Geissele Super 42 Receiver Damage

**panzerr** · 05-06-17, 07:54

I recently dropped a Geissele Super 42 into my 10.5 Noveske. I was running an H2 buffer with a standard Colt buffer spring, so I added a tungsten weight to the Super 42 buffer to put it in the H2 configuration.

I ran 500 rounds of wolf through the weapon with no malfunctions in one range session. Everything seemed just fine until I broke the weapon down for service and found that I was now the proud owner of the fabled cam pin damage to the upper receiver. Clearly I need to add another tungsten weight to put the Super 42 buffer into H3 configuration, but I'm mystified as to why. The Super 42 spring is supposed to be stiffer than the standard spring, is it not? Or even if it were the same stiffness, I should have been good to go, especially with the underpowered Wolf. Has anyone else had problems with the Super 42?

In any event, despite the fact that the damage is functionally okay, I am not happy about it as there were only 3500 rounds through this SBR and it was pristine until I added the Super 42.

**GH41** · 05-06-17, 08:02

I hate it for you but isn't this the perfect example of trying to fix something that isn't broken?

**panzerr** · 05-06-17, 08:08

Originally Posted by GH41

I hate it for you but isn't this the perfect example of trying to fix something that isn't broken?

It is. However, I like the concept of a braided buffer spring and I wanted to try it. Sometimes, no matter how perfect I think a setup is, I like to try something different to challenge my preconceptions.

**RHINOWSO** · 05-06-17, 10:02

I went from a Colt H1 / blue Springco to the Geissele 42 H1 Buffer / Braided Spring combo and haven't had this occur. Right around 750 RDS with it in, Prvi M193 with some Federal SOST through it. Upper is a BCM BFH 16 ELW KMR-A Midlength gas with a Mega lower / LMT Buffer Tube.

**JulyAZ** · 05-06-17, 11:04

Deleted

**gaijin** · 05-06-17, 12:41

I also run the Geissle 42 with H2's in three AR's; 10.5" pistol, 14.5" and 16".
No issues with them to date.

**sinister** · 05-06-17, 13:35

Buffer and spring weight have nothing to do with cam pin head drag wear in the upper.

**panzerr** · 05-06-17, 14:18

Originally Posted by sinister

Buffer and spring weight have nothing to do with cam pin head drag wear in the upper.

Do you care to elaborate?

Geissele Tech support stated in response to my email inquiry about the wear: "If the buffer weight is too light, bolt bounce may be occurring. This could be a reason for an increase wear from the cam pin"

**sinister** · 05-06-17, 16:12

Originally Posted by panzerr

Do you care to elaborate?

Geissele Tech support stated in response to my email inquiry about the wear: "If the buffer weight is too light, bolt bounce may be occurring. This could be a reason for an increase wear from the cam pin"

If the buffer is too light then yes, indeed you'd have hammering at the rear of the indent (as yours seems to show) as well as drag wear. The cam pin head will wear due to the camming action of the cam pin track, whether or not it's an enhanced carrier, if there's a steel insert, or the material is fully machined away. A heavy or XH buffer with carrier weights is still going to have wear as well.

Perhaps if it's chamfered or you have a round head it might not contact the corner.

A 10.5 to 12.5 (especially with a suppressor) is going to show wear.

Examples:

Even with a steel insert (like here in Colt's 901) it's going to wear.

If I recall one the M4C shooters had this wear at 5,000 in a Ruger with a POF roller cam pin:

Yours indeed looks rougher, possibly from bolt carrier bounce.