GTA
All Springer/NP/PCP Air Gun Discussion General => Projectiles => Pellet Review Gate => Topic started by: Motorhead on April 16, 2015, 02:43:22 PM
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(http://images.airgundepot.com/ay/airgundepot/pdg-destroyer-pellets-22-caliber-150ct-5.gif)
Thanks to Dez sending me a hand full of these got a few down the bore over the Chrony to get some idea on just HOW MUCH POWER maybe required shooting these 27 grain heavy weights :o
My most powerful PCP a modified & Regulated AA 410 FAC with an aftermarket 21" Lothar Walther Match barrel.
Tests done at FULL POWER
* Below some baseline VELOCITY data collected with some lighter pellets so comparison makes sense.
JSB 15.9 grain .... 990 fps average = @ 34.5 Ft lbs
JSB 18.1 grain .... 955 fps average = @ 36.4 ft lbs
H&N 21.3 grain .... 885 fps average = @ 37 ft lbs
*PDG 27 grain .... 730 fps average = @ 32 ft lbs
Early test CLEARLY show ( In this PCP rifle test ) efficiency is WAY DOWN :( and in spite test rifle being able to make great power with lighter lead falls short of getting even close to launching these DESTROYERs effectively.
Appears all this weight is of little help in an attempt to make greater energy on target having the Ft Lbs power produced even lower than a pellet 11+ grains lighter does :P
To get this much weight up to speed is going to take more than 2000# pressure ( Where my regged gun is ) to get these moving faster.
It is at this point just a guess ??? ... but unless you have a PCP rifle such as a Sumatra or Evanix that is already making 45-50++ Ft Lbs power these pellets will not perform very well for you.
Additionally after inspecting a couple shot into a bucket of water for undamaged inspection ... the rifling engagement was near full length the cylinder body of the bullet. VERY HIGH BORE DRAG comparatively to a Diablo skirted pellet.
All I got ...
Scott
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Thanks Scott, the report is good verification for me. I had very poor results with a mid-power ranged springer. I used a springer to have a steady power source and not worry about fluctuations due to air changes. But my results were less than lovable either. LOL
I did save a few and will test them in maybe my AT44 or my highly modified Disco. Or even my 27fpe+ XL1100.
So far though the PDG has not become a favorite of mine. I'm used to hearing an airgun may be pellet picky. Not used to at all the phrase that a pellet is airgun picky.
LOL
There's a niche market for these, we just have to find it.
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It may be the .22 Sumatra as I think MonkeyDad had great success with them in his.
All others, please continue to submit data ;D
BZ
Side note, Dave do you have any in .177 still?
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If you have any left maybe drilling them out to a 23-25 grain hollow point? ... it sure helped them expand... and the bullet shape out of the barrel makes up for some(how much?) of the lost efficiency in wind bucking and by having much less drag... If you can get them accurate.
My disco barreled pumper(normally 800fps) well 14.3s at 750 fps = 558 fps with the bombs (less barrel drag) so at tops I would get 600 fps without a larger valve.
At 558fps the barrel harmonics made two .5 groups at 30 yards...
I will be doing a larger (.37 ci rather than current .242ci)valve later this year and will try them again...
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Look all. I said in the beginning that they liked to shot be shot hard and fast. My Sumatra loves them. The Bombs in my Disco look promising. I have drilled out the centers of the Destroyer and they expand pretty nicely out of the Disco. I have no issues with them putting in work. Heck, 190 yard head shot on a P-Dawg with the Sumatra on the red dot on the first revolution of the power wheel. Complete pass thru.
Joe
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Thank you for the info Joe.
If they make them in 25 I will try them in the Sumatra.
And probably be really happy with them.
Dave
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Scott, you recon there may not be enough plenum in that reg'd rig you tried them in? 2000psi seems high enough to get the speed you want. You know how it all works, I was just being nosy ;)
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Scott, you recon there may not be enough plenum in that reg'd rig you tried them in? 2000psi seems high enough to get the speed you want. You know how it all works, I was just being nosy ;)
Not sure plenum space is the issue here ? .... what i do know or think anyways, is that all the accepted wisdom on what makes a PCP tick and what is required to launch a conventional Diablo pellet of more typical weight may very likely fall into error with such a heavy projectile ???
Can somewhat assume if someone had a NON-regulated .22 cal PCP that made somewhat equal power to my test weights of 15.9 / 18.1 / 21.3 ...... Then shot a 27 grain having the entire storage tanks volume to get behind the shot while valve was open it would support that viewpoint ? I honestly have no idea ???
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Scott, not knowing anything about PCP's, except what I read .... I was reading about FX PCP's .... they talk about a smooth twist barrel. You mentioned earlier that too much drag from a normally rifled barrel may have slowed that monster down too much .... just thinking with FX power and that barrel ... those pellets might perform well?
Just a thought ...
Allan
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full length bullet slamming into the rifling yikes... I think it would not work well.
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Through my daystate they are an extremely right fit! The bombs on the other hand may prove z to be good.
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Awesome work Scott.
No way my little B-50 can push those beasts. I have to charge my gun to 2900 psi just to hit about 930 fps, and that's using a JSB 14.35 grain pellet. I'm not running a reg either.
What was much more of interest to me, was the fact that a 2.1 grain increase from the 15.9 to the 18.1 JSBs dropped your MV by a whopping 35 fps. That's a bigger drop in fps than I would have imagined considering an only 2.1 grain increase in weight. Not to mentions that these are the same pellet shapes from the same manufacturer.
I think Bob's boat tails would work better than the PDG and even the PileDriver pellets. Sadly though I think Bob's pellet is something like 41 grains for the .22 cal. Correct me if I'm wrong:)
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What was much more of interest to me, was the fact that a 2.1 grain increase from the 15.9 to the 18.1 JSBs dropped your MV by a whopping 35 fps. That's a bigger drop in fps than I would have imagined considering an only 2.1 grain increase in weight.
That is VERY typical between those 2 weights and more telling is the FACT it picked up Ft Lbs energy which is actually an INCREASE in power in spite the fps loss happening.
The 21.3 grain does the same thing ... loses speed but picks up energy.
This is the efficiency curve you read about with PCP's ... they do generally better with heavier lead !!
well ... untill ya go too heavy and then efficiency falls off sharply :P
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Sorry for posting this in your thread Scott, but didn't want to start another one.
I went out today shooting at 50 yards. Jsb 18.13 gains were shooting at 880 fps, where the destroyers and bombs were going 650fps. So much slower, but to be expected for to the heavy pellet. But at 50 yards the jsb pellets were attacking within .500", where as both the destroyers and bombs were around 18"at 50 yards. So needless to say these pellets are not for my daystate mk4.
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I also tried out the destroyers and bombs in my steroid 392PA. At 50 ft they grouped at about 3/4". My regular exact pellets went into 1/2". All this was with 10 pumps and open sights. It was interesting that they all hit at about the same POI. I did notice that the destroyers were a really tight fit. I had to push pretty hard on the bolt to seat them. I wanted to see what would happen at slower speeds (less pumps) but I was too tired today after all the pumping. I also wanted to try a few at 14 pumps but just didn't have it in me today to try that. I need for my grandson to put on some muscle and years so he could go along to do the pumping for me.