Author Topic: Millennium Pumper Production - The Beginning - And The Lousy End (Read 292437 times))

Matt15 · « **Reply #300 on:** January 01, 2015, 09:48:53 PM »

Quote from: CarsonRatSniper on January 01, 2015, 09:24:42 PM

Its a Disco tube, so the OD of the piston is .740"
The length of the piston assembly from the back of the follower to the face of the piston is 7.4"... the stroke length is 7.2" if measured from the center of the pivot pin hole.

The follower & piston head are bottomed out tight onto the rod...then there's the lock nuts.
I'm locating the check valve in the tube so that there's only a few thousandths between the piston face and the check valve face...which will make adjusting the flat top piston really easy.

Mike

Okay. Looken good.

Millipede · « **Reply #301 on:** January 07, 2015, 03:38:57 PM »

That magazine looks cooool. I've been waiting so long for someone to make a breech with that style of magazine like the crosman 760 has. Would it fit on a crosman gun or maybe a qb78?

CarsonRatSniper · « **Reply #302 on:** January 07, 2015, 06:47:17 PM »

They will fit on a Discovery/22XX - we're using a Discovery tube...I'm not sure about a QB.

I will have a functional powerplant tomorrow

Here's the positive closure check valves

I had Jim machine a barrel on one end of the check valve to house a light spring retained by a cotter pin.
The check pin itself is stainless steel.

More to come in a few days!

Mike

rsterne · « **Reply #303 on:** January 08, 2015, 12:32:16 AM »

I like the check valve.... no spot milling for the screw head?....

Bob

CarsonRatSniper · « **Reply #304 on:** January 08, 2015, 12:49:02 AM »

You know what...I *missed* that!
I will have Jim mill the spots - we forgot!

The valves have them...I guess I got tunnel vision because I'm going to have a .30 cal to SHOOT next week and overlooked it

Good call Sir...Thanks!

One thing I forgot to mention - Jim is going to make the pivot pins out of 316 stainless steel, stake a ball and spring on the ends (just like an AR15 pivot pin for mating the upper & lower) then harden the pin - That way the rifle is truly *field serviceable* without tools...Ok, at least you can remove the piston assembly with just a small punch for the pivot pin and link pin

Jim made a hollow punch with another smaller hollow punch in the middle then hardened the cutting surfaces - now we are punching out our own heavy felt wipers for the piston assembly.

The entire powerplant of the rifle has been standardized using -113 o rings everywhere in the powertrain except for inside the valve (-111) and check valve (-003).

Mike

rsterne · « **Reply #305 on:** January 08, 2015, 03:30:19 PM »

I like the idea of using the #113s everywhere.... they are less prone to shaving on the gauge and screw holes, and it's nice to have them standardized.... Like the idea of a spring loaded main pivot pin as well....

Bob

QVTom · « **Reply #306 on:** January 08, 2015, 03:39:41 PM »

Quote from: CarsonRatSniper on January 08, 2015, 12:49:02 AM

One thing I forgot to mention - Jim is going to make the pivot pins out of 316 stainless steel, stake a ball and spring on the ends (just like an AR15 pivot pin for mating the upper & lower) then harden the pin - That way the rifle is truly *field serviceable* without tools...Ok, at least you can remove the piston assembly with just a small punch for the pivot pin and link pin

Mike

I'd be curious to know how Jim will harden 3XX SS. As far as I know, most will choose 4XX or 17-4 when a hard condition is required. If there is a secret I'd sure like to know

Tom

YEMX · « **Reply #307 on:** January 08, 2015, 05:33:02 PM »

Quote from: rsterne on January 08, 2015, 03:30:19 PM

I like the idea of using the #113s everywhere.... they are less prone to shaving on the gauge and screw holes, and it's nice to have them standardized.... Like the idea of a spring loaded main pivot pin as well....

Bob

#113 oring?

EDIT: Nevermind! yes, oring... I need to read more!

CarsonRatSniper · « **Reply #308 on:** January 08, 2015, 08:09:54 PM »

I don't know Tom - I will ask when I see him tomorrow morning.
Does 316 not harden the same as 4xx series? That's out of my area of knowledge.

Mike

Big Bore Bart · « **Reply #309 on:** January 08, 2015, 08:38:05 PM »

The 3xx series Stainless steels are very low carbon, and therefore do not harden. The 4xx series are high carbon , and will harden.

CarsonRatSniper · « **Reply #310 on:** January 08, 2015, 11:20:08 PM »

Thanks!
I will make sure we use 416 rod or similar...

Mike

jeff76 · « **Reply #311 on:** January 09, 2015, 11:51:18 AM »

nevermind

CarsonRatSniper · « **Reply #312 on:** January 13, 2015, 10:07:57 PM »

Well, I assembled a lower today and installed a factory breech with a TJ's 1:14 twist .250" barrel today

(the Millennium breeches aren't finished yet).
No gauge manifold either - I'm waiting on some more parts to arrive.

The rifle was assembled just like Bobs original Millennium. It only took about 45 pumps to get to 1800 psi from dead empty (I will accurately record the pumps tomorrow - I was too excited to shoot it!).
The rifle is shooting at 40 ft lbs - there's sear drag on the hammer so we will try adding brass bushings under the Mrod trigger tomorrow to correct that. I also turned a TP out of Delrin...its too hard to get a good seal even though the part was made spot on with about .005" crush on it.

My 45gr slugs were shooting at 635 fps with 13 pumps per shot. Kings were shooting at 855 fps.

I'm using a 2" long 10# hammer spring - I have lots of things to tweak tomorrow. Since I was using a factory top end the hammer stroke was shorter than I wanted...tomorrow I will make the side cocking knob and tap the striker - that will lengthen the stroke.

I know once I lengthen the stroke, get a solid TP seal and get rid of the sear drag the numbers will come way up.
The pump effort (no stock or pump handle) was similar to a Steroided Benji at 14 pumps.
Yes! My left hand is dented LOL

I ordered some 5/16" Teflon rod for the TP's - I will try poly tube tomorrow after I fix the other issues.

First shot was 40 ft lbs out of a pumper though!
Pressure dropped from 1800 psi to about 1400 psi...a second shot yielded 625 fps with my 45gr slug.

More to come guys...I will take pics tomorrow. I just wanted to update you all.

For the *first shot* on an assembled lower that had a cobbled together top end I'm happy.

Mike

jvanschoonhoven · « **Reply #313 on:** January 13, 2015, 10:20:38 PM »

I bet pumping with a stock on the rifle will be so much easier!
Were you getting those velocities with the 25 inch barrel?

I can't wait for my gun! Im so excited i can hardly contain myself. Glad i waited for these rather then going with the fx independence.

CarsonRatSniper · « **Reply #314 on:** January 13, 2015, 10:24:35 PM »

I used the *old* barrel from my .25 Challenger...I think its at 25.5" or so.

Pumping with the stock on it will be really nice! This is not a pumper that kids can shoot though - you definitely need to bring it in close to your chest when you close the pump arm. The Steroid Benji example is the most accurate way to describe it.

I want my 65+ ft lbs tomorrow!

Mike

rsterne · « **Reply #315 on:** January 13, 2015, 10:28:03 PM »

Quote

It only took about 45 pumps to get to 1800 psi from dead empty

That sounds low, even without the gauge manifold, I think my Millennium Pumper was more like 80 pumps to 1800 from empty.... but it sure puts a smile on your face to see 40 FPE with a pumper, huh?....

Bob

CarsonRatSniper · « **Reply #316 on:** January 14, 2015, 12:44:46 AM »

Yes it t does! I was disappointed but happy at the same time...I mean a *Pumper* hit 40 ft lbs

Bob, it only took 13 pumps from dead empty to 500 psi and another 30 or so to get to 1800 psi.
I nicked the first o ring on the piston after I fired a few shots so we'll need to really port an angle in the pump arm slot on the tube where the piston o rings initially squeeze into the tube diameter...they bowed up slightly in the slot when the pump arm was open.
That positive closing check valve sure is nice...I saw pressure on the gauge with just 3 pumps!

I assure you it *did not* take 80 pumps to get to 1800 psi! I didn't have a pump handle on the lever and *you* know what its like pumping it that way raw handed LOL

The tube around the check valve was getting pretty warm while pumping - its definitely moving some good volume when pumping it up.
1500 psi back to 1800 psi only took 8 pumps.

We're also making custom pins for the Foster fill nipple so they are positive closing with a light spring too.

I will document everything and report back tomorrow after I fix the little issues I discovered today...

Mike

rsterne · « **Reply #317 on:** January 14, 2015, 01:00:12 AM »

My Millennium Pumper, with the 3 cc gauge manifold but not the CO2 cartridge, lost 300 psi for a single 45 FPE shot, and that took 11 pumps to replace....

Bob

CarsonRatSniper · « **Reply #318 on:** January 14, 2015, 01:17:36 AM »

Hmmm...I will have to check that gauge (brand new from Crosman) as soon as I have a manifold together...I'm just waiting for Marine Tex so I can glue the CO2 bulb in. I will have a gauge manifold to install no later than Friday.
Then I can hook up my regulated 1800 psi bottle or my CF tank and see if that gauge is accurate.
Maybe I wasn't anywhere near 1800 psi - that would help explain the low numbers too.

I won't know for sure until I have something to compare the gauge against.

Mike

rsterne · « **Reply #319 on:** January 14, 2015, 01:45:10 AM »

That was my thoughts.... Some of those 1" gauges are pretty far off....

Bob

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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 292437 times))

Millennium Pumper Production - The Beginning - And The Lousy End

Author Topic: Millennium Pumper Production - The Beginning - And The Lousy End (Read 292437 times))