Best speed for .177

[SteveKralsAround]

I was wondering if there is an optimal speed for the 17 cal pellets .

For the .22 I hear 880 fps or there abouts .

Looking for a starting point to save me time setting up a new regulated Kral NP-3 for 30yrd. pest control .

Thanks ,

Steve

 

[JadedC]

In general the optimal speed for most diabolo shaped pellets ranges from around 880-910 fps. Some people have reported great accuracy with speeds slightly higher than that such as 950, but the general consensus is like you said around the high 800's. This would be a good place to start you accuracy testing, and maybe tinker from there.

 

[DonC]

Field Target shooters have a limit of 20 ft/lbs because higher energy will damage the targets. These competitors are super accurate in .177 at this energy level. Most guys I know will shoot 875 for 17 ft/lbs.

 

[shambozzie]

The gun will tell you the best speed for accuracy. A clean bbl. Tin of pellets, full tank of air, and chrony. Nice way to spend a couple hours and bond with your gun. 860/880 should be good.

 

[bandg]

The gun will tell you the best speed for accuracy. A clean bbl. Tin of pellets, full tank of air, and chrony. Nice way to spend a couple hours and bond with your gun. 860/880 should be good.

And it could be much higher for some guns and some pellets. Best usable velocity seems to be very much determined by the power level/barrel/pellet combination, not just the velocity.

 

[SteveKralsAround]

I'm just starting to tune it . Fixed 4x scope , 16" barrel . regulator at 120 bar , transfer port open fully . 9.6gr Baracuda H.E. . 882 fps .

Now I'm off to shoot some groups .

Trigger pull is factory at 2.5 lbs. I'll stone polish the sear later ; I'm ok with the trigger for now .



Update: I'm getting 3/8" groups at 30 yrds , that's good enough for pesting .

 

[cmatera]

Listen to shambozzie

 

[DanielL]

Barrel and pellet dependent. Though, many guns use the same CZ and WL barrels so it can carry from gun to gun. Polymags can handle more speed than standard diablos. Generally, most will have optimal accuracy at lower speeds...below even 800 FPS but many can be pushed faster. The goal is to find that speed right before groups start to grow. That will yield accuracy with a flatter trajectory and least wind drift.

 

[bandg]

Yes, it seems very much barrel and pellet dependent. Doesn't seem to be any specific velocity determinant per individual pellet generally. Often it seems that flatter trajectory from higher velocity can aid "accurate shooting" (hitting a target reliably) more that any loss of absolute accuracy (group size), especially as the target becomes smaller and within effective range of course. Surely there may be an upper limit for such but it may be much higher for some barrel/pellet combinations than for others.