Heavy weight .177 offers high smile ratio :)

[Erockrocket]

 I've been toying with this 22xx based SS tube and Powerhouse valve using a bolt blasting configuration. Decided to see how well it would send .177 pellets. Its a 15" LW barrel prepped to fit the 22xx.
Started with Monsters for 1004 fps, also tried some 15gr H&N Sniper Magnums, and 21gr Piledrivers. The 21gr chronied at 820fps, I believe port size is limiting my energy. Even at 820 fps the Piledrivers  performed well. A few sight ins at 70, then a 4 shot group. It's been fun to shoot, and slightly cheaper than shooting my big bores.
 I'd like to test it for further distances, the 21 gr may hold some surprises?
 Just thought I'd share the fun these airguns are, big, and small calibers.

[Ribbonstone]

The BC of the Piledriver is impressive, and actually comes close by observed readings to the published figures (about .08).   Energy isn't everything, but it may surprise you just how well those pellets hold on to their velocity/energy at longer ranges (windage is pretty much based on velocity loss over distance, so those high BC .177 pellets do very well in the wind).

[anti-squirrel]

I'm very intrigued by these results.  Those Piledrivers are cutting some nice holes- you said at 70?   

That ballistic coefficient is working well for you

[Motorhead]

Do know that when shooting JSB Monsters ( 13.4 grain ) in Field target keeping the under the legal 20 ft lb limit at @ 805 fps they do buck wind better than lighter pellets ( 10.3 & 10.5 ) being more typical in FT competition.
Only down side is the loopier trajectory requiring more precise range estimation.

With the small area of .177 caliber for pressure to work against and your wanting to really launch the HEAVY stuff at high power, efficiency in doing so I see as being pretty poor when looked at against a .22 of equal power.
Dang state law on the calibers above .177 would really su ck for sure.

[Erockrocket]

I'm very intrigued by these results.  Those Piledrivers are cutting some nice holes- you said at 70?   

That ballistic coefficient is working well for you

 Yes, making nice holes at 70 yards.
Only reason I used the heavies at 1st, I knew anything lighter would just crack the sound barrier. Currently using icemaker tubing for the transfer port, it measures 4mm. Going to  4.20 mm may help. I may step the fill pressure to 3500, see if it responds? These Powervalves really shine with heavier weights and higher fill pressure.
 I'm lucky I found an extended pin style probe that works well with these long rebated style Piledrivers. The pin pushes exactly center, just past the barrel port.
 Today was windy, the heavies didn't seem to mind. I need to work on a more stable shooting rest setup. I know it'll do better, to further yet.

[Mod90]

Nice to see you've joined the ranks of the .177 sniper corps. I and others I know have long seen that the heavier cylindrical pellets performed better at longer distances. Glad to see you've discovered the same.

Really nice group you got there

[K.O.]

Just for a future experiment a while ago... I picked up a Daisy 953 barrel ( 1:15 twist no choke about 20") with thoughts of sleeving it to .5  for a  .25 Mrod with the Piledrivers in mind...

Wonder how fast it will send them out at...just need to get off my rear and order some tubing and piledrivers and do a bit of redneck drill press work.

will the .177 and .22 bolts fit the .25 or will I need to mod a .25 bolt?

It would be cool to get around a 35 fpe .177  for long range if it is accurate with them... The Monsters and Sniper Mags do very well out of my BSA Buc.

[anti-squirrel]

Do know that when shooting JSB Monsters ( 13.4 grain ) in Field target keeping the under the legal 20 ft lb limit at @ 805 fps they do buck wind better than lighter pellets ( 10.3 & 10.5 ) being more typical in FT competition.
Only down side is the loopier trajectory requiring more precise range estimation.

With the small area of .177 caliber for pressure to work against and your wanting to really launch the HEAVY stuff at high power, efficiency in doing so I see as being pretty poor when looked at against a .22 of equal power.
Dang state law on the calibers above .177 would really su ck for sure.

This is always the dilemma I come back to- the .177 isn't quite as efficient as the .22.  But longer-range results like this make me want to do it anyway.  Even lighter-weight "heavies" like my Skenco 13 grain pointed buck the wind far better than 10-grain and less in my PP770- and I'm sure I'm still south of 700fps.

[screwwork]

Eric,
Nice shooting with the Piledrivers!
What is you barrel port ID?
Thx Randy

[Erockrocket]

Eric,
Nice shooting with the Piledrivers!
What is you barrel port ID?
Thx Randy

Thanks.
Currently the barrel port is at .110  I'd never thought I'd be sending 21gr pellets with this barrel, may open the port to .150?  Or even oval .110x.150"?
 Efficiency really isn't a concern, I shoot off a 3k tether mainly. May try a 3.5k fill with a bigger port.

[Ribbonstone]

Took me a lot of airgun testing to find any that really like those Piledrivers well enough to use at longer range.  Have some .177's that could push them into the middle 30's for energy, but not accurately.  Unfortunately, the best shooting barrel was (at the time) one on a 12 foot pound PCP.  Retuned, it still shot well at 19-20 foot pounds.

Anyway, figured good accuracy and 20 foot pounds would be enough to really test the observed BC of those pellets.  Harry (Yarrah) did some work with them, with very accurate barrels, but he is working with old stock UK verions of this pellet (he found an Au. stash of them and bought them up) which may be different than the H&N version (or may not).

He was getting some very high BC's, getting higher as distance increased (like +.1). The H&N web site lists them at about that same BC (call it .08). My tests found them to be somewhere between .075-.082 at "normal" ranges.  That's very high for any pellet, but after all, it's more a bullet than a pellet.

Shooting these things fast did produce the by-product of high energy. Wasn't really the goal;  goal was accuracy with much reduced windage.

Piledrivers showed to be stable in flight, leaving nice round holes in test backing (old dry wall works great, if the pellet is tipping, will retain that oval  imprint). Was getting fully round holes at all ranges tested.

But was getting some indications of pellet's tipping (tumbling) after impract. Was shooting old food. Apples, oranges, sweet potatos, etc. and getitng very large exit holes.  Captured pellets showed no expansion, so suspected some tippping/tumbing after a couple of inches of penetration.

SO..being courious...sacrificed a (store bought/already dead) chicken.  BAsically stuffed the chicken with cheap hotdogs, wrapped it up tight with an old T-shot, put some dry wall behind it, and shot it at hunting ranges.  Then took the chicken apart for internal inspection and checked the dry wall backing.

The Piledrivers did show tipping/keyholes in the dry wall.

So evidently, they're stable in flight...but after a certain amount of penetration in meat, tend to get unstable.  Not an unusal thing, many firearm militarty bullets do the same thing (but are going fast enough that they fragment when they turn end around).


Chicken/penetration tests:
http://www.network54.com/Forum/79537/message/1473009275

[aPpYe]

I wanted to try out the snipers because they are cheap, and the piledrivers because they seemed really awesome.  Straight from the tin, I am able to get 1.5" - 2" at 50 yards with both the snipers and piledrivers ...  I have not bothered to try sorting the "bad" pellets out because the consistency was horrible, just looking at all the pellets in the tin.  The gun was shooting at about 34FPE for the piledrivers and well above and below 900fps for the snipers.  I couldn't get them to group well.  Granted, I was only trying these in the one PCP I own, but look at these inconsistencies:

Lots of examples of each in both tins, each with varying degrees of flattened domes on the snipers and elongated tails on the piledrivers.  I was rather disappointed, considering how consistent the JSB Beasts were...  I am not a brand name type of guy, but I gotta say that JSB pellets have always been very consistent in size and shape for me.

I am thinking piledrivers would be better if I were to sort them, but I don't think I should have to bother with that, so

[Erockrocket]

I wanted to try out the snipers because they are cheap, and the piledrivers because they seemed really awesome.  Straight from the tin, I am able to get 1.5" - 2" at 50 yards with both the snipers and piledrivers ...  I have not bothered to try sorting the "bad" pellets out because the consistency was horrible, just looking at all the pellets in the tin.  The gun was shooting at about 34FPE for the piledrivers and well above and below 900fps for the snipers.  I couldn't get them to group well.  Granted, I was only trying these in the one PCP I own, but look at these inconsistencies:

Lots of examples of each in both tins, each with varying degrees of flattened domes on the snipers and elongated tails on the piledrivers.  I was rather disappointed, considering how consistent the JSB Beasts were...  I am not a brand name type of guy, but I gotta say that JSB pellets have always been very consistent in size and shape for me.

I am thinking piledrivers would be better if I were to sort them, but I don't think I should have to bother with that, so

The 2 tins of both Piledrivers, and Sniper Magnums I recieved are so far excellent quality. I weighed a few from each tin, they were within .010 grains, each one. Maybe yours were early editions, I'm impressed with mine.

 Added a second barrel band, and a short 2 piece quad rail. While the rifle was apart, we opened the barrel port to 75%/ .132"  Hoping to see slightly higher fps now, and with the more rigid barrel bands, tighter groups.........range time will tell.
 I don't currently hunt, punching paper and popping eggs are my airgun passion.  This heavy .177 will give me another option for sending lead, it's been fun assembling, and now testing.
 I'll post more once I've tested further, thanks for the responses, I'm glad to see others having fun with high power .177