What power spotting scope do I need to see the target to sight in a 5.56 M4 at 50 yards and 100 yards?
IMHO…Comfortably, at least 20X. I have had an older Bushnell with 36X capabilities that I can see holes on Buff Colored Targets or White Paper Plates at 200 yds. with. It was fairly inexpensive, and it’s rubber coated for shock resistance, and has a Camo Pattern paint job. This is it http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=230856&t=11082005
It also comes with a little, flimsy tri-pod that I replaced with one that has adjustable legs for elevation that you can get at a camera store, or maybe even WalMart, Target etc. in the Video Camera Dept. I have the size tri-pod that you sit on a bench. You can adjust it for sitting or standing behind the bench. Mine also came with a Hard Plastic case which I don’t use. The scope just stays in my gear bag with the tri-pod. The scope also comes with lens covers.
I don’t advocate that this is a Mil. Spec. type piece of equipment, but if you’re just using it at the range, it works well.
Tack
more than magnification, you need contrast. white paper on dark brown cardboard, for example, will make holes appear black on white and easy to see with the naked eye at 50yrd, or easy to see with a 12x scope at 100-200 yrd. I can easily see 223 holes through my 4x acog on moderate contrast targets like regular brown cardboard with no paper. however, I could not see holes (I suspect this is on purpose) in the center of the EAG targets, which is a hatch pattern over Multi-cam, and something i’d call low-contrast.
(On a side note, I think the fact that it was difficult/impossible to see my shots on these targets helped cure me of my gamer habit of pulling the gun down immediately after firing to look for my score. So instant feedback isn’t necessarily always desirable. I’ve been working on scanning, and patience.)
this obviously, is why shoot-n-see’s work so well. a splash of neon yellowish-green contrasts nicely against the black.
of course, YMMV, and in fact, my mileage is varying 
as I just had lasik and my vision (uncorrected) isn’t quite what it was (corrected) 2 months ago.
anyway, even if you can’t pick your targets, even with 10x cheap glass, I rarely feel the need to walk 50 yrds and look at the target in person.
I use a cheap 18x-36x and I use the SHOOT•N•C Sight-In Targets 12".
I would like to know what brand name and power spotting scope does everybody use to sight their M4 red-dot and scopes in at 50 yards and 100 yards?
I just bought whatever was cheap from Tasco. Don’t obsess over it, just buy the cheapest thing you can that comes with a bipod and move on. 100 yards isn’t worth shelling out big bucks over.
+1
Everthing you need to know has been addressed.
Tack
I just wanted to know what other M4CARBINE.NET shootes were using to see the target bullet holes.
Understood, but you have the answers from some of the Sr. members who have a lot of ( >30 years) of experience each with optics. If you were wanting something to see out to 500 yds. the choices become much more defined, and the costs are much greater.
If there were more to this decision…you’d PROBABLY have more inputs by now. It’s just not a big thing. “Everybody” doesn’t use the same spotting scopes in this price range. It’s not like an RDS where EOTech and Aimpoint are THE way to go and you’re going to spend between $350 - $550 plus another $90- $100 for a LaRue mount.
Get something as cheap as you can that has 18X - 36X variable magnification, and you’ll be set out to 200 yds. I’d plan on spending $100 - $125. There are sources all over the web doing a search for "Spotting Scopes. www.opticsplanet.com is a great source.
If you want top end, look at Steiner, Zeiss, BSA and KOWA. All are top grade, and >$1,000. The difference will be in contrast, and definition. Magnification is magnification.
Tack
this looks an awful lot like mine, but I doubt I paid even $100 for it.
That’s exactly like mine, and it WAS less than $100 fifteen years ago. Works great out to 200 yds.!
Tack
I would take a look at the Kowa scope line. You truly get what you pay for and it will always have resale value or pass it on to your children. I have the 27x long eye relief and 5.56 holes at 200 are no problem. Power isn’t everything.
Mark