300 bar and numbers with Helium
Hi everybody!!!
I have tried with haelium in different ways, and I reach the conclusion:
It can reach a 25% more velocity than air.
What does it mean?
If you have your stock rifle, haelium gives you a 25/% more velocity.
So, if you cut the choke, change the hammer, spring, valve, you change the barrel for a barrel more “fast” etc etc etc., you will be a 25% faster that you ever been with ANY modification.
So the question:
WITH AIR: does anybody have tried with a standard condor with 300 bar?
if any of you have performed a modification, can you specify what kind of modification and the chronys with 300 bar?
Thanks.
Gustavo.
All Replies
in short i do not make or mess with valves anymore !
do NOT write to me asking to do so
if you want to discuss the design, need help etc, then lets do it openly on this forum
Thanks
Gippeto could you explain a little about your drawing….i cant really make heads or tail about it….
all videos work….try a different browser if it doesnt
well the SS in bigbore form shoots roundballs at around 1000-1100 fps thats about 145 grain, i could get 15 good shots out of a fill the power curve is pronounced…but due to weight and shape the speed differance is neglible at 50 yards….and at a 100 yards it translated to a 3-5″ group….still carrying a shitload of power, plenty to knock the socks of a cyote …power around 300 fpe
shooting 400 grain slugs however, the rifle turns into a beast making around 500 fpe…because of the SS’s light front and heavy back the recoil is pretty pronounced, i had to make an endcap that went into the frame in steel just to weigh it down a bit out front to control it a bit better….i wanted to make a brake for it…but never got around to do it…..a moderator would tame it quite a bit, as well as limit the noise…but the huge amount of air involved made it hard to keep on the rifle without threading the barrel
with 500 grain slugs i could get it to 601 fpe (my record) felt pretty much like shooting the 400 grain…butcher45 is my witness he was there when i did it…he supplied the 500 grain slug IIRC
the noise with RB would be like a 17hmr….less then a 9mm powderburner….with the heavier ammo the sound became less sharp and more boomy, easily comparably to a 45acp in sound
well the reason i stopped messing with it is 1 i got a kid, i moved from the perfect concrete basement to a wooden garage cant testfire here without the neighbors knowing(possibly calling cops)…and can now own powderburners which i couldnt in the other state….basicly my 44mag revolver can do the same as the rifle…so i went back to normal airgun calipers….for fun…and the 44mag for hunting(well that was the plan anyway)
present day….i can own PB’s so i dont have a need or reason to go bigbore in airguns….so i enjoy what the “small” cal. arguns have to offer….i still have a high interest in airguns…which is why i want the new crosman rouge
shoot just about any highpower bigbore airgun and its going to be loud….the really how powered stuff (450+ fpe) is going to be really loud, not suited for target shooting unless your on a range or have a lot of land to shoot on or is out hunting
i dont really get the reason for bigbore airguns (ok i do…its FUN), unless your a felon and cant own firearms, or your in country where firearms are illegal or hard to obtain and store(say denmark)….then it makes sense but for me airguns are about low noise, precision, able to shoot at/in home, less dangerous…a pellet(assuming 16-18 grain and not the heavy stuff) coming down from say a 45 degree trajectory is unlikely to injure property or people…shot a bigbore 9mm+ at 45 degree angle the the sheer weight of the projectile is gonna overcome airresistance and come down with a bunch of energy…dangerous
i did the calculations on my .308 with a 118 grain….when shot it would have 230 fpe….at 200 yards it would have about 190 fpe(more than a .22lr)….do the same with a pellet in .22 shot at 30 fpe and you will find it has little power left at 200 yards (sorry havent calculated the precise numbers)
Sweet! That thing is loud! Are the boolits too big to feed with the thank on?
no comments at all ?
Those last two videos scared me and I’m fearless!
If you got an air rifle making that much noise please don’t start playing with gun powder or the whole world is doomed.
PS the 1st video is black screen with very little audio?
This is more what I had in mind….not to scale…lots of details missing..yada..yada…yada, but this is the rough idea.:)
One o-ring seals, the other acts to absorbe/disipate the energy of the spool.
wow everyone is quiet….either my drawing is total crap…or everyone rushed to their machine shop….
no comments at all ?
heres the .457 valve i got up to 601 fpe out off (shooting 500 grain slug, fill pressure was 250bar)
http://cid-2f3883d3069ad8f5.office.live.com/self.aspx/Public/45%20bigbore%20talon%20valve.PDF
f you decide to try make this…it is at your own risk….working with high pressure is dangerous …yada yada yada…dont come crying to me when it blows up in your face….the drawing is purely for educational purposes 😉
as you can hear from the videos its quite loud…not what i would call backyard friendly….but hey its producing power at .357magnum and 45acp levels ….
i forget the barrel length …it was 30 or 32″ long
something like this
if you decide to try make this…it is at your own risk….working with high pressure is dangerous …yada yada yada
i didnt come up with the basics of this….but i think it could work
the idea is that theres only atmospheric pressure + little pressure from the valveseat on the stem…which is much less that the 3000 psi on the whole bottom of the stem…..
this way you can really ramp up the pressures….or just stick with small springs
the return spring must be somewhat strong to close and keep the valve closed…a softer material on the valveseat like an oring might be needed.
the solid part of the valvestem could be made of perforated tubing so it takes up les air volume
as a safety measure i would make a valveseat on the solid part of the stem near the end inside the tube….so in case something snaps or breaks that will keep air from rushing out backwards (not in drawing)
also a cap on the rear of the tube with holes to vent air away from the shooter in case of failure would probably be nice (not in drawing)
drawing is not to scale…its just a drawing of concept…..the tube with the valve would have to be big enough to hold all the air needed for the shot, i would limit the flow from the bottle…to get a bit of censistency
problems
orings are holding the pressure from escaping out backwards, there will be quite a bit of force on them
closing the valve hard enough to make the valveseat seal, other materials then delrin should be considered
valvestem must be thick and rigid enough that it wont bend inside the tube
probably other problems too
Been at the baked beans again have ya? 😆
Same as hydrogen….or any flammable gas…requires a mixture within the volatile range for anything “unpleasant” to happen.
😆
1/4″ dia 3,000psi = 147.26 pounds force
4500psi = 220.89 pounds
Cyg a valve sketch would be cool
Yer thinking of Dave(spooky) and the Raven. Pure art. 🙂
I’m planning something roughly similar Cygnus….Balanced spool valve. Easily configured so that a light hit is all that’ll be required regardless of chamber pressure.
Externally adjustable valve spring (tuneable dwell) should allow for anything from full chamber dumps to multi shot. Green Mountain .45 barrel should be here anytime. 🙂
Plan is to make the top hat as part of the breech cover….BIG valve…nearly 1″ porting….short travel. 😎
Looking forward to getting started. 🙂
my .308 and .457 ran at 250 bar….the only thing on the rifle that was airforce was the frame….everything else modded by me….
the 250 bar did yield more power, and more shots pr fill….well sort of…the extra pressure/spring and hammer moved the working pressure of the rifle…normally between 2700-1100 psi to 4350-2700…below that and speeds started to drop rapidly….
i did try and go higher pressure than that, but the nature of my highflow valves meant i had to up the hammer spring and hammer to unreasonable levels….but my valve seats where quite a bit larger than the airforce…the bore was more than 9mm in one valve !
now when your gonna hit the valve with that much force you better choose the right materials…and get the thickness of the valve walls thick enough to handle the hammer slap….also the delrin valveseat has to be upped to keep it from compressing and get shot out the bottle…and to be able to handle the extra force that 300 bar is going to be closing the valve with….theres quite a bit of force at work here
cocking the rifle proved very difficult ! because of the strong spring….a lever system like the aa410 and many other rifles incorporate would be needed for it to be doable.
that whole bunch of force placed on the breech is kinda scary too….ever read about the guys that have had a digit get slammed off in an under/sidelever rifle ? sure the spring is not as strong as in a springer, but on more than one occation i have had the breech slam close on my thumb due to trigger malfunction….luckily i had a two hand cocking handle so the hand still on the cocking knob was able to dampen the blow…and i was just left with a blue thumb nail
i was running 250 bar…..i was able to get 220 fpe in .308, and 601 fpe in .457…at 200 bar it would still do 450-500 fpe in .457 ..how much more power do you need…..or are you looking at more shots pr fill….cause then all you gotta do is stuff a regulator on one of those 4500 psi bottles…and get a co2 adaptor that airforce sells…it has standart co2 bottle threads and will work with paintball tanks too….tweak the reg a bit and your all set
i got a rough design of a valve that i havent made yet that would eliminate the back pressure….im not sure it would work…but it is used in co2 valves for soda machines….and theres the guy who makes AF looking rifles for oilrigs where you dont want muzzle flame starting a fire (i guess theres some gasses on a thing like that) its his idea….i just found a way to use it on our rifles…i think….it relies on orings for sealing…im not sure how durable it will be but if interested i will post it (have to draw it up first)
Been at the baked beans again have ya? 😆
Same as hydrogen….or any flammable gas…requires a mixture within the volatile range for anything “unpleasant” to happen.
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The spool resides within a “firing chamber” much like in your drawing.
The tube in which the spool moves,(where the spring is) is open to atmosphere on the back.
The force holding the valve closed can be changed by changing the diameter of the spool at the rear, the diameter of the seat at the front, as well as by adjusting the spring force.
What might be termed the “top hat” in an Air Force rifle, is now attached to the breech cover, which has limited travel (3mm or less) once locked down. Transfer porting can be cut into the diameter where it’ll be against the face of the valve.
Typical of the AF layout, the hammer strikes the breech, which in this case, strikes the stainless retainer on the spool. Thinking UHMWPE for the spool…light weight with good impact resistance.
The spool only needs to be cracked open by the striker blow in this case…then chamber pressure takes over. Much more force will be available to open the valve, resulting in rather impressive valve accelleration. Total valve travel given the diameter, need not be more than one third barrel diameter. Time to full flow should be in the 1ms range or less.
Given the relatively huge port area available with this layout, the barrel (even big bore) becomes the choke point for the flow.
Al