Carter buzzard Issue.....

[Walker]

This is a recap and continuation of a troubleshooting thread that I mistakenly continued in the For Sale Section:

History: I sold Moodog a Carter Buzzard that I failed to properly test before shipping it out. He encountered issues with it, and put it up for sale. Moodog was entirely in the right, the problem was caused by me in the first place, and I bought it back from him. I should never have sold it in the first place without proper testing and full disclosure.

Issue recap: Per Moodog:

It leaked and did not shoot at a playable velocity. I have since fixed the leak but regardless of what I do I cannot get it to shoot above 170FPS. I have tried all sorts of different spring combinations, but I believe the problem is something with the internals. When you adjust the IVG more inward the sear no longer catches on the bolt, despite having standard nelson springs.

Troubleshooting steps taken after I received the gun back.

Sounds like a powertube issue. I’m guessing it’s too long and choking the air

Co2’s sweet spot is more like 825-850psi I find just about anything designed to run on CO2 will run on HPA at that pressure unless designed to run on liquid CO2

Carters usually like to run around 850 like a Phantom. I’m with SoCal it’s likely a power tube issue or something is hanging up slowing the hammers operation. Could be the sear sear slot or something is mis alined those front block style Carters can be a pain to aline. I usually leave them a lil loose wiggle them around till you get the right feel in the action and tighten them down. Issue could arise where the mount screws are stripped enough that it won’t stay. In this case I drill the threads out to except CCI phantom stainless threaded inserts and red lock them in.

The sear being unable to latch, when the TPC was adjusted all the way inward, was caused by the powertube being too long. When the TPC was adjusted all the way in, the tip of the powertube was hitting the inside of the front of the TPC not allowing the bolt to come back far enough to latch the sear. When cocking the gun, the hammer stopped 3/32" away from the shoulder on the powertube. I trimmed 5/32" off the powertube to resolve that issue. I adjusted the TPC all the way in to test, the sear latches with no issues. Also, Carter's hammer has a lip on the inside (right at the back) that stops the TPC from exiting through the rear. Unlike a Phantom which can pass all the way through.

As for velocity, I'm using a red main spring and a very light valve spring. With my 650psi output HPA tank, it is shooting 238-246 fps with the TPC adjusted all the way in. Still a work in progress, I need to get a better selection of springs. And make me a Carter velocity adjust tool..... And maybe some different powertubes......

What kind of power tube was it? Carters usually do well with a cut down phantom power tube. I wouldn’t try to squeeze velocity out with a heavy mainspring fully compressed. It’s a good way to snap the power tube

What kind of power tube was it? Carters usually do well with a cut down phantom power tube. I wouldn’t try to squeeze velocity out with a heavy mainspring fully compressed. It’s a good way to snap the power tube[/quote]

Phantom on top.....





Inside diameter:
- Phantom: .172
- Carter: .145

Diameter where it enters the valve cap:
- Phantom: .248
- Carter: .274

Diameter of tube forward of collar:
- Phantom: .248
- Carter: .235

Length of tube, forward of collar:
- Phantom: 1.386
- Carter: 1.520


The Phantom power tube will work, but there is a bit of slop due to the difference in diameters. Changing just the powertubes causes a velocity drop when the Phantom tube is used.

All three power tubes:


The Lapco is very similar to the one for the Phantom, it is just longer.

Does the phantom valve body nut thread in? I have a Carter with phantom power tubes in it, but I don’t recall if I had to make a bee valve body to match the nut or not.

The Phantom nut will not thread into the Carter. The Carter takes a larger diameter.

Some more twiddling....

1. Carter powertube, heavier than red main spring, stock silver valve spring, TPC set to middle of run, 800psi output 13/3000 with a fresh fill. Shooting 212 to 220fps....
2. No change to parts in step 1, TPC one more turn in, shooting 220 to 228fps.
3. Change just the valve spring to a very light one, shooting 238-241fps.
4. Change tank only to a 625psi output, charged to 3000psi, expected the velocity to drop, and it didn't! It went up to 248-255psi....
5. Mounted a 12-gram changer, stuck in a twelvie, charged it up, no leaks. Expected a change, but not a great one. Wrong again! <shakes head> Velocity dropped to 215-217, very consistent over 10 shots.

Am I going to have to put a regulator on this and find the sweet spot? Yeeshhhh.....

So it looks like the issue could be the cup seal side of the power tube. I’m thinking the same way you had a bottoming out issue with the front the same is happening in the back. Does your valve body compensate for the longer back end of the power tube/ cup seal assembly? Could be that standard nelson springs are causing the valve not to open properly. Also I’ve never seen a Carter power tube with such small holes maybe flow being choked there as well especially when not using straight co2.

the next step is to unscrew the valve body nut and see where the inlet holes line up when the power tube is in the complete open position. See if there is any under or over travel. The inlet holes should just barely pass the edge of the valve nut. Also completely assemble the valve and see how far you can push the power tube with your thumb against the valve spring. See if it’s bottoming out too early before the valve has a chance to open properly

Thanks for all the help! I appreciate it......

1. Ensured TPC was at center of travel.
2. Clipped 2 turns off the lightest spring I have.
3. Stiffer than red main spring.

Inlet holes:


Powertube completely closed with spring installed:


Results (3 different tanks):

Low = Velocity of the slowest shot
High = Velocity of the highest shot
Average = Average velocity of all shots
Extreme Spread = High velocity minus low velocity
Standard Deviation = Standard deviation of the string of shots
Ten shots taken on all strings


1. HPA, 800psi output, First Strike 13/300
- Low: 238.3
- High: 266.2
- Average: 252
- Extreme spread: 27.88
- Standard deviation: 8.83

2. HPA, 625psi output, Riva 68/4500
- Low: 242.8
- High: 262.5
- Average: 251.6
- Extreme spread: 19.68
- Standard deviation: 6.08

3. Co2, 12-gram
- Low: 216.2
- High: 236.2
- Average: 227.5
- Extreme spread: 19.98
- Standard deviation: 6.24

Note: The port between the air chamber and the valve chamber on the Carter is 3/32", that on the Phantom is 3/16".

[Chuck E Ducky]

We need to sticky this.. I ❤️MCB

[Painthappy]

Good suggestion. Done.

[Socalpumpballer]

I guess the only thing left to do is open up the power tube for more flow. Also I wouldn’t go lighter with the valve spring too much dwell can cause low velocity.

[BOOSH]

If you still have that gun I'll buy it from you. I worked for Earon for 2+ years in Fullerton - The tube you say is the "carter tube" looks nothing like any carter tube I've ever seen. It's possible that he moved away from the 3-hole tube he used to make in the subsequent years. The phantom tube looks MUCH more like the old Carter tubes 3-holes drilled at an angle. These guns are deceptively simple, without being able to put my hands on it, it looks like that brand of cup seal could be sticking inside the valve seat. The pic where the valve is completely closed looks like a valve completely open - it's possible that there is not enough room in the valve body for the tube to open up completely - that's why you have to slam it so hard to increase the dwell time.
SOCAL is right you should be able to fix the velocity by simply opening up the transfer holes (or better yet, elongating them) a little bit if you are still stuck for velocity.

[Chuck E Ducky]

I wonder if you can fix the 2.0 phantom valve that way. I was going to try hogging out the valve body inside for more volume.

[Walker]

Boosh - I still have the gun. I assumed it was a Carter tube, as it came in the gun and fit the opening in the valve seat. By closed in that one pic, I meant the powertube collar was closed (pressed) against the outer face of the valve seat which meant the valve was opening completely and was not being blocked by the cupseal/compressed spring hitting the back of the valve chamber stopping it short.

[Socalpumpballer]

Here are some of my Carter Powertubes for comparison. The left one is a 3 hole, the broken center is 2 hole turned down and has ramped holes with flats. The right is 2 hole also turned down with flats

[Walker]

Mine do not look like that at all.....

[Socalpumpballer]

Yours is a very specific era of Carter power tubes that are not standard nelson spec and had its own specific valve nut. was suppose to be the most efficient one he ever made allegedly. I would ask Bacci if he has anymore info on them. Even other examples I’ve seen have larger holes though

[Walker]

I dropped a note to Dan.......

[Socalpumpballer]

[Walker]

The inside diameter of mine is like a Lapco #2, the Phantom ones I have are the size of a Lapco #4.

[Painthappy]

Even carter power tubes came in different sizes. I think I have some #3 ones here. The set up you have, hard valve spring and soft main spring needs a big holed #6 valve tube.

Or you need to soften your rear valve spring to keep it open longer.

[Ecapnation]

Worth mentioning... The later Carter's we're all over the place with specs and things didn't mix well.

[Painthappy]

I know I've already said my peace, but you need to change out that power tube. Those inlet holes are just too small for how we know we play ball now-a-days. Change that, and you'll be good. You can change the springs, but that will effect your efficiency. If you just want it to work, we can do that. If you want it to be efficient, you'll have to switch out the valve tube.

[flyweightnate]

BOOSH had an interesting point with the face seal being so small compared to the valve nut. I saw some Phantoms with soft seals get them stuck in the nut; maybe a washer closer in size to the cup seal OD? At least before you go boring or drilling powertubes.