Most SF lights will fit a 1" ring.  But, when you start inquiring about recoil related failure it's more than a just bezel issue.  The shock isolated bezels are a key component but on the true weaponslights you also have battery retention, both of these features are there to preserve the lamp from the from recoil abuse.  The s.i. bezel will cushion the shock from muzzle blast while battery retention prevents the batteries from slamming into the back of the lamp assy.  F4YR's pics here better clarify what I'm trying to explain -

www.ar15.com/forums/topic.html?b=3&f=20&t=204486

On a rifle like the AR-15 (in 5.56) you can perhaps get away with not having battery retention & some even say you can skip the s.i. bezel (I've heard about many guys over in Iraq having basic G2's installed on their lights) but the reason those features were developed are to preserve lamp life.  Personal carry lights like the G2 & 6P don't have those components and that  means lower cost for those models.  Those features are incorporated into a weaponslight as well as different mount & activation option which push the cost.

The two primary choices are Surefire and L.D.I.  My primary focus has been on Surefire due to compatability and adaptablity but I'll be carrying LDI soon too. If you're not concerned about cross compatabilty with your personal light or you don't care about future upgrades then the LDI lights can be a good choice.

Here's a brief overview of the SF weaponslights that may help you out some -

www.ar15.com/forums/topic.html?b=2&f=142&t=142268

Specific details on the M95/M96 series are:

The 6v M95x MU systems use the P60 (65 lumen) & P61 (120 lumen) lamps. The weight w/ batteries is 9.2 ounces (ARMS mount) and the length is 6.125".

The 9v M96x MU systems use the MN10 (125 lumen) & MN11 (225 lumen) lamps. The weight w/ batteries is 11.5 ounces (ARMS mount) and the length is 7.75"

The std. lamps have a battery runtime of approx. 1 hour & the high output have a battery runtime of approx. 20 min.

The M95x will use the same lamps as the personal carry Surefire G2, G2Z, 6P, C2, M2 & Z2 lights.  The M96x will use the same lamps as the Surefire M3 combatlight.

For good, clear target illumination the 6v system has an approx. range of 60 yds. while the 9v system has a range of approx. 80+ yds. of clear target illumination.

Quoted: What's something like the M95 with the QD lever go for?  I found one link with a pic of a mount with thumbscrews & they wanted $275.  Why is it so much more?

Please don't look at the SF retail prices and think that's the best deal, contact one of us SF dealers and see what we have to offer.

Quoted: OK, now I think I'm starting to get it, but what is the difference between the M952C and the M952P? There appears to be something different going on with the button at the back.

The 'C' switch is a clicker style so that when you apply partial pressure it's momentary and when you press deep it will 'click' for constant on.  The 'P' variant is momentary activation only, you'll need to twist the t/c in clockwise to get hands free constant on.

Here's the basic breakdown of Millennium model #'s -

1st two digits - M9xxx = Millennium Universal system

The 3rd digit indicates volts:

M95xx = 6v system
M96xx = 9v system
M97xx = 9v but turbohead variant
M98xx = 12v turbohead only

The 4th digit indicates mount style:

M9x1x = thumbscrew mount
M9x2x = ARMS throw lever mount

The start of 5th digit indicates switch type:

M9xxP = momentary push button activation or twist for constant on
M9xxC = partial pressure will give you momentary activation or if you press deep it will click for constant on/off
M9xxSU0x = tape switch style tailcap, 0x would indicate length (06 would = a 6" wire plus the pressure pad.)

And to further confuse folks, there's new XM tailcap that's out (C switch & SU0x combined) which should has the coding M9xxXM0x.

Quoted: I must have either out of spec Weaver rings or out of spec G2 because 1 in. ring won't work. Just got a Weaver (actual manufacture) 1 in. scope rings and  it takes a good snap to put the ring on top of the G2 and there is a 3/16 in. or so gap between the upper and lower ring. The screws that come with ring are too short to connect and really the gap should be much smaller - about 3/32 in. or less. Perhaps 30 mm rings would be better.... YMMV

There are some variances with the G2 bodies and the std. steel cap Weaver ring is not one that will adapt to those differences, sometimes they fit and other times they don't.  I would recommend a two piece ring that's what I call a 50/50 design where it looks like two equal halves, the screws are usually longer and will work for you.  

A 30mm ring will definitely be too large.