Author Topic: P-Rod Build (Read 3086 times))

FuzzyGrub · « **Reply #20 on:** June 17, 2020, 03:27:12 PM »

Quote from: Jzizzle on June 17, 2020, 01:31:12 PM

Quote from: FuzzyGrub on June 17, 2020, 12:08:28 PM
Quote from: Jzizzle on June 17, 2020, 11:35:02 AM
Appreciate your input. Let's see what gains come from opening the throat first.

At its current state, we already achieved 37fpe unregulated and 32fpe regulated at 2400psi with the jsb 33.95gr.

I only have used up to the 25g pellets. If I understand your build correctly, your plenum is basically the whole air tube.

BTW, you are overdue on pictures.

Yes the entire oem reservoir is the plenum.
If you can lend a hand in uploading a picture. I simply snap a pic on cell phone and attempt to attach but says file is too large.

I send it from my phone to email and select “medium” resolution. On the email side I do edit it for rotation and save it. Then use the browse for file posting option.

PikeP · « **Reply #21 on:** June 17, 2020, 03:28:58 PM »

I use an image hosting service, as I find it better for lurkers to be able to have access to see pictures. Where as using the forums built in function requires membership and to be logged in to view said pictures...kill 2 birds with that 1 stone.

Jzizzle · « **Reply #22 on:** June 17, 2020, 04:05:32 PM »

This is original setup. I now have the fittings swapped out with a tee for a reg pressure gauge and it allows the bottle to sit slightly higher. I also have a 3d printed bipod mount. I'll upload them.

Tucobenedicto · « **Reply #23 on:** June 17, 2020, 04:15:30 PM »

Nice,the only thing that scares me is the unsupported bottle,i suppose you have a plan about this.

Jzizzle · « **Reply #24 on:** June 17, 2020, 04:17:52 PM »

Absolutely, temporary zip ties but eventually print a bottle/barrel support.

Jzizzle · « **Reply #25 on:** June 17, 2020, 04:21:15 PM »

I ended up getting a photo editor so I can crop the image to a smaller size so I can upload.

I'll post up the revised setup once I finish with the valve and reassemble.

Tucobenedicto · « **Reply #26 on:** June 17, 2020, 04:27:45 PM »

I am courious to see your work and final numbers,i was thinking about a carbon fiber tank to raise my fill pressure,there are 2" diameter bottles around?

Jzizzle · « **Reply #27 on:** June 17, 2020, 05:00:30 PM »

Yes, the 220cc has 2" diameter, the 350cc like then one I'm using is 2.4" diameter.

Tucobenedicto · « **Reply #28 on:** June 18, 2020, 01:11:01 AM »

Thanks,found even a 250cc in UK but not cheap at all (about 140 pounds),i will wait to source something direct from china,not fast in this moment due to the covid.

Jzizzle · « **Reply #29 on:** June 19, 2020, 04:45:12 PM »

Next step here was opening up the throat to .250.

2500psi
18.13gr at 895fps for 32 fpe

2800psi
18.13gr at 926 fps for 35 fpe
33.95gr at 726 fps for 40 fpe

Comparing to previous regulated tests before opening the throat gained 10fpe or 126fps using the 18.13gr. The 33.95gr increased 76fps for 8 fpe.

So we hit 40fpe regulated thus far. Long way from 15fpe out of the box. Too bad the 33.95 are not accurate out of the prod at 70 yards. I have the 25gr on the way so hopefully these are accurate and we can keep the fpe up over the 18.13gr.

I now have it tuned with reg at 2500psi, hammer backed out for 875fps on 18.13. About 100 shots for 1.18 efficiency.

Jzizzle · « **Reply #30 on:** June 19, 2020, 04:48:48 PM »

Temporary bottle retention setup. Currently working on a 3d printed support.

Also need to swap out the bottle gauge for an accurate one. Bottle is filled to 4k but gauge reads very high. I'm using a talon tunes gauge for monitoring reg pressure.

Backyard Shootr · « **Reply #31 on:** June 19, 2020, 06:01:03 PM »

Quote from: Jzizzle on June 19, 2020, 04:48:48 PM

Temporary bottle retention setup. Currently working on a 3d printed support.

Also need to swap out the bottle gauge for an accurate one. Bottle is filled to 4k but gauge reads very high. I'm using a talon tunes gauge for monitoring reg pressure.

That does not look very safe to me.

larspawn · « **Reply #32 on:** June 19, 2020, 06:20:33 PM »

Quote from: Backyard Shootr on June 19, 2020, 06:01:03 PM

Quote from: Jzizzle on June 19, 2020, 04:48:48 PM
Temporary bottle retention setup. Currently working on a 3d printed support.

Also need to swap out the bottle gauge for an accurate one. Bottle is filled to 4k but gauge reads very high. I'm using a talon tunes gauge for monitoring reg pressure.
That does not look very safe to me.

Yeah that would scare the crud out of me. Lots of force on that connection. I guess it’s after the reg so it’s “only” 2500 PSI. What could go wrong?

Jzizzle · « **Reply #33 on:** June 19, 2020, 06:24:46 PM »

You are referring to the fittings connecting the bottle to reservoir being unsafe?

These are extreme pressure fittings off McMasterCarr .

larspawn · « **Reply #34 on:** June 19, 2020, 06:28:11 PM »

You’ve got a 12-15” lever putting a lot of force on that connector. You’d be better off with the printed bipod holder extending up to the original tube. That would support bottle more safely.

Jzizzle · « **Reply #35 on:** June 19, 2020, 07:03:47 PM »

Quote from: larspawn on June 19, 2020, 06:28:11 PM

You’ve got a 12-15” lever putting a lot of force on that connector. You’d be better off with the printed bipod holder extending up to the original tube. That would support bottle more safely.

Right, that is what I'm working on currently.

If it wasn't clear on the previous post, this setup in the pic is temporary.

Jzizzle · « **Reply #36 on:** June 19, 2020, 08:25:54 PM »

Until I can print the barrel/bottle bracket, I've moved the bipod back and is secured with a bolt to the OEM barrel band. I think I will use this in conjunction with a 3d printed barrel/bottle bracket.

larspawn · « **Reply #37 on:** June 19, 2020, 11:07:30 PM »

Quote from: Jzizzle on June 19, 2020, 08:25:54 PM

Until I can print the barrel/bottle bracket, I've moved the bipod back and is secured with a bolt to the OEM barrel band. I think I will use this in conjunction with a 3d printed barrel/bottle bracket.

That looks way better John. You know they always say two points of contact are better than one! I think that solidly locks the bottle to the gun and you've removed a lot of stress on that connector.

Jzizzle · « **Reply #38 on:** June 20, 2020, 12:06:22 AM »

I appreciate the feedback.

I'm still learning on cad but in progress of designing a bottle support that will also wrap around both the OEM reservoir and barrel shroud. Plan is to add this in conjunction with current setup. Maybe even use 2 of them.

Eager to try out the 25gr but they won't be here for another week.

So far we have a high of 40fpe with the 33.95 Beasts and 35fpe with the 18.13 jumbos. 25gr will test end of next week.

The more I shoot this the more I want that side lever breech...

Tucobenedicto · « **Reply #39 on:** June 20, 2020, 01:22:17 AM »

Great results!

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P-Rod Build

Author Topic: P-Rod Build (Read 3086 times))