I just completed a four day TMACS/Pat McNamara course using the Ruger SR-762.  800 rounds fired over the duration.  No broken parts and no unusual signs of wear.  

I'll try to go through my notes and get a class review put together.  I do have a couple photos (none of me shooting the Ruger) that I'll sort through and get posted.  Probably under a new thread.

ETA:  I just got my rifle back from Ruger and it is like yours.

I picked up the 561-07xxx rifle photo'ed above. It came with three Gen3 mags all still sealed in plastic.

I will see if I can't take some photos of the seated mags with ammo in relation to the feed pawls on the bolt but I can tell you the rounds sit noticeably higher in the new gun.  In the old rifle, just the bottom 25% or so of the bolt was making contact. In the new rifle it is more like 50-60%. This should help explain why many of the early rifles have bolt over base malfunctions since it looks like the rounds hitting the feed ramp are probably camming under and away from the bolt as they travel to the chamber.

I still need to give the new rifle a good workout with BTHP, SP ammo, etc but I'm confident it'll work properly now with the latest Magpul magazines. I should also get a couple C Products steel mags to try as well.


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Mine is in the mid 04000 range and functions fine with DPMS, GenII, and GenIII mags. I have a couple of C-Products mags. After sitting loaded for three months they will no longer fit the mag wells properly. I suggest sticking to the three mentioned initially.

My interest in the metal mags is more for the curiosity rather than anything else.

Ideally I'd like to try some KAC and Larue mags but they're too expensive for me just to test compatibility.

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So I've been following this thread for 7 pages and am still confused. I don't know much about AR 10ish mags and compatibility.

If I buy some PMAGs, then buy the SR762 in a few months will it work? Or is it still a risk? Can someone please summarize for a retarded 13er?

You might be wondering why buy my mags first? I have my reasons. Mostly involves money flow.

I'm a neophyte myself but I'll do what I can to help you.  As I understand it, there are three patterns for the "AR-10" magazine format.  

The first is the ArmaLite pattern as used on the very original rifles from the 1950's.  This pattern has evolved and is now the current pattern used by Larue, Knight's and DPMS and is really the most common type.  This is what Ruger's using and is what the Magpul magazines are supposed to work with.  Magpul recently made some slight modifications to the design.  These are what are called "Gen3" magazines and are incompatible with the early Ruger rifles.

The second is the current ArmaLite pattern that are based on existing M-14 USGI magazines.  The early magazines were actually existing mag bodies that were modified to work in the reproduction AR-10 rifles.  This was done during the Clinton ban to allow shooters the luxury of normal capacity magazines since production was limited to 10-rounders during that time.  These mags work in the Geneseo, Ill rifles as well as the Noveske rifles.  I think Aero Precision also made (or makes) lowers that work with these magazines.

The third type is foreign military surplus pattern.  These are lowers that are designed to work with either FAL or G3 magazines.  Rock River builds a rifle that is designed to work with FAL mags and CMMG used to make a rifle that would work with G3 mags although I think that product has been discontinued.

I hope that doesn't muddy the waters and if anyone sees an error in the above, please don't hesitate to correct as necessary.

Thanks for the reply, that simplifies it some. What does ARF recommend to avoid an issue buying magazines? If I just stick to Gen II PMAGs, I should be good even if I get an early serial number rifle?

Do we know what approximately what serial number Ruger got it fixed at?

I guess I'm assuming they are assembled by order of serial number.

Gen2 mags should work in all guns but it does sound like there might have been a few guns that didn't work with Magpul magazines of any vintage.

Anyway, I'd buy all the Gen2 mags you can.  That way you've covered your bases.  Early or late serial number and you should be good.  With that said, I wouldn't dwell on it.  When you are ready to buy a rifle it'll probably be a later production gun.  If it isn't and it does have problems, send it back.  Ruger will fix it.

Good to know. ARF gives me yet another cause to spend money on. They look like sweet rifles, wanted one the minute I saw them.

If you want to try metal mags I would suggest staying with either the DPMS or the Stoner mags. They have the highest rating. I have used the Stoner mags for AR15's for years with no issues. Midway has the Stoner SR25/DPMS pattern mags for $18, they even have them in FDE.

MidwayUSA

Thanks...I was thinking about that. Metal holds up better over time, but the plastic is lighter...Decisions decisions. Most of my AR 15 mags are metal.

Here's my original 561-02xxx with a Gen2 magazine.  Note the position of the feed pawl/lug in relation to the top cartridge in the magazine.  




Here's the new rifle, which is serial number 561-07xxx.  Note the round sits much higher.  The same magazine as pictured above is used here.

I have been following this thread since it started, and was wondering if anyone has been able to get any definitive answers from Ruger if this is fixed. Do we know what the problem actually was/is? I was gonna order one from buds last week, but they will not tell you what serial # you are going to get, or what #'s they have in stock. I just don't want to get on the shipping back and forth roller coaster.

I think the basic problem was a rifle that was built and spec'ed around the DPMS steel magazine.  The original Magpul mags seemed fairly compatible with the DPMS pattern but the new Magpul mags (called Gen3) are slightly different and don't work as well, if at all.  Ruger addressed the change in magazines by increasing the height at which the magazine sits in relation to the bolt.  

I'd guess that anything you're likely to receive from Bud's or any other high volume retailer is going to be a current production item and not likely to have any issues with the newest magazines.  I think the easiest way to tell is which magazines come with the gun.  Original Magpuls or DPMS mags=older production.  Gen3 Magpul's=current production.  Maybe ask Bud's if they can at least check which mags you'd be getting.

I wouldn't use the higher magazine catch as an indicator.  When they fixed my rifle, which has the lower magazine catch, they replaced the bolt and the upper receiver, and it has worked with every mag I have tried since getting it back from the factory.  Well, except for the fact that I no longer have Gen2 mags to try in it.  I sent mine in with the rifle and they sent me all new Gen3s.  I have one Gen2, but it came with my Colt, and it has an extra tab to prevent over-insertion in the Colt, so I can't use it on the Ruger unless I grind the tab off.

I understand the redesign of the lower to have the higher magazine catch. Thanks to whomever posted the pics that showed that. It looks like that may have been the problem all along. I am still perplexed at what changing the bolt and upper done to fix some rifles that still have the lower catch. I believe I read in earlier post and on some other forums that changing out the upper and bolt still did not fix the problem. I wonder if the uppers and bolts had problems, or if it was the catch all along, and Ruger just got lucky by changing out some uppers and bolts. Basically throwing parts at problems and seeing what worked.

I haven't verified this with anyone but I suspect the "fix" is actually related to both the upper and the lower.  I'm guessing that the mag catch has been raised but also the height of the bolt and carrier inside the upper has been tweaked to lower the reciprocating parts and get them a little closer to the magazine.

Weeeeell, Stop by my LGS today and they had a SR762 on the shelf. I checked out the S/N first, and it was 561-090XX (not sure why people x-out the #'s, but I will do as the locals do). The second thing I noticed was how close the gap between the bottom of the bolt stop and the top of the mag catch was. It was just like your first rifle Melvin.  Wonder why there is inconsistencies on this.

http://i1276.photobucket.com/albums/y464/reposuave/Mobile%20Uploads/photo2_zpsdc59dd55.jpg?t=1401484618http://i1276.photobucket.com/albums/y464/reposuave/Mobile%20Uploads/photo2_zpsdc59dd55.jpg?t=1401484618

http://i1276.photobucket.com/albums/y464/reposuave/Mobile%20Uploads/photo1_zpsd474a1db.jpg?t=1401484615

Melvin, I made a mistake on my last post. The smaller gap between the bottom of the bolt stop and the top of the mag catch is the newer version and that was the way you posted it on your earlier post. I am sorry if I may have confused anyone by my own confusion. I bet all you guys were sitting back laughing at me on that one. If they still have that rifle tomorrow I think I will take a chance on it. It seems like the problems have simmered down a bit and looks like Ruger done what was right to fix everyone's issues.

There's a fairly standard write-up of the Ruger SR-762 in the July 2014 issue of "American Rifleman."

No mention is made of the whole Gen2/Gen3 mag issue. The author was report hitting steel all the way out to 800 and says he was getting five rounds at close to an inch at 100.  Overall, he was pleased with the rifle and says the 2-stage piston does a good job of reducing felt recoil.

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Picked up mine from the FFL about a week ago and it had three Gen3 PMAGs and the upper receiver looks like yours.  Haven't had a chance to bring it to the range, but I'm looking forward to it.  The trigger is gritty as all get-out, I think a Geissele is going to find it's way in there soon.