First experience with a Marauder

[REARSPROCKET]

[Informed Skeptic]

From what I understand, and I'm sure I'll be corrected here, is that you cannot increase pressure and increase velocity directly. How about this... You can turn the velocity to max by the velocity screw, with a fill of 2000psi and still get a max FPS the same as a 3k fill, just with a different peak and less shots in the peak.

Am I even close?

Also, I know for a fact that the Crosman pellets are much harder than the JSBs. Try shooting at a tin sheet or thin wood and watch as the Crosman pellets punch through or penetrate deeper and retain much of their shape. The JSBs are noticeably softer and transfer their energy much quicker. I've read that the Crosman pellets have a high antimony content.

The choke of a barrel is to swage, or size, the pellet and is usually no more than a thousandth of an inch less than the bore. As I understand it, of course. So a softer pellet, like the JSBs, would probably pass through the choke with a little less resistance, while still being shaped before it leaves the muzzle. I can't see how a harder pellet would take the same benefit. The harder Crosman pellets might work with the Crosman barrel so that their harder composition works better with the barrel specs. I can't compare JSB and Crosman pellets in a way that could help me understand this better, or anyone else for that matter.

The bottom line, I guess, is that the head size of the pellet, before and after the choke, would have to do some magical internal ballistic type stuff to get results. It makes sense that the manufacturer of the barrel also makes the pellet that performs best in it. Whatever the case may be, having to "massage" the barrel to get it to work with what are arguably the most popular pellet available seems a bit silly to me. Is Crosman really selling that many overpriced tins of their Field Pointed at $8 for 175?

A friend and I had this discussion and when I stated that I can outshoot the Marauder with my break barrel springer, he pointed out that my springer has a much better barrel. Over simplified and maybe obvious, but probably true. I would be willing to lend my Diana 34 to anyone here who can't shoot better than 2" groups at 50 yards with their Marauder for a comparison.

[Teryx]

The Crosman barrels are choked .003", same as the LW barrel. I've measured 1/2 doozen of them and they vary only by a few ten thousandths. The LW however has a slightly longer lead into the choke, where the Crosman is fairly short.

The only way to match the performance of 3000psi at 2000 psi is increase the flow through the valve and transfer port. You can't get there with adjustments alone. On the other hand, if the rifle is tuned for a lower pressure, increasing the fill pressure may actually lower performance. The tuning parameters have to be matched to the fill pressure, but unless you change the flow characteristics, the tuned high pressure will be faster than the tuned low pressure

Teryx

[Informed Skeptic]

Thanks Teryx.

I was expecting you to chime in. You could be the Moses of the Marauder legion and the sooner the better. I'm sure that I speak for everyone here when I say I hope that you get some (more) free time and some (more) motivation. Soon. It seems that you've set the foundation and only need the resources to build upon it. Are you as close as I think you are?

[Teryx]

Skeptic.
I'm pretty close I'm pretty sure I know what the operative elements are, and how to correct them, but I'm not saying anything till I have the data acquired and analyzed. I've got considerable engineering time in on this. Moses?? Man, don't hang that on me

Teryx

[Informed Skeptic]

Okay, I'll take the moniker away as long as you only put a 5 year patent on your findings so Crosman can get back in the game.
You'll still be able to fund your next project with the millions you'll make.

I don't know where you live, but if you were closer to me I bet I'd still have a Marauder.

Good luck.

[REARSPROCKET]

[Informed Skeptic]

Thanks RS,

I read that article and it's very comprehensive. I did adjust the hammer spring to accommodate the higher fill pressure, and consistency improved, but not accuracy.

I appreciate the time the forum has taken to help me with this issue. Unfortunately, I'm going to have to try the Marauder again, later, as I feel there are still too many production type problems with the rifle. The private tuners are going to eventually lead Crosman to the improvements necessary for the rifle to truly compete with the rest of the field. Until then, I'll let the dust settle.

Thanks again, and good luck.

[Oneshot]

This is my first posting on this site but I wanted to share what I found with my .22 Marauder. I had similar results period. I was getting good velocity but the accuracy was terrible by standards. It was shot over 1 1/2" average for the first two groups from 20 yards and didn't get any better. I backed up to 30 yards and some groups were around the 5" range. I called Crosman and talked to a woman in customer service. She said they expected the rifle to shoot between 1 1/2" to 2 1/2" at thirty yards!

I decided to take matters into my own hands and see if I could improve it. I bought a couple of packs of brass #10 round head bolts from the hardware and some 1/4" ones as well. I chucked a #10 in my drill and put some metal polishing compound on it (similar to Flitz). I mashed to screw into the crown of the barrel and started polishing. I would use a bolt only a short time and switch to a new one to try to keep the head of the screw from wearing and moving into the lands. I was able to get it down to about 1 1/4" at thirty yards. I thought I could do better and kept trying. It started to get worse so I decided to try the 1/4" bolt which has a larger head and less slope to it. After polishing the crown by using several new bolts my last group measured 0.643" center to center for 9 shots at 30 yards. In all I probably tried the procedure about a dozen times! I was pleased with the results but by that time I had become so disgusted with it I that ended up selling it.
As for the trigger, it is not bad but is long and reminds me of shooting a cap gun when I was a young boy.
The power is tunable but doesn't seem to shoot as smoothly as it should. It makes me think, "now I know why Greg Davis polishes every internal part of the rifles sent to him". For the money it would be a good buy if Crosman would only put a good barrel in it or at least a decent crown on the barrel.

[DRAGON64]

What are the specifics on the ammo you used? My understanding is, that he Marauder is ammo sensitive...

This is my first posting on this site but I wanted to share what I found with my .22 Marauder. I had similar results period. I was getting good velocity but the accuracy was terrible by standards. It was shot over 1 1/2" average for the first two groups from 20 yards and didn't get any better. I backed up to 30 yards and some groups were around the 5" range. I called Crosman and talked to a woman in customer service. She said they expected the rifle to shoot between 1 1/2" to 2 1/2" at thirty yards!

I decided to take matters into my own hands and see if I could improve it. I bought a couple of packs of brass #10 round head bolts from the hardware and some 1/4" ones as well. I chucked a #10 in my drill and put some metal polishing compound on it (similar to Flitz). I mashed to screw into the crown of the barrel and started polishing. I would use a bolt only a short time and switch to a new one to try to keep the head of the screw from wearing and moving into the lands. I was able to get it down to about 1 1/4" at thirty yards. I thought I could do better and kept trying. It started to get worse so I decided to try the 1/4" bolt which has a larger head and less slope to it. After polishing the crown by using several new bolts my last group measured 0.643" center to center for 9 shots at 30 yards. In all I probably tried the procedure about a dozen times! I was pleased with the results but by that time I had become so disgusted with it I that ended up selling it.
As for the trigger, it is not bad but is long and reminds me of shooting a cap gun when I was a young boy.
The power is tunable but doesn't seem to shoot as smoothly as it should. It makes me think, "now I know why Greg Davis polishes every internal part of the rifles sent to him". For the money it would be a good buy if Crosman would only put a good barrel in it or at least a decent crown on the barrel.