10-8 U-notch - which notch?, (M&P)

[m4brian]

I have three M&Ps. 2 9s and 1 45. All have the same slide length - mid size.

I have old eyes. Close is good; far I correct with one contact on my dominant right eye.

I have decided that three dots is confusing, so I want the rear 10-8 standard U notch.

Should I get the .156" or .140" notch?

Also, I need to drift out my sights. Is a brass or nylon punch sufficient? (like this http://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/punches/6-way-nylon-brass-punch-set-sku080475106-512-2141.aspx). On the 9s I have Night Sights, and I assume from other reviews that the U-notch works with the standard front NS. I would like to do some polishing and shaping on the plunger while doing the sight change.

Thanks.

[prez1967]

I'd go for the .156. Sights like these are for combat accuracy, and being able to pick up that front sight easily.

There are other options if your looking for bullseye shooting.

[snakedoctor]

I'd go with the .156 notch. Also, 10-8 sells punches.

[m4brian]

I guess that is why BCM has the .140 notch for so cheap.

[JW5219]

I have the 10-8 u-notch on my Glock 17 and it is a .156. It is what they (10-8 people) recommended and I'm glad I went with it. Nice sight picture.

[kodiakpb]

It depends on the width of the front sight being used.

[SPDGG]

It depends on the width of the front sight being used.
^ +1 Agree, & Type of Front Sight . . . Application would help as well: Carry/Training-type/Comp.

[dwhitehorne]

I have the factory night sight on the front with the .156 rear. It works well for me. David