Regulated .30
I have had a TJ’s .30 cal pellet barrel for awhile. I even sent it to get coated last time I had stuff done. I used a one piece bushing I made for .308 barrel and all I had to do is open it up .003″ for this barrel. I also have a 100 gr hammer from a .257 build where I was taking off 5 grams at a time for testing.
I decided to throw it in my first .308 frame that I ended up replacing so I could make it a side cocker. This frame has been a test piece for anything I don’t won’t to do on a good frame. I was the first frame I had striped to make sure they did it right. I also used it to convert a old collared frame to the new drop in spin lock. I chucked it up in my lathe in the 4 jaw chuck and bored in the recess. I will do my .25 and .257 when I brake them down for anodizing here some day.
Next experiment will be to remove all but .375″ of the scope rail and install a .750″ wide solid one. It will be slotted to fit over what’s left and also will run a 1.250″ ball end mill down it. It will fit on top of the frame perfect and cover the old slot. Then it will be converted to side cooker and both sides caped like I have done in the past.
So to test it threw it all together with a old .257 breech and used my .25 reg tank. I just removed the stem and put in a stem with a .375″ tophat to match the breech. My .25 tank is set at 1800 psi and shoots JSB’s in the mid 930’s for 100 shots.
So I put the stem in with no spacer and it had a gap of .215″. I figure I was going to need everything I had so I shot it. Well I was a little surprised when it was shooting 44 gr at 865 for and real consistent.
So I decided to drop in a spacer just for kicks to see what happens. The biggest spacer I had was .110″. So I topped off to 3000 psi and started shooting. I was really surprised when now it is shooting around 915 fps.
So now it’s running .105″ TH. So I dig through my spacers and stack 2 to come up with a .085″ TH gap. Now it is shooting around 905 fps with dips into 898 fps. These pellets are not very consistent and can vary 2 gr.
So now I fill up and do a shot string to see how many it will get. On shot 51 it came off the reg with a 888 fps shot and shot 50 was 900 fps. So I was thrilled but I think there is more in it if I make the reg chamber larger. I would like 60-70 shots around 880-890 fps.
These pellets don’t do good over 900 fps. I have a friend that converted his .22 evanix to .30 and he is shooting it at 875 fps and gets sub MOA at 100 yards with 44 gr. JSB’s and 70 gr custom boattail slugs.
So as time permits I will work on this and a .357 version also. Need to have options for EBR and maybe the .357 will be to my advantage.
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No .257 has never been regulated except by tethering to 88 cf tank.
I haven’t figured it out yet.
I thought you did a similar set up (with a collar) w/your .257? Maybe it wasn’t running a JDS reg? Hmmmm… Time to go searching for that post again… 🙄 I really wish my brain worked better!!
My reg setup won’t work on .257 either. Not until I make it with a huge chamber. Will be working on that with AVTom on the GTA here soon.
I use a adapter. My version of the etac. It is angled down 5°. I run high rings on all my guns now. I use to use med but wasn’t comfortable anymore.
You need one to clear the frame and it has the gauge and fill nice on it.
I was talking about your JDS/*your valve*/your collar design set up w/a 62/3000 tank! 😆 I know of the rabbit hole of the “AF in-tank reg”!!
.257 is not going to work with a regulator unless you have 1 cc per fpe of regulated air.
For mine I need 200 cc which is a little over 12 ci. That’s almost half of the AF bottle.
The bottle is a crossfire and is 8″ long and 3.20″ od. It is to short so that’s why mine will be attached to a 17 ci adapter.
On the metal tanks I glue a disc on the end of the tank so you can screw on a but stock.
Another weird question- W/that tank, how is the fit of the rifle? How high is the scope? Is it comfortable? W/the factory tank, and medium rings, the rifle was NOT comfortable for me to shoot. What are your thoughts? When you made the new scope rail for this frame, did you make it any taller than factory?
Doug, you’re such a goddamn enabler!! Thank you! 😆 Well, I picked up a 62/3000 tank… for under $40. I guess there’s no turning back now….
It is around 3.6″ The 4500 psi tanks are fatter. They are around 4.1″OD.
I’m going to build a setup with a 45 ci 4500 psi tank without a reg. It will be around 62 ci when done. It will be for my 7 mm and will run on 4000 psi. Still trying to figure out a regular setup similar for .257.
Doug- what are the dimensions for your tank? I think you said 10″ OAL for just the tank itself? What is the O.D. of the tank? I’m finding a lot of 68/4500 tanks that might fit the bill… Ninja makes a tank that’s 45/4500 that’s 10.25″ OAL w/the reg… Also- what are the required threads? I would think that a 4500 psi tank would net more shots than a 3k psi. Just spit-balling here.
Yup- I’m reading your stuff over there too!! How many of those tanks do you have left?
You would be better off running the tank I use. Reg setup is 3.5″ long. Stock bottle is 12″ and 62 ci bottle is 10″.
If I had a larger chamber I could get the same numbers on 1400 psi reg. I did some testing and 1600 psi was 950 fps and 1800 psi was over fps.
I’m getting lots of help over on the GTA with what’s needed to be efficient in a reg setup.
I wonder how well that reg setup would work w/a 490 cc, 4300 psi tank? How much longer is your reg set up compared to factory, Doug? 1600 psi is astounding!! :8:
It is a reg from JDS air. It is washers.
The chamber is around 50 cc at most. It needs to be 85 cc to be totally efficient. I need to come up with a different setup to get that big. I am going to make a larger setup for .357. I’m hoping around 80 cc.
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so it was just a 62/3000 tank w/an etac (with or w/o a collar?) and one of your valves? Or was it just a 62ci tank with one of your valves and a longer mount? Sorry to bugger your .30 page… PM?