BCG comparison BCM vs Core15

AR/M4 AR Technical Discussion
1

Starting this thread over. If there are any mods listening, could you please change the title to BCG comparison BCM vs PSA vs Core15? Also feel free to delete the attached images if possible

By biggest concerns about the Core15 BCG are the finish and the composition of the firing pin. The finish on the Core15 feels rougher than the other two, and any other BCG I have encountered for that matter. The firing pin also looks lighter, it doesn’t have that smooth chrome finish you typically see.

If anyone more knowledgeable than me could comment on if these differences should be concerning, please do. The machining and construction look fine on the Core15. I’ve just never seen a park job like that before. Anyway, on to the pictures.

First the staking

Order: BCM PSA C15

More staking, good shot of the Core15 finish.

Bottom view if anyone is curious. PSA in middle

Different view, top to bottom Core 15, BCM, PSA

Here are the firing pins. It’s really hard to appreciate the contrast without holding it. Left to right, Core15, PSA BCM

Close up, Core15 vs BCM

2

Meant to add that the specs listed on the core15 site are comparable to BCM or PSA but side by side they look quite different

3

Are the firing pin heads the same size? Do you have calipers to check?

4

Thanks for the pics but any chance on better quality ones? I can not really see much from them.

5

Re the firing pin heads. Don’t know but I do have calipers to check.

Sorry about the pics. I tried uploading some from tapatalk and apparently that method sucks. Learn something new everyday. Will take better ones tonight and host them properly.

Can include the PSA BCG in there as well.

6

PSA
Overall Length: 3.279
1: 0.249
2: 0.157
3: 0.371
4: 0.152
5: 0.103
6: 0.060

Core15
Overall Length: 3.279
1: 0.252
2: 0.158
3: 0.372
4: 0.152
5: 0.102
6: 0.060

Sorry, didn’t get the BCM. I had already put my rifle back together when I remembered about this part. If anyone really wants the measurements I can get them

7

My LMT carrier definitely does not have a smooth finish either(compared to a Colt, BCM and DD carrier), is rather rough, VERY similar to the Core15 that you are showing.

I have had ZERO issue with it and the gun runs great.

8

I did not know that PSA used a MIM gas key. Interesting.

C4

9

That does not evoke confidence. MIM parts from my experience are shit…

10

They can be. They can also be very good. Just really depends on the quality (heat treating, etc).

C4

11

Interesting for sure but understanding the role I the gas key I’m not sure I would worry too much.

12

LMT has had good luck with their MIM gas keys (I think). Where they (LMT) ran into problems is their staking job (cracked around the staking).

C4

13

There’s a LOT of MIM parts out there. 1911 guys are certain that MIM parts fail all of the time but that’s not usually the case.

14

Honestly, it depends on the quality. There is a lot of POOR quality in SUB $1k 1911’s I think.

C4

15

Agreed; I was just trying to note where a lot of the MIM hate comes from.

16

Ya, I think you are correct.

C4

17

interesting.

I have an LMT carrier that has a slightly loose gas key. The staking, to me, looks good and I dont think the screws have turned. Might have to get out the ol magnifying spectacles and take a closer look.

18

Which is funny, cause a lot of the same guys will praise their M&P (that uses some MIM parts) but claim the MIM in sub-par 1911’s is the cause of it being junk…

But like Grant said, its a matter of quality of the parts and the way they are made/treated.

19

Grant, any thoughts on the core15 BCG?

Thanks for your time

20

How can you tell it’s a MIM part? (not trying to be a smart ass, I really don’t know and am curious for my own knowledge).

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