New Aimpoint M5

[17K]

While 7075 has higher hardness, ultimate tensile strength, and yield strength, the fracture toughness of 6061 is actually higher; all assuming the same temper (T6/T651) and material thickness.

Saying one is better than the other using such a simplistic analysis as the choice of raw material is not necessarily correct.

If you're gonna cut threads in it then the harder of those two materials is better.

[Don Quijote]

If you're gonna cut threads in it then the harder of those two materials is better.

They are both hard enough to cut good threads into. "Better" isn't always better. Sometimes "better" is a waste of money for no practical gain.

And I thought we were talking about toughness (as in resistance to damage) not machinability. Move the goalposts?

In any case, the Aimpoint-published vibration and shock test limits are the same for the M5 as they are for the M4 as they are for the PRO. Saying one is "tougher" than the others without evidence is not convincing.

[Boba Fett v2]

I won't be trading in my T2 for an M5/M5s, but I do plan on picking one up. That said, I really do hate the "mushiness" of the illumination adjustments on the Aimpoint micro series. It's sad when cheap Chinese red dots demonstrate a more positive click adjustment. Not that it's that important, but for what an Aimpoint costs they should be doing much better than that.

[17K]

They are both hard enough to cut good threads into. "Better" isn't always better. Sometimes "better" is a waste of money for no practical gain.

And I thought we were talking about toughness (as in resistance to damage) not machinability. Move the goalposts?

In any case, the Aimpoint-published vibration and shock test limits are the same for the M5 as they are for the M4 as they are for the PRO. Saying one is "tougher" than the others without evidence is not convincing.

I'm not moving goal posts. Threads in 7075 will resist pulling out better than 6061. Thread stripping was a problem with the 6061 T-1, the T-2 was 6061 with Heli-Coils, the M5 is 7075. The shock and vibration would more than likely kill the electronics before the body.

[Don Quijote]

Thread stripping was a problem with the 6061 T-1, the T-2 was 6061 with Heli-Coils, the M5 is 7075.

Overtorque a screw and blame the material. OK.

[17K]

Overtorque a screw and blame the material. OK.

No, but when the difference between too loose and stripped out is less than a few inch-pounds the material or fastener is at the limits of it's capacity.

That's why Aimpoint went with the tougher 7075 material for the housing.

[Don Quijote]

No, but when the difference between too loose and stripped out is less than a few inch-pounds the material or fastener is at the limits of it's capacity.

That's why Aimpoint went with the tougher 7075 material for the housing.

Where are you finding the information of what alloy is used in which housing? What's the M4 made of? Do its threads strip out easily?

Maybe the Comp series was pure genius.

[MistWolf]

A hit that will crack 7075 will bend or dent 6061. But 6061 will bend or dent before 7075 will.

I will tell you from experience that threads in 7075 will last longer than threads in 6061. However, regardless of alloy, a bolt or screw can only be torqued in aluminum threads so many times before the aluminum threads fail and that number isn't very high.

I didn't care for the layout of the M5, but an M5s might be worth considering.

[Don Quijote]

I will tell you from experience that threads in 7075 will last longer than threads in 6061. However, regardless of alloy, a bolt or screw can only be torqued in aluminum threads so many times before the aluminum threads fail and that number isn't very high.

All true

What I don't get is why is thread stripping an issue with the T-1s. Even if Aimpoint doesn't include a torque value for the screws that hold the sight to the mount, the internet is chock full of standard torque values by fastener size and thread material. Following those guidelines, and adding some thread locker for insurance, makes the problem pretty much moot.

Here's one: https://mdmetric.com/tech/Standard_t...ing_torque.pdf

It even tells you to back torque off 50% from standard for joints with aluminum threads and other similar, softer materials. Who knew?

On the subject of thread cyclic failure, while you're correct, the joint between the sight and its mount is supposed to be semi-permanent not something that gets done and undone on a regular basis.

[17K]

Where are you finding the information of what alloy is used in which housing? What's the M4 made of? Do its threads strip out easily?

Maybe the Comp series was pure genius.

From Aimpoint techs.

The Comp M4 are 6061 but use use a much bigger, coarser, deeper thread than the Micros.

Yeah, the Comp M4/M4s are awesome in the toughness department. The Comp M5 is the first Micro size to be up there with it. I wish they would have used the Heli-Coils in the M5 too.