Air Gun Home :: View topic - Marauder pistol write up...good stuff here

Mark5043 · Silver Status Member

So the first baby M-rod's are being released today.... Mr. Green

Here is a good write up by Jim Chapman,which includes shot string analysis.

http://www.americanairgunhunter.com/mrod_pistol.html

packrat · Senior Member

Wow ! If I had a deposit down for one of those, and then later I read that review, I would call and cancel my order.....real gun seems a lot different from all the hype about it.....but-that's nothing new with manufacturers.

Mark5043 · Silver Status Member

rsterne · Moderator

On average (each pellet is a bit different) it looks to me like you should fill to 2400 psi and shoot down to 1800.... That looks like about 24 shots (ie 3 clips) within a 5% range of velocity which is PLENTY good enough for a pistol.... Heck, if you are happy with a 10% variation (which is still OK for a pistol IMO).... you could probably fill to ~2600 and shoot down to ~1600.... That should get you close to 5 clips (40 shots) which is pretty darn good for such a small air reservoir.... It looks like the average energy is around 12 FPE which ain't half bad....

A lot of people, when a gun CAN be filled to 3000 psi, expect it to perform best there.... In fact, most do not, at least in stock form.... The "sweet spot" in the shot string is usually centered more around 2000 psi.... ie running from say 2500 down to 1500.... Yes, it will work at 3000 psi, but not much better than it will at 1000.... If you lean on the hammer spring, then you can move the sweet spot up the range so that it shoots flatter from, say, 3000 psi down to 2000.... but with fewer shots at higher power.... That is exactly what the MRod pistol curve tells me.... I'm guessing that with no other changes, you could bump the velocity up to at least 700 fps (ie about 16 FPE) and get at least 2 clips (ie 16 shots) at that level.... Those numbers could be conservative (see below)....

It looks to me like the (usuable) air reservoir is about 9" long.... that's similar to a 2260 tube with a gauge or extended valve front end.... in fact, I wouldn't be surprised if the tube is exactly the same dimensions.... The overall length of the gun is 18", and you can scale the other dimensions off the screen with a ruler pretty close.... I also don't believe that the barrel is only 8" long.... The shroud is 11" according to the specs given.... and that scales out OK.... However, the EXPOSED part of the barrel (forward of the breech) is about 8".... but look where the magazine is.... That barrel must be at least 11".... The valve isn't a Disco valve, because the mounting screws are too close to the magazine port.... However, the manometer location is just like a Disco.... I'm guessing the air reservoir is about 65 cc.... a bit less than half that of a Disco (135cc)....

OK, so assuming it's a 2260 size tube, what can we expect?.... My 2260 PCP Carbine Grouse Gun uses one, filled to 2000 psi and shooting down to 1000.... and I get 16 shots at 700 fps with 18.1 gr. JSB Heavies (20 FPE) from a 14" barrel.... The MRod pistol uses a shorter barrel, but a higher fill pressure.... You lose on the barrel length, but gain on the pressure.... I'm thinking that the MRod pistol could easily be tuned to give ~16 shots at ~20 FPE.... and anything in between that and what it is now (~24+ shots @ ~12 FPE).... and keep the velocity within a 5% window....

I think that's pretty darn good.... Mr. Green

Bob

sniper · Silver Status Member

I wasn't too impressed with the power. however 3.5 fpe still
goes all the way thru a rat. Twisted Evil

so on that note...
it's on my wish list. if they were able to balance it like
the rifles it's probably a nice shooter.

12 fpe of pfffft rodent death Twisted Evil

say, i have an extra red dot laying around here. Razz

Mark5043 · Silver Status Member

Well Bob when you break it down like that it seems Crosman in fact dialed the pistol to have both decent power,AND shot count....a balanced trade off if you will.Can't really complain there."By the way the tube is exactly the dimension of the 2260/Disco"...so it seems they actually did a pretty good job balancing it all out,based on what your saying.I was just expecting it to have more juice out of the box,but that can be easily accomplished with some tweaks at the expense of shot count...which is fine by me..... Cool

Oh,and Sniper,your right ..3.5 is all you need for rats...But...a power tweek producing 16 shots @ 20FPE would be a devastating rat flipper, since the ivy starts at only 5 yards from the side of the new place we recently moved into.....Still have yet to unpack my stash of Pred's,and Crowmags Laughing

......

.......... Shocked

Next on the wish list.....night vision,and infrared movement sensors hooked up to a "ding donger"
When the Mrs.goes away for the weekend the boys will play..... Wink