need help with colt mag block issues...unknown brand

[TobyJ]

Hello there,

 

I have a registered SBR lower, that I'd like to build a PCC on to dabble in the division.  I mentioned this to a buddy at the range, and he told me he had some blocks, bolts, and mags that he' make me a good deal on. He's out of town for a month, and I'm not sure how much experience he had with these anyway, so I figured I'd ask my questions here.

 

The pic attached is what he gave me...told me to figure out what, if any of it worked for me, and we'd figure out a price. 

 

First the blocks...Of the two, the 'two toned' one (left in the picture) is an extremely tight fit in my lower, whereas the all black one drops right in.  with the upper off, both mags (colt and modified uzi, from what I can tell) both insert fine and drop free. One I add even a stripped upper, both mags get noticeably harder to insert, and no longer drop free.  It would appear that the upper is squishing the top of the adapter into the mags.  I've tried searching this, and didn't find anything directly to the point, but I did read where some folks had better luck with metalform mags in the 'drop free' category.

 

Next the bolts.  I am currently running a law tactical folder on the lower, and would like to keep it.  It appears that the bolt on the left is standard length, and I'd just need to modify the weight to allow me to get the LT bolt extension installed, and adjust buffer weight accordingly, so that's the one I plan to go with.  As with the mag blocks, I don't know any manufacture info on either bolt, so any input is welcomed.  Both bolts are ramped as well, and would seem to be compatible with my Layke Tactical trigger.

 

Other than the low investment, I don't have any real reason to use these, over other stuff out there.  So if I can't get the block sorted out, I will probably turn to a Kak or Hahn unit (leaning toward kak, as I'd like to keep the investment down...as I'm still dabbling at this point.

 

Thanks for any input,

 

Toby

[Tampa-XD45]

Let's start with the mags.  Both mags in the pictures are UZIs.  Do you have access to any brand of Colt style 9mm mags testing?

 

Read my post about mag blocks here:  https://forums.brianenos.com/topic/258139-which-magwell-adapter/?tab=comments#comment-2875702

 

See the pic I posted in this thread showing proper magblock & bolt alignment:  https://forums.brianenos.com/topic/252550-colt-9mm-magazine-feed-question/?tab=comments#comment-2810470

[TobyJ]

Quote

 

Thanks Tampa-XD45 (I grew up in Tarpon Springs, BTW)...I had read your posts when doing some searching the other night.

 

So they are both Uzi mags...huh...one is clearly 'modified', but the other looks like a factory mag release cut.  Good to know.  I don't have any colt mags handy, but I'm sure I can come up with some to try.

 

Another question about the bolts...what's the difference between glock and colt?  I haven't been able to find any good pics, and some manufacturers claim one or the other, while some just say colt / glock compatible.  Picture of the faces of the two bolts I have is attached.  If I end up having to get a different mag block, I would consider glock, since I shoot glock handguns

[Tampa-XD45]

Most 9mm BCGs work with Glock or Colt mags.  I don't see any functional differences in your two bolt faces.

[Norther]

I got started just this way. I ended up building a dedicated PCC because I got tired of always switching the buffer, mag block, and Law Tactical extension. I like to keep my SBR in its proper caliber when not actually using it in another.  I have some Mean Arms Endomags on preorder, and may go back if I don’t have to deal with the mag block. 

 

Not all bolts will work with the LT extension. The hole in the back isn’t standardized. Spinta works, JP doesn’t. Can’t answer for others. 

 

I concur, both mags pictured appear to be modified UZI.