FX Barrel, Slug or Pellet Side?

[Opfor]

So I'm sure many of you FX owners are aware that our barrels have a pellet side (one hole) and slug side (two hole) at the end where it attaches and you rotate down the projectile you will be firing. I have had my on slug side from the advice of a friend even though I'm shooting pellets. He stated it would not matter and would give you more air in the end should you need more power. Lately I'm having lots of issue with keeping my POI consisent as it seems to change and vary day to day and yes my scope rings and mount are very secure and barrel has been cleaned. Shooting fx pellets both 18 and 25 grain around 900fps and both change about 1" at 50 yds.

My question is could it be that being on the slug side of the house and shooting pellets causing this change of POI? I've rotated the barrel 180 Deg and now trying the pellet side to see if things improve but just curious if anyone has had any experience with this and how you roll?

 

[dens228]

Did you retune after switching to the slug port?
Doing so allows more air through, so you need less pressure and different hammer spring settings.
I much prefer the slug port, more air at once, quicker burst, all with a more efficient cycle in my mind.
I don't notice accuracy difference with either once properly tuned.
As I think about it I do use the heavier side of pellets for a given caliber......but lighter slugs........lol

 

[Opfor]

Maybe that is part of my problem. Not 100% what all needs to be done when you say TUNE. I have my 1st Stage reg at 150 and my second at 110, believe they need to be within 40 of each other? I make sure that I'm shooting 880 to 920fps so what more am I missing with regards to tuning? Still a bit new at all this. Good to hear your thoughts on the two sides. I love shooting this FX wildcat but very frustrating finding my POI changing so much with it. It should not be jumping 1" to 1.5" groups day after day.
thx

 

[dens228]

I'm not familiar with the Wildcat. I have an M3 and had a Maverick.
If you didn't change anything except the port I'm sure that's your issue. You are now blasting quite a bit more air at the back of what was an accurate tune.
I'd have to believe there are specific tuning video's for the Wildcat but the first thing I'd do with yours is turn the second reg down about 10 bar or so and start from there.

Here are two video's

 

[Opfor]

Will check these out, thanks for posting. From what I understand the maverick and wildcat are pretty much identical, just the stocks that make them different.
Curious what caliber your maverick is? What do you have your first and second stage regs set at?

 

[dens228]

It was a .25 and I don't have it any more. I honestly can't remember the reg setting and don't want to guess and have you chasing the wrong number.

 

[Opfor]

What about your impact? Just curious to see how close you have your 1st and 2nd stage reg pressures to each other?

 

[dens228]

I looked up an old post of mine, on my .25 cal Maverick I had the 2nd reg at 112 and 34 grain pellets I was averaging about 908 fps, 600mm barrel.
My M3 is in 22 shooting 25 grain pellets. First reg is around 160, 2nd reg is 108, averaging 914 fps. I've never touched the 1st reg as long as it was 30+ above the 2nd which it always is.

 

[Opfor]

Sounds like I'm in the ballpark of your numbers as well. I also shoot the 25 gr and try to be around 900 on it. My first stage is at 150 and second 110. So if I do this does this techincially mean I'm tuned?

One thing I notice is that my fps still vary sometimes as high at 25 fps apart, that seems like a bad sign.

 

[dens228]

Sounds like I'm in the ballpark of your numbers as well. I also shoot the 25 gr and try to be around 900 on it. My first stage is at 150 and second 110. So if I do this does this techincially mean I'm tuned?

One thing I notice is that my fps still vary sometimes as high at 25 fps apart, that seems like a bad sign.

The large swing in fps is your hammer strike. You need to adjust the hammer tension. If your close to fps lower your hammer wheel, take a few shots and increase it until your fps keeps increasing. Then start turning the wheel back down until you're about 10% below peak speed. That's a pretty good tune for that pressure. It should be covered in the video's posted above. Watch the Ernest Rowe video for sure.