S&W 76 recoil spring guide rod
- Thread starter navgunner
- Start date
Billinbama
Well-known member
Yeah, what Kickstand said, in spades.
I purchased two of these. One for my MK760 in 9mm and another that I shortened to replace the plastic one for my Subguns 22. conversion kit. Yes it is a larger diameter but the recoil spring fits nicely and it works just fine.
Austin:
Nice video illustrating the multiple functions performed by the recoil spring guide, and nice workmanship on the recoil spring guide I got from you.
The amateur engineering historian in me is intrigued by the MK Arms guide in your video. More specifically, I am trying to figure out when MK Arms switched to a casting for the back portion of the guide. Do you know anything about the gun that guide came from? Early or late production? Stamped magazine housing or cast magazine housing? That sort of thing.
Thanks,
Jim
Nice video illustrating the multiple functions performed by the recoil spring guide, and nice workmanship on the recoil spring guide I got from you.
The amateur engineering historian in me is intrigued by the MK Arms guide in your video. More specifically, I am trying to figure out when MK Arms switched to a casting for the back portion of the guide. Do you know anything about the gun that guide came from? Early or late production? Stamped magazine housing or cast magazine housing? That sort of thing.
Thanks,
Jim
Austin:
Thanks for the info about the factory recoil spring guide in your video. Interesting that it is from a Fruithurst gun.
It appears that this is one of the components that Mr. Ruplinger upgraded when he moved his operations to Irvine. My Irvine recoil spring guide has a machined back half. Additionally, the tube front portion is a press fit onto the back half (which expanded the O.D. of the tube about 0.006” for the length of the press fit). It also has a roll crimp right next to the flange. Even so, I prefer the one-piece construction of your guide. Keep up the good work.
Jim
Thanks for the info about the factory recoil spring guide in your video. Interesting that it is from a Fruithurst gun.
It appears that this is one of the components that Mr. Ruplinger upgraded when he moved his operations to Irvine. My Irvine recoil spring guide has a machined back half. Additionally, the tube front portion is a press fit onto the back half (which expanded the O.D. of the tube about 0.006” for the length of the press fit). It also has a roll crimp right next to the flange. Even so, I prefer the one-piece construction of your guide. Keep up the good work.
Jim
MontanaRenegade86
UZI Talk Supporter
The recoil spring guide rod was the first NavGunner part I bought and installed in my 76 and 760. I looked for that part for years.
…
Jim, do you have an early Irvine?
…
Jim, do you have an early Irvine?
Montana:
I am not sure. I suspect my Irvine is in the first half of production simply because it has a stamped magazine housing. The guns I have seen with a cast magazine housing appear to have higher serial numbers than those with a stamped housing.
Is there a better test or a more precise way to identify its vintage?
Jim
I am not sure. I suspect my Irvine is in the first half of production simply because it has a stamped magazine housing. The guns I have seen with a cast magazine housing appear to have higher serial numbers than those with a stamped housing.
Is there a better test or a more precise way to identify its vintage?
Jim
MontanaRenegade86
UZI Talk Supporter
Jim, I was just curious if maybe you had a Irvine with an early serial number.
The MK I have is one of the first sixty to come out of Irvine. It has always been a solid shooter, but it certainly got some use from the previous owners.
The MK I have is one of the first sixty to come out of Irvine. It has always been a solid shooter, but it certainly got some use from the previous owners.
I think the best way to tell is to look at the serial # prefix. Generally, speaking the S prefix stand for factory SMG. If your Irvine gun has a S, it likely wasn't a rush job (obviously, a lower Serial Number would be a good thing to see too). At least from my understanding, that's the case.
Regarding prefixes they usually look like this: The serial number prefix (generally) S (factory SMG), P (pistol), C (Carbine / rifle). The pistol and carbine were originally intended to not be a SMG but they changed them over to get them registered before the ban. It's my understanding that there might be a couple of outliers too (with weird prefixes, probably rushed to get them in before the ban too).
Montana - Not as early as yours, but early enough to have a stamped magazine housing with the stylized MKA logo on it. Based on your serial number range, I suspect your gun has a stamped magazine housing, but does not have the stylized MKA logo on that magazine housing. How good is that prediction?
Kickstand - My preliminary research suggests that the production history of Irvine guns may be more complicated than some initially thought. Based on what I have found so far, it looks like both S and CO serial number prefixes were used simultaneously during production of the SMGs. I have not seen enough of the PO prefix guns to tell if they follow the same patterns. (They may have been set aside for later if their grip blocks did not originally have the required cuts for the stock, but that is nothing more than a hypothesis at this point.)
Jim
Kickstand - My preliminary research suggests that the production history of Irvine guns may be more complicated than some initially thought. Based on what I have found so far, it looks like both S and CO serial number prefixes were used simultaneously during production of the SMGs. I have not seen enough of the PO prefix guns to tell if they follow the same patterns. (They may have been set aside for later if their grip blocks did not originally have the required cuts for the stock, but that is nothing more than a hypothesis at this point.)
Jim
MontanaRenegade86
UZI Talk Supporter
You nailed it, Jim.
Thanks. One more test of my data set if you do not mind.
So far, on the S prefix guns I have seen:
So far, on the S prefix guns I have seen:
- Guns up through number 138 have a 5-character serial number with the letters SO as a prefix followed by a 3-digit number - SOxxx.
- Gun with number 219 and higher have a 4-character serial number with just the letter S as a prefix followed by a 3-digit number- Sxxx. (I do not know the exact transition point.)
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MontanaRenegade86
UZI Talk Supporter
To my eyeballs, it looks like that SO (ess-oh) is more like a S0 (ess-zero), but otherwise, right on. That is also what is listed on the Form 4.
Those letters and numbers are pretty small. The SERIAL NO. that precedes the actual number is a much bigger font.
Interesting. I have only seen the large SERIAL NO. stamping on Fruithurst guns. Pure speculation, but I wonder if the tube portion of your gun was started in Fruithurst and then brought to Irvine where it was completed and numbered.
Regardless of the reason, it seems there were a lot of variations in markings on the first 150-ish Irvine S guns.
Regardless of the reason, it seems there were a lot of variations in markings on the first 150-ish Irvine S guns.
Billinbama
Well-known member
I got my recoil spring guide Friday, installed it in my gun and expect it to last a long time, I can see a big difference in it and the original. Navgunner is providing us with durable parts that will extend the life of theM76 for years to come. Gonna try it out, along with the suppressor he sent me, in a coupe of hours I hope, and from earlier reports I expect good things.
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