Polymag .25cal: What Max. Velocity? ▪ BC? ▪ Expansion?

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JungleShooter

JungleShooter

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Sep 5, 2018
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Polymag .25cal
●Max. Velocity?
●HP Expansion?
●BC?

Yupp, that's what I'm interested in.


🟠 (1) What is the max. velocity where you still got acceptable precision/accuracy?
(Most helpful would be the specs: ▪What range | ▪velocity | ▪group size | ▪shots per group?)


🟠 (2) What kind of expansion did you get of the hollow point?
(Specs: ▪Impact velocity [or muzzle velocity and range] | ▪ballistic material [what kind of ballistic gel, or what animal] | ▪how much did it expand [photo?])



🟠 (3) Did you do any BC measurements?
(Specs: ▪What range | ▪What BC calculator did you use | ▪Did you enter atmospheric data?)



Thanks a lot for any light you can shed on this pellet!

Matthias 😊
 
09D70035-6ABC-47BF-BB3C-32897A67A280.1608820030.jpeg
 
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18.13 said:
View attachment 410171
Click to expand...

Thanks, yeah, I have that chart, too. ✅

The chart just doesn't inspire a lot of confidence when they use a drag law ("drag coefficient") for a projectile (G1) that is so drastically differently shaped from a Polymag.

Besides, we know nothing at what muzzle velocity or at what range this value was obtained, or which ballistic calculator was used. 🤷🏻‍♂️


➠ I was hoping that someone has done their own measurements, using a better and more transparent setup.... 😊

Matthias
 
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I have done some of the “technical” testing of these pellets but it has been years ago.

“Practical” perspectives I can share include:
- when compared to Diablo pellets, the accuracy was only acceptable to me at a max of 35 to 40 yards.
- there is no denying the terminal effect of these pellets at a velocity of > 750 fps or so. The “splat” sound when the pellet meets flesh is always extremely satisfying and the results are very impressive on small game and pests. I never lost anything I shot at with them.
 
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I have two guns that shoot them well enough to hunt with in .25. Two completely different barrels, two completely different guns. The CZ on my RTI shot them and the TJ on my P15 shoots them. Both guns in the 875-900fps range. Both fantastic out to 50 yards. Somewhere between 50 and 75 they start falling apart. I don’t have detailed notes on either gun on when they start to open up. I shot them out of the RPB barrel on my P2 but I can’t remember if they shot as good as the CZ shot them. That info is in my notes and I won’t be home until the end of the week. I’m on another hunting trip and have my .30 RTI with me this time.
 
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JungleShooter said:
Polymag .25cal

🟠 (1) What is the max. velocity where you still got acceptable precision/accuracy?

Matthias 😊
Click to expand...

When I first got into this hobby I looked up my state's airgun hunting regulations and found that they require 1) a rifle that was rated from the factory to shoot 1000 FPS and 2) that a "hunting pellet" be used.

Not wanting any trouble from Fish and Game officers, I figured there would be no confusion if I showed an officer a red tipped Polymag.

I next went about searching deep in the archives of AGN and GTA about people who had shot them at near or over 1000 FPS with accuracy.

Much to my surprise there was a decent amount of success with them at fast speeds in .177, .22 and .25.

I had no desire to hunt squirrel with over 50 FPE, especially out of a short barreled Leshiy Classic, so I never attempted to test .25 Polymags at those speeds.

Forum software has changed since then but I do recommend doing a deep dive into the archives and see if you can find what you're looking for. I feel like measured BC's can be found on GTA and anecdotes of fast shoot .25 Polymags can be found on both forums.

I will add that I ended up talking to a Fish and Game officer and he told me not to worry about tuning my Leshiy to shoot 1000 FPS. He said if I preferred to use .22 at slower speeds that was fine. He said as long as I wasn't out there hunting with a cheap BB gun he wouldn't even check to see what speeds I was using.
 
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I just looked, there is nothing in my notes about me shooting a poly out of my RPB. But, I was shooting H&N Baracuda Hunter HP’s at 967fps and was pleased. They are 27.47gr and shoot well surprisingly far. If I ever go back to a .25 on my P2 I won’t hesitate to test Polys this time. I can’t believe I didn’t. My squirrel hunting pellet shooting .25 Impact won’t shoot Polys. None of my FX liner guns in any caliber shoot them. I’m getting ready to build a real barrel for my pellet M3 and hope that it shoots them.
 
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I don't know specs. Upon use, the polymags are best at 40 yards or less and great with low density bodies, IE birds. Otherwise, hades/Atomics would shoot with close terminal effect and increased accuracy based on design. If I want minimal penetration and close range termination of soft body targets, this is my go to. otherwise hades/atomics.
 
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Thank you all for your help, I appreciate it! 👍🏼


🟠 And a loud loud cheer to Yrrah, from my continent to yours!! 😃
So glad to hear from you!
And guess what, I have registered your data in my collection, from 2011(!), that I found here:

www.tapatalk.com

Yellow Airgun Forum Archive-.25 Predator Polymag and BC thoughts ...

is information that i wish some air gun ballistician would perform also.
www.tapatalk.com www.tapatalk.com

No clue what BC calculator you used back then, what drag model, and if you had the chance to take into account elevation/ air pressure.


➠ But as always.... — you researched, you documented, you published — always helping, always moving airgunning forward. 👏🏼

Thanks for all your years of faithful service, Harry!

Matthias
 
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Scouty said:
When I first got into this hobby I looked up my state's airgun hunting regulations and found that they require 1) a rifle that was rated from the factory to shoot 1000 FPS and 2) that a "hunting pellet" be used.

Not wanting any trouble from Fish and Game officers, I figured there would be no confusion if I showed an officer a red tipped Polymag.

I next went about searching deep in the archives of AGN and GTA about people who had shot them at near or over 1000 FPS with accuracy.

Much to my surprise there was a decent amount of success with them at fast speeds in .177, .22 and .25.

I had no desire to hunt squirrel with over 50 FPE, especially out of a short barreled Leshiy Classic, so I never attempted to test .25 Polymags at those speeds.

Forum software has changed since then but I do recommend doing a deep dive into the archives and see if you can find what you're looking for. I feel like measured BC's can be found on GTA and anecdotes of fast shoot .25 Polymags can be found on both forums.

I will add that I ended up talking to a Fish and Game officer and he told me not to worry about tuning my Leshiy to shoot 1000 FPS. He said if I preferred to use .22 at slower speeds that was fine. He said as long as I wasn't out there hunting with a cheap BB gun he wouldn't even check to see what speeds I was using.
Click to expand...


Scouty,
your forum finds of successful shooting reports of 1000fps+ Polymags is encouraging!
It seems like it's worth trying at least! 👍🏼

Thanks!

Matthias
 
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Vetmx said:
I just looked, there is nothing in my notes about me shooting a poly out of my RPB. But, I was shooting H&N Baracuda Hunter HP’s at 967fps and was pleased. They are 27.47gr and shoot well surprisingly far. If I ever go back to a .25 on my P2 I won’t hesitate to test Polys this time. I can’t believe I didn’t. My squirrel hunting pellet shooting .25 Impact won’t shoot Polys. None of my FX liner guns in any caliber shoot them. I’m getting ready to build a real barrel for my pellet M3 and hope that it shoots them.
Click to expand...


Thanks, Frank, for checking your notes, it means a lot to me that you did. 👍🏼
The data on the Baracuda Hunter is helpful, too — as that is another candidate that I whish to try at warp speed — if the Polymag somehow does not turn out well for me.



OldSpook,
yes, I have gone through the HardAir BC tables as if they held hidden clues to a next gen PCP...! 😆
Thank you for responding! 👍🏼

Matthias
 
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Yrrah said:
.25 cal Predator Polymags are brilliant when shot from original Smooth Twist barrel. Nothing else beats their expansion at reasonable velocities. The sound on a rabbit or fox is like a bat hitting a mattress.

View attachment 414123
Click to expand...


🔘 Harry,
your shooting skill puts you right up there with Dirty Harry. Thanks for those data points, such good groups at 52y and with pretty high velocities are very encouraging. 👍🏼




🔘 rangur,

40y is about the range I'm looking for, maybe 10y more if possible.





🔘 bdyjlz,

your description of the impact sound as "extremely satisfying" seems to describe the Polymags as capable of Glory Kills, at 750fps IV and above.
If Harry's shots that sounded "like a bat hitting a mattress" were with a MV 880fps, they had your IV of 750fps out to 30y.


😊 Matthias
 
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I took my .25 P15 hunting one day with a Sightmark Wraith 4k on it. Didn’t feel like switching back to a normal daytime scope for just one hunt. The gun shoots Polys about 900fps. Since squirrel were plentiful I didn’t mind the hassle of recording my shots. I shot 4 or 5 squirrels. If I was a video poster you would get a kick out of the stupid pops those pellets make. It actually echoes down valleys. Makes a guy wonder if having a silent gun is even worth it.
 
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Vetmx said:
The gun shoots Polys about 900fps. [...] You would get a kick out of the stupid pops those pellets make. It actually echoes down valleys. Makes a guy wonder if having a silent gun is even worth it.
Click to expand...


Good to know — I'll throw a Shogun on my gun and try for the kick and the pop. 👍🏼

Matthias
 
Last edited:
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Where do I go from here?

Thanks to your help I will hit the range right after Christmas, much better prepared. 🔆


➠ I'm going to start with the best case scenario...:

● Polymags — for maximum expansion and terminal effects

● At 1000fps MV — for the same reason

● Out to 50y — my max. range for this pesting scenario

● Regulator on the Prophet II Compact at 130bar



If I can't get — for pesting — acceptable precision, I will:
● reduce the range to 40y, and subsequently

● reduce the velocity by 20fps to 980fps — again at 50y.


If still not enough precision, I will repeat the above reduction cycle. 😊


Can't wait for range day!! 😃
Matthias
 
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