Chrony AA S410 ERB .22, BSA Scorpion .177

[TCups]

Got a chance, finally to do a bit of shooting this afternoon.  Got my scuba tank topped to 3300 PSI.  Reworked both fill adaptors w/ the quick disconnects (Foster?).  Applied teflon tape to all of the threaded connections and tightened each carefully.  Applied silicone grease to the o-ring fittings.  Hurray!  No more air leaks.  Charged both the AA 410 and BSA Scorpion to 200 BAR, set up the Chrony and started shooting strings and zeroing the scopes (critically) at 25 yards.  So here are the results:

The BSA Scorpion will shoot Beeman FTS 8.80 grain pellets at an average of around 915 FPS or 16.4 FPE.  
The AA S410 ERB will shoot Beeman FTS 14.85 grain pellets on half, 3/4 and full power as follows:
Half power - 815 FPS, 21.9 FPE
3/4ths power - 900 FPS, 26.7 FPE
Full power - 960 FPS, 30.3 FPE

Got off one full power round that chronied at 1049 FPS!  That has to be a fluke.  Haven't put all the data into the chrony program yet, but those numbers are pretty close based on several 10 shot strings.  Wow.

PS:  My secret is out.  The good wife says, and I quote " Stop buying air guns!  I am going to have to send you to Airguns Anonymous -- weekly -- and cut up all your credit cards!!"  She, of course, is right, but fortunately, is not really angry with me.  I guess 35 years of marriage to me have prepared her for this sort of thing.  

[shadow]

She is a beauty Tommy and look's like she's gonna be a hammer on the critter's.;) The AA meeting's have failed us all here lol, it's now a place to bring our babies and talk airgun shop. Also some of the member's are having new shooters shipped to the meeting place  instead of their home to keep it from the wives hehehehehe. Ed

[PelletPaul]

Awesome looking guns, Tommy.  I' am trying to decide between the S410 and a Daystate.  Both are exceptional and expensive.  Their are three more members of GTA here in Tucson and tomorrow we are shooting for the first time.  Will start AA meetings at my house in the near future.  Again great looking guns.

Paul

I don't hunt to live, I live to hunt.

[TCups]

Paul:

Don't know the Daystate, but I do know that both the BSA Scorpion and the AA 410 are outstanding shooters.  I see David Kirby has decided to keep his S410 rahter than sell it.  Sure, David, we know --  you can stop any time you really want to (lol).   Let us know what you choose and send some pictures from your shoot and of the new air rifle when you choose one.

[TCups]

Here are the data from 35 consecutive shots, in 5-shot groups, at 30 yards with the BSA Scorpion .177,  from a 3200 psi fill, shooting Beeman FTS 8.80 grain pellets (unweighed).  The BSA is shooting 16 FPE, avg.  I included some photos of my set up.  The target bulls are 1.2 inches (30 mm).  Notice my fancy computer and printer I strap to my knee with Velcro when I am shooting strings over the F1 Chrony.  A nice day in SC -- T-shirt weather, just a bit windy.

[PeakChick]

Very nice results Tommy. Those BSAs are pretty uniformly accurate shooters. Have you tried any JSBs or CPLs through the Scopion? My Ultra shoots very well with both Exacts and CPHPs. Your field ballistic computer is pretty high tech!  :)

[DanoInTx]

I feel like such a slacker now.  I've had my S400C for probably 6 months and have yet to run it across the chrony, and I've had my S200 for probably 2 months and it hasn't gone over the chrony either.  That is usually the first thing I do with a new PCP, run it over the chrony and find the sweet spot in its fill pressure.  Does this mean I am slipping, or losing interest?  Maybe I need to set up my indoor lights and do some testing tonight, but....brrrr...it's cold in the garage:)  Good testing Tommy, and I do like that ballistic computer you have strapped to your leg:)

[TCups]

How do you determine the sweet spot?  I just filled to the max and started shooting.  And why does the velocity start low and climb?  Is that an indication of over filling damping the hammer valve or some such thing?  Remember, I am an absolute rookie when it comes to PCPs.  And without a pressure gauge on the BSA, I have to go by the small pressure gauge on the scuba tank.  Unless I do a full fill and equilibrate the pressure with the fill valve open, I can't accurately say to what pressure I have filled the BSA.  Her big sister, the AA S410 has a pressure gauge so I can see what the fill pressure and remaining charge are.

[melloroadman]

http://www.pyramydair.com/blog/2008/12/understanding-performancepower-curve-of.html

[TCups]

OK, Thanks Marvin.

I understand the "Power Curve" better now.  Practically speaking, I am still left with charging the BSA to the tank pressure.  As 3300 PSI doesn't exceed the 220 BAR upper limit of the gun and since it covers the power curve, looks like I am OK to keep shooting, and as the manual says, around 40 shots per fill.  I think the last charge was more around 3000 PSI / 200 BAR as I refilled the AA 410 just after the BSA Scorpion, and those were the readings.

And Peak:

I opened a new tin of .177 JSB Exacts -- except that they are JSB "not-Exact-lys".  Her a a hundred or so that I weighed to get some of  exactly the same weight for my test groups tomorrow.  Take your pick.  The horizontal rows are weight distributions starting at 8.25 grains and going to 8.60 grains.  Not much of a bell-shaped distribution, I'd say.  Guess I will load up the 8.50 grainers and see how they group vs. the 8.8 grain Beeman FTS pellets. I shot today.  Will see how they do.

I gave up on the Carolina Panthers, AKA Carolina Rented Mules (as in "getting beat like a rented mule").  

Good night all.