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Gas Ram conversions

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nunga View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote nunga Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jun 2013 at 4:20pm
Ok i have my new ram. I am converting my old Crosman first to see how it goes. I have spent the most part of the day sorting it out and have finished it just now. It is getting dark outside and the rain is coming so i will test it tomorrow if the weather lets me.


The New RAM.





I made a home made valve spring compressor to compress the Gas Ram. As you can see it is very simple but does the job nicely





The ram fits nicely almost like a brought one!!, Just need to finish putting it back together now.












So thats what i have done so far. Testing will be tomorrow.
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(pink)MIST View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote (pink)MIST Quote  Post ReplyReply Direct Link To This Post Posted: 13 Jun 2013 at 9:32pm
waiting to see how yours turns out.
what model crosman are you converting? calibre ?
do you have pre - gasram chrony figures to compare with as well?
And what brand of gasram are you using? (stabila, theoben , benjamin, etc)

When mine was done, and I first heard it being shot, I felt disheartned at first. Quieter and a lot less visible recoil. surely these were signs of a drop in power.....
nope
a slight power gain was had, matched with alot more consistency in chrony results.
That plus less felt recoil meant alot more hits were going exactly where I asked them to,  on paper the groups shrank in size considerably.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote nunga Quote  Post ReplyReply Direct Link To This Post Posted: 14 Jun 2013 at 1:11pm
Originally posted by (pink)MIST (pink)MIST wrote:

waiting to see how yours turns out.
what model crosman are you converting? calibre ?
do you have pre - gasram chrony figures to compare with as well?
And what brand of gasram are you using? (stabila, theoben , benjamin, etc)

When mine was done, and I first heard it being shot, I felt disheartned at first. Quieter and a lot less visible recoil. surely these were signs of a drop in power.....
nope
a slight power gain was had, matched with alot more consistency in chrony results.
That plus less felt recoil meant alot more hits were going exactly where I asked them to,  on paper the groups shrank in size considerably.




The gun is .22 Crosman Optimus.

Pre gas ram was 680fps with RWS super dome. after the conversion 750fps.

The gas ram is a no-name. It was built to my specs what i asked for :). She is currently sitting on 60KG of moving force.

I have ordered a second strut but this one is charged to 90KG. it also has been made with a touch of oil between the main seals to keep the seals from drying out this will also act as a damper system. When the strut is near its d-compressed state it wont hit so hard at it's last 2mm of stroke this should keep the seals intact longer and have less of a kick. it is rated to 20,000 compressions before it will need re gassing. It will be here mid next week.

Keep you posted !
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Post Options Post Options   Thanks (0) Thanks(0)   Quote nunga Quote  Post ReplyReply Direct Link To This Post Posted: 20 Jun 2013 at 9:21am
My supplier just got in touch with me. the beast will be here tomorrow. I will install it tomorrow afternoon and hopefully have it tested by tomorrow night. Hope the weather blows over and fines up a bit by then.

Very excited at the moment ha ha :)
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Post Options Post Options   Thanks (0) Thanks(0)   Quote (pink)MIST Quote  Post ReplyReply Direct Link To This Post Posted: 20 Jun 2013 at 6:59pm
saturday and sunday are looking good for the weather, i wouldnt hold my breath for friday though

when mine was first done, the lack of recoil provided a huge improvement in feel and accuracy.
If you havent done the GRT trigger replacement yet, then youre in for a treat once you do, 
after shooting gasrams for so long, I almost found it hard to go to the TX200, and on some points i like the feel of the gasram better still.
Now if only someone would figure out how to ram a TX.............
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AA TX200 MK111, Optisan Viper 8-32x60 JSB. VMach, TbT, maestro design.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote nunga Quote  Post ReplyReply Direct Link To This Post Posted: 20 Jun 2013 at 11:01pm
I do have some ideas about that TX problem, but need a sample to play with.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote nunga Quote  Post ReplyReply Direct Link To This Post Posted: 28 Jun 2013 at 8:32pm
Well i have the new high spec ram installed in the gun today but i have noticed right off the bat that it would not preform as i would like, I could see this even before i installed it. the outer shaft seal is not what i wanted and i could see it would not do the job.

Used using a simple compression test on the bench I could tell they did not put the vent groves in like i wanted and as a result when the pressure is released off the ram there is back pressure building up inside the seal and this will restrict the movement of the shaft moving forward.

I did install it just to see what would happen but as i thought the thing did not preform. Very disappointed in the end result. I took a hacksaw to the base of the ram and cut the end off. pulled the ram apart and checked it to see how they made it.

It looks very simple and i can easily knock one up in my workshop with the specs that i know will work. I can see improvements of the ram that they have sent me that will increase the life span of the ram as well. Will keep you posted

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Post Options Post Options   Thanks (0) Thanks(0)   Quote nunga Quote  Post ReplyReply Direct Link To This Post Posted: 10 Oct 2013 at 11:04pm
Just an update. I have been holding off on this for a little bit as i have had a part on my lath brake and have only just managed to get a replacement part shipped in from England. I am hoping it will be  here tomorrow and can start work on the ram over the weekend.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Grantrow Quote  Post ReplyReply Direct Link To This Post Posted: 12 Oct 2013 at 11:08am
Greetings.
This is my first post. I signed up last night.
Any way, I am new to air rifles / air guns, but have been reading a lot about them lately, and am keen to get my hands on a good reliable, QUIET, low recoil air rifle, that is easily capable of knocking over possums, and is accurate. I don't have a FAL, and can't be bothered with getting one again. I have a possum v fruit tree problem !! (sorry - not trying to side track this thread)

Anyway . . . I am interested in this topic regarding conversion from spring to gas ram. Can any / most spring guns be converted ? I'm not technical, but could most gun shops do a conversion if a ram was obtained ?

Good luck with your conversion. You obviously have pretty good technical skills to manage this process. I will be keen to read your results.

Cheers,
Grant.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote nunga Quote  Post ReplyReply Direct Link To This Post Posted: 14 Oct 2013 at 11:59pm
Well i just got in from the garage, My new part came in the post this morning so i have been in the garage installing it. I had to machine up a new bush for it before it fit. ( i dont think it was the exact model that i ordered)

Everything is good now :) very happy camper at the moment. The auto feed and thread cutting is back online :)

Grant, most rifles can be converted with the exception of the guns like Weihrauchs etc these can not be rammed due to the trigger latch coming out of the middle of the piston.

But if anyone has one they are willing to donate for science I do have some ideas :)
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