GTA
All Springer/NP/PCP Air Gun Discussion General => Bargain Gate => Topic started by: BigBird on October 26, 2020, 02:52:49 PM
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https://www.amazon.com/Beeman-Rifle-177-Synthetic-Stock/dp/B01MU32XXI/ref=mp_s_a_1_37?dchild=1&keywords=air+guns&qid=1603734386&sr=8-37 (https://www.amazon.com/Beeman-Rifle-177-Synthetic-Stock/dp/B01MU32XXI/ref=mp_s_a_1_37?dchild=1&keywords=air+guns&qid=1603734386&sr=8-37)
Can't remember how low it was before but $69 now.
Beware, seller fluctuates price all the time. He probably watches our notifications which are of course advertised beyond forum members (I checked all the time before becoming a member).
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https://www.amazon.com/Beeman-Rifle-177-Synthetic-Stock/dp/B01MU32XXI/ref=mp_s_a_1_37?dchild=1&keywords=air+guns&qid=1603734386&sr=8-37 (https://www.amazon.com/Beeman-Rifle-177-Synthetic-Stock/dp/B01MU32XXI/ref=mp_s_a_1_37?dchild=1&keywords=air+guns&qid=1603734386&sr=8-37)
Can't remember how low it was before but $69 now.
Beware, seller fluctuates price all the time. He probably watches our notifications which are of course advertised beyond forum members (I checked all the time before becoming a member).
I think I paid around $65 it could have been $68 back in August, I was going to wait to see if it would drop lower but chicken out. They are a lot of fun to shoot.
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For the tinkerers amongst us, I think it’s still the best value in the sub-$100 bracket. So much potential. Ditch the fiber filter in the valve, open up the airways, and polish up the trigger components. Added cost? $0 and some time.
To make it even more enjoyable, swap out the spongy poppet with Delrin or PET-P or PEEK and fit a shortened MDS nylon or PEEK hammer. Then drill and tap the end cap for an RVA and remove the rear cocking pin to convert it to cock-on-open. Cocking effort goes down to one finger and the shot cycle is so sedate that you just might fall asleep at the bench. Not to mention the CO2 or air savings.
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For the tinkerers amongst us, I think it’s still the best value in the sub-$100 bracket. So much potential. Ditch the fiber filter in the valve, open up the airways, and polish up the trigger components. Added cost? $0 and some time.
To make it even more enjoyable, swap out the spongy poppet with Delrin or PET-P or PEEK and fit a shortened MDS nylon or PEEK hammer. Then drill and tap the end cap for an RVA and remove the rear cocking pin to convert it to cock-on-open. Cocking effort goes down to one finger and the shot cycle is so sedate that you just might fall asleep at the bench. Not to mention the CO2 or air savings.
I have a QB78S that I want to reduce the fps from 620 to 500 and increase the shot count per CO2 cartridge.
Where can I find a video or directions to do that?
How do I "remove the rear cocking pin to convert it to cock-on-open".
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Hi Earl,
There are a few directions this could take depending on how much effort you want to put into it and how refined you want the results to be.
For example if this is for short-range indoor duty (10m), you may want to just try backing off the hammer spring until the velocity drops to where you want it. Two ways to go about it. Either clip coils (tedious trial and error approach, but easy) or do the RVA mod so you can adjust it on the fly…it’s so handy. We are talking about a 1/3 reduction in energy so it would be operating at a state of partial valve lock which is great for efficiency but the ES will not be so good. At short distance it may not influence the POI enough to matter. Notice I also stipulated indoors because the temperature dependence of CO2 would make it sensitive to temperature changes. I mean the ambient temperature only. Any self-cooling would be drastically reduced.
A better solution would be to incorporate an SSG. That will allow you to stop the CO2-wasting hammer bounce. However it will still be subject to the high ES if you simply reduce hammer strike to get the velocity down from 620 to 500fps. Install a slightly smaller transfer port to accomplish that.
In other cases using an O-ring buffer (bstaley) between the hammer and the valve stem would be a simpler alternative to the SSG, but the QB is not a candidate because the backer block behind the valve leaves very little of the stem protruding.
Yet another option would be to install a harder poppet and a lightweight hammer. That will likely leave a bit of hammer free flight (like an SSG without the SSG) to eliminate hammer bounce, with the added benefit of vastly easier cocking and a very pleasant shot cycle absent of all the vibration. It’s hard to appreciate how nice it can be until you experience it.
BTW you may want to post this question in the PCP gate where more tuners can see it and pitch in.
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Hi Earl,
There are a few directions this could take depending on how much effort you want to put into it and how refined you want the results to be.
For example if this is for short-range indoor duty (10m), you may want to just try backing off the hammer spring until the velocity drops to where you want it. Two ways to go about it. Either clip coils (tedious trial and error approach, but easy) or do the RVA mod so you can adjust it on the fly…it’s so handy. We are talking about a 1/3 reduction in energy so it would be operating at a state of partial valve lock which is great for efficiency but the ES will not be so good. At short distance it may not influence the POI enough to matter. Notice I also stipulated indoors because the temperature dependence of CO2 would make it sensitive to temperature changes. I mean the ambient temperature only. Any self-cooling would be drastically reduced.
A better solution would be to incorporate an SSG. That will allow you to stop the CO2-wasting hammer bounce. However it will still be subject to the high ES if you simply reduce hammer strike to get the velocity down from 620 to 500fps. Install a slightly smaller transfer port to accomplish that.
In other cases using an O-ring buffer (bstaley) between the hammer and the valve stem would be a simpler alternative to the SSG, but the QB is not a candidate because the backer block behind the valve leaves very little of the stem protruding.
Yet another option would be to install a harder poppet and a lightweight hammer. That will likely leave a bit of hammer free flight (like an SSG without the SSG) to eliminate hammer bounce, with the added benefit of vastly easier cocking and a very pleasant shot cycle absent of all the vibration. It’s hard to appreciate how nice it can be until you experience it.
BTW you may want to post this question in the PCP gate where more tuners can see it and pitch in.
That sounds too complicated for me.
I do not know what SSG and RVA and bstaley and ES mean.
So, I will just shoot it like it came new.
Thank you for trying to help me.
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No problem. If you change your mind, be aware you can simply shorten the spring and swap in a smaller transfer port. No advanced fabrication involved, just time and an interest to do it.
ES is extreme spread....difference between the slowest shot and the fastest shot.
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"ES is extreme spread....difference between the slowest shot and the fastest shot."
I should have been able to figure that one out.
I blame it on having a "Senior Moment".