TD257 Improved and 1st groups at 100 yards
Will do a complete story later on the gun. Complete with VIDEO of course. You guys know how i do it…lol!
A little detail for now but much more to come later.
Doug finished my 53ci bottle and valve. Its all new from the ground up. NO FACTORY OEM PARTS anywhere in the bottle now!
1010 FPS with 74 gr Lyman 257420 bullets. 875-880 FPS with 101 gr Spitzers by RJ Porter and the same fps with UNREPENTANTSINNER’s Hoch 108 gr FP bullets. That’s 168 FPE for the 74 gr FPS and 185 FPE with the heavier 100-108 gr bullets. And the new bottle will make the exact same power for over 5 shots with no decrease.
The OEM bottle with better valve stem made 900 fps and 133 FPE with the 74 gr LYMAN bullets and 820 FPS and 150 FPE with RJ Porters 101 gr Spitzers for only close to 2-3 shots and not as consistent.
So in all, that’s a 2-3 shot improvement as well as a 110 fps gain with the 74 gr bullets and 55-60 fps improvement with the Heavier bullets. The FPE gains between old and new bottles are, 35 FPE for the 74’s and 30 FPE with the heavier bullets.
And just to clarify, the improvements in shot counts are not total shots but shots with the most consistency before the numbers start to fall off more than 5-10 fps per shot. So far, i’m up to 20 shots with the new bottle off 1 fill with no signs of tank dump. AGAIN, this is a “SMALL” Big bore and not meant for 30 shots per fill or anywhere close. More info to come on shot count.
The gun with new painted bottle, Limbsaver and Air Stripper:
Unrepentantsinners HOCH 108 gr FP bullets:
GROUPS with Urepent. Hoch bullets. Note the difference that a little power wheel adjustment makes (2-8 vs 3-1):
Needless to say, it’s all been worth it and i’m very impressed with not only the gun but with Doug’s work on it.
***BTW*** I MANAGED TO SHOOT A SMALL ROCK FACE AT 402 LASERED YARDS WITH SOME GREAT CONSISTENCY FOR HOW I WAS HOLDING THE GUN. PRETTY SOON, I THINK I’M GONNA GO FOR A COKE CAN AT 400 YARDS WITH AN AIRGUN SHOT….LOL! SERIOUSLY, I AM!
All Replies
That was my .25 on helium.
I keep a 53 ci tank with helium in it just for fun. It does weep a little but I have a cap with a o ring on it and that gets a little pressure in it. Not sure if I remove the cap it would leak more. What ever is getting out isn’t noticeable after months of sitting.
.25 makes 230-240 fpe on helium and that is not my best valve.
I did the .308 once and it was 415 fpe I think. That was in the early stage of the .308 valve building. I’m sure now it would be around 500 fpe.
I guess I need to pump up a .257 tank and see what it will do. I have a 1000 psi left in a 80 cf tank. I paid $42.00 for the fill. Now they want $222.00 to fill it and where I got it from can’t even sell it to me anymore.
IT DOES over time. Orings are pretty porous and the Helium molecules are SUPER tiny and they slide right on past normal orings.
Allen Avrems new big bore gun uses seals that stop the Helium from leaking.
😈 Hummm!
The only problem I have heard on helium, is because of molecules are smaller than air, it tends to lead down in the bottles.
Guys, the 53 ci is NOT that much bigger than the Factory bottle and i have no added difficulty using it compared to the stock bottle. I didn’t have to use any other rings nor do i tilt my head down further.
Its the shorter but much fatter 63 ci tanks like what doug uses that’s much fatter.
But hey, the tank works and works well for me…lol!
KNIFE AND SYN, yes, it was helium and NOT nitrogen…lol! Fresh from Dougs lab. It it were more available, i would shoot it in all my big bores. And yeah, the 223 might have been a bit much but i swear dude, while in the middle of the desert, IT MADE MY EARS RING! No airgun or even my 17 hmr makes my ears ring while in the wide open. Dougs 308 on Helium DID!
Trying to picture it RC. Sounds a little like one of the FX guns. Two tanks!
That would give me 53 ci with a ergonomic cheek weld. With the intermediate valve and 53 ci I am assuming I would get around 8 to 10 shots. Might even help with frame flex.
Whether all this is worthwhile for a guy who owns a Haley .257 is the question.
Maybe just too much spare time on my hands.
RC
I think that would turn this rifle into a “bench rest only” I know that you do most of your shooting that way but from a “resale” pov….I decided to go with the the stock AF tank instead of the 53ci for the same reason and so I could use the Mad Dog stock. I am simply going to tether to my 4500 psi guppy tank. Even if I wanted to walk in the bush the guppy tank is light enough and I have it sitting in an old water canteen bag.
And yes, you do have too much spare time on your hands 😈
Dam Tof! I was just kidding about the Helium! 😯
Took my Talon SSS out this morning and tethered it and shot at 100 yards.
I have a 18 inch LW barrel with the choke cut off giving me 17 inches which the stretched frame shrouds.
I am using angled tank adapter and a AF tank with what I call the intermediate Dyotat valve which Doug makes for the standard valve body reamed out to accept a larger better ported valve stem, a 105 grain hammer and heavy spring.
I was shooting 73 grain Lyman 257420 cast out of 20-1 and sized down from a as cast .260 to .255 and lubed with silicone 50 weight oil. I don’t like sizing bullets down that far, but they fly reasonably well.
My target was a 18×24 inch steel target that I have posted about on here before.
I set my chrony at 6 feet from the end cap and shot at 3000-3200-3300 PSI.
Velocities:
3300PSI@865 FPS/121FPE
3200PSI@855 FPS/118FPE
3000PSI@825FPS/110 FPE.
Penetration on flesh would range from 12.5 to 13.5 inches at 100 yards, more than enough to kill a deer.
I was getting groups that ranged from 3 inches down to 1.35, the higher the PSI the larger the groups, many of the groups at 3000 PSI had 4 shots under an inch.
However I also noted a shift in POI at the higher PSI.
I really like the extended frame shrouding the 17inch barrel, while not backyard friendly it sounds like a fart from a 80 year old Orange county taxpayer compared to the Haley 257 shooting the same bullet.
But I can’t help from thinking about modding it further.
The problem is I will soon have a spare 36 inch TJ barrel and could if I wish put it on the rifle.
If I got 10 fps per inch, I would be up to 1000 fps with the 74 grain Lyman. That is getting close to Tofazfou’s AF monster.
Plagued with a large nose most of my life, I don’t really like the idea of that big 53 ci tank sticking in my face.
I am toying with the idea of a under frame mounted 22 ci tank and a line running from that tank to the AF tank. I think if I used three or more scope rings, with the ring portion milled off and pipe clamps threaded thru a slot milled in the remainder of the ring, I could attach a tank very firmly under the frame.
That would give me 53 ci with a ergonomic cheek weld. With the intermediate valve and 53 ci I am assuming I would get around 8 to 10 shots. Might even help with frame flex.
Whether all this is worthwhile for a guy who owns a Haley .257 is the question.
Maybe just too much spare time on my hands.
RC
Were you shooting Helium or Nitrogen..? 😉
I agree California sucks, but the Helium shortage is global. 😆
Wish i could Knife. Down here in good ole CUMMUFORNIA, its getting harder and harder to get as well as HELLA EXPENSIVE when you do get it.
I had a chance to shoot HELIUM in DOUG’s 308 Condor and HOLY FUCK, his Condor sounds honestly like a 223. SERIOUSLY!
Time to break out the Helium! 😀
For the balloons, and may be a little extra speed? 😎
And then I’m proud of my 1 shot hits at 160yrds…this is going to keep me awake for the next week.
I’m hosting a long range shoot later this month where our max distance will be a measly 220yrds (compared to what your rifle is capable of) with a gong shoot and popping a balloon. I’m still trying to get my brain to accept that you guys can do it at 400-500yrds. I’m sure sometime in future, 600-700yrds will be possible. Awesome stuff.
Not only that Nick BUT, doing it accurately!
RC and RJ and John Bowman have the horsepower to shoot heavier and higher BC 257 bullets at the same speed i shoot the 74’s. With the right bullets, i’m sure they could even hit the 500+ yard mark and wouldn’t just be LOBBING bullets but placing them in an accurate fashion. Don’t think we can get MOA at that range YET (its coming) but we can at least put them out there somewhat accurately on a perfect day. RC is already up to MOA at over 200 yards!
And yeah, at 402 yards, the bullets hit the rock face IN LINE with the crosshair. So the coke can is very doable and shouldn’t take too many shots to do it. I’m actually going for a 1st shot HIT 😯 . But of course i gotta take a couple of sighters
Geez, to think that its possible to hit small targets such as coke cans at 1/4 mile with an airrifle is just mind boggling. Excellent work Cedric, I’ll be following this thread. Looking forward to the new info.
- You must be logged in to reply to this topic.
😯 😯 😯 Doug, Why has it gone up so much. I mean, it is after all, the most common element in the universe. And why are the suppliers refusing to sell the stuff? 😕
Is this some kind of National Security thing. They trying to lock down the rights to Helium in the Universe now? 😆
Mike