Guns, Bows, Shooting Sports, and Hunting So, you're looking for advice on your first AR...

[Sticks]

I have not done a great....well...any research into the differences between forged and machined. Our mighty Cummins is a forged/cast block, and only one series had a casting flaw that made a ripple in the reliability out of all the ones out there.

A billet is machining everything from....a forged/cast/extruded block of the same material. Might be a touch stronger, and if I were shooting a .308 mag or larger cartridge in an AR platform, I might want something that is that touch stronger.

Now regarding the "weak" points that you mentioned. If both types are to MIL spec dimensions, then billet or forged, they are the same strength wise, given that the material is the same. When the upper is mated to the lower, there are two pins holding it together, full contact along the mating surfaces, the force against the pins is shared with additional backing by the upward curve of the RE, and the force against the RE is linear. In respects to those that have the proprietary parts (forged or billet) - they usually have made the ears for the pins thicker, as well as the RE mount, ergo making them a touch stronger. As much as I hate engineers, they have put a great deal of design and testing into this and evidently it works - so forged is the standard.

Having said that, a quick google search yielded some conflicting info on this. I'll summarize it by saying it comes down to aesthetics and $$$ insofar as custom features, and appearance.

Bottom line is they are both aluminum, are subject to getting deep scratches, areas where there are moving parts will wear fast, and can bend/deform or break under the correct circumstances. This is why we take some care in assembly, don't use them primarily as clubs, hammers, pry bars, and keep them lubricated.

The Vltor upper as far as I know does not have any proprietary parts in the Forward assist or dust cover. The big difference is the thickness of the upper towards the front where the barrel mounts, and the entire left side of the receiver. There have been isolated reports of some free floating handguards/rails on the market not mating up to the receiver. That is the only point that I would contact Diamond Head and inquire about that prior to purchasing if you have decided on that handguard. Regardless, I'd stick with the Vltor.

If I was swimming in money, then I may go with a billet lower, upper, or mated set just because I can. All I would have is a Ferrari that shoots just about the same as the bulk of the sedans at the range.

 

[GHarman]

Sticks!
Hmmm, The last comment that you made really makes me think about using the AERO Lower in the first build!
PS, Brownells has them on sale, this weekend. http://www.brownells.com/rifle-part...1&spJobID=182661164&spReportId=MTgyNjYxMTY0S0

All I would have is a Ferrari that shoots just about the same as the bulk of the sedans at the range.

Now, you understand, that I have some metallurgical background from a welders point of view and a long time rifle nut! Some formal, work related classes, notwithstanding:-laf!
I do take issue with the thought that the grain pattern is similar between a forging and billet. I can tell you that billet starts as being molten and poured into a mold. Then it is rolled into shape. For all practical purposes the grain is linear and not well refined(depending on how many rolling mills it had to pass through). Forging starts with a billet which is further hammered into a final rough product shape. This refines the grain structure and changes the orientation of the grain. That being said? I am not privy to the manufacturing process, but can tell you that I have serious doubts that the billet is stronger than forged, given similar dimensions. Aluminum alloys such as 7075 T-6 have special heat treating and aging process on top of the grain reorientation and work hardening during forging. A machined billet is not work hardened to the degree that forging allows, and the heat treatment is, as it comes from the mill, in raw billet form. The Anodizing process creates the hard aluminum oxide surface coating that protects against premature wear, but it is in fact a very HARD abrasive, in itself. Aluminum Oxide is used to make grinding wheels. It also melts at (2054 *C.) about 3X the temperature of the base aluminum. Now 7075 T-6 is not considered a weldable alloy. But some Billet receivers are made of 6061 T-6. I have worked with this alloy, extensively and can tell you that I would never consider a receiver made from this soft aluminum. In spite of being T-6 solution hardened. Heres some technical data on each material (Which does not consider billet vs forging).

http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA7075T6

http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA6061t6

Without metallography, it is more difficult to discuss the benefits of forging.
Now this is IMHO, based on want I know! If I am wrong, Please feel free to correct me! That benefits everyone!

Engineers vs common sense, reality and practical application. They should be inclusive. The difference is that an engineer can (in theory) describe, through Physics, Mathematics and Chemistry, what exactly is going on! Some are brilliant people. Some are not! I have worked with both!
GregH

 

[GHarman]

A PS on the above;
I did a little research and believe that die forging is the most likely the process being used for forged receivers.
Certainly not the mental picture some have of a traditional forging operation.
Here is a good article that speaks about the "grain orientation" and other advantages. However it is a little lengthy!

http://www.aluminumprecision.com/what-makes-a-good-aluminum-die-forging-candidate/

GregH

 

[Sticks]

Greg,

A well respected member posted the following on another forum that I belong to, and I am going to pass it along. It does not apply so much to the question of Billet vs. Forged, but there is some very accurate info that I could not have said better if I had spent a month trying.

I try to explain this about forging a every time it comes up so some truth can be spread...

there are only a few forgers used for upper receivers and lowers, similar to how only a handful of companies make barrels. But, this in no way means they're the same.

Yes, they're often from the same place, but each rifle manufacturer will have its own specs it will allow through, and often times each manufacturer will do the finishing themselves, like drilling the holes.

So, let's just say Colt, Noveske, RRA and DPMS all come from the same place (which they don't, but for sake of explanation....)

Colt will adhere to the TDP and will have a certain allowed spec that wil pass QC. This way, all uppers and lowers will work together without issue.

RRA will have theirs finished, or finish themselves, to considerably tighter tolerances. This is why I've personally seen at least three RRA lowers that would not work with every upper... And also why a buddy that SBR'd his RRA lower then finally mated his LMT upper to it after getting his stamp had major issues with reliability. His upper worked on both of my lowers and a few others we tried that friends owned. He eventually found a solution, though time consuming and costly.

Noveske will ill be more in line with Colt, but what passes QC will often be even more strict, which is why Noveske lowers have a slightly more precise fit. Not RRA tight, but of 100 lowers, they'll almost all fit exactly the same where some colts might have a little less or a little more play. (For the record, a little receiver play is NOT an issue and can be a benefit for reliability).

DPMS (and most other hobby grade rifles like Bushmaster, Olympic, Model 1, etc) will have much looser tolerances and most anything will pass QC. This matters little when buying a complete rifle but can be an issue when using multiple lowers. Unlike the others, these hobby grade manufacturers, for lack of a better explanation, will have a pallet of uppers and a pallet of lowers. Those that are out of spec lowers will be matched with out of spec uppers. While these may still work with in spec receivers from other manufacturers, they also might not.

Look at FN barrels, which companies like PSA, BCM and Centurion Arms use in their rifles. They all come from FN but they're different quality barrels. Centurion uses a completely different profile with a straight taper and double chrome lining. These are some of the best CHF barrels on the market, similar to Noveske and have a service life up to four times that of other manufacturers.

PSA and BCM will look the same on the surface and will perform similarly. PSA has (or had, maybe not any longer) less strict QC and barrels that wouldn't pass BCM might have passed at PSA.

Regardless if a lower comes from the same place or not, it means very little in terms of quality. It is understandable to think that a lower from DPMS or Bushmaster and a lower from Noveske or Colt will be the same thing. But they are not. It may not be a major issue when buying a complete rifle, but it may become an issue when using other uppers on that lower. Or, the pins might start to walk because the holes are slightly out of spec, are at a slight angle, not perfectly round, etc.

Stick to a quality lower, and most possible issues will be avoided. Price is no excuse here because a PSA lower can be had for less than just about anything. You can always swap out the pins and trigger with better parts, but you can re-drill the holes in the lower.

 

[The patriot]

i'm pretty sure surplus ammo has them on sale too.

 

[GHarman]

Well, I did pull the trigger on a BCM Bolt Carrier Group, today!
GregH

 

[GHarman]

i'm pretty sure surplus ammo has them on sale too.

Yes, with discounts for quantities as low as $194.99 for 3 units.
Still discussing and thinking! Like Sticks said, in the beginning of this thread; "Pay once and cry once" or I am not independently wealthy:-laf!
GregH

 

[The patriot]

http://palmettostatearmory.com/inde...lower-and-ptac-blackhawk-lower-parts-kit.html

http://palmettostatearmory.com/inde...wer-magpul-moe-edition-black-no-magazine.html

http://palmettostatearmory.com/inde...y-ar-parts/psa-blemished-safe-fire-lower.html

http://palmettostatearmory.com/inde...ay-ar-parts/ptac-stripped-upper-receiver.html

 

[Sticks]

If you were going to jump on a lower, that PSA Blem lower is the one, do it now and as many as you can afford. Often the "Blemish" is "Where, cause I can't see it". Strictly cosmetic, not a failed QC matter. Even if it's a scratch in the finish - if it's used like it was made to, it's gonna get scratched.

Getting back to the Billet vs. Forged question -

I get that there are grains in the metal, and that forging aligns them better than what you would find in a chunk of billet stock. I don't know at what point though that the numbers in strength would make a difference in the application. Maybe it's a matter of repeated stress/shock from firing that would bring out the differences, though I suspect that that number of firings would be north of 20k before you would potentially be at that weak point where side load [READ ~ force in a direction other than designed] on a smaller part (ear) may fail.

I have a fairly decent ability for spacial visualization, and all the smaller tabs and ears that may be potentially at risk, are backed by stout material when designed force is applied.

 

[GHarman]

Just received the Bravo Co. Bolt Carrier Group. Bought the upgrade extractor spring and pin kit.
I don't understand, what is the purpose little neoprene o-ring? Have a spare? with the BCG, also
Looking at lower receivers, this Morning.
Have my mind set on the forged Seekins. Will get a price, today. If not? The shop in Arvada, on Wadsworth, has the Aero's.
I missed the PSA sale with the transfer procedure. To much other stuff going on. Maybe another time?
Greg

 

[Sticks]

Are you going carbine length gas system or mid length? (I recommend mid length)

If Carbine, you may need the o-ring on the extractor, otherwise put it in storage.

Bummer you missed out on the PSA sale. One of those need to keep an eye on them every morning.

They still have their stealth lowers, and pictogram lowers. $89
http://palmettostatearmory.com/index.php/featured/psa-stealth-lower.html

Lots of Grip/LPKs on deal, some of them with Geissele triggers at a smoking deal. SSA-E LPK kit for $230

So you still need to choose receiver extension, stock, barrel, and commit to a handguard/rail and barrel assy. and some strays. A long way to go now that I think about it.

If you can find one, I'd recommend the Vltor A5 system for the receiver extension & buffer. You can put any milspec stock on it, just can't collapse all the way, which is not a big deal unless you have itty bitty arms and need to be in position 1 to shoot.

 

[GHarman]

Here it is, 10 December and not much coming together.
Today, I did call Ruger on my SR556.
Decided its no use to even waste time or running ammo through it!
I am not going to accept it the way it is! I requested a refund!
I'll be digging up my receipts and making copies.
Need to write a letter, to include with the rifle, to explain why this particular firearm does no deserve the Ruger label.
Why, unauthorized changes to the configuration and substituting inferior/used accessories for the original new components and leaving
dings, scratches and other handling marks that were not placed there by the owner, really constitutes the lowest form of customer service I have ever endured,
except at the hands of our local Dodge dealer!
From what I gather, from other Ruger owners, this is a unusual occurrence.
Well, we shall see how they respond to this third and last Repair Maintenance Authorization! They even gave me a new number!

So, the next purchase, I am looking at, is the Upper/lower receivers.
I was recently introduced to JD Machine Tech. The lower is forged, mil-spec with tighter tolerances.
Upper the same. What do ya think?

http://www.jdmachinetech.com/product/223LWR/223LWR.html

http://www.jdmachinetech.com/product/223UPR/223UPR.html
M-4 of course.
GregH

 

[Sticks]

WOW - Sorry to hear you are having such a horrid time with your Ruger. I did not know you were having to send in back in yet again. Hopefully they will buy it back.

JD Machine - I wonder if that lower comes with the 50% LPK as shown in the pics. As I noted in a quote earlier, they probably buy base lowers from one of the manufacturers and do the finish work. I've never heard of them so final specs are iffy. IMO - stick with a PSA, BCM, maybe Areo or Seekins (sp - too lazy to scroll up to verify).

PSA is still showing their brand lowers in stock, for much less - and I have never heard of any quality issues with them as far as parts fitting or mating up to uppers, and there is a metric crap load of them out there. I'm running 2 of them and have a combined total of over 8k rounds through them problem free - though it is just a lower and all it's really doing is holding the upper, receiver extension, and FCG. Having said that, I had no problems assembling either of them. Holes were in spec (not too tight, not loose, in line, and nothing is backing out (pins will back out under use if the holes are not drilled correctly) or coming loose.

I'd stick with the Vltor upper receiver. Thicker, can't beat the quality.

 

[GHarman]

Sticks!
Thanks for your reply.
Got the UPS scheduled to pick up tomorrow.
They are gonna ship it by air! The call center Folks at Ruger were really good to work with. I must give credit where credit is due!

Yes, I am sold on the VLTOR MUR upper. However no one has them in stock, including VLTOR.
Probably go with the AERO on a carbine build. Would like to use the SEEKINS lower on a "designated marksman/varminter" build.
Cant find BCM lowers. PSA is a possibility. Right now working on financing the build(s).
GregH

 

[HHhuntitall]

GHarm, got some scuttlebutt on the JD Machines earlier today.... Stopped by a friend's house, he's a retired grunt and retired LEO.... he's got two of the JD Machine lowers, and they're pretty tight.... Even the mag wells are tight, which was his only negative comment.... some mags fit too tight and don't fall freely.... Every upper he's put on them has fit extremely tight, and he said a friend's LMT wouldn't fit, as it was too tight, too.... Sooooo, thought I'd forward the words..

Also, I recently got to play with some Core15 lowers, and they have functioned flawlessly. I put together several lately, and other than the generic DPMS trigger groups, they've all worked perfectly. Combined with an EGW or Aero precision upper receiver, they've all been tight. I've hesitated to comment on the Core15s until there have been some rounds downrange, but after 120+ rounds in mine, plus various others, I'm pretty happy with them.

 

[GHarman]

Thanks HH! Thats good information!
Now to find an FFL dealer that has the proper accounts with these manufacturers.
The dealer I have been in contact with has the Aero lowers in stock, but no uppers. I understand making a profit. $120 is $40 more than Brownells cost to me!
But it costs $30 to receive on their FFl plus the Colorado $10 2nd Amendment violation fee.
If I was to get the JD machine lowers? I would get their uppers, also. Same with the Aero precision.
The Seekins lower is the one I thought would be a good fit/use for the VLTOR MUR upper.
Waiting on the Ruger decision.
GregH

 

[Sticks]

Vltor upper http://www.gandrtactical.com/cgi-bin/commerce.cgi?preadd=action&key=MUR-1A

BCM Complete lower http://www.gandrtactical.com/cgi-bin/commerce.cgi?preadd=action&key=LWR-BCM-FDE&reference=/cgi-bin/commerce.cgi%3Fsearch%3Daction%26keywords%3Dlower%20not%20follower%26searchstart%3D27%26template%3DPDGCommTemplates/FullNav/SearchResult.html

and

http://www.gandrtactical.com/cgi-bin/commerce.cgi?preadd=action&key=LWR-BCM&reference=/cgi-bin/commerce.cgi%3Fsearch%3Daction%26keywords%3Dlower%20not%20follower%26searchstart%3D0%26template%3DPDGCommTemplates/FullNav/SearchResult.html

Greg, I don't mean to pry, do you have some bias towards PSA? If it's because they don't have your preferred FFL on file, you can have your FFL fax their license over, unless they refuse to do business with them - in which case I would find another FFL to handle the transfer. I use G&G guns on Colfax in Lakewood, and though it's been over a year since I was in there, they were really reasonable about the transfer fee. The only bad thing that I know of with PSA, is that they do take a while in shipping. It's a hit or miss kind of thing, I've learned to live with it. Figure on at least 2 weeks from time the order is placed, even though they "create the shipping label" right away and send you the tracking number, it's just part of their order process.

HH's statement on the JD Machine would be enough for me to steer far away from any of them. Tight is a bad thing. Especially in the mag well. You don't want a lower that only takes one type of magazine. Worse would be to get a lower that you can't get an upper to mate up to, particularly if you get more than one (Lower as the base shooting platform, one upper for precision/varmit 20" barrel, a second for HD/SD/SHTF 16" barrel). Another reason to stay away from mated pairs [uppers and lowers] - that smacks of they kept trying different uppers to see what fits on the lower or vise versa.

I would not be too picky on a lower unless you are going into competition, where the only thing would be a flared mag well. Otherwise, all things being equal (properly machined) it's the receiver extension, grip, and FCG that you install that makes the difference. Ergonomics and either a hair trigger, or standard MIL 4# pull. The upper is where the duty comes in, and then it's the barrel and BCG. Otherwise it's just another housing ~ all things being equal (Vltor being thicker and I'll go with less likely to have any recoil flex) where the components that you install make the difference.

 

[GHarman]

Sticks!
Thanks for those links!
NOW I could go for a BCM Lower!
The VLTOR MUR in your first link is "Not in Stock"!
Yes, G&G Guns and one other are the alternative FFL's.
I just might go for the BCM lower, just to get an AR, in hand!
I'll make some calls when I get home later, this Morning!
Thanks!, again!
GregH

 

[Sticks]

Vltor upper - Oops, missed that one - sorry. I'll do some more searching tonight or this weekend. Several on BuyItNowBay, but they are in the low $200s. Might hit Gunbroker.

 

[The patriot]

Good luck in finding a BCM lower.
I believe they only make them for their complete rifles.