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MarkHolding

Can a gas ram be improved

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I have a Gamo Whisper IGT and it is shooting at an average energy of 9.4 ft/lbs energy. It has been like this since new about a year ago. Will shimming the gas ram, as with a normal spring add extra power, or does the gas ram pressure remain constant even if shimmed. I have been told that the HW90 could be adjusted by a valve at the rear of the ram and a special pump. I haven't had the rifle apart yet, but wondered if anyone had fine tuned their gas ram. My goal would be 11 ft/lbs, so not much extra energy required, possibly 50 or 60 feet per second.

post-33650-0-89894000-1487342750_thumb.jpg

Edited by MarkHolding

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you should have taken it back when you first chronographed it.

you'll now need a pump.

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Getting a pumps no problem, I just wondered if the Gamo gas rams were adjustable. I will have to take it out and have a look to see if the gamo rams are designed to be adjusted or not, as you never see many comments on this. If this is the case I will record my procedures and share for anyone else that has a Gamo gas ram. I realise that the Theoben rams are adjustable, but are other brands??????? Thanks for your imput rapid slayer

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I phoned Countryman of Derby, who told me to take it back. They are returning it to BSA/GAMO for a replacement ram, as it still has 2 months on the warranty.

Edited by MarkHolding

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There's no need for a separate pump if you have either a manual pump or a pressure bottle. Just an adapter and a LOT of care to ensure you don't put too much pressure into the ram, if the ram's adjustable.

 

I have a Fenman and it was my favourite shooting rifle - when I could still shoot; Ahem! - It used to lose just a wee bit of pressure over a long period and with a bottle, I've topped it up a couple or three times over the years. It must be pretty low now and I really should flog off some of my guns as they have had no use for some years.

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Just an update to say that I got my rifle back from The Countryman gunshop in Derby within a week of sending it back to BSA in Birmingham. It's all been looked after at the factory, with even parts added that I didn't send it in for, so quite a good customer service from GAMO/BSA. I haven't tested it yet, due to the -excrement-ty weather, but hopefully it is now doing what it should have done in the first place. It had about 2 months of warranty left.

 

 

post-33650-0-59772400-1488646252_thumb.jpg

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Whats it like with non heavy, power usually rises and would be too close a call.

 

Try chrono in a different light may see a good 100ft/sec drop or an increase, common in uncontrolled environments.

No led type chrono is immune to it certainly the Caldwell having briefly had the IR giving wildly random results in controlled lighting to not registering at all.

What im saying is dont take the chrono reading as being correct.

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Posted (edited)

Your video looks very professional but you seem to lack the information that a Gas Ram has the same performance characteristics as a springer, i.e. lighter pellets produce higher power readings, you need figures from a wide range of pellet weights and head sizes to determine the maximum power output of an air gun. 

Bear in mind that the word in law "Capable" can be interpreted to mean "If we stick the pellet of our technician's choice in your gun and run it over a chrono" 

 

Edited by magicniner

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I'm with Magic on this my Sirocco absolutely hates heavy pellets and will only perform with light flavours it's favourite being Hobbys amazingly.

You should try as many different types of pellets as you can to see which your rifle prefers.

 

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On ‎2‎/‎17‎/‎2017 at 2:48 PM, MarkHolding said:

I have a Gamo Whisper IGT and it is shooting at an average energy of 9.4 ft/lbs energy. It has been like this since new about a year ago. Will shimming the gas ram, as with a normal spring add extra power, or does the gas ram pressure remain constant even if shimmed. I have been told that the HW90 could be adjusted by a valve at the rear of the ram and a special pump. I haven't had the rifle apart yet, but wondered if anyone had fine tuned their gas ram. My goal would be 11 ft/lbs, so not much extra energy required, possibly 50 or 60 feet per second.

post-33650-0-89894000-1487342750_thumb.jpg

 

When I think about it it should only affect the 'lock time' because the pressure inside the gas ram cannot be altered in these rifles which develop the same power whatever the length. The gas ram rifle is designed around a particular power source (ram) so altering the travel will probably have an adverse affect.

Never had mine apart yet (strange for an inquisitive engineer I know) but your question intrigues me so I might just try an experiment.

I get great accuracy using non lead 5.4 grain ThUnderbolts (the spelling is correct) and develop 11.35ft/lb at 973 fps and that was straight from the box. Overall 10 pellet types were tested in strings of 10.

Hope that helps, but keep me posted please........

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Few hours on and curiosity got the better of me so I stripped my Gamo Maxxim springer, the 10 shot one and being a Gas Ram looked to see if that too was adjustable. Sadly it appears not because I cannot see anywhere on the Gas Ram anything to which anything can be attached to.

Would the Gas Ram, if it is adjustable, from the Gamo Whisper fit my Maxxim? Strange thing is that I once had the Gamo Whisper but sold it because I did not like the synthetic feel and bought the Maxxim because it had a wooden stock, adjustable cheek piece and of course was a ten shot plus a built in moderator and 2 magazines.

Gamo Maxxim.jpg

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Posted (edited)
On ‎6‎/‎18‎/‎2018 at 12:57 AM, magicniner said:

Your video looks very professional but you seem to lack the information that a Gas Ram has the same performance characteristics as a springer, i.e. lighter pellets produce higher power readings, you need figures from a wide range of pellet weights and head sizes to determine the maximum power output of an air gun. 

Bear in mind that the word in law "Capable" can be interpreted to mean "If we stick the pellet of our technician's choice in your gun and run it over a chrono" 

 

Almost correct but the Gas Ram has a shorter 'lock time' than the spring type even if the power developed is the same due to the Gas Ram having less components causing friction against moving parts than the spring/piston/spring guide type of action and that even includes those with sliding compression cylinders such as the TX200 or LGU.

Why not try 'green' pellets (RWS Hyperdome for instance) which are the lightest of the light and see where that leads?

Also wondering if it is possible to add 'power washers' at the rear of the ram?

 

Edited by itsray
power washer question

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