Legality of .177

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narach93
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Re: Legality of .177

Post by narach93 » Tue Mar 13, 2018 4:20 pm

Dear Jha sahab. You are outstanding of your passion and understanding of the ARs. Pleasure to learn so much from you.
Regards

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prashantjha19
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Re: Legality of .177

Post by prashantjha19 » Wed Mar 14, 2018 10:12 am

narach93 wrote:Dear Jha sahab. You are outstanding of your passion and understanding of the ARs. Pleasure to learn so much from you.
Regards
So humbling compliment, dear Narach93! Thank you. I must acknowledge equally humbly the many practical aspects learned on this forum, ....including from members like you and many others.
However, as I am seriously inclined towards researching and experimenting with the many aspects of ME, shot cycle behaviour, accuracy factors, etc. I do have to look elsewhere extensively as well as do everything hands on myself. All of it keeps me too preoccupied. Sad, am not able to share across as much bcos of lack of time; but would always chip in where I can with my 2cents.
Best regards,
Prashant

Rover solomon
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Re: Legality of .177

Post by Rover solomon » Thu Mar 15, 2018 9:49 pm

prashantjha19 wrote:One imp factor I missed to mention in my last post is - stroke, that manufacturers alter to conform to legal limits of diff countries products get shipped to. To put an example - the underlever LGU for German market is 70mm stroke and the same one for UK is 88mm, the latter with a stiffer spring and a slightly tweaked TP specs has been reported to deliver up to 17 FPe.
The max stroke alteration that I have been able to manage as a shed tuner is of 13.5mm so far on a local Indian AR....long stroked it from 72 to 86mm. Of course it was a project in itself...quiet nightmarish because it essentially is designed as a short stroke AR. And to extend it beyond reasonable limits required altering everything from the piston size, cocking slot, shaft to base block and comp tube. Of course, the result has been more than worth....super smooth, dead accurate with barely any hold sensitivity, visible energy enhancement and no trace of dieseling . Originally, it was snappy but not once could it shoot without dieseling (typical of short stroke designs).

Regards,
Prashant
Dear prashant

Thanks for sharing your knowledge.i am very surprised different power for different country.

Is there any way achieve original intended power ?any body tried ?

Rover

prashantjha19
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Re: Legality of .177

Post by prashantjha19 » Fri Mar 16, 2018 11:19 am

Rover solomon wrote:
prashantjha19 wrote:One imp factor I missed to mention in my last post is - stroke, that manufacturers alter to conform to legal limits of diff countries products get shipped to. To put an example - the underlever LGU for German market is 70mm stroke and the same one for UK is 88mm, the latter with a stiffer spring and a slightly tweaked TP specs has been reported to deliver up to 17 FPe.
The max stroke alteration that I have been able to manage as a shed tuner is of 13.5mm so far on a local Indian AR....long stroked it from 72 to 86mm. Of course it was a project in itself...quiet nightmarish because it essentially is designed as a short stroke AR. And to extend it beyond reasonable limits required altering everything from the piston size, cocking slot, shaft to base block and comp tube. Of course, the result has been more than worth....super smooth, dead accurate with barely any hold sensitivity, visible energy enhancement and no trace of dieseling . Originally, it was snappy but not once could it shoot without dieseling (typical of short stroke designs).

Regards,
Prashant
Dear prashant

Thanks for sharing your knowledge.i am very surprised different power for different country.

Is there any way achieve original intended power ?any body tried ?

Rover
Dear Rover,
Yes, there are ways (to achieve "original intended power"),.... but it would call for very high proficiency in AR tuning and moderation, ....usually the turf of seasoned (read professional) tuners who have access to precision tools, and high quality consumables such as delrin strips, polyurethane rods, and such others, and are good mechanists themselves having high precision lathe machines etc.

However, one doesn't really need go for the highest potential power outputs ....as our American friends are realizing of late (Many seasoned air gunners are actually de-tuning their magnums to settle around 12 to 15 FPE of ME as that is where most ARs generally are most fun).

And hence, I would encourage you (and every passionate air gunner) to try your hands at modest alterations, at least to begin with. This, you could start first with altering the preload; Next, you could go to tweaking the piston weight (add or remove spacers and/or tophats/inside washers); Next, you should try playing around with different spring rates and getting the feel of how modest change in stiffness (which is an interplay of wire dia, coil dia, active coils and coil bound length) affect the 'feel', energy efficiency and shot cycle behaviour; Next, comes the altering of stroke. This can get pretty tricky and may need a range of alterations; and unless you are confident of handling the stuff to completion, it may get messy. Remember though that Rod-less pistons (such as in PH guns) are a real pain to work with (most unmanageable design, and therefore also pretty fool proof!!).

For tuning, there's is enough stuff on the forum to guide you, too; So do not miss out on them. Can let me know for anything specific you may need on the above please.
Cheers!
Prashant

Added in 6 minutes :
PS: [Sorry! why this thing of foremost importance couldn't have occurred to me earlier!!]
Do pls remember that often just smoothening out the internals and proper lubing would do wonders to your ARs.....and you may not need any alterations!! specially true for our local makes!
Regards,
Prashant

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