Author Topic: Inside an Air Javelin (Read 11766 times))

darkcharisma · « **on:** February 29, 2020, 03:39:47 PM »

Got an Air Javelin the other day. Umarex shipped it quick and i got it in less than 3 days.

upon arrival. it is super light! the unit without Co2 cartridge weight in at 1671 grams.

I opened her up and this is what the inside looks like after unscrewing all screws on the right side of the rifle.

The valve unit looks like a one piece pcp valve that has a small plenum. i havent been able to get the valve apart but its nothing but pins on the sides. i may need a screw to pull the plugs. I lined them up with an hpa bottle to prep and see if fitting one would be feasible. 13ci bottles may be best given it has smaller OD.

now that i got to see the insides, $169 is doable and priced right...$100 would be a Great deal and $200 would be too high.

the synthetic two pieces are flimsy and can flex side ways with just a bit of force, it is semi firm and flex little when forcing up or down.

Trigger is horrible, long pull and lets go at the very end of trigger travel. this is because the sear is not anchored via a one solid hole but the whole sear can move out from the trigger shoe due to an elongated anchored hole. stupid! it would have a better break if its a round hole. is this one of the safety features? then why have a safety trigger pin?

darkcharisma · « **Reply #1 on:** March 01, 2020, 01:39:24 PM »

Shot one dozen today. the speed is 267fps max for the included 169grains on first shot. not as advertised at 300fps.

then it averaged out at 230fps...

man oh man. i am not excited about that. but then again...i am not one to complain for a refund. i will just mod it later for 800psi hpa.

Rob M · « **Reply #2 on:** March 01, 2020, 02:12:11 PM »

very similar design to many paintball guns ive dissected and modified.. not much going on in there as its consolidated in the valve casting.. I do think regged 850 hpa will get your numbers up there.. thanks for sharing the pics.also looks easy to swap out the hammer spring , or add a power adjust of some sort ( spacers and the like)
id does appear like the molding is inhibiting the hammer travel , not sure if thats true in real life , but id test that theory in real life and make sure than hammer can really smash that valve stem home to get the max potenial.. efficiency should not even be considered for this design

darkcharisma · « **Reply #3 on:** March 02, 2020, 01:42:20 AM »

before the 12 shots, i put a 1/2 inch thick spacer in the back of that hammer spring. its smacking the valve pretty hard. going hpa will make it consistent and up the power some. seems the valve can be modded too if once i have some time to get into it.

screwwork · « **Reply #4 on:** March 02, 2020, 08:12:29 AM »

Looking good for hpa conversation Duy.
What is the barrel OD & ID and length? I may convert my Arrow Prod to that barrel & bolt combo.
Thanks 😊.

Rob M · « **Reply #5 on:** March 02, 2020, 11:04:43 PM »

Quote from: darkcharisma on March 02, 2020, 01:42:20 AM

before the 12 shots, i put a 1/2 inch thick spacer in the back of that hammer spring. its smacking the valve pretty hard. going hpa will make it consistent and up the power some. seems the valve can be modded too if once i have some time to get into it.

is there a an adapter for regged tank to 88gram m16 threads?? or will you make one ? anyway keep us posted on the HPA numbers, should be interesting

Acapulco · « **Reply #6 on:** March 03, 2020, 01:40:14 AM »

At what temp were you shooting??

darkcharisma · « **Reply #7 on:** March 03, 2020, 02:59:04 AM »

Quote from: screwwork on March 02, 2020, 08:12:29 AM

Looking good for hpa conversation Duy.
What is the barrel OD & ID and length? I may convert my Arrow Prod to that barrel & bolt combo.
Thanks 😊.

Randy, it's 7mm OD, 6mm ID and 13 inches long barrel. 14 inches long bolts.

Rob, I am sure there is an adapter. But I would think a straight adapter would not clear the OD of the 13ci bottle. I may have to measure it up again, might be able to machine down an ASA adapter. I didn't even measure the thread pitch and size. Is 88 gram and 90 gram co2 using the same M16 threads?

I was shooting when it was 70-72 degrees, Acapulco

Rob M · « **Reply #8 on:** March 03, 2020, 09:04:11 AM »

id have to go measure but the 90 grams as i recall are m16-1.25 .. ill double check in the shop later. So quite a but smaller than the regular paintball connection thats around .820 -14 threads.

darkcharisma · « **Reply #9 on:** March 03, 2020, 12:17:27 PM »

I measured it. its actually 16x1.5. going to need 3/8 off set for the adapter. i may as well go 3/4 off set to mate a bigger bottle later on down the road.

Arkmaker · « **Reply #10 on:** March 09, 2020, 12:29:50 PM »

Thanks for the inner pics!

Mine shot at 320 and 305 on the fresh tank. On a refilled tank which was underfilled due to the cold, I was at much lower. If memory serves it was around 260. Both times I shot over the chrony it was about 60 degrees. I gave up on the chrony and just had some good fun shooting.

tkerrigan · « **Reply #11 on:** March 16, 2020, 12:26:33 AM »

Any luck on finding offset adapters? Bakerairguns sells straight ones. If the offset adapter has to be made, it might be good to incorporate some room for a plenum. Regards, Tom

darkcharisma · « **Reply #12 on:** March 16, 2020, 01:33:41 AM »

it has to be made. and it has plenum space already. maybe extend it. i have the parts and tools to be made...no time yet

darkcharisma · « **Reply #13 on:** March 27, 2020, 01:37:28 AM »

i guess this is happening. i made some parts to fit a bigger bottle. i should have it ready for testing soon. i hope to get consistent shot to shot velocity. and more shots per fill.

after this i need to start up old projects. oh yah

Rob M · « **Reply #14 on:** March 27, 2020, 09:05:41 AM »

awesome cannot wait to see the numbers.

screwwork · « **Reply #15 on:** March 27, 2020, 04:28:48 PM »

The project is coming along pretty dang good and you're getting quality shop time in too.

darkcharisma · « **Reply #16 on:** March 28, 2020, 05:49:13 PM »

Finally got it done. Dang it, that was a waste of 3 days. The first drop block was no good. Learned the operations and mistakes, Remade this one in a day. She gained about 1 lb I think. And she is at 1700 psi.

. I hope I don’t have to play with the hammer weight and spring a whole lot. That requires opening the two halves...uh..

shots later!

darkcharisma · « **Reply #17 on:** March 28, 2020, 07:03:15 PM »

As suspected, hammer can’t open the valve at 1700psi. Shot from 20 MPA to 16 MPA for 17 shots. Should have netted 32-34 shots from 20 MPA to 12MPA or 1700psi set point.

Highest velocity is 239, lowest is 226. So about 13 fps spread. Not bad. Time to tune the hammer or lower the set point.
======

Well I’ll be darn. I went ahead and shoot it off regulator. Shooting down to 10mpa still net me 240fps. Last shot was 259fps as the psi lowers, my last bolt blew up. Shooting into packed clothing...those bolts don’t last long at all...Here comes the halt...just when it got better...

Rob M · « **Reply #18 on:** March 28, 2020, 07:56:04 PM »

Sounds like u simply need more hammer. Both weight and preload. You're close to valve locked if you lost speed on that pressure

Rob M · « **Reply #19 on:** March 28, 2020, 07:57:04 PM »

Also the gun looks awesome. !! This would be a great kit for that gun once the hammer is sorted

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Inside an Air Javelin

Author Topic: Inside an Air Javelin (Read 11766 times))