a few unexpected (surprise) things of the Dark side

[Ribbonstone]

Not looking at the disappointments right now..maybe should have expected the better results than expected, but I didn’t.. I learned something along the way.,


#1: More of a mystery than a surprise.  Crosman’s old Challenger 2000 12gr. Co2 rifle.


Cured the trigger, got it uniform (but slow), fixed the see-saw bedding.

The question became why were captured pellets coming out in a polygon shape  from a round barrel crown?

This pellet shape out of this hole didn’t make sense.

Image57 by Robert Dean, on Flickr

Image13_zps5879b8b9 by Robert Dean, on Flickr


Cut back and re crowned….now it shot better (although still slow even for a “match” rifle)...Poly hole spiting out a poly pellet did work better. 

Image100-1_zpsa7607d53 by Robert Dean, on Flickr

Have no idea if this was intentional or just an accident of birth (now like I’m going to hunt down a half dozen of them just to find out)….but it shot a lot better with the new crown.

Lesson: The crown should be smooth and mimic the pellet’s shape at exit.


#2. Power of lower pressure.

Can certainly go higher, but with +50 foot pounds and 2600psi fill….made me thing if I really needed to.


a755bb17-de48-4407-9ff3-928211ebbfea by Robert Dean, on Flickr


Lesson: smooth gas Flow beats  rougher flow and higher peak pressure.  It’;s more a matrer of “right now” low pressure gas than “wait a bit” high pressure gas.


#3. Cheap Chinese pump...but it’s still working 6 years later.

Would have bet my ARSE in 2014 that this cheap one was doomed to an early death.  6 years later, it’s still filling PCP’s.

177a1cd8-509c-42e3-aedd-242f18cd1eb2 by Robert Dean, on Flickr




#4. Non regulated rifles and shot count.


Did take some pharting around with the Disco.

c85a175c-7963-4cf9-9eee-67e88e006d84 by Robert Dean, on Flickr


Only took a bit of twiddling around with the provided adjustments with an AA200T.

9725ca7f-0cc2-4fbe-af58-9732c9daec8e by Robert Dean, on Flickr

Lesson: some where  near moderate speed, there is a “sweetest of the sweet spot” where non-regulated rifles do really well.  It’s usually at some moderate power setting; not jacked up and not slowed down too much.


#5. Price and accuracy does not have to go hand in hand.

Simple (really cheap) Chief.  Never did get 1MOA like some of the vids.   Did get right about 1MOA at 40 yards, but more like 1.33MOA at 100 on a good day.


15dd7690-d574-4a0a-b913-9bfc2367f455 by Robert Dean, on Flic

Lesson being: a good barrel is a good barrel no matter who made it.


#6.  Did not expect this level of accuracy for an AR 2078.  Co2 or HPA conversion, may have changed WHICH pellet could. Shoot like this..but some pellet could.


0b08fb5a-7cfc-415a-b4ff-a7c20d27b747 by Robert Dean, on Flickr


Lesson pretty much the same as #5 (good barrel)..think of it as confirmation over a wider velocity test.

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Were definitely some disappointments too….rifles (more expensive) that promised so much, but could never get them to deliver on the promise.

[mrbulk]

Your hard-earned insight and invaluable airgun research over time are much appreciated.

[ranchibi]

Ribbonstone, just to think to cut the round crown to see what is causing the poly shape skirt is well, sheer genius! Didn't know Crossman even used poly's....h,mmm. I have 2 Chinese hand pumps, the second one was for back up....never used the second one and it has out lasted my Hill mkiv! Nice groups there!

[SpiralGroove]

Yeah Ribbi,
Getting back into my QB79 HPA's and AR2079 HPA's.  I much prefer the AR stocks to the QB's - also prefer the AR's trigger.  It seems a bit gimmicky, but it works better.

So far, have just made peek poppets in additional to all other HPA mods - Maxi valve, rear cocking and RVS.

[Hoosier Daddy]

Ribsy.. You posts always make me ponder... Thank you so much.

I learned lesson #4 early on with my first PCP.
Maxine has a 2000psi fill pressure but shoots best at 1600. So I bought a 48CI bottle and a reg from Joe B. set to 1600.
All-day-fun shooting tethered.

Yep.. AR2078 is amazing grins for the dollar.

My Chinese hand pump is still going strong after 3 years... but the YH compressor gets more of a work out now, and that surprises me even more!

[Ribbonstone]

Addendum to the first post:


#6. Tried that same 2078 several ways over the years.  Thinking that one dates back to about 2007.

12gr, bulk fill co2,  tethered to a big co2 tank, tethered to a large HPA tank, converted to tanker co2, then 13ci HPA.

IMG_4805 by Robert Dean, on Flickr

Kept to the same basic power (12 foot pounds), doesn’t seem that the pellets care how you push them.



#1 No clue why the barrel is they way it is.  Rifle dates back to 2000, think I bought it used about 2010.  Wife  has claimed it, so I don’t get to play with it much.

Recently did get to play with it….wondered just how slow/weak would still make decent groups.

DSCN0057 by Robert Dean, on Flickr


DSCN0056 by Robert Dean, on Flickr


Definitely not as good as it’s best, but even with a start of 2.9foot pounds (and a whole lot of shots for a single 12gr. Rifle), could at least make sub-dime sized clusters.  Does make even slight back yard winds challenging, but it’s kind of fun to be able to watch the pellets along the way.


#2.  The old FDPCP is a 1500psi .22 PCP…..and yet (for a very few shots), if you want 27-30 foot pounds you can get it. 

(same pump as in #3):

DSCN0024 by Robert Dean, on Flickr


How that one shot when down to 800-900psi really got me to thinking about regulated rifles; the need for more pressure vs. the need for more volume to get where you want to go.


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2 new ones:


#7.  Bent bolt probes or wobbly bolts. Pushing a pellet in off center does absolutely nothing good for accuracy.


(looking down into the hollow skirt):

Image49 by Robert Dean, on Flickr


#8. Fat skirted pellets can have fins.

Image30 by Robert Dean, on Flickr

We go to all the trouble to make a nice smooth even crown (so it releases the pellet nice and evenly), then end up with a ragged based pellet.