Why are modern AR10 pattern rifles so much heavier than the 50's originals?

[Aries144]

ArmaLite's Dutch AR10s, made in 57-58 or so, were between 6 and 7 lbs and are reportedly capable of sub minute accuracy (according to Mr. Knight). Why is there no modern equivalent with a 1913 rail? Most available models weigh in excess of 9 lbs and the "lightweight" versions (still in excess of 7 lbs) seem to display mediocre accuracy.

What changed? Why so heavy? Why such difficulty producing accurate lightweight barrels?

I don't buy that this is some sort of lost art. Examples of Dutch and (possibly?) Sudanese AR10s exist in the US. It wouldn't have been hard to copy them. Changes were made for some reason that lead to the rifles' increased weight and the only things I can think of are patent issues, production cost issues, or possibly durability issues discovered later in the originals that could only be addressed in a way that added weight.

Does anyone here know more about why modern AR10 type rifles are so much heavier than the 50's originals? Any books or videos that cover the subject?

[SteyrAUG]

Last time I held a Sudan it was about 9 lbs. and not much lighter than a G3 or FAL.

[Defaultmp3]

Does anyone here know more about why modern AR10 type rifles are so much heavier than the 50's originals? Any books or videos that cover the subject?Most modern AR10s are in a large-frame format; small-frame guns are just over 7 lbs., such as the DPMS GII or Mega SF-MATEN.

I'll note that I've heard arguments from fairly experienced shooters that a .308 semi-auto rifle being too light makes the recoil excessive. As our own Failure2Stop said:


From a performance standpoint, I don't like getting under 8lbs with a semi-auto 7.62 if I am going to shoot it much. There is a definite advantage to some weight in soaking up recoil. A decent multi-purpose compensator will help, but there's still that whole suppressed use part.Source: https://www.facebook.com/groups/PSPrimarySecondary/permalink/1139701132743052/?comment_id=1141064562606709 (private group)

[nova3930]

I'll note that I've heard arguments from fairly experienced shooters that a .308 semi-auto rifle being too light makes the recoil excessive. As our own Failure2Stop said:

Physics. It's not just a suggestion, it's the law lol :D

[Firefly]

If it were the 50s, yeah an AR-10 but really I think some of the "lightness" came from thinner barrels and bakelite. Hence that big comp on the Hollywood(?) AR-10s.

My ECC weighs less (to me) than my HK91.

I don't think AR-10s are a lost art at all. Look at the SR-25. If historical value were not an option, I'd sooner take an ACC into a murky unknown than any of the legacy AR-10s.

Seriously, that ACC is crazy light but I dont have anymore organs to sell and gigoloing is kinda slow right now.

But someday...until then I suppose my ECC will have to suffice

[Digital_Damage]

Never heard of a 6lb flat AR10, most were closer to 6.9lbs and that was the composite barrel that was blowing up.

The 7.2lb small frame were mostly polymer.

The URX 3.1 7.62 alone is 1.7lbs.

So if you were to swap the polymer handguard for a URX 3.1 you are in the ballpark of a the 8.4lb modern SR25 ACC.

[MountainRaven]

I seem to recall that the Portugese had reliability issues with the early AR-10s, and the weight is a result of the fixes.

[Falar]

The trigger style charging method and side-mounted gas tube sure were different than what I'm used to.

The .308 ARs of today are more like up-scaled AR15s than the original AR-10.

[JC5188]

My ArmaLite weighs 8lbs with irons only, which is how I keep it. Adds less than .5 lbs when fitted with my inforce.
25 rd mag loaded adds another 2 lbs


Sent from my iPhone using Tapatalk

[Dienekes]

I'd have to check, but a few years ago I got to shoot an original Armalite 7.62 offhand (I think it was a Portuguese) and it hefted about like an M&P 10 with irons only. Not heavy, but not all that light either.

[Moose-Knuckle]

Unloaded and without glass my DD5v1 comes in at 8.3 lbs.



Some of you might find this video of interest . . .


https://www.youtube.com/watch?v=0kH_l83mDkQ

[Hootiewho]

The APC/ECC is where it is at. Just the right mix in weight and robustness. I've seen several examples of the ACC that didn't quite do what I felt they should precision wise when you consider the price (even LE/Mil price). If I were buying one again today I would get an APC, shoot it 100-200 times, then send it out and have the barrel nitrided/melonited. < which ever type treatment is best.

I used my APC to snap shoot a running deer while I was hunting last year. I had just topped off a scrape dripper in front of a trail cam I had out, and had the rifle slung. Buck came barreling by me wide open, about 35 yds or so away. I had no problem at all getting the APC up and dropping him while he was wide open. Cool part was the trail cam caught the action including the impact shot. You can actually see the bullet exiting and puff of hair out the exit side in one of the pics. I had a MAMS on it and the scope stayed right on the deer during follow through. This happened in a flash, no warning. I honestly don't think a 6-7 lb 7.62x51 would have stayed on target even with a MAMS. That said, I have since picked up a MR762 and I am extremely pleased with the precision I have been getting with that package especially with Hornady 178gr BTHP Match. To me it feels very similar to the APC in handling. There are some great options out there now days that in many ways you cannot go wrong.

I'll try to find the series of pics the cam caught this evening. They were up on the cuddeback site last fall.

[Aries144]

Great info guys, thank you.

I haven't personally played with a 7.62x51 that was lighter than a SCAR17S, so the input on recoil is appreciated.

Hootiewho, link away sir.

[Aries144]

Ok, so the AR10 went dormant until 1993 when Stoner got with Reed Knight and designed the SR-25. It looks like Reed Knight would be the guy to talk to about design changes affecting overall weight.

http://www.sadefensejournal.com/wp/?p=2418&page=2

[Moose-Knuckle]

Ok, so the AR10 went dormant until 1993 when Stoner got with Reed Knight and designed the SR-25. It looks like Reed Knight would be the guy to talk to about design changes affecting overall weight.

http://www.sadefensejournal.com/wp/?p=2418&page=2

That was a good read.

[Aries144]

Found this. He looks like a good source for study-quality firearm books too.

http://www.historicalfirearms.info/tagged/ar10

http://www.historicalfirearms.info/post/124606840864/the-portuguese-ai-ar-10-during-the-late-1950s