Author Topic: Millennium Pumper Production - The Beginning - And The Lousy End (Read 292657 times))

CarsonRatSniper · « **Reply #780 on:** October 29, 2015, 09:20:02 PM »

Jeremy had a check valve failure - I'm ditching the stainless steel pin with 003 o ring & making a Teflon check seal like the Benjamin has.
The little O ring is getting beat up too fast.

Mike

CarsonRatSniper · « **Reply #781 on:** October 29, 2015, 09:41:42 PM »

New Teflon check

Mike

rsterne · « **Reply #782 on:** October 29, 2015, 10:43:04 PM »

The other style check valve you can try is a fixed, flat head screw with an O-ring riding on it.... Only the O-ring moves, no spring is required.... The air flow path is along a small groove cut into the threads of the screw.... The O-ring wedges into the space between the taper on the flat head screw and the flat surface it is threaded into.... On the pump stroke it flexes away from the screw shank and the air just blows past it.... This was pioneered by Steve in NC and proven to last extremely well in use....

Bob

CarsonRatSniper · « **Reply #783 on:** October 30, 2015, 12:48:42 AM »

#1 has pumped up & held air just fine since I first out it together & used it as our test rifle...but having the first gun I shipped have a problem is unacceptable, so I'm working with the parts I have.

Looks like an easy to make check that you showed though

I aired up #1 to 2000 psi, fired a .30 cal pellet and it took 18 pumps to get back to 2000 psi...and that's at mid 70 ft lbs!
Maybe Jeremy's had a burr in the pin but I'm not taking any chances - it would explain why it was taking him 30 pumps to get the pressure back up.

Mike

CarsonRatSniper · « **Reply #784 on:** October 30, 2015, 12:50:16 AM »

I installed.the new Teflon check in my rifle, aired it up to 2500 psi to cold flow the Teflon - the needle hasn't moved in over an hour...time to put it back together and see if she pumps up.

Mike

jvanschoonhoven · « **Reply #785 on:** November 01, 2015, 02:12:40 PM »

So I figurd out why it took so many pumps my headspace was off a bit so it was not pushing enough air. Fixed that changed the oring and deburred the plunger and now one shot takes 18 pumps not the 30 that it was taking.

c670809 · « **Reply #786 on:** November 03, 2015, 06:09:05 PM »

Interested in seeing .22 numbers when you have the time.

Thanks

CarsonRatSniper · « **Reply #787 on:** November 04, 2015, 05:02:33 AM »

I will have .22 numbers in a day or so.

In the meantime, I wasn't happy with the durability of the 113 O rings so I machined the grooves on the check valve & piston head to accept a 206 O ring. They have a 1/8" cross section.
The 113 is on the left & the 206 is on the right - the check valve has the new 206's on it.

The new Teflon check pin seal that's replacing the 003 O ring I originally had.

The piston head machined for the new O rings - the center is a little thin but its 7075 T651 aluminum so its just fine.

Piston head with 206's installed...its a really beefy seal!

I'll post more in a day or so - I'm at it 100% for the next 4 days.

Mike

Frank_Zuccarini · « **Reply #788 on:** November 04, 2015, 07:33:55 AM »

Very cool stuff. Thanks for sharing all these details with us.

Given the extremely limited nature of these guns, bullet-proof construction is highly desirable. Thanks for taking the time and effort to do it right.

Frank

Matt15 · « **Reply #789 on:** November 04, 2015, 09:12:30 AM »

What kind of o-rings are those?

CarsonRatSniper · « **Reply #790 on:** November 04, 2015, 11:39:34 AM »

Matt - They're Viton 75
I was going to use Mil Spec 90 Duro Urethane 206's but my supplier is out - the Urethane seals are also very stiff and hard to work with...these Vitons should never fail if kept properly greased.

Frank - You guys have been waiting a long time for these guns & been *very* patient and you don't know how much I appreciate that...I want these rifles to have the original seals 50 years from now

All the rifles will be lubed with divers silicon on the felt wipers for the piston assembly. Due to the bearing surface area of the new seals its going to need a true grease for a buttery smooth pump stroke.
I've been using divers silicon on my 1322 Super Pumper for 6 years and I haven't had *any* issues - the pump stroke is unbelievable and nothing like using traditional pump piston lube. I have to credit Gil Irvin for that idea when I bought his triple O ringed flat top piston for my 1322.

I'm in my shop this morning working on my mini lathe modifying the check valves and piston heads and machining the little Teflon check pin seals.

I'm assembling a .22 first as soon as I'm finished & will run it over the chrony if there's time - if I run out of light it will be first thing in the morning.

I'll be posting daily pics through Saturday - I'm in the home stretch guys!!!

Mike

c670809 · « **Reply #791 on:** November 04, 2015, 12:07:18 PM »

Those are some beefy o-rings. Looking good.

Thanks for the progress pictures. Looking forward to seeing them as they come along.

Matt15 · « **Reply #792 on:** November 04, 2015, 12:51:26 PM »

Quote from: CarsonRatSniper on November 04, 2015, 11:39:34 AM

Matt - They're Viton 75
I was going to use Mil Spec 90 Duro Urethane 206's but my supplier is out - the Urethane seals are also very stiff and hard to work with...these Vitons should never fail if kept properly greased.

Mike

Okay. I use mil spec 90 in all my pumpers.

CarsonRatSniper · « **Reply #793 on:** November 04, 2015, 12:59:09 PM »

Here's the new piston assembly...the follower ring at the back is still a 113...the 206's make those look wimpy and we thought 'those' were an upgrade!

Mike

CarsonRatSniper · « **Reply #794 on:** November 04, 2015, 02:35:34 PM »

Here's the difference between the pistons for 113 O rings vs the pistons for 206 O rings.

Mike

jvanschoonhoven · « **Reply #795 on:** November 06, 2015, 06:28:25 AM »

Ok guys i finalized the monocore design for the full shroud today. On full power the pellet striking the target at 25 yards is louder then the shot. Definitely back yard friendly. To be honst if I would have shot it this way at first ai would have thought it didn't have much power.
If I drop the fill presure to 1400 psi and turn the hammer spring out .200 I get 5 shots at 25 yards under an inch spread all with more then enough power for big squirrls and the like and its super quiet. Each shot on this power takes 10 pumps to refill. This gun is super easy to tune for whatever power and loudness you want. And so far accuracy at different power levels are amazing. If you pump up for every shot then they are making one hole groups on high or low power. Right now im working on figuring out my zeros for the different power levels. I can get 3 super consistant shots at full power then power down and get another 5 shots and end at 1000 psi.
High power seemse to take about 20 pumps per shot. If your in good shape pumping this gun is not that hard.
I pumped up from empty to 2000 psi and it took less then 5 minutes. This is not a gun your going to take plinking but for a hunting rifle its amazing! Super accurate field tunable and you will never run out of air. Its a great feeling to walk outside and just take a tin of pellets and my gun and not need anything else.

Some things to note are that it is a bit hard to chamber the .25 jsb pellets in this barrel but i think that is part of wny it is so accurate with these.
Loading the gun after each shot is actually faster then I first thought it would be. One important thing to note is when you cock it dont slip off the cocking knob or you will fire the rifle. As long as you always cock befor you chamber a pellet then this wont be a danger but if you decide to chamber a pellet then cock it you could actually fire it if you slip just like an old singe action revolver.
If you guys have more questions please fire away!
I don't personally have a chronograph so i cant give numbers yet but should chrono soon

jvanschoonhoven · « **Reply #796 on:** November 06, 2015, 06:41:10 AM »

Oh forgot to mention that I got a racoon tonight with the pumper! It was attacking my dog. Flashlight in hand and my illuminated reticle came in handy. Thought at first I might need a follow up shot but the first one did the trick

rsterne · « **Reply #797 on:** November 06, 2015, 02:38:12 PM »

Sounds like it's working great!.... Your reports are much appreciated....

Bob

CarsonRatSniper · « **Reply #798 on:** November 06, 2015, 10:42:29 PM »

John, this is for you...I hope your health gets better & I'll see what I can do when we do our first big run of guns.

#2 will be fully assembled tonight - here's a sneak preview...

This one is going to Texas - it'll be used in a filmed hunt that'll be aired on the Outdoor Channel (don't know when yet - I'll post when I know the airing date) and you guys might want to pick up a December issue of Gun Digest

Because of time constraints it couldn't wait for the monocores - I machined 5 Delrin cups with an internal boring @ 1". Just blowing through it quickly it has that Hollywood quiet gun whistle to it.
I'll be testing it tomorrow & will take sound decibel readings as I shoot.
The cups are .900" long and spaced cup towards muzzle - the first chamber vents very freely into the shroud...it ought to be pretty dang quiet.

All of the major parts for everything have been completed - what's taking me time is some little detail parts (like a custom stainless breech locating pin), every stock has needed fitment work and then locating, drilling & tapping for the forearm. The forearms lining up with the rear stock has been my greatest ... Uh ... Challenge, so to speak. I'm getting it done right but its all hand finish work that doesn't go quickly.
I'm doing each rifle as I go so I know each one is perfect.

I'll post completed pics in an hour or so with range data to follow tomorrow. This one is also .25 caliber.

Mike

jvanschoonhoven · « **Reply #799 on:** November 06, 2015, 11:12:35 PM »

That looks sweet!
I did some more testing today and a bit of hunting!

Pellet went through the ear right where I had the cross hairs. It was about a 25 yard shot.

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Millennium Pumper Production - *The Beginning* - And The Lousy End

Author Topic: Millennium Pumper Production - *The Beginning* - And The Lousy End (Read 292657 times))

Millennium Pumper Production - The Beginning - And The Lousy End

Author Topic: Millennium Pumper Production - The Beginning - And The Lousy End (Read 292657 times))