Early Mac Upper Stamps

[Jerikeaux]

Noticed these number and letter stamps on the front trunion of this mac upper. I think its an early powder springs upper with a cast bolt. Just wondering if anyone has seen these markings, or know what the stamps were for? There is also a small p stamped on the top of the barrel near the front sight.
Thanks,
Jerikeaux

 

[Tommyboy]

All of the original Powder Springs uppers that I have seen have those markings, including the M11 in .380. If you had an original box with the gun, you’d find the same markings stamped on the label. In the second picture you can see the letters GAB2KER stamped in ink under where it says “Identification Card”. The “GA” portion of the letters should be stamped underneath the receiver in front of the trigger guard. Most of the barrels also have a “lot” number in addition to the “P” mark.

 

[Jerikeaux]

Thanks for the info Tommy, sadly i only have the upper. Doublechecked the barrel and could only find the p stamp on this one.
Thanks for your help,
Jerikeaux

 

[timkel]

Pre-auction Ingrams were all stamped that way. Probably some type of inspection markings.

 

[Jerikeaux]

Hi Timkel,
Thanks for the info and pictures. I also have a .380 upper that i thought was an early Ingram, but it doesnt have any markings on the front trunnion. Also lacks the slot for the strap hanger. Will try to get a picture this afternoon.
Really appreciate your help,
Jerikeaux

 

[Jerikeaux]

 

[Tommyboy]

If the .380 upper has the barrel retaining pin located on top of the barrel, it’s a Powder Springs upper. It the retaining pin is below the barrel and hidden from view when the upper is installed on the lower, it’s an RPB or later upper. Below picture is from a Powder Springs M11.

 

[Jerikeaux]

Looks like its an Rpb or later upper. Also noticed thet the front site assembly is a little more narrow than my cobray marked upper. Thanks again for your help Tommy.
Its hard to find any info on these without the lower recievers.

 

[timkel]

The pre-auction bolts also came with various markings.

 

[Jerikeaux]

There is a L cast into the .380 bolt, but no stamped numbers.

 

[MitchWerbellsGhost87]

View attachment 40122

Upper on the left is RPB, upper on the right is SWD.

The pre-auction bolts also came with various markings.

RPB bolts also came with these markings. The RPB M11 bolts were identical to the MAC counterpart and the M10 bolts were the same casting but they were not milled as intricately around the edges as the earlier MAC bolt. The MAC bolts have numbers stamped on top next to the letter L, M, N, or K, there may have been others. RPB bolts just have the letter. These are M10 bolts in this picture, the charging handle on the left is a navy seal handle and the 2 on the right are both later SWD mfg handles.

There is a L cast into the .380 bolt, but no stamped numbers. View attachment 40125

this is a standard RPB M11A1 cast bolt, either leftover MAC or mfg by RPB using the MAC tooling.

 

[MitchWerbellsGhost87]

View attachment 40124
Looks like its an Rpb or later upper. Also noticed thet the front site assembly is a little more narrow than my cobray marked upper. Thanks again for your help Tommy.
Its hard to find any info on these without the lower recievers.

This is an RPB upper, later one, same as the upper used on the RPB open bolt semi auto pistol, no provision for a strap hanger. The countersunk takedown pin hole was for the RPB “push pin” type takedown pin that had a small wire spring detent built into the pin that would catch on the lip of that hole.

 

[atfsux]

Kind of unrelated, but sort of is,...I was watching a YouTube video a few days ago on a channel called the Socialite Crime Club,...and my eye was immediately drawn to their logo, which for a moment I thought they had ripped off from COBRAY.




But upon closer inspection, it seemed it was perhaps merely inspired by COBRAY.

 

[MitchWerbellsGhost87]

Kind of unrelated, but sort of is,...I was watching a YouTube video a few days ago on a channel called the Socialite Crime Club,...and my eye was immediately drawn to their logo, which for a moment I thought they had ripped off from COBRAY.


View attachment 40146

But upon closer inspection, it seemed it was perhaps merely inspired by COBRAY.

View attachment 40147

Wow, looks like the older pre-MAC sionics logo, the Cobray symbol was originally intended to represent the letter “S” for “Sionics”. Sounds like this channel is doing the same thing with a very similar design

 

[Jerikeaux]

Thanks for all the info Mitch. Super interesting history on these guns.
Heres a picture of the .45 bolt. It has an 82 stamp and cast J.

 

[MitchWerbellsGhost87]

View attachment 40148
Thanks for all the info Mitch. Super interesting history on these guns.
Heres a picture of the .45 bolt. It has an 82 stamp and cast J.

That’s a MAC bolt and a MAC takedown pin as well

 

[Poacher]

View attachment 40148
Thanks for all the info Mitch. Super interesting history on these guns.
Heres a picture of the .45 bolt. It has an 82 stamp and cast J.

Do you know if that’s the original buffer? I’ve seen a few of those thin black buffers on supposedly unfired guns.

 

[timkel]

Yes, that looks like an original buffer. The original buffers were black in color and were installed over both the recoil and ejector rods. That buffer is most likely rotten. Replace the buffer with a modern one.

 

[MitchWerbellsGhost87]

Do you know if that’s the original buffer? I’ve seen a few of those thin black buffers on supposedly unfired guns.

As he said above me, it’s original but I’d like to ad that it looks to be in excellent shape. Some of the old buffers had a tendency to crumble over time, I believe it was mostly RPB buffers that did this, they were made of a more rubbery black material that would dry rot. The buffer you have is more of a shiny hard plastic and they last damn near forever. There were also buffers made of a white gauze looking nylon that turns yellowish with age and a clear amber urethane material (the best ones).

 

[timkel]

The buffer might look fine but that's not a good indicator. Check the buffer by flexing it. Pull the edge back with your finger. Look for hairline cracks or tears.