Author Topic: SR25 Proprietary Parts  (Read 3329 times) Share

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Offline Vielwerth

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SR25 Proprietary Parts
« on: April 12, 2010, 01:10:41 pm »
The gearbox in an SR25 is an "extended" version 2.
This means that certain parts are unique to this gearbox and can't be used in anything else. Conversely, this naturally means certain "standard" version 2 parts can't be used in this gearbox.

For example, the piston used is an extended piston with 19 teeth instead of 16 teeth found in normal version 2's.

However, some parts used in the "extended" gearbox are the same as normal version 2's. I'm trying to put together a list of what parts, in the SR25 gearbox, is specific to the SR25 gearbox, and what parts are just normal version 2 parts.

Any help will be rewarded with cake.

EDIT -

My SR25 is an A&K gun, which is an exact clone of the Classic Army SR25. Just in case.

Confirmed List -

Piston,
Tappet Plate,
Bevel, Sector, and Spur gears
Air nozzle
Cylinder
« Last Edit: April 12, 2010, 02:03:32 pm by Vielwerth »

Offline hunter101

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Re: SR25 Proprietary Parts
« Reply #1 on: April 12, 2010, 01:20:29 pm »
Air nozzle, piston, tappet plate, cylinder, gears. Off the top of my head, if i remember anything else i'll update.

There is a spacer mod you can do to allow you to use a normal piston and standard sector gear. But in my opinion the CA bore up kit would be the best option

Offline Vielwerth

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Re: SR25 Proprietary Parts
« Reply #2 on: April 12, 2010, 01:57:51 pm »
But in my opinion the CA bore up kit would be the best option.

I saw that. What's the difference between "bore up" and "non bore up" kits?

Offline Castor

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Re: SR25 Proprietary Parts
« Reply #3 on: April 12, 2010, 02:00:42 pm »
Hi Veilwerth, after speaking with you at DV you had concluded only needed a new piston if that is correct try this link:

http://www.airsoftworld.net/extended-piston-and-head-for-r85a1-and-sr-25.html

Hopefully you can get the SR25 working by the next game with this replacement piston.

Offline Vielwerth

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Re: SR25 Proprietary Parts
« Reply #4 on: April 12, 2010, 02:10:26 pm »
Hi Veilwerth, after speaking with you at DV you had concluded only needed a new piston if that is correct try this link:

http://www.airsoftworld.net/extended-piston-and-head-for-r85a1-and-sr-25.html

Hopefully you can get the SR25 working by the next game with this replacement piston.



Yeah, that's right. We found that the teeth on the piston had been worn down so much that gears were "tickling" it rather than engaging the teeth.
I was planning to get my piston from Airsoft world too, but I've been thinking about maybe putting a few other upgrades in the gearbox too, like a silent piston head and cylinder head.

Offline hunter101

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Re: SR25 Proprietary Parts
« Reply #5 on: April 12, 2010, 03:36:26 pm »
The bore up kit is good for a stronger spring and longer barrel.

Offline stewpidbear

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Re: SR25 Proprietary Parts
« Reply #6 on: April 12, 2010, 06:55:06 pm »
If he puts a longer barrel in a SR25 it'll be taller than he is!
Remember we have the right to arm bears!

Offline hunter101

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Re: SR25 Proprietary Parts
« Reply #7 on: April 12, 2010, 08:23:06 pm »
SShh don't tell him that  :P :giggedy:

Offline stewpidbear

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Re: SR25 Proprietary Parts
« Reply #8 on: April 12, 2010, 08:26:30 pm »
Also BIG Hint don't carry it across your chest when running into a room, I kid you not have actually seen it happen.............best olympic speed limbo I have ever seen.
Remember we have the right to arm bears!

Offline Vielwerth

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Re: SR25 Proprietary Parts
« Reply #9 on: April 14, 2010, 02:42:36 pm »
Well, as soon as I've bought a fresh piston and fine tuned the gearbox, I'll be selling the whole caboodle, scope and all.  :bravo:

Offline Vielwerth

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Re: SR25 Proprietary Parts
« Reply #10 on: April 14, 2010, 09:21:18 pm »
Right, a little digging around has revealed that "extended" version 2 gearboxes have a fatal flaw that occurs only in the UK. (I'm being dramatic here, but hey)

This "flaw" will result in the piston teeth eventually being stripped.

What happens is because the piston is longer than standard, the gears have chance to complete their cycle before the piston has come to rest. This is essentially the sector gear trying to pull back the piston (for a new BB) while the piston is still travelling forward from being pulled back for the previous BB.

This results in the piston teeth being stripped, starting with those towards the rear (like Russ and I discovered last Sunday).

Having an "uber-powerful" spring that gets the piston back forward quicker would resolve this problem. (whether completely or not, I can't say.) But then you'd have a useless gun firing at over 350FPS and disallowed at most sites.

The solution here is to use the "spacer mod" mentioned by hunter above. This is a block of metal between the piston and piston head which allows you to use the normal length 16 tooth piston (which works fine at - 350FPS levels). This will require a regular, rather than an "SR25" sector gear.

So before I sell this, I will be purchasing and putting in this upgrade which should make people a bit more confident.
I have a sector gear from my LR300 which isn't being used (and being A&K it's nice and strong and will have no problems with 350FPS) and I may buy an upgraded piston instead of using the stock one from the LR300.