98 Custom PS ACT -- Stuttering Issue

I've been working on this issue for a few weeks now, and am still having trouble. I have a 98C PS w/ACT that started stuttering. Every trigger pull will result in about three or four cycles of the rear bolt before the sear will catch. I'm not low on air, I've replaced several of the o-rings for good measure, checked my power tube and springs. All of it seems to be in good condition.

I did notice that the sear pin seems to have a lot of play in it. Almost like the pin hole in the receiver halves are wore out. This concerns me a little bit since this 98 has only been in action for about three months. Has anyone else had any issues with this? While at the field I took one of the older 98 customs apart to look at its sear pin and it was held in place very securely. So, I'm guessing this is probably my issue unless anyone else can think of anything.

Thanks for the response pbnoob, I did check that. I am using the the black pin for the sear and the springs are in the right places.

Just seriously getting into paintball and I'm hoping you guys can assist - 

This probably should have been put in a new thread;  the bumping of year-dead posts is generally frowned upon here.  However, as this is on topic and a general question rather than one aimed at a specific poster I'll try to help.

Jonas Hove wrote: Hello, I'm new on this forum, but I've been renting out paintball supplies for 4 years. I never had problems with my 98 PS Rentals, but I now have the same problem "stuttering" with 8 out of 10 new markers I bought in june 2011. Can someone please help?

More information would help us help you.  Things it is useful for us to know would be any modifications made to the markers, air source that is used on them, conditions that stuttering occurs under, etc.  However, I can give a few general guesses/pieces of advice that might help even without the additional information.

If you aren't regularly oiling/maintaining the markers, do so.  There is a general paintball guide in the new players section that has some maintenance suggestions in it.  Here is the short version:  A half-dozen or so drops of oil in the ASA before each use followed by about thirty shots of firing without paint and a squeegee down the barrel will keep the internals well lubricated which does wonders for performance.  It doesn't hurt to put an additional drop or so of oil on the side of the rear hammer that you can see near the charging handle, on the spring you can see inside the marker and on the other side of the chamber beyond the spring.

Specific to stuttering, you should check the sear and bottom of the rear hammer for wear as well as checking the condition of the o-ring on the front of the rear hammer.  (Worn parts may not properly catch and a bad o-ring will allow air to get past the hammer decreasing the amount of force pushing it back, which could keep it from going back far enough to catch on the sear.

Additionally paint debris or build-up inside the marker can add additional friction which keeps the hammer from going back far enough to reset on the sear as well.

The CO2 is probably a large part of your problem.  It just really isn't a good cold weather propellant due to its temperature sensitivity.  The best test to verify this would be to try one outside, then bring it in, let in warm up and try it again.

It also wouldn't surprise me if it was the ACT markers acting up because of the CO2.  The ACT system adds additional spring pressure which must be overcome by the propellant to reset the rear hammer.  If operating pressure is already reduced because of the cold that additional resistance might be sufficient to cause problems.

Do you have any compressed air tanks you can try on one of the malfunctioning markers?

Small clarification on HPA tanks. While all HPA tanks have to be rehydroed, only CF tanks have a lifespan and it's 15 years.  Aluminum tanks can be used indefinitely as long as they pass rehydroing. At least thats the way it is here in the States. Maybe Belgium is different? HPA tanks themselves have come down considerably over the past few years, but the compressors I know are still quite expensive.

Edited by oldpbnoob - 25 February 2013 at 5:02pm