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Author Topic: PA or RVA or SSG, (is what it is called ??)..  (Read 870 times)

Nvreloader

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PA or RVA or SSG, (is what it is called ??)..
« on: June 23, 2017, 07:56:00 AM »
Guys

I need some help to accomplish what I want to do, if reasonable and safely.
Here is some info, I want to accomplish, if possible,

I have a brand new OTB QB 79, 22 caliber, scoped with a 4x14x44 mm ( Mueller APT), running Co2  now,
with 88/90 gram cylinders and with HPA/reg in the future, using the smallest bottle to provide, 25-50 shots,
the average shot string runs are,

14.3 gr CPHP pellets
Temp 85* >
Shot over my Magnet V-3 chrono
H= 585 fps
L= 576
A= 579
SD =2.6

Shot over my Oehler 32 chrono
H= 585 fps
L = 568
A= 577
SD = 2.6  .

This QB has not been modded yet, but soon will be.  ;)
I want, (if possible) to have the best accuracy (with the correct pellets, after testing), out to 50 yds,
with the highest FPS possible with both fuel types while hunting small game and pesting birds.

I have been haunting several different sites,
and read about a this rear adjustment thingy that controls the power of the valve spring etc,
I can't find the site with this info, IIRR, I believe that Bob posted the info, but not sure etc.

My question is,
Would this valve adjustment thingy, be advisable/help for tuning my QB when using both fuel types,
with what I want to accomplish for both fuel types with the best accuracy and FPS etc ??

I will be running Co2 in the summer, and HPA in the winter times.

I would greatly appreciate any and all info possible, on reaching my goal for this AR.

Thank you,
Don





 
« Last Edit: June 28, 2017, 05:29:25 PM by Nvreloader »


  • Western NV
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"We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker.
It is time to restore the American precept, that each individual is accountable for their actions"
Ronald Reagan

"Speeds fine, but Accuracy is final"

oldpro

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Nvreloader

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Re: Rear spring adjustment thingy? (don't know the proper name for it)
« Reply #2 on: June 23, 2017, 05:47:34 PM »
Thanks

Oldpro,
Your link does not show any info on the $200 pcp,
or least I could not find any info etc.

Thank you,
Don
  • Western NV
NRA Life member

"We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker.
It is time to restore the American precept, that each individual is accountable for their actions"
Ronald Reagan

"Speeds fine, but Accuracy is final"

Gerard

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Re: Rear spring adjustment thingy? (don't know the proper name for it)
« Reply #3 on: June 23, 2017, 05:51:22 PM »
His link got broken for some reason. If you copy and paste the WHOLE link it takes you to the correct and very informative thread.
http://airgunguild.com/ask-bob/qb-79-ninja-the-$200-pcp
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Nvreloader

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Re: Rear spring adjustment thingy? (don't know the proper name for it)
« Reply #4 on: June 23, 2017, 07:42:27 PM »
Oldpro

You are correct, the info is there, on pg 2,
I guess I need to clean my glasses,
blind as a Bat without them.

I am sorry about the wrong info I gave in reference to your post,  :-[
I"ll go stand in the corner.

Tia,
Don
  • Western NV
NRA Life member

"We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker.
It is time to restore the American precept, that each individual is accountable for their actions"
Ronald Reagan

"Speeds fine, but Accuracy is final"

Monkeydad1969

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Re: Rear spring adjustment thingy? (don't know the proper name for it)
« Reply #5 on: June 24, 2017, 08:34:52 AM »
Re: Rear spring adjustment thingy?

A power adjuster (PA) or RVA (Rear Velocity Adjuster) is what it's called.  Real handy to have on a co2 or pcp for sure.

Joe
« Last Edit: June 24, 2017, 08:38:17 AM by Monkeydad1969 »
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Nvreloader

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Re: Rear spring adjustment thingy? (don't know the proper name for it)
« Reply #6 on: June 25, 2017, 08:52:34 AM »
Hey MD,
Being a new to the AR field,
I was not SURE what it was called, and since most poster do not provide a any info, ie,
like COTBH = WHAT's it mean? in their posts etc, the reader is left to figure it out, if possible etc,
but I was close, and close only counts in horse shoes, grenades and atom bombs.  ;)

When you have been reading thousands of posts, for the last several months, on 4+ sites about the QB rifles,
and you remember seeing/reading something about a thingy/do hickey etc, that might be useful on your AR,
and just where you saw that info, sometimes it's hard to remember where you saw that info etc.

I am lucky to get my pants on the right way, being an Old Fart,
instead of a Whipper Snapper, that's wet behind the ears, like you.  ;D  ;)  LOL

Tia,
Don



Re: Rear spring adjustment thingy?


A power adjuster (PA) or RVA (Rear Velocity Adjuster) is what it's called.  Real handy to have on a co2 or pcp for sure.
Joe
  • Western NV
NRA Life member

"We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker.
It is time to restore the American precept, that each individual is accountable for their actions"
Ronald Reagan

"Speeds fine, but Accuracy is final"

Monkeydad1969

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Re: Rear spring adjustment thingy? (don't know the proper name for it)
« Reply #7 on: June 25, 2017, 08:24:07 PM »
 ;D no worries, gramps! :o ;D ;)
« Last Edit: June 26, 2017, 08:46:53 PM by Monkeydad1969 »
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Nvreloader

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Re: Rear spring adjustment thingy? (don't know the proper name for it)
« Reply #8 on: June 26, 2017, 12:12:29 PM »
MD69

At least you something right,  :)
I am a Gramps  X 4   ;)  LOL

Tia,
Don
  • Western NV
NRA Life member

"We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker.
It is time to restore the American precept, that each individual is accountable for their actions"
Ronald Reagan

"Speeds fine, but Accuracy is final"

Alan

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Re: Rear spring adjustment thingy? (don't know the proper name for it)
« Reply #9 on: June 26, 2017, 01:23:36 PM »
You're just a youngster. I have 13 and4!
  • Roswell, New Mexico
Alan

I have an Omega compressor. If you're a fellow Guild member, and you pass through Roswell, NM, I'll fill your portable tank as a courtesy.

Nvreloader

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Re: Rear spring adjustment thingy? (don't know the proper name for it)
« Reply #10 on: June 28, 2017, 01:32:44 PM »
Thanks Alan
I needed that info.
I have been around this world ONCE, and that was enough for me,
Kinda rode hard and put away wet.   LOL   ;)

OK
On to the next question,
Does a PA, RVA  and an SSG do the same thing, or have the same function?

I am attempting to understand just what function each of the above performs,
and which item would be the best on an AR using/running both fuel types,
Co2 for summer and HPA for winter times,
to get the best performance (read accuracy 1st and ballistic efficiency 2nd, for the 22 cal.

Tia,
Don
  • Western NV
NRA Life member

"We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker.
It is time to restore the American precept, that each individual is accountable for their actions"
Ronald Reagan

"Speeds fine, but Accuracy is final"

Monkeydad1969

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Re: PA or RVA or SSG, (is what it is called ??)..
« Reply #11 on: June 28, 2017, 06:16:33 PM »
A PA and RVA do the same thing.  They allow you to increase or decrease hammer tension, more power or less power.  An SSG allows you to have more shot to shot consistency.  Hopefully someone who has an SSG or knows how they exactly work will chime in.

The Monkey
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Alan

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Re: PA or RVA or SSG, (is what it is called ??)..
« Reply #12 on: June 29, 2017, 05:18:57 AM »
The premise is to reduce hammer bounce, by preloading or other means, so the hammer hits the valve only once. In reality, it may still hit the hammer again, but not with enough force to reopen the valve. This is why these systems offer more shots per fill—no wasted air in other words. Electronically-controlled valves do the same thing, but are obviously more complex.

The one "device" which intrigues me the most, is the TSS—twin spring system. It is so simplistic, some find it difficult to figure out how it works. However, it is a very good example of the physics of inertia, and the law of conservation of energy, with a bit of friction thrown in to complicate the issue. It is almost genius, actually.
  • Roswell, New Mexico
Alan

I have an Omega compressor. If you're a fellow Guild member, and you pass through Roswell, NM, I'll fill your portable tank as a courtesy.

Nvreloader

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Re: PA or RVA or SSG, (is what it is called ??)..
« Reply #13 on: June 29, 2017, 08:23:41 AM »
Thanks Guys,

I think I may have to stay with a PA-RVA, for now until I really understand the difference of a SSG etc.

Still in the 1st grade understanding all this info/lingo,
and then ALAN throws another BIG word into the mix called a TSS - twin spring thingie,  LOL.

I wish, I had TBBGCESM -
the Big Blue Cookie Eating Star Wars Monster's knowledge on this AR stuff,
and he had my good looks, we would both be tickled Pink.  LOL   ;D  Gotcha........

Tia,
Don
ps,
It would be a very good idea, to have a brief explanation of what each of these items do for an AR,
to help understanding it's function, for anyone (like me), which would cut down on the dumb questions asked etc.
« Last Edit: June 29, 2017, 08:32:22 AM by Nvreloader »
  • Western NV
NRA Life member

"We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker.
It is time to restore the American precept, that each individual is accountable for their actions"
Ronald Reagan

"Speeds fine, but Accuracy is final"

Gerard

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Re: PA or RVA or SSG, (is what it is called ??)..
« Reply #14 on: June 29, 2017, 09:59:54 AM »
I'll have a shot at very brief explanations:

RVA - Adjusting bolt/guide for the hammer spring which allows changing preload of the spring to hit harder or softer, increasing or decreasing hammer strike on the valve stem.

SSG - A 'stopped spring guide' which captures the spring, still using the gross adjustability as in the RVA but now with a positive 'stop' in the form of the tip of the spring guide. This stops the hammer on rebound, like a dead blow hammer, preventing second strikes. Also secondary adjustment built in for spring preload. At least a small gap is important such that the SSG tip does not contact the hammer while the hammer contacts the valve stem.

TSS - A 'twin spring system' uses a larger and a smaller spring, one within the other, usually wound in opposite directions so as to avoid entanglement between spring coils. The stronger outer spring contacts the hammer and is usually fixed in position, with preload adjustment being done by trimming the spring. The inner, usually weaker spring stops at least slightly shy of the hammer. The hammer hitting the inner spring on rebound damps the impact to prevent second valve stem strike.

There are of course a lot of variables involved with each of these which can change performance, with a lot of variation in how each is built, but I think the above covers the basics. The most elaborate descriptions with imagery and a lot of discussion seems to be found on GTA PCP forums, with Bob Sterne's work particularly valuable, and a lot of other airgun gurus contributing.
  • Vancouver, Canada