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How do your like your QB 78/9 to cock?
1. I like it to cock when I close the bolt (stock) 11%  11%  [ 5 ]
OR: I would like it to cock when I open the bolt 38%  38%  [ 18 ]
2. If it meant having an RVA, cock on open would be OK 36%  36%  [ 17 ]
OR: Even with an RVA, I would like it to cock on closed 15%  15%  [ 7 ]
Total votes : 47
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PostPosted: Wed Dec 07, 2011 12:22 pm 
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The standard setup on the QB 78/9 and AR 2078/9 rifles is to cock the hammer when you close the bolt.... It is a relatively easy mod to change that to cock the hammer when you open the bolt (like a Crosman 22XX).... it just requires removing the rear cocking pin and fitting a spacer (or adjuster) behind the spring carrier.... While there have been Rear Velocity Adjusters (RVAs) made that will work with the forward cocking of the QBs.... I am not aware of them being commercially available.... so they are "one-of" customs, AFAIK.... If the gun is modified to cock on open, then making a velocity adjuster is much easier.... With that in mind, please select one of the top two options in the above poll, and also one of the bottom two options (with RVA).... Comments are welcome....

Bob

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Last edited by rsterne on Wed Dec 07, 2011 12:45 pm, edited 1 time in total.

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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 12:33 pm 
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cock on open.

allows better feel as pellet is seated. A sweet mod for sure. Have one done and will do more if I come back to them.... :)

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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 12:55 pm 
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Not to be funny about it- but I think I know where this is going, so the question becomes- why not have the "fabricator" of these custom bits actually produce something they have already been given to produce?

You can design things until the cows come home- but if no one is actually building them- what is the point?

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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 1:09 pm 
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AirGunEric wrote:
Not to be funny about it- but I think I know where this is going, so the question becomes- why not have the "fabricator" of these custom bits actually produce something they have already been given to produce?

You can design things until the cows come home- but if no one is actually building them- what is the point?


say it ain't so!!!!

good call Eric.

Bob? is this the deal?

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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 1:17 pm 
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Nope, just an idea I had.... I'm gonna do up something unique for my own QB.... just wondering how many people might be interested in an RVA type device if it incorporated cock on open as well.... As I've done with everything else I've designed, the info will be available (free of charge) should someone want to make them.... As an example, Derek Vinyard got all the drawings for my Uber-Carbine.... but I think all he produced for sale were the breech bands....

But funny you should bring up Stan.... I have a big box of parts on the way here at the present time.... so it would appear that the prototype stage is nearly complete.... Heck, it took less than a year.... :roll: :shock:

Bob

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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 2:30 pm 
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Having been down this route...I built the "Al Stone" RVA for use with cock on close, in all honesty, if you're going to make an adjuster for sale, doing so with cock on open makes more sense.

The cock on close RVA works well...don't get me wrong there....not sorry I made it by any means. More that if you're trying to sell at a price point where it'll move...you need to simplify and lower the parts count.

Cock on open is as simple as it gets...Believe Steve Woodward did this mod...but isn't selling it currently that I'm aware of. Essentially, he drilled and tapped the rear tube plug off center....this allowed the "stock" receiver mounting arrangement to be retained, while allowing adjustment of striker spring tension. On the yellow or Chinese forums...

Have tried the cock on open mod as well, I was after improving the feel of the pellet/transfer port/leade interaction as Walter noted. Can't quite put my finger on "why" I changed it back, but I did.

Al Stone designed RVA in the white...
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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 2:52 pm 
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Gippeto wrote:
Having been down this route...I built the "Al Stone" RVA for use with cock on close, in all honesty, if you're going to make an adjuster for sale, doing so with cock on open makes more sense.

The cock on close RVA works well...don't get me wrong there....not sorry I made it by any means. More that if you're trying to sell at a price point where it'll move...you need to simplify and lower the parts count.

Cock on open is as simple as it gets...Believe Steve Woodward did this mod...but isn't selling it currently that I'm aware of. Essentially, he drilled and tapped the rear tube plug off center....this allowed the "stock" receiver mounting arrangement to be retained, while allowing adjustment of striker spring tension. On the yellow or Chinese forums...

Have tried the cock on open mod as well, I was after improving the feel of the pellet/transfer port/leade interaction as Walter noted. Can't quite put my finger on "why" I changed it back, but I did.

Al Stone designed RVA in the white...
Image


I'm betting you lost pellet loading room? :)
solved that on mine by making a new hammer, added an HDD, extended slot about 3/8"

:)

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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 3:16 pm 
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Yes, Lost Pellet loading Free-Space/Room( as per Walter). Then place Hammer Pin on rear Half of Hammer and milled a cocking slot in the rear half of Receiver/Breech. Was still not Happy and so return to Stock.
It would be a Good Thing if a Kit was Offered that removes most of the little obstructions/Pain.

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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 5:10 pm 
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Voltar1 wrote:
I'm betting you lost pellet loading room? :)
solved that on mine by making a new hammer, added an HDD, extended slot about 3/8"

:)



Sounds like reason enough to me.

Nice fix..may have to revisit and give that a go. :)

Al


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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 5:24 pm 
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Gippeto wrote:
Voltar1 wrote:
I'm betting you lost pellet loading room? :)
solved that on mine by making a new hammer, added an HDD, extended slot about 3/8"

:)



Sounds like reason enough to me.

Nice fix..may have to revisit and give that a go. :)

Al

Will bring it next shoot to show you see if you like it :)

Walter....

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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 7:22 pm 
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that looks cool


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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 7:29 pm 
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Well guys.... I had no idea that converting the QBs to cock on open would lose basically all the pellet loading room.... but I sure found out in a hurry.... Unfortunately, I spent most of the day making my Dual-Power adjuster before I found that out.... Here is the adjuster, shown with the end cap which is drilled out to 3/8" to accept it....

Image

Below is the adjuster set on low power....

Image

Below is the adjuster set on high power....

Image

The nut and bolt on the inside end is to fine tune it.... Yes, it has to be removed to adjust it, but that's only one screw once the gun is out of the stock.... Once you have the adjuster set for the velocity level you want on high power, you simply give the rod a twist and it pops out to a lower preload for low power.... I quickly found out that I had twice the travel necessary, at least on my 1500 psi HPA version.... The 1/4" of adjuster change in the slot dropped the velocity form 900 fps to 150 fps.... I didn't make another adjusting rod, but a 1/8" change of preload dropped the velocity from 900 fps to 630 fps.... which is a 50% reduction in FPE.... I think that's pretty cool with a flick of the wrist.... push in and turn clockwise for high power, and turn counterclockwise (and it pops out) for low power.... :mrgreen:

Now to this cock on open problem.... I found out that now the bolt (when opened for loading) sits against the sear, instead of all the way back.... That reduces the room for the pellet, of course.... To load the pellet, you have to hold the bolt back against the hammer spring, which is inconvenient.... If the adjuster is screwed in all the way, there is even less room (you can't even pull the bolt back to the back of the slot), but that could be changed by simply grinding/turning off the back of the bolt.... I don't see an easy way around the position of the bolt sitting against the sear, however, unless I make a whole new bolt (or maybe hammer).... As I missing something?....

Bob

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Airsonal;
Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!


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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 8:03 pm 
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great stuff,
i think i need to get my qb shooting in a lower fps, i think it is shooting too fast
would that power adjuster give a lower fps than before?


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 Post subject: Re: Poll - QB Cocking
PostPosted: Wed Dec 07, 2011 8:06 pm 
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As I mentioned, it cut the power of my HPA version in half (ie 70% of the velocity).... I have no idea how it would work on CO2, it would probably need the 1/4" travel for that.... It is necessary to convert the gun to cock on open, however, and that causes loading problems.... so unless an easy solution can be found it's a non-starter, I'm afraid....

Bob

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Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal;
Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!


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 Post subject: Re: Poll - QB Cocking
PostPosted: Sat Dec 10, 2011 12:18 pm 
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I found this photo of a QB hammer with a spacer fitted to give more room when cocked in a gun that has been converted to "cock on open"....

Image

It seems to me that the sear would now catch on the spacer?.... If that's that case, yes you would have more room for loading, but the hammer fall distance is increased, isn't it?.... that might be great if you were looking for more power, of course (providing you could still close the bolt, which would limit how far you can go with this mod).... Wouldn't it need to be hardened so that it wouldn't wear?....

Bob

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Airsonal;
Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!


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