Tuning DO I HAVE A BAD REG?

[2D1C]

I have a modified Impact .25cal. I was out shooting at the range topped it off and loss 200FPS. It was shooting 885 to 905 on power level 2( MKI 34 gn). After the top off it was at 775. Turned the power wheel to 5 jumped to 940ish worked my down to level 2 again and it was back where it was. Topped of again and same thing happened. Any ideas?

Thanx in advance



Dennis

 

[corny]

 

I would guess if it fluctuating that much…ur reg gauge should show it? 
make note of pressure as u shoot it down.

I’ve seen the plenum overfill after topping of the gun, but generally speaking it takes one shot to clear that. 

 

[2D1C]

I did not watch the reg no. I will next time out

 

[Motorhead]

Given sufficient hammer energy to open poppet valve over a wide +/- range of your running at setting ..... SWINGS IN REGULATED PRESSURE will indeed change velocity !!

For the Pressure is the energy that is absorbed into moving said projectile down the barrel .... pressure changes velocity changes !!

Unless tuned on or near the knee of pressure, hammer strike and velocity will one see more plenum pressure decreasing velocity. See above ^^^^

 

[Jlacouturec]

check the orings in the piston of the regulator.... without those orings working good, your rifle will behave as an unregulated platform!

 

[2D1C]

@motorhead

I was pleased with my power wheel range 850ish on min and 940ish on level 5, big jump between level 3 & 4. Then after the second top off it it dropped big time.

@jlacouturec. I bought this used a year ago or so and never have had the reg out but I will!

@Bigragu thanks for that vid I will be watching it soon

 

[Glem.Chally]

Step 1 Monitor reg gauge, if its acting strange you'll see it.

Step 2 Go from there.

 

[Keyman62421]

Just for giggles, Make sure your hammer spring adjustment hasn't backed off @ wheel!

 

[KatoKevin454]

Lube it..... O-rings are probably dry

 

[2D1C]

So I finally got time to work on reg. Took it out and apart changed all the o-rings cleaned and lubed everything then reassembled. Man am I glad I bought that piston install tool!!!!!. The Crown reg is much easier to get in and out! Anyway It's back up and running like it used to.

Thank all of you for your insight and suggestions.



Dennis

 

[bigHUN]

This happened to me, a month ago I refilled one of my 14L SCBA tanks and I knew it picked up some moisture from the basement air but I let it run. (in meantime I got a big two chamber water/oil separator from ali) 

Last week at my range the speed started spiking bigger a bigger spreads. Initial thought the C1 got loose but checked that one right away when I got home and the measurement was acceptable number, everything was OK.

I toke the Reg apart today for a very first time and it was all mud inside. New orings and polished the washers, will see tomorrow how it goes.