Umarex to make a 68 caliber, 5-shot revolver- HDR-68

[XEMON]

I haven't touched the spring ...
I did some machining inside the valve ... Once I field it and do some more test I may put up a "how to" if people are interested 👍

[Chuck E Ducky]

So a heavyweight spring helped up the velocity or just a longer one? Finally got some time off I want to mess around with mine.

[BrickHaus]

I need to tear mine open and mess with the plug.

[Ecapnation]

Ok.....fielded mine this weekend.

I immediately ordered number 2.

Using very old first strike i only had one brake but it was mid barrel so I think the zoom dot zoom died.

However..... If you look at the cylinder there's an interesting added bonus, a nub that aligns and fits into the groove on the round effectively forcing it to spin.

At full 280 fps it's a long balling champion. Once I get the hand of shooting and aiming it I could place accurate single shots well out of range of conventional paint.

[Nyknight01]

I think the thought is the foamie to be flush to the bolt tip....so when the bolt is sprung back the foam does not protrude into the cylinder.
this would need to be a new designed tip...

[COB]

I might be wrong, but then that's not new. The back of the cylinders have a flange, making them front load only. So the bolt can only move forward until flush with the flange on the back of the cylinder. Wouldn't this make the foamy thing useless?

[XEMON]

Great idea, the problem is that once the gun is pressurized, the bolt move forward and is flush to the back of the cylinder ... We may have a few thou, but that's about it ...
Punching a gask t material the proper thickness might be a better solution ... I have some thin and soft silicone sheets that would be great if they fit in there ...

[BrickHaus]

S9. Xemon has me thinking. Let's get dimensions for that foamie tip figured out and we can 3d print a mold. Then with my rocket foam, I pour a 2 part polyurethane foam to make a bunch in one shot.

[XEMON]

Made an awesome foamy tip:




But once it's aired up, the bolt move forward and become flush to the cylinder ... So the cylinder won't turn with the foamy tip:



On a good news, after the third attempt at upping the velocity, I'm now between 250 and 280 fps on a fresh CO2 👍
I may or or may not try to go a bit higher ... I really don't want to go above 3 and have to drop it down ...

And here is a "slow mo" (as slow as my phone can take) of the bolt firing:

[Grendel]

99% sure the Mag's Foamy is low durometer neoprene but a low durometer TPU would likely work as well.

[XEMON]

Yes, when firing, the bolt protrude into the cylinder ...

[Nyknight01]

Wait, so it's a revolver but there's still a bolt that makes contact with and chambers each round? Through the cylinder?

I didn't pull it apart yet but I believe that is the case as there is a spring in front of the bulb which almost looks like a blow forward type thing you find an automags..
Xemon... They are a dense foam however I have made 3D copies of them in flex material which work on Automags... Once I mess with the gun a little more I'll be a little more intrepid to tear it down and take a look

[The Inflicted]

I am strongly thinking the breakage is coming from teh impact of the bolt onto teh ball and not the air ...

The front of the bolt has a "ventury style" face ... it looks a hell of a lot like a mag bolt (similar valve design)

I am wondering if putting a foamy tip, similar to the one on mag bolts, wil help reduce breakage ...
Does anyone know what those foammy tips are made out of?

Wait, so it's a revolver but there's still a bolt that makes contact with and chambers each round? Through the cylinder?

[XEMON]

I am strongly thinking the breakage is coming from teh impact of the bolt onto teh ball and not the air ...

The front of the bolt has a "ventury style" face ... it looks a hell of a lot like a mag bolt (similar valve design)

I am wondering if putting a foamy tip, similar to the one on mag bolts, wil help reduce breakage ...
Does anyone know what those foammy tips are made out of?

[The Inflicted]

One trick I sometimes used with my .50 revolver was to pack the back of the balls down with a little bit of tissue paper or cotton ball. Wonder if that might help the blow-through issue at all.