The HK 416 Pistol and Rifle are both the same in construction. the lowers are the same also. It is a scaled version of the HK 416/417 model (.223) only a dedicated .22 rifle. the place the Buffer-tube inserts is capped for pistol specs. But yes a buffer tube from a full length 416 .22lr should work. Be aware that by putting the Buffer-tube WITH a stock constitutes a short barrel rifle and is illegal unless you pay the ATF the $200 tax stamp and process the request to own through them.
Yes it is complete, no it does not include a buffer or spring- and is rather pricey IMHO.
Yes. It unscrews just like the fake suppressor on the MP5 22lr rifle.
There are many numbers that are divisible by 416 these include: 416, Basically the 416 times table
416 x 10 = 4160 416 x 9 is 416 less than that. Estimate 3740.
416 = 41,600%
It is: 416 = CDXVI
The product is 416
816 - 416 = 400
416 * 213 = 88,608
416 + 34 = 450
237 + 416 = 653
465