Author Topic: Liberty plenum (Read 6274 times - 1 votes)
)

Rohmpm · « **on:** March 28, 2019, 11:26:13 PM »

Some of you are aware of the plenum I've been working on for the Liberty. I received my new, unmodified gun, I am starting from square one.
The gun is a new 22 Liberty with absolutely no modifications testing with four pellets.
Filled the gun to 3k. Average of five shots each, these numbers are specific to this gun, all shots single loaded.

21.14 Barracuda match 744 fps 25.9 ft lbs
28.5 Eunjin 637 fps 25.7 ft lbs
15.89 JSB 860 fps 26.1 ft lbs
18.13 JSB 817 fps 26.9 ft lbs

Next I removed the factory plenum and replaced it with the one I have pictured previously,
No other changes. The guage I have on the plenum indicated 21-2200 psi. I would assume that the factory plenum would have been the same. Again, average of five shots each.

21.14 Barracuda match 784 fps 28.8 ft lbs
28.5 Eunjin 679 fps 29.2 ft lbs
15.89 JSB 905 fps 28.9 ft lbs
18.13 JSB 860 fps 29.8 ft lbs

With no other changes on a bone stock gun, the larger plenum was about three ft lbs to the plus on all four pellets.
Tomorrow I will enlarge all ports to .187 and test again. I reposted the prior pics of my modified gun with the large plenum.

dpittman · « **Reply #1 on:** March 29, 2019, 12:05:50 AM »

Will you have them available. That along with a barrel port drilling could be awesome

RDB · « **Reply #2 on:** March 29, 2019, 12:14:11 AM »

Subscribed. I love watching a plan come together.

Rohmpm · « **Reply #3 on:** March 29, 2019, 12:48:07 AM »

Quote from: dpittman on March 29, 2019, 12:05:50 AM

Will you have them available. That along with a barrel port drilling could be awesome

I plan on offering them when testing is complete. Looks like two versions, one that will fit unseen within a modified stock, very simple in synthetic. I also bought a wood stock gun to see what is necessary for fitment, definitely not as simple as the synthetic version. The other will be larger in volume, requiring more modification and protruding slightly from the bottom of the stock, for those seeking the most power.

green · « **Reply #4 on:** March 29, 2019, 01:00:56 AM »

Billy,
Great idea to start a new thread regarding the plenum since the original one seemed to be going in all directions. Looking forward to following your work and testing. Once you have the plenums available for sale, will you start some type of list to sign up and purchase?
Thanks again for taking the time to do this for us, Tom

darkcharisma · « **Reply #5 on:** March 29, 2019, 03:28:02 AM »

I think Billy might have had the list constructed already. i just know i am supposed to be one of the first on the list.

...cnc plenum, who doesnt want them?

good work Billy. cant wait to see the tesults with all the ports opened to 3/16 and 7/32 if you are up to it?

Letum · « **Reply #6 on:** March 29, 2019, 04:26:44 AM »

Looking amazing Billy!!!!

What sort of increase are you looking at with the larger Plenum?

I am definitely keen on a larger one, now hurry up

as I want to build myself a new stock which will be designed with your plenum in specifically.

kzz1kaw · « **Reply #7 on:** March 29, 2019, 05:04:25 AM »

+1 on the plenum 😎👍🏾

dpittman · « **Reply #8 on:** March 29, 2019, 07:41:00 AM »

Can you post a pic of both plenum side by side. I guess with a wood stock you can't make it too wide or it will sacrifice the strength of the stock at the plenum.

Lastdog · « **Reply #9 on:** March 29, 2019, 07:45:59 AM »

+1 got a synthetic parts gun just to add you new and improved plenum. MORE POWER arrrrrrr.

FuzzyGrub · « **Reply #10 on:** March 29, 2019, 08:02:12 AM »

Quote from: Rohmpm on March 29, 2019, 12:48:07 AM

Quote from: dpittman on March 29, 2019, 12:05:50 AM
Will you have them available. That along with a barrel port drilling could be awesome

I plan on offering them when testing is complete. Looks like two versions, one that will fit unseen within a modified stock, very simple in synthetic. I also bought a wood stock gun to see what is necessary for fitment, definitely not as simple as the synthetic version. The other will be larger in volume, requiring more modification and protruding slightly from the bottom of the stock, for those seeking the most power.

Looking forward to what you come up with on the wood stock.

I agree, from what I see, it will be a bit tricky with the wood stock (narrower) and being right at the balance point of the rifle. Protruding items, would be an annoyance. If it was at least flush with the gauge removed, and plug inserted, would be great. It would be nice to have the gauge flush to the bottom, given the external reg adjuster, but don't know if that compromises too much on the plenum size. That won't satisfy the power users though.

FWIW: Your stock power numbers look right in the range of what I have observed.

dpittman · « **Reply #11 on:** March 29, 2019, 08:50:39 AM »

The stocks are so big and bulky in that area that a protruding plenum may not be that big of a deal. I think the gauge on the bottom is a great idea. You can monitor your reg pressure and creep if you have any.

dpittman · « **Reply #12 on:** March 29, 2019, 08:54:15 AM »

Am I wrong on this but with increased plenum size we can decrease our reg setpoints without losing power ( Maybe even gain power) and get an awesome number of shots without ridiculous (hand pump) fill pressures.

superchikn · « **Reply #13 on:** March 29, 2019, 09:36:52 AM »

Glad to see this in a new thread. I will be ordering one of these.

Orion · « **Reply #14 on:** March 29, 2019, 09:53:10 AM »

Subscribed, you guys are great! I'm so lucky to be a member of the Liberty Club

FuzzyGrub · « **Reply #15 on:** March 29, 2019, 09:53:19 AM »

Quote from: dpittman on March 29, 2019, 08:54:15 AM

Am I wrong on this but with increased plenum size we can decrease our reg setpoints without losing power ( Maybe even gain power) and get an awesome number of shots without ridiculous (hand pump) fill pressures.

Yes, and that is my primary motivation to wanting a bigger plenum.

While it is nice to have the ability to fill to relative high fill pressures, I'd prefer to get more shots from a 3500 fill.

Orion · « **Reply #16 on:** March 29, 2019, 09:59:34 AM »

Quote from: FuzzyGrub on March 29, 2019, 09:53:19 AM

Quote from: dpittman on March 29, 2019, 08:54:15 AM
Am I wrong on this but with increased plenum size we can decrease our reg setpoints without losing power ( Maybe even gain power) and get an awesome number of shots without ridiculous (hand pump) fill pressures.

Yes, and that is my primary motivation to wanting a bigger plenum. While it is nice not to have the ability to fill to relative high fill pressures, I'd prefer to get more shots from a 3500 fill.

The only thing that I really miss on the Liberty is the ability to tune the HST easily...I'm too spoiled with my Taipan...

cosmic · « **Reply #17 on:** March 29, 2019, 10:44:41 AM »

Put me down for a wood stock plenum ( it can protrude ) Billy...

Rohmpm · « **Reply #18 on:** March 29, 2019, 01:13:59 PM »

Quote from: dpittman on March 29, 2019, 08:54:15 AM

Am I wrong on this but with increased plenum size we can decrease our reg setpoints without losing power ( Maybe even gain power) and get an awesome number of shots without ridiculous (hand pump) fill pressures.

I have already demonstrated that with a gun that was already modified so the results could have been inconclusive. Exactly why Iv am startind anew with a bone stock gun to document each change.

dpittman · « **Reply #19 on:** March 29, 2019, 01:29:12 PM »

Thanks Billy I really appreciate the effort

Thank you to our advertisers!

Liberty plenum

Author Topic: Liberty plenum (Read 6274 times - 1 votes) )

Author Topic: Liberty plenum (Read 6274 times - 1 votes)
)