FWB 800x not grouping well

[abrasivereshaping]

We have been testing pellets and I'm not sure what to make of this.

Shooting from a rigid fixture into Sius HS10. Shooting through paper to visually back up Sius and have Scatt setup as well, to track any movement just in case.

Chronographed gun also and it was in FWB spec with ES 6-7 and SD 2

Tried 12 lots of RWS R10 8.2gr from 10pt9
Tried 12 more lots of JSB and Chinese pellets from Podium.

Here's the kicker...no matter what, the gun would group no better than a 6.8-7.2mm cloud.

I ran a boresnake between different lots and shoot 10 shots to recoat barrel with that lots lube.

Any suggestions?

Thanks everyone...hoping to goto JO'S with better grouping pellets

Also had Abbey Stanec @ Akron test the gun on their fixture and netted same results while we were there for a NRA Sectional

[redschietti]

What was the velosity?

[abrasivereshaping]

What was the velosity?

565-575fps with the RWS R10 8.2gr 4.5mm
570-580fps with the RWS R10 8.2gr 4.49mm

577-589fps with the JSB Diablo midweight 8.02gr 4.49mm

[redschietti]

Id bump it up a bit before i sent it in. 175-180 maybe 185 m/s seems best

[SailAwayAK]

and how much air in they cylinder? I noticed that when it starts dropping it doesn't group as well.

[abrasivereshaping]

and how much air in they cylinder? I noticed that when it starts dropping it doesn't group as well.

I usually top of air cylinder to 180bar and refill right around 150bar. From full, after my son shoots sighter plus 60rds for standing, the tank is usually around 150 bar. We will top off right be finals when he makes it to finals.

So for testing, I am trying to duplicate it.

[Mtl_Biker]

and how much air in they cylinder? I noticed that when it starts dropping it doesn't group as well.

Interesting. I shoot my 800 right down to about 100 bar without any pellet droop. I believe that since the gun is regulated and probably gives about 100 bar per shot through the regulator, there shouldn't be ANY difference in POI or velocity until the pressure drops to what the regulator is set to. I can easily shoot 3 full 60-shot matches on one cylinder fill.

At what point do you see your rifle start grouping poorly?

[abrasivereshaping]

and how much air in they cylinder? I noticed that when it starts dropping it doesn't group as well

At what point do you see your rifle start grouping poorly?

The gun poi doesn't really move from full to 100bar. Maybe a couple clicks up at best when low.

[abrasivereshaping]

So today I really cleaned and patched the daylights out of the barrel. I used my usual method of TSI 301 till clean and then dry patches...just did it 3X as much.

So I set everything up and woo hoo first 10 shots from a clean bore netted a group of 5.6mm!!!

Then it went to crap real fast...I gave up after shot 40. It never grouped better than 7.5mm after that.

I did run a wet patch though twice then dry patches to see what would happen. As I suspected the groups immediately tightened up and held 5.5-5.6mm for 5 shots. Then shot 6,7,8,9 and 10 would bounce horizontal back and forth almost a scoring ring.

I think I have a barrel issue. Some internal defect that is grabbing lead off the pellets and throwing them into horizontal group. Maybe the crown of the barrel or something with the rifling...

UGH...right before JO's

[remmy223]

Take the tube of the barrel and take a look at the crown