.25/.257 Condor Build
Well here is my next build when I have the time. Will be able to switch between .257 and .25 barrels. This Condor will be like no other Condor.
.25 barrel is machined and half the hammer is also. Will machine the .257 barrel next and make a one piece bushing for it. Looking for 200 fpe in .25 and 220 + fpe in .257.
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I think Doug can modify a JDS Airman 4500 psi reg to have an output of 3200…
Sweet! That large tank is giving quite a Bell Curve! Not to mention 118 FPS more velocity! 😯
Thank you for posting this Doug!!!
So what would happen with a reg with say a 3200 psi out put and 4000 input, (if such an animal exist?) should be a Killer shot count. :8:
Knife
I guess I forgot to post some numbers I got playing around with my HPA tank and .257. I put the valve back in it today and did some testing for a shot string also.
70 ci tank 4500 psi tank
83.3 gr
3490-1020 fps
3448-1028 fps
3404-1031 fps
3361-1038 fps
3318-1031 fps
3274-1027 fps
3228-1028 fps
3172-1028 fps
3120-1019 fps
3070-1020 fps
3022 ending pressure.
10 shots 468 psi
1026 fps 194 fpe average for 10 shots
4000 psi fill
74.0 gr 1138 fps 212 fpe
83.3 gr 1103 fps 225 fpe
94.0 gr 1083 fps 244 fpe
doug, this .257 yu built for me is really comeing along. It has shot quite a few 1/2″ and under groups on my short 80 yard range.
I have only been able to shoot at things other than paper at longer range. Today, I was shoothing at a rock on the bank of a pond at slightly over 200 yards, leaning on afence post. The rock was apx. 5″ tall, by 10″ long. 100% of the shots in a row smacked the rock in the center. I then shot at the muddy bank, and two of the three shots at the bank went into the same hole. 😆
The biggest problems I am seeing is my bullet casting could be better. 😳 And it is just so damed loud. I got to figure out how to quieten this beast down. My LDC is about 11″ long, but 5″ of that is the barrel in side of it. So just 6″ of baffel area. Not enough for all the air this thing is putting out! 😯 😆
Knife
Thanks.
I just sold my .308 so it will have a replacement here soon. 32″ 1-14 and will be the twin brother to my .257 except being .308.
A mandrel is $300 and barrels are $4.25 a inch up to 29″. 30″and longer are $4.75 a inch.
Barrels are hammer forged chromoly.
Thank you for the insight on LW, what did you spend with TJ’s on a mandrel and a barrel if you don’t mind saying.
Very nice job on all of your rifles- Nice collection !
Craig
They only provide barrel blanks and AF machines them.
The last barrel I would buy is a LW. They are so hard to machine because they are soft. I don’t think TJ’s offers a 6mm but if you want to spend the money he will make the mandrel for what ever barrel you want. I had a .308 1-14 4 groove made and I have the mandrel on my bench.
Going to send it back and have him make the mandrel .0005″ smaller and make me a couple more barrels.
Doug, I just picked up a Condor with two barrels 12 and 24″. I am considering fitting it with a 243/6mm rifle barrel. 1:14 twist and 6 grooves.
The reason for the 243/6mm is that in this really out of control state that I Live in (Cali) a pellet gun is considered to be no larger than 6mm otherwise it is a bigbore and can be considered a destructive device. So for now until I move my business elsewhere AZ,UT,ID I am going to play it cool.
Any thoughts on the 243 cal ? Bullet grains, twist rates, grooves and rifling. I was going to contact Lothar Walther and see if the can do a custom contour in .243.
Makes sense since the provide oem barrels for airforce rifles’
Regards,
Craig
BTW I have been watching all of Tofazfou video’s
Really? Do tell how exactly it is you draw this conclusion.
cheers,
Douglas
long complicated-looking equations would probably be useful in this endeavour.
The valve open distance is NOT set by the hammer energy. 😀
hey-Hey!!!,
On the hammer weight ‘thing’, valve open distance is set by hammer energy. This is 1/2*K_spring*(cocked distance^2-preload distance ^2). The hammer momentum is of course dependent on both mass and speed. With spring energy, and mass, you can get velocity, and then momentum. the momentum sets the dwell…all else being equal.
They y’all can worry about the losses sucking energy from the hammer. They ought to be small; unless somebody goo’d them up with moly paste to fix that…:) I suspect the percentage will go up with lighter, faster hammer action, but still be a small number.
cheers,
Douglas
gotta find a way to get output from equation editor in here…I’da left the force over distance integral un-solved…lol
Oh, this rifle will be a side cocker… I wouldn’t have it any other way! I HATE the factory AF loading… It’s also only going to be right side feed, to stiffen up the frame a bit. I think I’ll be alright with the idea I have for my bolt handle, should be nice and strong!
Shroud is real effective. It is 22″ long I think but that is because I have a 32″ barrel.
13 lb spring works fine with 100 gr hammer. I am experimenting with hammer weight.
You really need to make the gun a side cocker. The load put on the breech with I handle is quite a lot with a heavy spring. That’s why I have the cocking knob on the hammer. The hammer is a barrel guided and it on the thicker part of the barrel instead of off the end of the smallest part of the barrel.
I will make my new .308 the same as the .257 with 2 knobs.
Sweet!! I have an idea for a bolt handle, someone’s done it before… should work out nice- is a 13 lbs spring too much you think? is that why you’re lowering the weight of the spring? How long is your shroud for your .257? How effective is it?
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Man, I love this AG Stuff!!! :8: