Etha bolt bumper substitute?

[homerj]

So along with the detents, this morning i found that the bolt bumper on my gen 1 Etha was basically paste. It had the consistency of gasket maker if you’ve ever used that. The parts kits that came with the Etha didn’t include spares & i was hoping to give this thing a spin Saturday. Has anyone found a substitute for the OEM bumper? I feel like i could find something that would work as far as diameter. It’s the thickness that might be an issue, not having anything to compare it to.

[nak81783]

Any ideas on dimensions? Automag bumper? TiPX bumper? Check out neoprene washers at your local hardware store. Might have to stack them and/or cut to size.

[homerj]

My first thought was Automag bumper. I don’t know the dimensions though. Like i said, it was just paste. Really sticky too. I’m surprised it shot at all when i tested it Sunday.

[Booska]

I replaced the bolt bumper with an o-ring on my Etha 1 in a pinch and it's had no problems so far.

My Etha 1 is only used as a loaner though, so it maybe sees the field once or twice per year. It's held up with the o-ring just fine though.

[Pumpytrilly1]

I think I have like 10 I could sell

I never found a substitute.

[homerj]

How much?

[homerj]

So when the bolt is at rest there’s actually a gap where the bumper would sit. I found an o-ring that fits on the tube & fills that gap perfectly. As long as the o-ring can withstand the punishment, it SEEMS like it will work. We’ll see i guess.

[Booska]

Yep that's exactly how mine is. I think it was an o-ring from the small parts kit that came with it. It's janky, but it works.

[MrBarraclough]

Looks like the dimensions should be easy to determine with calipers. Outer diameter matches the OD of the bolt guide's body and the inner diameter should be just large enought to accomodate the OD of the shaft on the front of the bolt guide. Thickness is just the gap left when the bolt is at rest. As others have said, it does look awfully similar to an Automag bumper.

Doc has a set of round cutting dies he uses to cut reg seats out of sheets of various rubbers. I wonder if he could cut something to this size.

[MrBarraclough]

In looking up the Etha 1 manual and reading through the firing cycle, I must say, damn there's a lot of Automag DNA in that design.

[homerj]

So just to update, i found the parts kit from when i rebuilt a mag a while back. I had changed out the bolt bumper even though the old one was perfectly fine. Since the old one was still plenty useable i kept it & can now confirm that it fits the Etha perfectly. After ~1000 rounds last weekend the o-ring i used in place of an actual bumper looked fine so still think that’s a viable replacement. In a pinch at least but could last as long as an OEM bumper.