MAC-10 45ACP Magazine ID Help

[TheUz1Button]

Who is the mfg of the mag shown below? Are these the Component Metal Products 40rd magazines?

Mag shown next to a 30rd grease gun mag for reference...

 

[HK45]

Are those 40rd mags still made and for sale?

 

[TheUz1Button]

Are those 40rd mags still made and for sale?

I dont think they are still in production. The last time I saw them they were just under $90 each.

 

[BlackBelt]

I don't think those are Component Metal Products mags. The CMP mags had a fancy "CMP" logo on them. I had probably 2 dozen of them at one time.
I would like to know who made that mag in your picture though.

 

[herd118]

Yep, they were made by Component Metal Products, for the J.P. Foote designed Enfield/Encom/CMP model MP-45 in the 80's.

 

[Bunker Hill]

Hey TheUz1Button, could I trouble you to pop the mag spring out of that 40-round mag and see if it's identical to the spring in the 30-rounder? I have four of the RPB manufactured 40-round mags and none of them feed reliably. When I went to investigate the reason for the malfunctions I discovered that, despite the longer mag housing, all four were still fitted with standard 30-round GG mag springs. I'd often wondered if any of the companies that produced aftermarket 40-round mags ever took the time to engineer a longer spring to account for the extended mag housing. If your mags feed reliably, I'd be curious to see if they are doing so while using the standard GG mag spring.

Thanks,
BH

 

[TheUz1Button]

Hey TheUz1Button, could I trouble you to pop the mag spring out of that 40-round mag and see if it's identical to the spring in the 30-rounder? I have four of the RPB manufactured 40-round mags and none of them feed reliably. When I went to investigate the reason for the malfunctions I discovered that, despite the longer mag housing, all four were still fitted with standard 30-round GG mag springs. I'd often wondered if any of the companies that produced aftermarket 40-round mags ever took the time to engineer a longer spring to account for the extended mag housing. If your mags feed reliably, I'd be curious to see if they are doing so while using the standard GG mag spring.

Thanks,
BH

The 40rd mag has a little bit longer spring, yes.