Future PPQ 5" slide purchase and legalities after SSE ends

[utc]

Hi, just picked up my second 4" Walther PPQ M1 (paddle mag release.) I was going to use my last sse for something other than a PPQ 5", and came to a realization. No serial number on PPQ frames (just on barrel and slide.) My plan was to next year, have my brother who lives out of state buy a 5" PPQ and sell me the slide (like buying a caliber conversion kit for my sigs.) Anyone have any info on this whether it would be legal (since traditionally the frame is the registered part,) or cause me to violate the laws here in CA? any info or links appreciated.
Kinda bummed right now, since I only have funds for one more sse before end of year.
Thanks for reading the post.

[bwhited]

It is not the frame that is considered to be the firearm.
It is the serialized part that is considered to be the firearm.

[utc]

10-4. Thanks bwhited. Guess that changes my plans this year.
much appreciated.
chow cz 85 combat, hullo PPQ 5"

[bwhited]

You always need another CZ.

10-4. Thanks bwhited. Guess that changes my plans this year.
much appreciated.
chow cz 85 combat, hullo PPQ 5"

[utc]

hard to pick...

[bajadan]

Yours doesn't have the serial on the back? Must be only the imported ones then?

[utc]

Thanks Bajandan.
wow. I'm an idiot. I could give a long boring explanation about having a fever last night, and picking my second ppq up this morning on an empty stomach (true story,) but immaterial since I already have one with about 150 rounds thru it. But, I'm just going to suck it up and call myself an embarrased dumass. Sales guy told me they didn't have #'s on frame, and I only gava cursory look at the one I was picking up. duh. Can't wait to point it out to him...
Thanks again everyone.

[penguinofsleep]

Seems like you get it, but what you mention is legal. If the frame is serialized along with the barrel and slide, those are not considered the "firearm", just the frame.