.40 Badger

[Quad82]

"BigTinBoat"

"Quad82"Maybe I have not explained it well enough. It has not mattered what my fill pressure has been. Weather I fill to 4300, 4000 or even 3800, my first shot is slower than shots 2 and 3. But it always hits higher on the target. I understand you should only get a short bell curve when you fill past what the valve will handle. But I have gotten one at each fill pressure. This has to be false I know. But the target clearly shows this. I have let the rifle cool down after the fill up. I have taken up to 15 min between shots just to eliminate the “hot barrel” possibilities. Ya, I am laughing at this too.

I think maybe your testing is not precise enough.
1 - Get a 3" gauge so you can get the precise pressure readings
2 - weigh all of your ammo prior to shooting to insure they are w/i 1-2% of each other

The slugs I have been using are Air Venturi 232 grain. I have run them through a sizing die and sorted them to within a couple grains each. As for the gauge, the rifle does not have a gauge port. So I see no way to measure pressure between shots. That is why I shoot 3 shots and fill. This way I can see or hear when the fill valve pops open to let air in. This shows how much air was left in the tube. 

 

[BigTinBoat]

"Quad82"
The slugs I have been using are Air Venturi 232 grain. I have run them through a sizing die and sorted them to within a couple grains each. As for the gauge, the rifle does not have a gauge port. So I see no way to measure pressure between shots. That is why I shoot 3 shots and fill. This way I can see or hear when the fill valve pops open to let air in. This shows how much air was left in the tube. 

Let your fill assembly attached, but shut off the valve to the tank. This way the gauge will show the pressure in your tube. Once you replace the gauge with a 3" it will be much more accurate.

Doing this will also save on air as you won't have to waste air bleeding the line.

 

[Quad82]

Been shooting the 40 with different weight slugs. Settled on 180hp. Going about 830 FPS. Doing poor-mans testing in milk jugs. It goes through 4 1/2 jugs and opens up pretty good at 30 yards. Tried them at 50 yards and get about the same penitration but they don’t open as much.

Tonight I shot a doe at 20 yards quardering away. She ran about 45 yards before piling-up. Broke 1 rib on the way in and took out the heart and both lungs. Didn’t find an exit hole. Might have lodged in the oppisite front shoulder. I looked through the gut-pile with my metal detector but didn’t find it. Might get lucky and find it when I skin her out tomorrow. 

 

[Tony.fryery]

From my experience with big bores, you can put a heavier hammer spring in the rifle and tune it to have a more consistent shot string. Lighting it up and dropping the fill pressure to like 3800 will also make it a more consistent shot string too. You want it where your first 2 shots are touching, and your 3rd follow up shot is maybe a hair lower. Get in touch with Cedric on GTA, tofast4U is his user name. Very knowledgeable on tuning this rifle and will tell you a few mods to help with accuracy and shot count.

 

[Quad82]

I have added to a couple of his post there. Thanks for the info.