3rd Generation Frame Strength?

I've recently acquired a 6906 which I'm growing quite fond of. Naturally, it's a used pistol, probably an LE turn-in. I consider it to be an extremely well-made pistol with an excellent design. I'm trying to learn as much as I can about this pistol.

Since I purchased my 6906 used, I have no idea how much it has already been shot. I replaced all of the springs recently, and it shoots great! I've been using good lubrication every time I shoot, and the pistol looks like it was taken care of pretty well by the previous owner(s).

My question relates to the frame. Are the aluminum frames on the 6906 pretty durable? Any idea as to potential life expectancy? Any suggestions to prolong the usable life? All input appreciated.

I have been told that they will usually out last their owners..

I read somewhere that the alloy frames were originally designed to stand up to the .356 TSW load in competition.

Depending on who you talk to the TSW can be the equivalent of a hot 9mm load or a +P+ load. Either way, I think you can count on the frame standing up to plenty of abuse as long as you don't remove the anodizing on it and keep the rails lubed well.

Some more info on the .356 TSW here.
http://smith-wessonforum.com/reloading/131869-356-tsw-reloads.html

Dave

If you spend way too much time on this forum, as I do, you'll find that the consensus is that they 3rd generation frames will last for a long time unless you abuse them. Even more so for the stainless ones, but all of them are durable and reliable.

You'll also find that the key is to lubricate the frame rails. Most people recommend grease for that although the factory recommends oil. Personally, I've started to use Lubriplate 105 engine assembly grease, but there are a lot of other favorites on the forum.

No expert here, nor do I have the depth of experience of many others on this forum. However, I can say that, as a fellow 69xx series owner (a 6904 and now, a 6906).... I think that you have little or nothing to worry about. My 6904 WAS a police gun (RCMP, to be exact). It is quite beat up looking, with lots of holster wear showing....and even some rust pitting on one side of the slide. Nevertheless, it is TIGHT and functions flawlessly. Slide to frame fit is perfect - and so is that of the 6906 I just purchased. I have no idea how many rounds either has seen. But, there is NO evidence of any frame wear (other than cosmetic)....and certainly no damage. Even the rails on both pistols are sharp edged and show NO wear.

So, as someone else said, keep your 6906 clean, lubed and maintained .... and the odds are you will be able to leave it to your children or grandchildren.... in good working order.

You could prolong its life by not shooting it.

Or, you could shoot it until it dies and buy another. It's not like they only made one!

Back toward the end of the 80's the FBI did some extended testing comparing some aluminum framed service-type guns to a proven steel gun in use by their HRT at the time (Browning HP).

It was observed that a couple of the popular alloy 9's of that time (including the 459) could develop frame cracks by 10,000 rounds.

Before someone freaks out about that, this was considered within perspective against the existing 5,000 round frame service life specified for some military pistols of that period. In the report, the president of one of the major gun companies (not S&W) was reported to have responded that if LE wanted a gun that would offer a much longer frame service life than a gun designed to just meet military specifications, the feds should make a request for such, and their engineers would design one.

As time passed, and the major gun companies wanted to win LE sales, we started seeing some improved aluminum framed guns. The S&W 3rd gen's were released about that time, and even they enjoyed continuing improvements throughout their production (culminating in the TSW's).

As other folks have mentioned, a few "secrets" to maximizing a useful service life with alloy frames aren't "secrets" at all.

*Keep them properly cleaned and lubricated. Run them dry, and you risk accelerating wear of the frame rails and damaging them.

*Periodically replace the recoil springs. S&W Armorers are told to replace recoil springs either every 5,000 rounds fired, or every 5 years, whichever occurs first. I like to replace mine a bit sooner than that, erring on the conservative end of preventive maintenance. (In the Chiefs Special pistols I replace them much sooner, as those are pretty short recoil springs, and those little guns develop some respectable slide velocities.)

*Use good quality factory ammunition of the proper caliber. (I prefer to use factory ammunition made by one of the major American companies who have acquired experience making duty ammunition for LE/Gov.)

Now, when all is said & done, steel is still steel and aluminum is still aluminum (although S&W did offer that rather nifty, and expensive, Scandium aluminum 4040PD for a short time).

I tried to wear out one of the issued 6906's I carried some years ago. I didn't keep an exact count of rounds fired, but tried to monitor boxes or cases of ammo fired on a monthly basis for preventive service needs.

I ended up replacing a lot of the common parts in the gun due to wear (starting with an extractor after I'd fired approx 12K rounds, but remember it was a previously issued gun before I started using it), and finally a slide (due to a tolerance issue in the extractor slot). I went through a lot of recoil & other springs, too.

I finally retired the gun after what I estimated was approx 45+K rounds fired (a mix of issued/approved standard pressure, +P & +P+ loads). The frame was starting to exhibit a lot of wear, but it remained within spec and normal functioning. I just decided that since it was my primary duty weapon for my regular plainclothes assignment, it might be prudent to retire the aging 6906 before it reached the useful end of its service life.

I had someone bring me a personally-owned 3913TSW (original version) for an inspection/service one day. I discovered a short half inch crack in the leading edge of the frame dustcover. The owner had thought it was a scratch, and since the gun was running fine he'd ignored it. He was a firearms instructor, and said the gun had been fired between 12-15K rounds by the time he noticed the "scratch".

The gun was returned to the factory. They said it was a puzzling spot for a crack to develop. They said it wasn't in what they felt was a critical spot, but since it was a crack, the frame should be taken out of service. They asked if the owner had been replacing the recoil spring within the recommended period (he had, since I gave him new recoil springs periodically). They commented that it was just one of those weird things that could happen, and cheerfully replaced the gun with a new version of the 3913TSW (apologizing that they simply didn't have any more of the original 3913TSW frames available by that time).

The owner of that new 3913TSW has been using the replacement 3913TSW for a lot of years, and has exceeded the total rounds fired through his first one some time ago. Still doing fine. (I could wish he'd keep the gun cleaner, but he shoots it all the time on the range he has setup on his rural property. At least he says he's periodically replacing recoil springs with new ones I give him between inspections. )

I've seen a couple of 5904's that experienced excessive frame rail wear due to being run insufficiently lubricated. That's one way to ruin a frame.

I remember the instructor during a Sig Pistol Armorer class continually repeating how critical it was to keep Sig P-series pistols properly lubricated. He said that if the guns were insufficiently lubricated, or were used "dry", they would be damaged and ruined. Not subtle about it. The answers to one of the written test questions about proper lubrication involved the presence of sufficient lubrication being able to be confirmed by sight & touch, BTW. And yes, he repeatedly mentioned that Sigs were considered to be "wet" guns ... but that they also shouldn't be excessively lubricated.

I certainly don't have the "answer" to how long any particular aluminum (or even steel) pistol frame may last.

I do, however, make every effort to maintain my alloy framed pistols in a manner recommended by the gun company who made it, and don't lose sleep about it.

There's another member who occasionally posts in this forum. He worked for the ISP, who enjoyed a long period of using S&W TDA pistols with alloy frames. His agency was also, if I remember right, involved in the development of the original 115gr +P+ loads by Winchester & Federal. He's sometimes related experiences of how well those older aluminum-framed TDA pistols lasted the folks at his former agency.

Now, also bear in mind S&W's ammunition warnings in their owner safety manuals.

Not all +P & +P+ ammunition may be the same. Buyer beware.

Also, +P+ means it exceeds +P standards, but it doesn't tell you by how much, since there isn't any defined upper range or limit for "+P+".

That's one of the main reasons I prefer to only use ammunition made by one of the big companies who have made large amounts of ammunition for LE/Gov customers, including the higher pressure loads like +P & +P+. It's in their interest to not provide duty ammunition that's likely to blow up good quality LE guns of modern design, right? Then again, sometimes signed waivers were asked of end users of higher pressure LE duty ammunition, too, and some of the ammunition was commonly restricted from the commercial market.

I've always asked questions during armorer classes about the viability of using different +P or +P+ loads in different makes/models of guns. Ditto asking different folks when calling back (as an armorer) to talk to other people at the companies (repair techs, engineers, LE sales, etc).

Sometimes I'd be told to use whatever was issued (with the presumption it was going to be something made by one of the big name ammo companies), and sometimes I'd be told to either limit the use of higher pressure ammo, or not use it. (I've been told that +P+ shouldn't be used in the Shield 9, for example, but some +P is okay.)

I went through a couple of folks trying to get a definitive answer about using +P loads in that older production run of 37-2's made for off-shore LE sales. (Some of which were apparently produced using what seemed to have been 442 barrels containing markings for +P loads.) I got a couple of "definitive" answers ... both approving and prohibiting the use of +P in my 37-2. The "final" answer I was given came after someone in customer service actually called over to the head of production, asking about the older "non-Magnum" 37-2 frames and using +P ... and the answer was that the 37-2 was NOT intended to be used with +P loads. Well, since the barrel on the particular 37-2 I'd received didn't have the +P language, I decided to go with the "don't use +P" recommendation in my gun.

Just my thoughts.

Excellent commentary! I appreciate everyone's input. This forum is incredibly informative.

I went back and added a couple of things toward the end.

I could ramble about this stuff at length, but remember that it's just "rambling" thoughts & experiences. I'm not anybody's expert, nor do I work for any of the gun companies at this time.

Most owners of handguns don't shoot more than 500 rounds through them over the whole time they own them. Many won't finish shooting up the first 50 round box of ammunition they bought with the gun. (Older industry statistics, though.)

Somewhere I still have that older issue of American Rifleman ('79?) where they "torture tested" a lightweight Colt Commander ... by shooting one for 5,000 rounds. I had a Commander at that time, which I shot a lot, and I was concerned I was going to wear out the "Coltalloy" frame. I finally traded it off for a steel Combat Commander ... and was kicking myself for letting it go for years. I should've kept it and stopped reading the gun magazines.

I have a bunch of the classic aluminum framed 9mm's and I think the S&W design is one of the absolute best designs ever created. I see much less wear on my 6906 per round fired than the Beretta or Sig Sauer. If you want to see an aluminum frame that gets chewed up by shooting, take a peak at a post war Walther P38/P1. Lots of steel/aluminum interaction, plus an aluminum feed ramp. For a 3rd gen S&W alloy (if lubed), I'd say a min of 10K rounds or more. For the steel frame 9mm like a 5906, it would be pretty much indefinite number of rounds something like 50k-100k. S&W really did their homework on these back in the 50's. The dual cam arrangement of barrel lockup is much better IMO than the pressed stud in the BHP or the slide stop pin in the CZ. Just outstanding work (although I love all my other guns too).