Brod build: 100 FPE; stock barrel; shot pic updated

[screwwork]

David
Nice looking Brod! It would awesome camo wrap on the LDC & bottle.

[PCPhack]

Sorry if I missed it but what spring setup and hammer are you running at the moment

I am using the JSAR MDS only hsmmer (not the brass core one), and a shorter than factory yet stiffer spring with a Speed Dial. This was perfect with the earlier JSAR valve thst I had, but I noticed the valves now with the revised internals, it can handle more hammer, so I will likely be experimenting some starting tomorrow when I get my air fill going.

Here is the Speed Dial, which is handy for easily putting a spring back to an exact know position without having to count turns. The Marauder rifle variant provides for 6 turns. I may modify this to do more. http://www.airgunsofarizona.com/parts/custom-speed-dial-100/

[PCPhack]

David
Nice looking Brod! It would awesome camo wrap on the LDC & bottle.

Thanks Randy!

[PeterL]

Sorry if I missed it but what spring setup and hammer are you running at the moment

I am using the JSAR MDS only hsmmer (not the brass core one), and a shorter than factory yet stiffer spring with a Speed Dial. This was perfect with the earlier JSAR valve thst I had, but I noticed the valves now with the revised internals, it can handle more hammer, so I will likely be experimenting some starting tomorrow when I get my air fill going.

Here is the Speed Dial, which is handy for easily putting a spring back to an exact know position without having to count turns. The Marauder rifle variant provides for 6 turns. I may modify this to do more. http://www.airgunsofarizona.com/parts/custom-speed-dial-100/

First time ever hearing of the speed dial. Is there a way to lock it down once your desired tune is found? How have you liked it and how much does it protrude out the end cap or does it replace it all together?

Peter

[PCPhack]

I can't recall now if it replaced the end cap or screwed into it, but I think it had just screwed into the factory one after removing the insert. I will take a picture the next time I have it out of the stock. It does have a small locking level on the edge of the dial area. If I was going for pure efficiency, I would certainly prefer a SSG setup, but for this purpose, where I have a large bottle, and want to precisely dial the spring in or out for pellet versus heavy slugs, it's great.

[PCPhack]

I noticed this morning that there is still a very slow leak somewhere. I had done a 48 hour test previously with tube and regulator, so the leak must still be coming from the valve. On the next teardown, I will replace the poppet orings, as well as air tube static orings for both valve and regulator (as some trash from the thread additions could have nicked somewhere before I cleaned it out).

[PeterL]

I can't recall now if it replaced the end cap or screwed into it, but I think it had just screwed into the factory one after removing the insert. I will take a picture the next time I have it out of the stock. It does have a small locking level on the edge of the dial area. If I was going for pure efficiency, I would certainly prefer a SSG setup, but for this purpose, where I have a large bottle, and want to precisely dial the spring in or out for pellet versus heavy slugs, it's great.

Ok. Gotcha. Thanks.

Peter

[PCPhack]

I have switched to the JSAR hammer with brass insert. Checking my notes from the earlier prototype setup (used old JSAR valve internals before the revision), I confirmed that I was having to use way more spring now to produce the similar ranges, so I upped the hammer weight in order to keep the spring requirement down. Air is now flowing, so hopefully I can run some strings this week.

New maximum with the heavier hammer and full spring tension on my speed dial with a heavier short spring is:
102.5 FPE @3300 psi with 65gr slug (843FPS)

[oldpro]

That thing is shooting HOT! Nice build my friend. My personal record is 111fpe shooting 73 grain spritzers at 3400psi with a stock barrel using a bored to the max stock valve and a 22lb spring and 90 gram hammer LOL...Glad those days are over.

[PCPhack]

That thing is shooting HOT! Nice build my friend. My personal record is 111fpe shooting 73 grain spritzers at 3400psi with a stock barrel using a bored to the max stock valve and a 22lb spring and 90 gram hammer LOL...Glad those days are over.

Hahaha. You can keep that record, that 22lb spring, and sore cocking finger. Impressive. I would be afraid of the sear failing with that much spring!

I have seen many duplicates on the chrono already. I can't wait to have time this week to run strings and check the ES. That WAR regulator is really solid, and the JSAR valve seems much more stable with the new internals and a heavier hammer/spring behind it than my earlier prototyping.

[oldpro]

 I agree I dont know how the sear survived but it was only set up for a few days just for bragging rights. It was a bear to cock and double loading was a frequent event.

[PCPhack]

OK, after serveral test shots to find my boundary conditions...I settled on the hammer striker turned in all the way flush. This gives me 5 full turns of the speed dial worth of hammer free flight and 1 additional turn with no free flight. At 5 turns in you can immediately hear the valve start to wheeze heavily and waste air.

I use Eunjins as a proxy for testing with the heavier custom slugs for now since  they are cbeaper and I have many tins of them.

1st string I will share, maximum power without the wheezing and waste. This is with the speed dial at 450, in other words half a turn from 500, so there is half a turn of free flight. I will run it again at various lower settings to see about more efficiency, but this is a nice tune already for high power as it will allow 2 full magazines to be shot before coming off the regulator using the 500cc tank with 4500 psi. If I swap in the 65gr slugs, the FPE are over 100. I stopoed here because I noticed the bolt lug getting loose and grinding on the top of the air tube. So I will tear it down now and also try to solve that slow leak.

"High Power Hunting Tune"
Name: H0; Speed Dial 450; Eunjin 43gr; Regulator 3250psi; JSAR valve and TP at .25 porting; barrel at .2 porting; JSAR MDS hammer with brass insert.
Notes: 4350 -3720 psi on 500 cc tank
Shots: 8
Average: 979 FPS
SD: 3 FPS
Min: 976 FPS
Max: 984 FPS
Spread: 8 FPS
Power Factor Average: 42
Power Factor Low: 41
Power Factor High: 42
Barometric Pressure: 30
Temperature: 88
Weight: 43.0 grains

Avg FPE/cu in/shot = .55
Avg PSI/shot 79

Index   Velocity   Ft/lbs
1   984   92.4
2   981   91.9
3   982   92.1
4   981   91.9
5   977   91.1
6   976   90.9
7   977   91.1
8   978   91.3

[screwwork]

Nice hunting tune at +90fpe! Ya gotta love those numbers 

[PCPhack]

Here is the picture of the Speed Dial.

[PCPhack]

Nice hunting tune at +90fpe! Ya gotta love those numbers 

The really nice part is that I can back off the spring and lose only 10 to 15 FPS (3 to 4 FPE), and the air usage is about half. I can set it like that, and go out all day. 

[PCPhack]

Ok, so I found the slow leak. It is coming from the large assembly lug that holds in the internals of the WAR bottle regulator. I had not suspected it at first because it held fine for several days in the earlier prototype rifle. Soapy water confirmed it. I will fix that tomorrow, and then get back to tuning around.

[oldpro]

Nice hunting tune at +90fpe! Ya gotta love those numbers 

The really nice part is that I can back off the spring and lose only 10 to 15 FPS (3 to 4 FPE), and the air usage is about half. I can set it like that, and go out all day. 

Sweet!!!

[PCPhack]

I fixed the WAR bottle regulator valve leak earlier today. There was 1 tiny leak at one of the gauges, and 1 tiny leak at the large hex lug for the internals. It has sat now with a fill whip with a digital gauge attached (with the fill tank closed of course), and it hasn't moved off 4410 psi for several hours. So I think I finally licked the leak. 

[oldpro]

I fixed the WAR bittle valve leak earlier today. There was 1 tiny leak at one of the gauges, and 1 tiny leak at the large hex lug for the internals. It has sat now with a fill whip with a digital gaige attached (with the fill tank closed of course), and it hasn't moved off 4410 psi for several hours. So I think I finally licked the leak. 

I feel some serious smack about to be laid down on and uninformed critter...Sweet build you have my friend.

[PCPhack]

They might actually get a break, as I am not sure we will go out to the lease again until fall, except for a cleanup. Hmm, maybe I should clean some varmints.

In the meantime....look at what I have. Heh. I also have some larger aluminum tube to match it. I might use this on the next build. I can only use it on this one if I marry the smaller tube to the larger one with a lathe made coupler, or add a riser to the breech.