PP750 power mods on Going!

[oldpro]

 Well the measly 480fps of my .177 PP750 was not cutting it so after a few very simple mods shes averaging almost 780fps with 8.4 jsb! Nice jump!!! No regulator change only simple mods. It’s over dwelling now so I’ll put it a lighter hammer spring also. Opened up TP to .170 and opened up breech block to allow flow plus original spring covered most of hole then put in a much lighter valve return spring and under cut poppet stem. Loving it!!!!😇 Thats tripple the FPE with hammer spring on lowest setting.

[RunsOnAir]

Thanks Travis for sharing!
I'm subscribing. If you have more to share, I'd hate to miss it
I have the .22. I am now tempted to do my first ever 'minor' mods on my first ever PCP
What I would like to do but have no clue how is to lighten slightly the 2nd stage of the trigger without going too far and make it dangerous.
Any advice from anyone as to where to look would be greatly appreciated !

[oldpro]

Thanks Travis for sharing!
I'm subscribing. If you have more to share, I'd hate to miss it
I have the .22. I am now tempted to do my first ever 'minor' mods on my first ever PCP
What I would like to do but have no clue how is to lighten slightly the 2nd stage of the trigger without going too far and make it dangerous.
Any advice from anyone as to where to look would be greatly appreciated !

Trigger is Next on my  agenda! I believe theres another 5fpe in the gun with some more mods without touching the regulator.

[oldpro]

just put in a spring half the in/lb rating and now cocks like butter!!!! Detuned down to 700 fps and even quieter than it was at 480 fps pre work. Also the second stage is much softer!!! WINNER

[Hobbyman2007]

I sure wish we had gun laws that made sense up here. Unfortunately for me I’ll just have to drool and watch. I did however find that the trigger adjusting screws can certainly use some polishing where the contact the sear. And the first stage spring got a bit of a clip to reduce the pull weight. I’m going to tackle the hammer and sear shortly and hope to reduce the creep .

[bear air]

Nice work Travis. So many tiny parts!!!!!

[superchikn]

Following.

[B.Guns.]

Where do you get different weight hammer springs?

[oldpro]

Where do you get different weight hammer springs?

I have a huge supply of springs from a decade of tuning. I just looked threw my stash

[Motorhead]

Honestly would put the HEAVY poppet spring back in and see what you get ?

[oldpro]

Honestly would put the HEAVY poppet spring back in and see what you get ?

It just makes it harder to open the valve and that puts a load on the sear, its a two step fix. Reduce opening force that then reduceds trigger weight.Its a sear drag system Scott

[oldpro]

Marked barrel thimble and there’s two thimble TP  and none are clocked at the breech TP so I filled the void and drilled new TP to .125 up at a angle to prevent pellet sliding into TP. Gun is tuned to 700fps before mod and when Epoxy dries I’ll report back. I want to keep this a pistol so I will not be making a longer barrel etc.

[Motorhead]

My suggestion based on the fact gun even tho making more power is now over dwelling.   Either heavier poppet spring or COBRA chamber will get the valve to close up quicker and chop the dwell time.



cobra cobra cobra .... says the Cobra King 

[oldpro]

 Ok results in we gained 32 fps!!!! Now to turn it further down and get back to 700 fps. Trigger is so much better and dwell much improved. On high we hit 820fps with 8.4 jsb. Still some left in there without changing regulator pressure I believe. My lowest spring setting is now 654 fps. I believe I can just about get this hammer in free flight!!!  More to come

[Rupertt]

just put in a spring half the in/lb rating and now cocks like butter!!!! Detuned down to 700 fps and even quieter than it was at 480 fps pre work. Also the second stage is much softer!!! WINNER

That sounds like a Real Winner..!!!
I found the pull weight on the cocking lever to be so heavy I'm afraid I'll break it.
I know you just pulled something out of your collection, but if you could give some sort of direction/link to a spring, I would be truly grateful....

[Toddspeed]

I just watched your review yesterday. When you said it was shooting 480fps I started to loose interest, then I remembered you got it from Canada and it was tuned down. Looks like you fixed that problem.

What is the shot count when shooting 8 grains at 700fpe?

[oldpro]

 Few more mods in the books! Wanted to fix the gritty feeling cocking and found the cause the bevel is sharp in the hammer bore as is the spring adjuster down some grinding and polishing did the trick plus the lighter hammer spring and now butter! Trigger is down to 2lbs so that’s perfect for me. Vented and polished hammer as well. New spring has my low at 600fps my high at 800fps so I’m done with that part. Next custom air stripper and baffles.

[bear air]

Excellent results Travis. I know Brian said they were pretty rough from the factory. With all those little parts I figured it would be in my best interest to have a professional airgun smith do the work.

[oldpro]

Excellent results Travis. I know Brian said they were pretty rough from the factory. With all those little parts I figured it would be in my best interest to have a professional airgun smith do the work.

I don’t know who Brian is but he’s correct it’s a bit rough but really not to bad! A little work and the diamond really shines! It’s a fantastic gun for the money

[mrbulk]

...*popcorn*...