.177 Twist Rate and Pellet Weight

[Reddleader68]

I've ready various reviews and tests on the ultra heavy pellets in .177 (HN Rabbit Mag etc) and most seem to be unfavorable. Has anyone tried a faster twist barrel with the heavy pellets? If so, what were your findings? By the way, what is the standard twist for a .177 barrel?

[K.O.]

Crosman barrels are 1:16, L.W. are 1:17.7 and the Daisy 953 barrels are 1:15,

For most pellets the Crosman and L.W. barrels are fine...

I picked up a Daisy barrel just to find out how well it would do with pellets like the JSB 18g Beast but have to put together another pumper to test because I think the 21 fpe is just a bit to little to send them effectively...Bob seems to think about 25 fpe is needed and he is usually right...

I ran the numbers thru the border barrels calculator and iirc it looked like the 1:16 twist was at the edge of working(on paper) for the length of the JSB Beast...

I do not know the measurements of the other pellets...

[michaelthomas]

FWIW....twist calculators aren't too reliable with pellets.  Pellets derive a lot of stability from their shape.....and don't depend as much on twist.

I know someone in benchrest shooting a .177" 1:26 twist Lilja that shoots the Beasts at around 900 very well.

Mike

[K.O.]

I agree but at the same time he is talking about the rabbit mags which are more bullet than pellet... and the JSB  monsters and beast are almost bullet like and the H&N 21g piledrivers well they are a bullet to me...

I do tend to think that the more bullet like a pellet is the more it will be able to be over spun...

[Reddleader68]

Yes, I am referring to the more bullet shaped pellets. My suspicion is that the longer bullet shaped pellets will need a faster twist barrel similar to a centerfire.

[michaelthomas]

You guys seem to be ignoring the post I made.

.177 Beast pellets (don't get more bullet shaped than those) shoot great out of a 1:26 twist Lilja barrel.  I personally shot a dozen or so with this combo myself a few weeks ago at a benchrest match in CA. 

Mike

[K.O.]

Not ignoring just it is a 400-600 $ barrel you are talking about and with no  specs 2groove -3groove land and groove diam...?

I certainly believe that both can work, slow twist and fast twist...

 The 60 grain subsonic .22 bullets tend to keyhole  in  1:16 Ballard rifling but do fine in the Marlins 1:16 Microgroove rifling...

so it is more complicated than just twist rate...


My 2 Daisy 953s like the opposite pellets that I thought they would at 20-30 yards... the 1:15 Daisy barrel likes the 8.3gr RWS Superdomes and the 1:17.7 L.W. barrel likes the AA 10.3g...  go figure... and that is down at 450-475 fps...

And that brings up how fast are you spitting them at... I can see my pumper hitting 800fps or so maybe a bit more...maybe shooting 700-750 fps at times... so that will bring down the rpm compared to 850-950fps...

The only other actual report of how they did was out of a bench rest rifle also.... at 870 fps with a L.W. barrel and they spiraled after about 40 yards... I think they do not like the choke (bullets do not like chokes) but it could be twist and choke and rifling style...

http://www.gatewaytoairguns.org/GTA/index.php?topic=87083.0

well there was this about a 1:24 Lilja from a while ago but I do not know about the posters so it was take with a grain of salt type thing for me...

http://benchrest.com/showthread.php?91765-Jsb-16-2-beast-in-high-power-long-ranger-with-lilja-177

So in the 20-40-80$ range of barrels I do very much think that a 1:15 twist barrel has a good chance of doing better with the rabbit Magnums and such than a 1:16 twist barrel...

But find me a trashed BSA Meteor and I will be open to stealing it's 1:19 twist barrel to try also...

[K.O.]

... and thanks for the input Mike, while I do not have the $ for bench rest, it does not mean I can not learn from what is going on in bench rest...