by B.B. Pelletier

Part 1

The Marauder sits on an MTM rifle rest at the AirForce test range–ready for 50-yard action.

Before I begin, another tidbit on the Pyramyd Air moving sale on Saturday, May 30. If you want to buy new items from the store, please bring a list of those items on paper.

Lots of interest in this rifle last week. Today, I’ll focus on the barrel. Although there are many interesting parts to the Marauder, some of the most anticipated features are centered on the tube with the spiral scratches. Just as a reminder, this barrel is American-made, choked, free-floated and shrouded.

I briefly mentioned that this isn’t a Lothar Walther barrel in the first report. It’s made by Crosman. Back when we were developing the basic requirements of the first- and second-generation PCP rifles Crosman would build, Crosman engineers were adamant that the second-generation barrel should be shrouded. I was equally adamant that it be choked. The subject of free-floating the barrel never came up in the discussions I attended.

Choked barrel
Crosman has been making good barrels for decades, so it isn’t a challenge to make another. But a choked barrel was a new concept. They discovered that all their major PCP competitors were using choked barrels, so just being able to put that into the ad literature was bragging rights by itself, but was it really important?

I can cite history–where famous barrelmaker Harry Pope clearly felt that a half-thousandth choke at the muzzle was a good thing. The intriguing thing is that many of Pope’s most accurate barrels were for muzzleloading rifles–yet they were still choked. Yes–the choke does squeeze the bullet down smaller than the rest of the bore as it enters the barrel; and no–lead does not “spring back” after being squeezed. But upon firing, the pressure of the explosion whacks the base of the bullet so hard that it squashes out to fill the bore tightly. This obstruction of the bore is called obturation, and all blackpowder arms do it. Diabolo pellets also expand at the skirt when hit with high-pressure air at the start. The force of the air is not nearly as great as the force of exploding gunpowder, but the skirt is made of thin lead and flexes more easily.

The choked muzzle then squeezes all exiting pellets to the same size as they leave the bore. And that’s been proven to increase accuracy. We shall see when we test for accuracy.

Free-floated barrel
In firearm rifles, a free-floated barrel allows the barrel to move as it heats up from firing. Since it doesn’t contact any part of the stock–the definition of free-floating–it never picks up a secondary point of contact to disturb its vibration. It’s free to vibrate the same with every shot–the same condition we strive for with the artillery hold. Free-floated barrels have long been known to improve accuracy over barrels that touch the stock along the forearm.

The barrel shroud has been removed, along with the baffles and end cap. The muzzle of the barrel touches nothing.

Here’s the muzzle sitting in the front hanger. As you can see, it touches nothing.

Here’s another view of the muzzle. There’s clearance all around. Note the stainless-steel Foster fitting with micron particle filter.

In a PCP, as the reservoir loses pressure, it flexes. If the reservoir is connected to the barrel, it will pull the barrel along with it as it moves. A free-floated barrel is not connected to the reservoir at any point. It tends to be accurate over the entire string of useful shots. In some rifles, like those from AirForce, the barrel is separated from the reservoir, so free-floating isn’t an issue. But in a rifle where the reservoir runs parallel to the axis of the bore, the potential for barrel movement due to reservoir flex is greatest.

One thing I must note is that the Marauder barrel shroud clatters a little when the rifle is handled. Actually, it’s the barrel inside that’s free to move around that causes the clattering. If you want a free-floated barrel, you have to put up with a little movement, and with the shroud being so close to the barrel, that means a slight bit of noise in the Marauder. Crosman engineers tell me they are working to minimize the noise, but I have to report on the gun I’m testing.

Shrouded barrel
Okay, here’s the thing so many want to know about. The shrouded barrel. Is it baffled? Yes, it is. How much quieter is it because of the baffles? Not much.

Huh? I thought baffles were THE thing for quiet rifles. Well, they can be if they’re needed and if they’re placed and spaced just right. But the muzzle of the Marauder is buried so deep inside the shroud (nearly 6″ from the outside of the end cap) that you can remove all the baffles, put the end cap back on and the rifle sounds almost the same. I just tried it and although I can hear a difference, it doesn’t amount to much. Maybe with a good sound meter that can freeze the high readings. If you had one that works fast enough to catch the fast peaks, there might really be a difference. But that’s like saying it’ll matter to your Collie but not to you. This rifle is quiet. Period. End of report.

No. Not the end. Not yet. I must be honest and revise my appraisal of what the rifle sounds like with the baffles installed and shooting a 10.5-grain Crosman Premier pellet at about 920 f.p.s. It sounds a lot like a Sheridan Blue Streak firing on one-quarter of a pump of air. Yes, that is louder than a ballpoint pen falling on a carpet. To all who went out and purchased ballpoint pens and had their homes recarpeted just to see what the Marauder sounds like so they didn’t have to risk buying one and being disappointed–I apologize. It’s still quieter than most weak spring rifles.

The end cap unscrews to remove the baffles that are just loose inside between the muzzle and the end cap. The shroud also unscrews so you can see the barrel. as shown in this report.

And there it is–the guts of the shroud. Four hollow Delrin chambers that sit in-line between the muzzle and the end cap. The o-ring sits behind the end cap, putting tension on the baffles behind so they don’t rattle.

Accuracy is also a barrel thing, but I’m not putting it here. We’ll have to get to it on a day all by itself. I’m thinking Friday.