Poly vs. Smooth Twist

My HP shoots incredibly well at 970 w 25.4s but not so much w 18.1s. Likes to be around 900 with them. Lubing is a necessity at 970 or really frequent cleaning. It will shoot an old batch of Premiers well at over 1000 but again ... lubing is a necessity .

Bob

My RW hp shoots the 25.4 redesign at 970-975 with very good accuracy out to 100 yards. 18.1 on low go 880-890 with very good accuracy out to 75 yards. Shoot mostly the 25’s and clean about every 600 rounds 

I know that STX barrels can be pushed higher with accuracy. But what about the poly barrels. If I'm shooting a 22 poly barrel, will it still be accurate at higher velocities? I'm asking because I have a certain HP gun with a poly barrel. It is NOT more accurate above about 940-950. Just wondering if that is the norm. Shooting both 18gr and 25 gr.



Crusher

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%100 normal. You will find some exceptions here and there, but generally, most pellets wont do well at speeds higher than that regardless of the barrel. (most will have more drift past 950. Sometimes to an extreme. Sometimes with less speed than that.) My STX does shoot 18.13s with way more accuracy than it should 1.5-2 moa ~1250fps 

My RedWolf .22 HP sweet spot is 940 fps with the 25 gr. Anything below 920 and above 975 is a scatter plot.

Basic pull through cleaning after a tin of 200 is best. Higher velocity equals more frequent, deep cleaning (JSB bore paste and seal replacement) is my working theory with the poly barrel. However, I need to experiment more to back my claim. 

I know that STX barrels can be pushed higher with accuracy. But what about the poly barrels. If I'm shooting a 22 poly barrel, will it still be accurate at higher velocities? I'm asking because I have a certain HP gun with a poly barrel. It is NOT more accurate above about 940-950. Just wondering if that is the norm. Shooting both 18gr and 25 gr.



Crusher

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My understanding is the twist rate is more important than barrel type when shooting pellets, this is because the forward speed of the pellet decays quicker than spin rate. The faster the pellet is moving the faster the rate of decay. High spin rates cause weird spirals.



At 920fps my .20 rapid with jsb exacts would shoot nice groups (with the occasional flier) @100yards, however in an effort to eek out a few more shots I started to back the speed down,. At 845fps it was like I was shooting a different gun, every single pellet tracked absolutely perfectly down the same hole.



Bb