but mag release, bolt catch are different as is the buffer + buffer spring. On the uppers the only piece that would be the same is the forward assist.

[archangel2003]

I was looking up BCG's and barrels and saw something listed as being NTF coated and can't find any info on what that is.

They list a bunch of different BCG coatings and what they are except that one.

[archangel2003]

Looking for BCG/s I saw a lot of cheesy looking ones out there.

I did notice that they did not have one that was lightened with round holes that also had a white coating (for the Swiss), or perhaps one that was white with random sized blue flecks (For the French).

[mrmackc]

Who was it that offered the NTF coatings?

Lightning holes would be against the needed weight (mass) for a .308 BCG. Why not just buy a complete DPMS upper?

That way is probably the way to be assured of a matching upper, since you are not building a true AR 10 rifle.

[archangel2003]

Who was it that offered the NTF coatings?

Lightning holes would be against the needed weight (mass) for a .308 BCG. Why not just buy a complete DPMS upper?

That way is probably the way to be assured of a matching upper, since you are not building a true AR 10 rifle.

Well, I need to piece it together as the funds become available and want to build it myself.

I'm also building an AR-15 at the same time and am focusing on the lower assemblies first.

[mrmackc]

Well, I need to piece it together as the funds become available and want to build it myself.

I'm also building an AR-15 at the same time and am focusing on the lower assemblies first.

OKAY  it will probably increase your costs above 50% and the reliability of piece by piece compatiability of components when you don't know much about building a LR308.

and the subject of NTF coating of the BCG?

[shepp]

OKAY  it will probably increase your costs above 50% and the reliability of piece by piece compatiability of components when you don't know much about building a LR308.

and the subject of NTF coating of the BCG?

some kinda nickle Teflon coating, doing a quick Google search everything I can find comes up on foreign sites, one in some kinda Asian writing.

 AA: don't take this the wrong way but being on a budget why not try doing one first (I'd recommend the ar15). then when you get that running proper try your Hand at the other? At least with the ar15 your going to have a mil spec standard to follow and a bit cheaper build price? 

[archangel2003]

some kinda nickle Teflon coating, doing a quick Google search everything I can find comes up on foreign sites, one in some kinda Asian writing.

 AA: don't take this the wrong way but being on a budget why not try doing one first (I'd recommend the ar15). then when you get that running proper try your Hand at the other? At least with the ar15 your going to have a mil spec standard to follow and a bit cheaper build price? 

That is the intent as I have both types of lowers to weld, and I already have a serialized poly AR-15 lower as a fall back if I screw up the weld together one.

I'm ordering parts for both as I find them and right now for the AR-15 all I need is the BCG, barrel, gas block/tube, hand guard and some sort of muzzle attachment.

Other than those parts listed above I still need for the 308, a charging handle, lower parts kit and barrel nut/parts.

[MikedaddyH]

Found this on my hard drive from May 2015 , may be it will be useful.??

[archangel2003]

I have the first 2 but the third is new to me.

It looks like a low profile gas block.

Do you have a full sized version of it?

[ChaseFan9]

Found this on my hard drive from May 2015 , may be it will be useful.??

How do you increase resolution on those pictures?  They keep showing up super tiny for me.
That 3rd one looks kinda like one of Toolndie's prints....