Sheridan Blue Streak 30 cal.

[brewbean]

Has anyone ever heard of a 30 Cal Sheridan Blue streak? I have because it's sitting here right next to me. The owner said that it was a prototype and there are no markings on the pump tube.

[avator]

Is it just me or does that bolt and handle look pretty fresh?

[oldair]

I was watching that one - seeing the plastic guide and felt on the cross-head, and the cocking slot cut into the tube, it reminds me of a custom .30 cal Streak built by James Perotti twenty or so years ago.  I was impressed at how professionally it was done (as with all his projects).

Don R.

[eeler1]

Sheridan made paintball guns using the Co2 platform,  but I don’t know what caliber paintballs are, or if this thing has anything to do with that line.

[Habanero69er]

68 cal.?

[bantam5s]

68 cal.?

Yes I believe they were 68 caliber, but all were co2.
There was the model K pump action co2 rifle, a pistol with available stock, and a couple others.

They also made Pnu-Dart projectors in .50 cal.
I don't believe they made anything in .30 cal and I highly highly doubt they'd ever want to experiment with making a gun in .30 cal.
.20 was their thing and if it shot pellets it was going to be a .20 cal.

[JPSAXNC]

That looks like one I built. The last owner I knew of was Jim, I think at Precision air guns in Montana I think? The bolt handle looks like an add on.

[JPSAXNC]

The barrel was a 32-20 barrel liner, the compression tube is chromoly tubing. The breech and barrel were brazed on to the tube, at the time I didn't think solder would be strong enough. The valve is made in two pieces, the volume is about 1 cubic inch. The front half of the valve was long, and the short back half if inside the front half and had to be sealed by an o-ring. But there wasn't enough material on the back half to make a full depth o-ring grove, so i had to make half of the o-ring groove on the back half of the valve and the other half of the o-ring groove on the front half of the valve, so it's tricky to assemble. That's the draw back of working out of my head instead of from a drawing. I originally made the gun for Ron Sauls. It took 75 pumps to get 2000psi. at that pressure it made 859 fps. with a 44 grain .310 ball ( there was no 30 cal. pellets back then) so i stuffed the valve to reduce the volume and could get 600fps. on 12 pumps. I built a second one that had better performance, 820fps. on 12 pumps, but they were both a bear to pump.

[Pellet Fun]

The barrel was a 32-20 barrel liner, the compression tube is chromoly tubing. The breech and barrel were brazed on to the tube, at the time I didn't think solder would be strong enough. The valve is made in two pieces, the volume is about 1 cubic inch. The front half of the valve was long, and the short back half if inside the front half and had to be sealed by an o-ring. But there wasn't enough material on the back half to make a full depth o-ring grove, so i had to make half of the o-ring groove on the back half of the valve and the other half of the o-ring groove on the front half of the valve, so it's tricky to assemble. That's the draw back of working out of my head instead of from a drawing. I originally made the gun for Ron Sauls. It took 75 pumps to get 2000psi. at that pressure it made 859 fps. with a 44 grain .310 ball ( there was no 30 cal. pellets back then) so i stuffed the valve to reduce the volume and could get 600fps. on 12 pumps. I built a second one that had better performance, 820fps. on 12 pumps, but they were both a bear to pump.

James, this rifle is fascinating on so many levels being a pumper. Did you base the achievable psi based on calculations since there doesn’t seem to have a gauge port. Regardless, this is cool.

[JPSAXNC]

Hi Gary, Steve Woodward would make calculations for me so we had an idea of what the pressure was. I should mention that the gun that made 820fps. on 12 pumps was air conserving, another of Steve's ideas. It had the same reservoir volume as the first gun but only used a portion of the air per shot, by debouncing the hammer.

[JPSAXNC]

PS. The second gun had a gauge and the same stroke and valve volume as the first, so we knew the pressure.

[Pellet Fun]

Plain brilliance. Thank you. I’d enjoy dissecting one of these puppies.

[JPSAXNC]

The reason the guns could make more power was the larger valve volume and being pumped to higher pressure. And being .30 cal. there was more surface area for the air to push against. To pump to higher pressure I machined the pistons for solid Teflon, the piston had a micro groove cut into the face near the edge so it would act like a parachute seal. But there was no lost volume because I cut the groove with an x-acto knife held in the tool post on the lathe, so no material was removed from the piston. The reason I made the pistons out of Teflon was that rubber will not hold up at higher pressures. Rubber will begin to gall causing added friction and the high pressure air will penetrate the rubber causing it to form blisters. The best transfer port size was between .210-.215. I used a custom poppet and lightened hammer. I found on the second gun that the barrel could be soldered to the tube with soft solder with 2% silver. The breeches on both guns were brazed on for strength. So there was nothing really exotic involved.

[Pellet Fun]

That Teflon piston explains a lot. I’ve wondered about a small hydraulic pump instead of the standard pump arm to get around the forces needed on our pumpers. I know it would add weight, but it wouldn’t have to be large. As far as cost, for a one off it wouldn’t matter.