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Pellet weight and gas-rams

December 3 2017 at 7:42 PM
gubb33ps  (Login gubb33ps)
YF

2 Questions about gas ram springers.
photo 1a08c5fa-09d1-461d-83d1-ae38178ea0f9.jpg
#1. While there is some debate about heavy weight pellets in spring-springers, are gas rams more immune to the possible heavy weight pellet problems?

#2. Not a "carp load" of reason to soft-ball toss 34gr. at 440fps, but it does shoot them well. So whatevert the problems others have been having with heavy weight 25's, it's likly not speed-stablity.

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Some general observations:

1. Yep...I know I need some "right" added to the little 4X scope, but once I got started, didn't want to change anything in the midde of shooting.

2. Big holes in paper always look closer together than small holes...it's that center-to-center thing.

3. Logic would have that the 19-21gr. pellets would be best in a slow .25....just has not worked out that way at all.

4. Not a use everyone has but it's about as good an urban rat-rifle as I could design. Shooting at much past 20-25 yards is like tossing lawn-darts, but the low speed "thunk" of larger chunks of lead tends to get a rodent's attention without blowing holes in the shed's siding or the shop's tin roof.


    
This message has been edited by gubb33ps on Dec 3, 2017 7:43 PM


 
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Yrrah.
(Login Yrrah)
YF

Q 1. I can offer one example re- a gas ram Theoben / Crow Magnum 111 in .20 cal

December 5 2017, 6:35 AM 

Shooting Crosman .20 Premiers at 26 fpe: when shooting 21 gr .20 special pellets the energy dropped to 17 fpe. The other half of that late 1990s experinment was to shoot both pellets from a very good Sheridan which shot in the 14 fpe zone with both pellets, the 21 gr pellet doing slightly the better.
In this example the drop in power from the overweight pellet was significant from the gas ram and the msp showed the trend of a pcp with a very overweight pellet. .... Kind regards, Harry.

 
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Yrrah.
(Login Yrrah)
YF

Duplicate removed.

December 5 2017, 6:35 AM 

Nt


    
This message has been edited by Yrrah on Dec 6, 2017 4:22 PM


 
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JW652
(Login JW652)
YC

Pellets

December 5 2017, 10:15 AM 

Have a lot of springers and several Theoben gas rams and believe that piston guns prefer medium weight pellets.

It has a lot to do with the (generally) 10:1 stroke volume and piston bounce. The heavier pellet starts moving later in the shot cycle which is shorter in duration and more abrupt as compared to the longer, smoother pcp cycle. Same is true if you overspring (or pump) a piston gun. It throws off the designed balance between spring, piston, guide, transfer port size etc and can cause more piston bounce which may feel like more power, but is not.

John Whiscombe is adamant about not using heavy weight pellets in his rifles and has convinced me.

 
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