FX Crown first shot hot

[bchannell]

Having a lot of fun tuning my Crown for multiple calibers and noticed an anomoly
The first shot is always 5-10 fps high, then the gun settles into its normal, less than 10 es for whatever string length I decide to shoot.
I just glanced at my reg gauge each time and it's always on 100 bar right where I set it. This is for 177. Any thoughts? I know some will say reg creep but I can't see it moving up.
When I get time, I'm going to pull my Impacts Huma and try it in the Crown.

 

[ImpactX]

I'm guessing a little reg creep not much to be notice by your guage but enough to effect the speed. Tune your hammer power down a bit. 5-10 fps is nothing to be chasing after. I know folks who will keep chasing after such little different that end up ruined their gun. For 5-10 fps different I would just leave it as is or just tune hammer down a bit. Don't go chasing that perfect number. I know I once did the same chasing that perfect numbers and never getting to it lol. Spend hours and hours wasted chasing a imaginary number.

 

[bchannell]

Yes, you make a great point, but it's just something that stuck out to me in chrono'ing various pellets. None of my other rifles have this problem and at least a few of them have Huma regs, so it made me wonder.

I can say, the Crown is startlingly accurate. I've shot some of the best groups I've ever shot with it.

 

[madeintheuk]

Could be valve stiction. I know it was a problem with the impacts. Could be mild on the crown also. Try putting a little silicone oil down the fill port when filling your bottle, and see after a few fills if it improves the issue.

 

[Bobbybeef]

Take the reg out take all of the washers out clean each one put a light coat of silicone oil could have a tiny spec of trash make sure you do not mix the washers they are different thickness and different direction pay attention.

 

[MushroomPsyche]

That is most definitely a slight reg creep. If it was me, I would just leave it as it is because 10 FPS is not much at all. You can also try reducing the hammer spring tension just a smidge.

 

[Corvid_hunter]

I haven't noticed it on mine yet. If I had a problem with the first shot I would definitely prefer to have it faster instead of slower.

 

[SilentSquirrel]

I've read the entire thread and just have to ask.
With 2 recommendations to do so, can you tell me why backing down a tad on hammer spring tension fixes the OP's "first shot" issue?

Always looking to learn
Edward

 

[Stubbers]

I've read the entire thread and just have to ask.
With 2 recommendations to do so, can you tell me why backing down a tad on hammer spring tension fixes the OP's "first shot" issue?

Always looking to learn
Edward

Assuming he's currently over-driving his valve, which when presented with regulator creep, an over-sprung hammer easily overcomes the added pressure and allows the new pressure to reach the higher pressure's plateau opposed to keeping fps at or under what his plateau would be without creep. Once the hammer strike is slightly reduced, it makes it so generally with creep, you'll get fps nearly equal to or a bit under than without creep present as the hammer strike can't overcome the added pressure (creep) anymore. Reducing the hammer strike too far however makes for an undesirable deficit in the other direction where your first shot will be much lower than desired.

-Matt

 

[yarns]

Had a similar problem with my new Fac Mk4 Impact. The first shot is always 20 to 25 FPS slower than the rest of the string. Throws all of the performance figures out of the window! Take it out and the standard deviation is always 5 to 8 FPS, which is excellent. AND that first shot drop in FPS made not a scrap of difference in accuracy at my 43 metre zero set up. IMHO don't go chasing the figures unless they are excessive. I understand FX are looking to resolve this first shot problem asap.