[tyronejk]

I was dry-firing my Eigenbolt to break it in, about the 3rd or fourth tank, and after the I emptied the tank, I took out the internals to clean and relube and saw that the front bolt guide oring was torn completely apart in two places. I just replaced both orings with the stock 12's, but they're really tight.

Has anyone run into different orings that fit a little better than the stock 12's or the red Lurker ones? The red ones are a little loose and seem too soft.

Also, will polishing the inside of the bolt make the tolerances better? and has anyone tried it out? I know the ID was supposed to be 0.507" but the machinist drilled them to 0.500".

[Counterfeit_Syn5304]

Yeah if lurker would shed some light on this issue it'd be nice. I had the same problem of the guide orings getting damaged. Can we get more of the red orings?

[inmylife2415]

Umami told me but I forget what material, they are for sure softer 12's tho.

[matt3]

They are silicone 12s. I just ordered some from McMaster

[Rhino1XL]

My front bolt guide o-ring failed today after about 1.5 cases of paint. Had to switch to my AXE to finish the day. Other than that, the shocker shot great and I was getting 1 pod of paint for every 350-400 psi.
I've replace the red silicone o-rings with new urethane 12's. so far they don't seam to drag too much since I broke in the bolt with the red silicone ones.

[Lurker27]

Thoughts:

Polishing? - http://www.pbnation.com/showthread.php?t=3819575

Buna-N
ID,
mm Pkg.
Qty. Per
Pkg.
1.5 mm Wide
9.5 100 9262K632 $4.26
Viton® Fluoroelastomer
ID,
mm Pkg.
Qty. Per
Pkg.
1.5 mm Wide
9.5 25 9263K571 $6.91


Buna-N
ID,
mm Pkg.
Qty. Per
Pkg.
1.9 mm Wide
8.8 100 93125K25 $7.09
Viton® Fluoroelastomer
ID,
mm Pkg.
Qty. Per Pkg.
1.9 mm Wide
8.8 25 9263K643 $14.82


Pretty upset about this but there has to be a perfect fit

[Nashorn]

I'm putting my money on the 1.5 x 9.5 o-rings. IIRC, they are about the thickness of a piece of card stock paper smaller than the #12. I would imagine that would loosen things up just enough to promote bolt movement without loosing the seal.

Benzy2 ordered a few sets of metric o-rings (including the 1.5 x 9.5) to play with. I hope he chimes in soon with some results.

[Rhino1XL]

I'm Also thinking along the lines of the 1.5 mm o-rings. I just don't have any!

Also, what brand of metal polish was being used in the polishing thread. I own Wenol brand, but it's justly for fine jewelry. (Not that I own jewelry....)

[gutgut2hi68]

think i could find 9.5 x 1.5/70 o-rings at a home depot?

[Shooter28]

You should be changing your orings about once a case during the break in. I think the 'sludge' is from broken down orings. Once you no longer see it developing, should be broke in. I've been using regular buna 12's. The orings I got from lurker swelled up on me after a few cases, makes sense why they tore.

[jim4130]

I've got some 9.5 x 1.5 in route to me to hopefully in my mail box today.

[Nashorn]

As Lurker and others have pointed out, these are the 3 metric o-rings that I think are the most likely substitutes for the #12 to get less bolt stick. If you plan on getting these o-rings, I recommend trying them in the order below from loosest to tightest. Product numbers from McMaster's website have been provided to hasten your purchase if you so choose to pursue this on your own.

Substitute #1: 1.6 x 9.1mm

This one is smaller in all dimensions (cord diameter, ID, and OD) than the #12. The OD is the smallest of the 3 and would actually be even smaller due to the additional stretching caused by having a slightly smaller ID than the #12. This would most likely be the loosest of the 3 and possibly more prone to leaking. But, if it seals, this bad boy should reap wondrous results.

Substitute #2: 1.5 x 9.5mm

If #1 leaks, then this o-ring is our middle man. It has the smallest cord diameter and largest ID of the 3. However, the OD still comes in a little bigger than #1 yet still a little smaller than #3. The larger ID and smaller cord diameter (compared to a #12) may give it a higher tendency to roll back and forth in the pocket and increase chances for spiral failure (though I think the problem is negligible).

Substitute #3: 1.9 x 8.8mm

This is the "fattest" and I would also dare say toughest member of the group. It has the largest cord diameter but the smallest ID of the 3. The OD is just over 2 tenths of a mm smaller than a #12, but the smaller ID will cause it to stretch in the bolt guide pocket and possibly decrease the OD just a little further. The larger cord diameter and tighter fit will make spiral failure almost nonexistent though I do wonder if it's sealing properties will be affected due to being stretched a little.

Everybody's guns will have small differences in dimensions and tolerances, so any or none of these could work for you. I plan on getting all 3 and just seeing how it goes.

[Rhino1XL]

Well said sir!

[Nashorn]

Hold on. I forgot about the 1.5x9mm. I will update shortly....

[tyronejk]

Damn, thank you tons, Nashorn.

[Nashorn]

I think we can forget about the 1.5 x 9mm. The OD is almost a full millimeter shorter and has to stretch a little more than a #12. There's no way that would seal. The tolerances couldn't be that far off.

[jim4130]

the middle man is what may or may not be sitting in my mailbox right now so hopefully.

[Nashorn]

Originally Posted by jim4130

the middle man is what may or may not be sitting in my mailbox right now so hopefully.

I look forward to hearing how it goes for you. Please post up either way it goes.

[amossbur]

Looks like I'll be giving these a try, but its too bad you have to buy these in packages of 100.....

[jim4130]

Thats a bad thing? Theyre like $5 a bag.

[tyronejk]

The more orings, the higher the chance that you get a couple perfect ones! Have you gotten yours yet, Jim?