Aluminium case out of a S&W 986

D

Darker Loaf

New member
OK, so I couldn't think of any reason NOT to use aluminum case 9mm out of my 986, except that I found extraction to be more difficult. Venom1956 bent one of my moon clips upon extraction.

Also, we noticed that the hammer was hitting the Federal AL case's primers so hard, that it was piercing through them! I'm not sure if the primers are just that soft or if it has to do with the case itself. But, even with brass, that hammer is hitting the primer very hard!

Are there any reasons that I might damage the gun (bent extractor rod) with aluminum case?
 
Last edited:
you shouldnt have any problems...this gun was made to pretty much eat any 9mm ammo you can feed it..i have had no problems with mine...its shoots everything i feed it..
 
9mm is a high pressure round and aluminum is soft.
No surprise the cases are hanging on to the cylinders and causing the primers to show signs of heavy strikes.
That might be caused by the the cases hitting the recoil shield upon firing, before the firing pin has fully withdrawn.
A stronger firing pin spring might help with that, and cleaning its channel real good.
But it's doubtful that the gun will suffer.
Enjoy, that's a neat shootin' iron.
 
The usual cause of "pierced" primers is a light, not heavy, firing pin blow. The reason is that the firing pin must have enough momentum that it will not be pushed back by the internal pressure of the primer after firing. If the firing pin is pushed back, a disc can be punched out of it and be blown back through the firing pin hole, causing the "pierced" appearance of the primer.

People seeing that sometimes think the firing pin blow is so strong that it is actually punching a hole in the primer and decrease the mainspring tension, exactly the reverse of what should be done.

Anyone who experiences "pierced" primers should check the firing pin area. In some cases, the blown out discs can actually jam the firing pin channel and prevent the gun from firing.

Jim
 
The reason I say that the pierced primers seem like the hammer is hitting it hard, is because even on brass, the primers are heavily dented in, much deeper and distinct than on striker struck brass. I'll be sure to look for debris in the firing pin area. Thanks for the advice.

Thanks! It's my first wheel gun, and I have to say that I LOVE it! It makes me want to go out and shoot it.
 
Re James K: I think you have been proven right!

On rounds 500-700, I had FTF from light primer strikes almost every single clip often two. It is very obvious to me now that the springs are too light. It may have not been the AL case at all. I guess it's time to send it back into S&W. Sigh. This has been the story behind every other gun I've bought, regardless of the company.
 
Before you send the gun back, check and make sure that the strain screw is tight. The strain screw is located on the lower front portion of the grip frame and puts tension on the mainspring. Many people mistakenly think that the strain screw is a trigger adjustment screw and back it out in hopes of a lightened trigger pull. The strain screw should, in fact be tightened to the point of bottoming out as its only function is as a means to relieve the tension on the mainspring for easier disassembly of the revolver. A backed-out strain screw is probably the number one cause of light primer strikes in a S&W revolver.
 
Re Webleymkv: Thanks for the advice--it seems very sound. This is precisely what Venom1956 had me do. I just have to find time to go to the range and function test the gun. That screw was indeed backed out pretty far. I guess I just shot it so much so rapidly that 50% of the screws in the gun came loose. Just my luck!
 
We fully tightened the screw, and achieved 100% reliability out of 77 rounds today... This is faaaaaaaaaaar better than 1-2 light-strikes per clip. However, the cases are still being pitched back into the firing pin, it seems. I had pierced primers with brass case Magtech 9mm as well, with a fair degree of frequency. The 7 Remington Golden Sabers looked fine, but that could have been a fluke.

Oh, also, I have round case marks on the back portion.... err... the firing-pin face side (name? revolver newb) from cases being thrown back into it.
 
Only times I ever had problems with aluminum cased ammo was with Titanium cylinders...S&W 340 (x2), 360 and 396 revolvers ...perhaps a function of the larger coefficient of expansion of the aluminum case, coupled with the relative coefficient of friction between the two metals?
I see that the 986 is a Titanium cylinder...
 
I don't think it was actually a problem with AL case, but it seems it was more so a case of an improperly (lose) adjusted mainspring. Though I did note that it began to happen with brass, too (the super-hard-looking, but actually light primer strikes, that is).

But I will grant you that the titanium seems "rougher" than polished steel and AL case is also less smooth than brass or nickle-plated brass.
 
The titanium is much more elastic than steel. It may be stretching more upon discharge than a steel cylinder would and then snapping back around the expanded aluminum cases to hold them tightly and make extraction more difficult.
 
i shot blazer aluminum in my 986 yesterday and had no problems..i did have problems with nato 9mm purchased from walmart...
 
You must log in or register to reply here.
Back
Top