METALMAGS AND DUCT SEAL...PICS

[airriflenut]

I'm still in the midst of fill/refill pressures, velocities and pellet accuracy testing for the Squirrel Whisperer .177 Disco.  Previous test data I am going to file but not use that information to form any conclusions, all of that testing was done with various springs clipped and Delrin power adjusters...way too much work involved and the figures were all over the place.

Now I have a "real" power adjuster so I can dial in or out as needed.  I didn't think to take pics of it for this post so I will get some detail pics to post later.  Today I shot Beeman Crow Magnum 8.8 grain and Predator MetalMags 8.5 grain over the chrony then for accuracy.  unfortunately the Beeman pellets didn't fare well in accuracy, I was getting 1 1/2" to 2" groups at 25 yards so further testing with those ended.  The MetalMags surprised me, in previous tests they shot worse than the Beemans, today they were shooting about 3/8" groups out to 25 yards (winds of 17 and gusts to 26 and the heat stopped testing) with a rare flier, most were operator error.  As I am still hunting for the best fill/refill pressure range I started at 2000 psi and shot down to 1050 psi ($5 for 80 cf 3000 psi fill I can handle).

Shooting from 2000 down to 1050 psi gave 30 shots, most I would call useable.  I won't give a shot-toshot rundown since it is long so I'll give the end results:  975.49 fps average, 161.7 ES, 49.84 SD, 17.96 fpe.  I will note that from 1600 psi to 1050 psi gave 15 very consistent velocities...something to start with next time.

Okay, here's the pics of the MetalMags in a food storage tub of duct seal, the tub is 4 1/4" dia. x 3" deep, the duct seal is 2 1/2" thick.


The tub


The duct seal with impacts before digging the pellets out.  Notice how much larger the 10 yard cavities on impact and penetration than the other ranges.


10 yards.  Penetration was 1.245", 1.243" and 1.232".  Clearly a devastating "wound" channel!!


15 yards...I still have no clue why I shot one pellet!  Penetration .995"


20 yards.  Penetration .717" and .721".  The other pellet is a JSB Heavy Diabolo 10.34 grain (also very accurate), penetration .916" with noticeable mushrooming.


25 yards.  Penetration .413" and .412"

The pics show just how devastating these rather expensive pellets can be.  Almost every pellet at each range peeled off the hollow ring with the heavier skirt/waist going slightly deeper, the brass tip was almost always sideways in the cavity.  The pellets look as though they were tumbling or yawing on impact, they were dead straight, I shot several in a 2"x6" board to make sure, the tub of seal was sat on top of a milk crate and had a slight upward angle.

When I dropped cash for two tins of the MetalMags I was hedging my bet on accuracy and devastating terminal performance.  The accuracy is here, the terminal performance is what I've been looking for...now all I need is a few squirrels!!

[BillK]

 I gotta get some new glasses.  
The PA will make it much easier to test.  Sounds like your having fun.

[tinker]

Sterling,
  Nice results but remember the duct seal is quite tough compared to flesh and blood.  Those predators are going to do some damage to your favorite game
  Isn't tuning a PCP is an adventure I find it quite enjoyable especially when you can see everything slowly coming together.  You seem to be getting close to the magic "tune". 

Glen

[airriflenut]

I gotta get some new glasses.  
The PA will make it much easier to test.  Sounds like your having fun.

Oh man, the PA is the cats meow!!  This one was a gift and a very nice one,  and, I actually managed to make one of my own for the pistol...a PA is the only way to go!!

[airriflenut]

Sterling,
  Nice results but remember the duct seal is quite tough compared to flesh and blood.  Those predators are going to do some damage to your favorite game
  Isn't tuning a PCP is an adventure I find it quite enjoyable especially when you can see everything slowly coming together.  You seem to be getting close to the magic "tune". 

Glen

Glen,
Thank you!  Yes, the duct seal IS tough!!!  I was very surprised at the depths of penetration as dense as the duct seal is.  Being a thick solid test medium and getting the penetratiom and fragmentation of the MM makes me very curious on how they perform on squirrels.

I can't test for how they will terminate after impacting hide, bone, muscle and soft internal organ tissues.  My thoughts are that they will perform better, especially if they fragment, I don't see why they wouldn't do better, there should be some serious hydrostatic shock and hydraulic effect!!  Autopsy on kills should be interesting.

[tinker]

Sterling,
  When I used duct seal to test penetration of different pellet I had similar results.  Seeing how much seal was displaced as the pellet penetrated the duct seal was always impressive.  Yes the pellets were turned inside out as the velocity got higher.

Glen

[Monkeydad1969]

Try modeling clay.  It will give you good results, but you will need a good backstop.  The pellets will penetrate.  But, the clay will show the hydrostatic shock and the pellets will leave the actual impression of the barrel rifling in the clay.  Sweet, huh?

Joe

P.S. Sterling, your care package will leave tomorrow or Wed.

[tinker]

Come to think of it, years ago I used to shoot at a bar of Irory soap. The "wound" channels were very impressive to see. 

Glen

[airriflenut]

Try modeling clay.  It will give you good results, but you will need a good backstop.  The pellets will penetrate.  But, the clay will show the hydrostatic shock and the pellets will leave the actual impression of the barrel rifling in the clay.  Sweet, huh?

Joe

P.S. Sterling, your care package will leave tomorrow or Wed.

Thanks for the tip Joe, I might have to give that a try and also Glens idea of Ivory soap.  I was kind of disappointed that the duct seal didn't show more of the actual wound cavity created from hydrostatic shock, they just more or less plugged straight in.  The plumbers putty showed more of the cavity than duct seal.

At least I do have some duct seal for some quiet, covert indoor shooting!!  I'm still trying to figure out some way to imitate the skull and tough hide of a squirrels head (also similar in size) for more "real world" testing.

Thank you for the care package, I do greatly appreciate it.  We will be out of town Thursday thru Sunday, so maybe it will come next week so I won't have to explain what I've received to sis.

[Monkeydad1969]

I can send it this weekend if that would be better.  You want .177 and .22?

[airriflenut]

I can send it this weekend if that would be better.  You want .177 and .22?

Sorry Joe, for some reason I'm not getting reply notifications again.  Our PM's a few days ago should have gone thru ok.