P.M.I. I efficency

splatmaster12 · 09-29-2012, 07:40 PM

I recently bought a p.m.i. I from a member here, it came leaking so I replaced all of the seals. Now it is only getting around 10 good shots per 12gram, which from what I know is really low. I dont hear any leaks and it isnt shooting over velocity, I dont know what else it could be. Any help would be greatly appreciated.

Long Beard · 09-29-2012, 08:17 PM

paint size is a big killer of efficiency in Sheridan's. Because you have a set barrel size and paint has become relatively small, you need to look for bigger paint to match as best you can. You could also do a performance tune on your valve (or have it done by Palmers or Walz) to increase efficiency a bit.

B-17 · 09-29-2012, 08:17 PM

There is no way that it should be getting less than 25 shots if it is chrono'd at 280.
I'd suspect the valve to be kept open by a weak valve spring if there is absolutely no leaks. I wouldn't rule out a leak as they can be very small.

Most of the time I have a leak it's from not screwing the co2 cap in enough.

Once you get it working.... It's possibly the most fun gun I've ever had.

WALZ · 09-29-2012, 08:22 PM

Sounds to me like you might need a new spring set (main & valve).
Also a palmer dyna valve pin will help you get more shots.
For me 100% stock pmi is getting about 16 or so good shots and with a palmers dyna valve pin about 20 or so and if you enlarge the transfer ports and modify the valve to a one hole type you will get over 30 good shots with sized paint.
Widgets can also help with fps issues...
Hope this helps a bit...
Hope this helps you out...

snaparen · 09-29-2012, 08:26 PM

air it up and submerge it in the tub and look for bubbles, that will identify slow inaudible air leaks. But with only getting 10 shots that would be a fast leak.

c6quad · 09-29-2012, 08:58 PM

submerging it will tell but i wouldn't recommend that simply because of rust. just air it up and leave it for a few hours or overnight and then check to see if it held air.

splatmaster12 · 10-09-2012, 04:15 PM

My plan was to air it up and fire one shot per day until it was out, but after the 10th day I gave up. Im guessing over boring is my problem, but thats not fixable seeing as I already shoot the cheapest paint at $80 a case. Anybody got a smaller bore body they would trade straight?

Murf425 · 10-09-2012, 04:20 PM

Not sure if there are smaller bore bodies...other than having a new barrel tube put on it.

c6quad · 10-09-2012, 11:56 PM

yeah, you're not gonna find one with a tighter barrel. they're all big. paint was larger in size back in the day. you can send it to someone like WALZ and have them put a small bore barrel on it.

chrislognshot · 10-10-2012, 08:33 PM

you will find paint size is killer on all old pmi 1 2 or pgp p68sc if your paying with rock and cock. since it hard to find paint to match the barrel. or any old pmi that use hopper too. i have short pmi 1 with hopper and on my 4oz tank i only get about 100 shots do to fact paint does not fit the barrel right.

09-29-2012, 08:17 PM	#2 (permalink)
Long Beard Fantasy Hockey Chump Join Date: Feb 2007 Location: Northwestern PA	paint size is a big killer of efficiency in Sheridan's. Because you have a set barrel size and paint has become relatively small, you need to look for bigger paint to match as best you can. You could also do a performance tune on your valve (or have it done by Palmers or Walz) to increase efficiency a bit. __________________ "Nelsons are like plastic plants. They work well for their design, but there isn't any life in them. " -BretG Help Fund My ADOPTION Big Sale Long Beard's Deal of the Week (New 5/6 Montneel) My MCB Feedback

09-29-2012, 08:22 PM	#4 (permalink)
WALZ MCB Member Join Date: Nov 2010 Location: coarsegold,ca	Sounds to me like you might need a new spring set (main & valve). Also a palmer dyna valve pin will help you get more shots. For me 100% stock pmi is getting about 16 or so good shots and with a palmers dyna valve pin about 20 or so and if you enlarge the transfer ports and modify the valve to a one hole type you will get over 30 good shots with sized paint. Widgets can also help with fps issues... Hope this helps a bit... Hope this helps you out... __________________ WALZ Feedback

10-09-2012, 04:20 PM	#8 (permalink)
Murf425 Pop-Up Ninja Join Date: Oct 2007 Location: Brandon, FL	Not sure if there are smaller bore bodies...other than having a new barrel tube put on it. __________________ My Feedback Thread Go ye therefore to all the nations, shooting them in the face with balls of paint. Proud member of Team On Target. www.teamontargetpb.com

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10-10-2012, 08:33 PM	#10 (permalink)
chrislognshot Post Whore Join Date: Jul 2006	you will find paint size is killer on all old pmi 1 2 or pgp p68sc if your paying with rock and cock. since it hard to find paint to match the barrel. or any old pmi that use hopper too. i have short pmi 1 with hopper and on my 4oz tank i only get about 100 shots do to fact paint does not fit the barrel right.