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All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Marc on September 13, 2021, 06:27:05 PM
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So I just got to shoot my new marauder pistol for the first time. It’s plenty quiet, and the trigger is excellent. But when I shoot there’s a little puff of air that comes out the back and hits me in the cheek. It’s a little annoying is this normal?
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So I just got to shoot my new marauder pistol for the first time. It’s plenty quiet, and the trigger is excellent. But when I shoot there’s a little puff of air that comes out the back and hits me in the cheek. It’s a little annoying is this normal?
I also recently received my new Marauder Pistol and shot it and mine does the same thing. I've read a few others with the same observations, as I believe this is normal behavior. Maybe someone who is 110% sure can chime in but AFAIK it's normal.
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I would be bummed if this is how they actually work. It’s pretty dang annoying.
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I would be bummed if this is how they actually work. It’s pretty dang annoying.
I tend to agree as I think it's annoying as well however as I read a while back I believe maybe it was The Marauder rifles that also did that and they actually came with the tiny little plug to plug that hole with so that the person was not blasted with that little puff of air. I very well may be remembering this incorrectly but I do know that one of the rifles that exhibited that same behavior did in fact have a tiny little nipple essentially that plugged that hole and you may be able to do the same with this PCP. Search the forum a bit harder maybe you'll find the answer good luck my brother
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with the mag in place and empty , loosen the set screws on the barrel.. shift the barrel back as far as it will go without compressing the mag.. This should bring the probe in contact with the internal 009 oring .unless its a different leak im unaware of , like the transfer port.
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It is coming from the lower tube. Air that escapes around the valve pin out the back. You can get a "BuckRail" AR style adjustable stock for the pistol. Much better cheek rest than the crosman carbine stock. About $50 and comes with everything needed. It screws into the hammer spring adjuster so no more air to the face.
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Yes - it feels like it's coming right out the back of the air tube where the threads are, best I can tell. If you add a Buck Rail - does it plug and stop this, or just move you up and out of the way?
Also - this is my first PCP and I hear about people having to fill the gun from empty - but this one came full of air. Is that normal?
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Plugs it as the buckrail stock has a big bolt running through it that attaches to the back of the air tube where you adjust the hammer spring. Also raises you face up above the air tube so if any air does escape through there, you won't feel it on your face.
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I just tried mine with the Buck-Rail stock and I don't feel any air at all.
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I've never noticed this. I shot initially with the stock it came with but never noticed a puff of air. I currently use a little stock I made. It is just a piece of 7/8 aluminum tube with a couple plywood discs sanded to fit the inside that hold fittings and a buttplate. I'll try and include a picture. On one end is a 5/16 fine thread bolt and on the other end is a 1/4 T-nut to attach the butt plate. Works great for me and it's lighter than the plastic stock. Doesn't wiggle either.
If you just want to block the air you could just put a short 5/16 fine thread bolt in the end of the gun. I assume that is where it's coming out. The hammer throw and force adjustment comes through the end of the gun and there are no O-rings to seal it up. When you pull the trigger, the hammer hits the valve inside the lower tube of the gun and the air then goes up through the transfer port that is between the two tubes and into the barrel to propell the pellet. At least most of the air does this.
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Probably the air that's being displaced as the hammer slings forward.
Air has to go somewhere and that's the path of least resistance..
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Totally normal.
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Probably the air that's being displaced as the hammer slings forward.
Air has to go somewhere and that's the path of least resistance..
+1
Also you can do a tissue test to make sure the transfer port seal isn’t leaking. Just place a tissue over the breach/mag and shoot in a safe direction. Tissue doesn’t move it’s ok and normal. If the tissue moves than it’s most likely the transfer port seal isn’t sealed.
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Is this something I should expect to mess with on a new gun? Just doesn’t seem right , out of the box.
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Is this something I should expect to mess with on a new gun? Just doesn’t seem right , out of the box.
It probably is just the hammer displacing the air in front of it, like mentioned before just put a bolt or even an earplug. shoot the darn thing and see if it hits the target consistently and have some fun :)
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So I know as much about PCP's as I do space rockets. So you guys don't think this is a defect type issue? The air does blow out pretty stiff.
If it's normal and I can put a Buck Rail stock on and it's good that's workable. If it's defect type thing I'd rather ship it back and let them sort it out.
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Totally normal as it is high pressure air blowing past the valve pin when the hammer drops. The hammer has flats on the sides so the air escapes past it. Was annoying at first till I plugged the hole with the buckrail stock. The hammer on my fortitude is round and fills the air tube so no puff of air in the face on a shot as the hammer displaces the air.
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Yes this is normal, the air in the hammer tube is being displaced by the hammer moving forward like a piston, it is designed to do this and the hole is for the degassing tool, you can place a short screw in the hole at the back of the hammer tube stop, I think it is a 1/4 x 20 thread, I could be wrong on thread size, try it.
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Thanks guys - you'd think they would put something in the manual to let a guy know it's normal. But I know, manuals can be a bit lacking at times.
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find a screw or a rubber plug to put in the hole.
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You seem to be a bit of a worrier from other posts. My gun did it too, but velocities were consistent... and in line with advertised velocities... shot accurately. No worries.
I recently installed a Hill kit and it seems to puff a little less, but there's still some air.
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Normal ? really ?
No way I would accept that !!!
Is this a thing in the new Marauder pistols ?
I don't remember that, my 1st marauder pistol I think was serial number 80 something.
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Nope - not a worrier. Just like to learn as much as I can and try to get things right the first time.
Thanks Nomadic Pirate - that's my thought. A new gun shouldn't be designed to need a fix right out of the box. Especially for a new owner that wouldn't know if this is a tiny fix or major malfunction.
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The valve does not have an O-ring on the poppet stem, so you can get a little blow by during the shot. You can also get some from the hammer moving forward. It is normal, and has always been the design of the mrod and prod.
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That is why knowledgeable prod shooters ditch that oem stock and use a replacement that screws into that hole the air escapes from.
Roachcreek
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Figured I'd go straight to the source. Called Crosman this AM and they said no way should it be like that - send it back.
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Normal. I put a short Button Head Socket Cap screw in mine. When I first got it I did'nt notice. Probably happens to all P-rods over time.
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Figured I'd go straight to the source. Called Crosman this AM and they said no way should it be like that - send it back.
Plug the rear cap with a short dome head or cap screw with an O-ring wound around it.
You could also wound a painter’s tape around the plug/rear cap (section where it goes into the tube), so that it is a tighter seal.
Punch the 2 screw holes with a pin, so that the rear breech screws go in without tearing or displacing the tape.
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Cover that rear end cap’s adjusting hole with just a little square of cheap tape.
If it’s just a little puff that goes away when the rear end cap hole is taped...then plug the hole.
If it still puffs air in your face, it’s coming from somewhere else.
Some PCP’s will just leak a little air past the sides of the valve stem shank….some create an air piston as the striker moves forward. Some transfer ports are NOT well sealed to the valve body.
Some PCP’s do use an o-ring on the valve stem shaft...some have a tighter fit and don’t leak much at all...some have no adjustments back there and use a solid end cap...and some just hide the adjusting hole by being covered with the stock. P-Rod is right in line with your face, isn’t o-ringed, and isn’t covered.
It’s the little things with P-Rods that are irritating.
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5/16 x 24 is the thread pitch of the PROD’s/17xx’s rear threaded cap—go to Ace Hardware.
The PROD is about the simplest of PCP design’s, just saying.
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Figured I'd go straight to the source. Called Crosman this AM and they said no way should it be like that - send it back.
I actually can't wait until you send in this gun and receive another one. Since the Crosman folks say it shouldn't be there, I want to see if they can send you a gun where there is none.
Every Mrod or Prod I have shot unless they have some sort of denounce modification done, has had this slight puff of air.
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true….without shooting it, hard to judge how much of a puff. Would be surprised if there isn’t at least a little air movement from just the striker acting like a vented piston.
“Just” airguns, but I still wear glasses when shooting (prescription or safety). Not so much for what does happen, but for what can happen.
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Sounds like the breech o-ring is missing
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with the mag in place and empty , loosen the set screws on the barrel.. shift the barrel back as far as it will go without compressing the mag.. This should bring the probe in contact with the internal 009 oring .unless its a different leak im unaware of , like the transfer port.
This is the solution probably. Someone isn't getting the barrels snug, if the o-ring is still there.
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true….without shooting it, hard to judge how much of a puff. Would be surprised if there isn’t at least a little air movement from just the striker acting like a vented piston.
“Just” airguns, but I still wear glasses when shooting (prescription or safety). Not so much for what does happen, but for what can happen.
This is where having a chronograph comes into use to narrow down what the problem is.
If it's a transfer port issue then surely the gun would be shooting at a lower fps/fpe.
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with the mag in place and empty , loosen the set screws on the barrel.. shift the barrel back as far as it will go without compressing the mag.. This should bring the probe in contact with the internal 009 oring .unless its a different leak im unaware of , like the transfer port.
This is the solution probably. Someone isn't getting the barrels snug, if the o-ring is still there.
I use a single-shot tray (SST) on my PROD from a Marauder rifle, which I bought from Umarex for about $7 shipped, as I never did like the funky colors nor the tire-like texture of 3D - printed SSTs.
Duh, never tried nor bought a mag for my built PROD.
Well, I think it’s (SST) for the Gauntlet, but I have read somewhere that MROD and Gauntlet mags are about the same.
I did lap the bottom a bit for it to fit.
Hmm, the probe to barrel distance is indeed somewhat crucial, but I just positioned the barrel so that it secures the SST snugly.
It’s easy to check the 2 transfer ports (top and bottom for the PROD but the same TP as the 13xx’s/22xx’s) without the need to degas-—just remove the top after sliding out the barrel band and unscrewing the 4 breech screws.
Yes, no need to remove the barrel or shroud unless you would like to position the barrel closer to the probe after loosening the 2 barrel set screws.
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A little light silicone grease on the sides of the hammer may also help. When the hammer hits the valve stem is pressurizes the end of the lower tube where the air is stored. The end closer to the shooter. The transfer port is at the top and has an seal on the top and bottom (the port is aluminum). If the hammer has a coating of lubricant on it, there should be very little if any movement of air towards the shooter, past the hammer spring and throw adjustment screws. Hard to imagine much air makes it past the hammer and through the threads for the adjustments.
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I would not use ANY lubricant but a light burnish of either tungsten or moly on the hammer. Grease will cause major inconsistencies in velocity.
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I think I used silicone oil instead of grease but I lubed mine last time I had it apart. I was doing a Bstaley tune and it shoots very well. 35 fps extreme spread over 30 shots (less for shorter strings). That area has silicone grease in it, however, because I used a light coating to hold the O-rings in place.
Metal to metal contacts will be lubed in my guns. Not slathered in lube but appropriately lubed.
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Late to the party, just looked at my Prod spare valve, there is enough space between the hole in the valve body and the poppett stem to let a little blast of air to escape during the shot cycle, no o rings there, as stated by another user above, nothing to worry about.