Getting better consistency

[mcoulter]

While the efficiency still ain't great, I'm now getting more consistent groups with the Kral BigMax.  I snipped about 3mm from the hammer spring and shot nine 10-shot groups at 53 yards (jsb 18s):





90-shot string (average fps 871 / 30.5 fpe)



I also took it to the range to test 100 yard groups.  While most of the "groups" where meh..., I did manage to get a couple of respectable ones:

[rangur1]

while i don't know much about kral guns. the grouping seem pretty good.

[mcoulter]

Thanks Marc.   It's definitely a project gun.  (It feels like it has decent potential.)  I'd still like to get more shots from the fill.  Getting 100 to 120 shots at  30 fpe seems reasonable from it's 850 cc of air capacity. 

I'm just enjoying taking baby steps learning how it reacts to simple changes.  :-)

[Back_Roads]

 On that air volume I bet if you get close to 1000 shots per fill you might win 
 Heard of 800 + on that volume , but not on that gun, keep on tuning 

[Glem Chally]

Nothing wrong with that!  Nice work so far.

[skorec]

On that air volume I bet if you get close to 1000 shots per fill you might win 
 Heard of 800 + on that volume , but not on that gun, keep on tuning 

YES swapping to next 300bar bottles whit regulated air may able to increase shot count a lot.
https://www.aliexpress.com/item/New-Paintball-Air-Gun-Airsoft-PCP-HPA-Tank-Cyclinder-4500PSI-300BAR-30Mpa-0-22L-0-3L/32898484970.html?spm=a2g0s.9042311.0.0.710a4c4dYjOqYw
https://www.aliexpress.com/item/New-Style-Constant-Air-Valve-External-Adjustable-Regulator-3000psi-Output-Pressure-HPA-Test-Valves-Aluminum-Alloy/32860427398.html?spm=a2g0s.9042311.0.0.710a4c4dYjOqYw

Notice:
YES,   free floating barrel have to work OK and horizontal spread/inconsistency  can be caused by wind only .

[triggertreat]

Color me impressed.  90 shots with a very low ES and averaging just over 30 FPE with good groups at 53 yards. That's pretty good of any airgun if you ask me.  I always have liked the looks of the Krals too.

[Orion]

a lot of 873 and 874 fps on the shot string! Nice work!

[rsterne]

I see 86 shots within a 1.4% ES (12 fps) before the velocity fell below 865 fps, which was recorded a couple of times MANY shots earlier, and could be considered the bottom of the "normal" range....

Bob

[mcoulter]

Thanks for the kind words guys.  Next up will be taking a closer look at the barrel.   So far I have not been able to get the end cap off.  I may need to apply some heat to it...

The larger thread protector (last section with the two lines of ribbing) unscrews easily exposing the male threads, but the inner one (narrow, single-ribbed cap) does not want to budge:

[mcoulter]

I see 86 shots within a 1.4% ES (12 fps) before the velocity fell below 865 fps, which was recorded a couple of times MANY shots earlier, and could be considered the bottom of the "normal" range....

Bob

Thanks Bob.  That was my target low-velocity on the gun.  I guess I got lucky with the 3mm snipped from the hammer spring. 

My next test will be to fill to 210 bar according to my tank gauge and shoot another full string.  In my best estimation this will give me a "real" 200 bar in the gun based on feedback from two shops where I had my tank filled in the past.   This should translate into another 15 shots or so.