Author Topic: CP2 gets a big upgrade. (Read 14302 times))

Pelletjunkie · « **Reply #20 on:** January 17, 2021, 02:30:36 PM »

Because of the tiny poppet stem and the way too long hammer spring, I used a bicycle inner tube patch instead of orings. Just cut a hole in it for the poppet stem, trim it to diameter, then peel and stick. Then I experimented with shimming the valve return spring with a washer or two. All the guns, from the CO2 CP1 to the HPA models waste way too much air out the barrel. Have to tighten things up.

avator · « **Reply #21 on:** January 17, 2021, 02:34:24 PM »

Good idea.... thanks

avator · « **Reply #22 on:** January 17, 2021, 02:51:28 PM »

Well now.... 30yds in a 10mph cross wind is not cooperating.
Given that... of what I've tried so far... CPHP at 7.9 are doing much better than anything heavier.

A bowl of home made taco dip and a bag of Doritos has slowed my progress.

avator · « **Reply #23 on:** January 18, 2021, 08:09:01 AM »

Frank.. at the risk of displaying my lack of tuning knowledge, I have a question.
What affect will a lighter valve spring have?

avator · « **Reply #24 on:** January 18, 2021, 10:36:38 AM »

Beautiful crisp morning out there. Sun shining bright and 0 wind.
I found what may be one of it's favorite pellets and it comes as somewhat of a surprise due to it's weight.

avator · « **Reply #25 on:** January 18, 2021, 10:40:44 AM »

I painted up the LDC with the only black rattle can I had on hand. Unfortunately it was gloss... not a fan of gloss. So, I let it cure for about an hour and ruffed it up. Gave me that warm and fuzzy well worn feeling...

avator · « **Reply #26 on:** January 18, 2021, 10:42:53 AM »

Got my target set out to about 19 - 20 yds. I didn't hit it with the range finder.... yet.

Hey, these things take time...

avator · « **Reply #27 on:** January 18, 2021, 12:53:47 PM »

Interesting....
This is why I asked about lighter valve spring.....
From 200 bar down to 100 bar.

avator · « **Reply #28 on:** January 18, 2021, 01:14:02 PM »

Just talked with Wes in Canada. What a guy. The hammer spring in the PP800 is much heavier than the CP1. He said he meant to send me one. I never ordered one so why would he? The thought never crossed our minds.
Anyhow... one is on e the way now.
Meantime, I'm a happy plinker.

miksatx · « **Reply #29 on:** January 18, 2021, 01:40:05 PM »

My Diana Bandit and mrodair Varmit PCP have the same hammer spring. All my Diana Chaser have weaker springs for running co2. I was getting bout the same numbers with a Chaser spring in my Bandit. Working on tuning my down to sub5 fpe. Working on keeping the pellet in the sparrow. And keeping the pellet in 1/2" cedar fencing.

Pelletjunkie · « **Reply #30 on:** January 24, 2021, 08:05:51 PM »

Quote from: avator on January 18, 2021, 08:09:01 AM

Frank.. at the risk of displaying my lack of tuning knowledge, I have a question.
What affect will a lighter valve spring have?

I’m sorry for abandoning this topic. The last thing you need with a short barrel is a weaker valve return spring. With the bulbous hammer in those guns, you want to shorten the dwell. Either lighter hammer or close that valve quicker by shimming the valve spring. That’s what I did. But I didn’t go shimming crazy. Just a thin washer or two made a difference. This winter if I run out of projects, I may revisit the hammer and put it in my lathe an lighten it. I lightened a hammer on my Kral Jumbo in increments and wow, that gun is a whole different gun.

avator · « **Reply #31 on:** January 24, 2021, 08:08:37 PM »

It's all good.. I got the HPA hammer spring coming...

Pelletjunkie · « **Reply #32 on:** January 24, 2021, 08:16:10 PM »

I just looked at your string. I wasn’t logged in before and couldn’t see it. You are still climbing in velocity at shot 54. That’s a good problem to have. When you swap springs, but control yourself from changing anything else, let’s see what that exact same string looks like. I’m curious. But it will be good data for the next step. One change at a time is key.

EdinGa · « **Reply #33 on:** January 24, 2021, 08:28:56 PM »

That's a nice looking carbine. I've got a .25 pp800 coming from Wes. It's supposed to be delivered tomorrow. I've already talked to a buddy of mine about making a stock for me. Can't wait to tinker with it and turn it into a little thumper.

avator · « **Reply #34 on:** January 24, 2021, 08:37:36 PM »

Quote from: Pelletjunkie on January 24, 2021, 08:16:10 PM

I just looked at your string. I wasn’t logged in before and couldn’t see it. You are still climbing in velocity at shot 54. That’s a good problem to have. When you swap springs, but control yourself from changing anything else, let’s see what that exact same string looks like. I’m curious. But it will be good data for the next step. One change at a time is key.

That's exactly the plan... I benched it and moved on to other things in the meantime.

avator · « **Reply #35 on:** January 29, 2021, 08:53:55 PM »

Someone once called me a bit 'chatty'. What an understatement that was !
I got the spring from Wes in the mail and scanned back my posts to bring this topic back to continue on it....
10 pages of MY posts back in 5 short days...

avator · « **Reply #36 on:** January 29, 2021, 09:01:43 PM »

Anywhich....
Like I said, the PP800 spring came in the mail from Wes today...
I got home from work and landed in the recliner for a couple more posts before I hit the gun room... After 'chatting' for 2 hours, I made it to the gun room...

I stuffed the new spring in and put it back together. Loaded a mag and stepped out back. I had left the air pressure about half full in the gun and it was right where I left it..... 5 days ago.
I aimed downrange in the semi darkness of the yardlights.
BANG !!
Oh Yeah ! This is gonna be a fun one.
Too dark and late to do much testing but you can bet I'll be all over it in the morning.

avator · « **Reply #37 on:** January 31, 2021, 09:39:09 AM »

Ended up going to a buddy's ATV park yesterday for a very large event.

So this morning I got around 4am and put the coffee on. After Betty Lou and Rambo got up I headed for the gun room.
First on the list was filling my 30min tank from 3k to 4300. That went well and took about 10min with the temp rising to 134f and the 5gal tank water climbing from 72f to 80f.

I pulled the hammer spring back out of the "CP800" (for lack of a better description) and clipped 1 coil off. Then I bent and dressed that end of the spring. I would guess I reduced the length by 3/16?.
I got the shooting bench all set up with the laptop and chrono. Mags are filled and ready to go. Gonna finish this coffee and smoke and hit the shower.
Then I'll get some numbers and see where we are.

Pelletjunkie · « **Reply #38 on:** January 31, 2021, 10:54:35 AM »

Snowing and freezing here so I will be checking to see what your results are.

avator · « **Reply #39 on:** January 31, 2021, 10:59:15 AM »

Frank,
I put the PP800 spring in it and only got 2 mags so I knew it was shooting too hot for my purpose.
So I clipped a coil before I even went to the chrono.

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CP2 gets a big upgrade.

Author Topic: CP2 gets a big upgrade. (Read 14302 times))