A New Method for Increasing the Efficiency of a PCP - the SSG

[t_jones98]

Hey Keith,
A lot of guys are looking at this for their 177s and 22s to smooth out for FT.   I'm more at a point similar to yours, higher power hunting. 

Do you feel the work and parts are warranted for a 25?  Enough benefit to make it worth while?

[triggertreat]

Hey Keith,
A lot of guys are looking at this for their 177s and 22s to smooth out for FT.   I'm more at a point similar to yours, higher power hunting. 

Do you feel the work and parts are warranted for a 25?  Enough benefit to make it worth while?

IMHO, yes.  It's cheap and easy.  You may have to adjust the spring rating for the 25s to a 14lb, but testing for your desired tune will determine this.

The main benefit of the SSG is preventing wasted air per shot and lowering the ES over traditional tuning.  Since your not wasting as much air per shot, the shot noise is reduced too.  The biggest con is increased cocking effort, but if all is smooth, it's not by much and very doable.

With the 21.1gn, I used to only get 25 shots at an average of 828 fps with the Bstaley BHB O-ring mod and now I've almost doubled the shot count with an average of 850 fps.  I'm working on lowering my current ES of 2.32% for 40 shots as I was getting 1.92% with the O-rings.  I have a new hammer that I have not polished yet and have not closed off the VMS yet so my ES should improve in the future along with shot count.  The report has been reduced too.

When drilling the hammer, I recommend to start drilling from the inside slowly so you can file smooth the exterior hammer easier than trying to file the inside of the hammer.  The hole must not have any burrs to grab the bolt or cocking and ES will suffer. Don't try to use the bit to smooth out the hole.  You want the hole to have a close tolerance to the bolt.  The same goes for the nylon sleeve.  They both should slide freely on the bolt though.

Make sure you check the bolt at the store on a flat steel shelf.  I've found some that were off a little and not completely round or were slightly bent.  I sand the bolt with 320 grit to make sure the surface is baby smooth.

The best results come from a hammer that slides very smooth within the air tube and slides on the bolt very smooth as well.  Make sure the bolt, spring, hammer and air tube are extremely clean and no lube is present.  You may benefit from some dry lube but I have not tried that.  If the air tube is not slick, you could benefit from sanding it with 320 grit using a large wood dowel or using a 1" ball hone with 320 grit or finer.

The SSG benefits will vary depending on how well your tune is now.  A poorly tuned gun will benefit the most and a well tuned gun will benefit the least.  All should see an increase in shot count to some degree.

I like the ease of tuning and SSG over the traditional method.  It's simple and saves on pellets.  To tune an SSG, set a gap around .020-.035".  To set the gap, remove the trigger assembly so you can insert a pre-measured object thru the trigger slot.  Fill to the middle of your desired psi.  Start aiming for your peak fps using the spring tension.  Refill back to your mid-point psi after several shots to maintain mid-point psi until you achieve your peak fps.  Fill to desired max psi and run a string.

You can adjust the gap to fine tune the fps but don't close off the gap, more is better.  Too much gap will cause you to have to increase spring tension and cause unnecessary cocking effort. 

[Buldawg76]

Keith
I would play with the VMS first since it an easy adjustment and especially if you clearance the stock to facilitate access without having to remove the action from the stock. I have done my two 177s and 25 that way so its just adjust and shoot with action still in the stock.

Just use a sharpie and mark where the VMS hole is in relation to the action in the stock and then use a round file or dremel sanding drum to make a groove to gain access or if you prefer you can drill a hole at an angle to intersect with the VMS screw. It makes adjustments a snap and if that does not tighten the spread up some then try the stock TP port.

Mike

Just to be clear, I'm going to fill back to my peak fps then start turning the VMS in until the fps starts to drop.  Then I'll back off to my existing peak fps.  I'll essentially keep my same tune but increase the shot count.  This is what I believe you're saying.

Keith
Yes you are correct in the way you would adjust the VMS by filling to your peak fps then slowly start to close off the VMS till you see a fps drop and once you see that then open the VMS back to the point where you had no fps drop and that will be the point of lowest air usage giving the highest shot count at your desired fps.

So same tune only gain a few more shots from same fill pressure since less air will be used per shot.

Mike

[triggertreat]

Ok Mike, I closed down the VMS to the peak and got better results.  I also went back to the stock TP sleeve and replaced the bent 1/4-20 bolt too.

The .22 synrod gun is completely stock except for the internal DIY SSG with 12.5lb spring.  I did drill out the air stripper holes bigger and removed the lawyer spring, but its stock everywhere else.

Here are the results: 

50 shots at 4%




40 shots at 1.65%





I'm happy with the smooth, consistent string with a much lower ES and SD compared to the previous H&N 10 40 shot string I posted earlier.

As far as the sub-10 challenge, here is the string analyzed for sub-10:





The internal DIY SSG I built and posted at the bottom of page 41 is what I used for this test.  No changes were made to it.  It's clearly worth the less than $15 in parts if you ask me.  I'm just going to enjoy it for a good while.  If I get bored, I'll get a HF barrel from Jim for something new to try.

[MichaelM]

Posted my disco SSG setup in the Disco thread here...

http://www.gatewaytoairguns.org/GTA/index.php?topic=104863.new#new

[Buldawg76]

Keith
I would say you have it tuned about as close as you will get and increased total usable shot count of 50 with still a respectable 4% ES and kept the same 40 shots at an even better 1.65 ES after closing off the VMS and reinstalling the stock TP port so you see a bigger port is not always the best for consistency and shot count.

If all out power is the goal then yes bigger is better but at the cost of efficiency and shot count so its always a compromise in what the end goals is we are after.

Glad you have it where you are happy so now its time to enjoy shooting it and learn its holds at different distances.

Mike

[Job]

Question for Bob Sterne and other experts
And finally Is better regulated 1CC / FPE + SSG or only SSG? 

[rsterne]

1cc / FPE is what I recommend for the plenum size in a regulated PCP, and it has nothing to do with whether or not you use an SSG.... Plenum volume is important to prevent the pressure from dropping too much during the shot, because the regulator cannot top up the pressure fast enough to keep a constant (or even near constant) pressure in the valve.... If you are putting a regulator inside the reservoir on a previously unregulated PCP, you may find that 1/2cc / FPE may be better, so that you don't lose as much of the HPA storage volume upstream of the regulator.... You will have to increase the regulator setpoint by about 10% to make up for the smaller volume in the plenum, but the overall shot count may be better with the smaller plenum....

Bob

[triggertreat]

New F.A.M.E mod by 22synrodn/triggertreat:

In my view, the biggest problem with the mechanics of the Marauder and other similar guns is hammer drag.  I’ve been trying to find a better way to limit this drag in my DIY SSG and have found a simple, DIY way to do this and have decided to share my idea with others.

I introduce to you the F.A.M.E mod which stands for Friction Assist Marauder Enhancement.

My idea lifts the rear of the hammer up and off the air tube which drastically reduces the friction/drag between the two.  I find my strings are more uniform and the cocking effort much easier and smoother.  Also dirt and dust does not affect the hammer nearly as much or as often.  My ES and SD numbers have dropped a considerable amount as well.
You can hone the air tube and polish the hammer but still can’t eliminate as much drag as this mod can.  The washer sliding on the top of the air tube has far less friction than the hammer to air tube friction.  The 1/4" tubing keeps the hammer centered and off the sides of the metal slot further reducing drag.

Here is a comparison of two very similar tunes with and without the mod and shows how much more uniform the mod makes the string:



Here is a top view of the F.A.M.E mod installed in my Internal DIY SSG setup.  I’ve been using this mod on and off for quite some time now and the differences are very evident to me.  So much so that I don’t want to tune without it.  The nylon spacer on the end of the bolt is not part of the F.A.M.E mod but is another mod I added to the DIY SSG to reduce rebound noise from the bolt hitting the gap adjuster.



Here is more details and the parts needed to do the mod:



Here is the mod to the breech needed to clear space for the washer to slide.  You only need to remove just enough of the slot to allow for the thickness and width of the washer used.




If you’re just curious is to how much drag reduction this will give you, you can do a quick test by installing the 1/4” tubing and washer to the hammer lug, tuning it correctly and running your hammer back and forth to feel the difference it makes before trimming the breech.  I think you will be pleasantly surprised at the difference as I was when testing it for the first time.

[PBguns]

New F.A.M.E mod by 22synrodn/triggertreat:

In my view, the biggest problem with the mechanics of the Marauder and other similar guns is hammer drag.  I’ve been trying to find a better way to limit this drag in my DIY SSG and have found a simple, DIY way to do this and have decided to share my idea with others.

I introduce to you the F.A.M.E mod which stands for Friction Assist Marauder Enhancement.

My idea lifts the rear of the hammer up and off the air tube which drastically reduces the friction/drag between the two.  I find my strings are more uniform and the cocking effort much easier and smoother.  Also dirt and dust does not affect the hammer nearly as much or as often.  My ES and SD numbers have dropped a considerable amount as well.
You can hone the air tube and polish the hammer but still can’t eliminate as much drag as this mod can.  The washer sliding on the top of the air tube has far less friction than the hammer to air tube friction.  The 1/4" tubing keeps the hammer centered and off the sides of the metal slot further reducing drag.

Here is a comparison of two very similar tunes with and without the mod and shows how much more uniform the mod makes the string:



Here is a top view of the F.A.M.E mod installed in my Internal DIY SSG setup.  I’ve been using this mod on and off for quite some time now and the differences are very evident to me.  So much so that I don’t want to tune without it.  The nylon spacer on the end of the bolt is not part of the F.A.M.E mod but is another mod I added to the DIY SSG to reduce rebound noise from the bolt hitting the gap adjuster.



Here is more details and the parts needed to do the mod:



Here is the mod to the breech needed to clear space for the washer to slide.  Although it works just fine, I butchered mine and look forward to a redo when my new breech arrives in a few days.  You only need to remove just enough of the slot to allow for the thickness and width of the washer used.




If you’re just curious is to how much drag reduction this will give you, you can do a quick test by installing the 1/4” tubing and washer to the hammer lug, tuning it correctly and running your hammer back and forth to feel the difference it makes before trimming the breech.  I think you will be pleasantly surprised at the difference as I was when testing it for the first time.

Interesting idea.
I had that very problem...(rear bottom of hammer galling aginst the main tube in my .25).
I ended up after lots of work on the tube and OEM hammer, just making a LW hammer. Glad I did....(getting a nice shot count and low ES).
That seems like it would be a great way to combat the problem, nice work.

[rsterne]

Interesting mod.... Certainly answers the question about what is causing the zig-zag pattern in shot strings.... it's friction, changing the hammer velocity a whisker....

Bob

[triggertreat]

Yes Mike (PBguns), you want have any issues with galling with this mod as it eliminates that issue.  Your comments also brings up something else I did not mention about this mod which is, for those power hungry shooters, you can increase the spring rating and still keep a decent and smooth cocking effort.

Bob (rsterne), it does smooth out the string with not having the varying resistance on the hammer slide.  I really enjoy tuning with it and can't wait to tune my new Jim Gaska HF barrel with it and the DIY SSG combo.  Pushing pellets through the HF barrel, I can tell it's going to be awesome, but really wanted your barrel after reading about it.  I didn't know how to order it.  Thanks again for pioneering the SSG!  I don't see myself shooting the Marauder without it and the F.A.M.E. mod currently.

[triggertreat]

Breech modification needed for new F.A.M.E mod.

[MichaelM]

I think this is a marvelous idea...  The only change I can think of is to swap out the steel washer for a brass or even bronze washer....  The lubricity (is that a word???)  of brass or bronze is far better then steel which should smooth it out even more and being the brass is softer only the washer should wear instead of both the washer and tube causing problems further on down the line.... 


I don't have time to test it out right now but you can bet I will very soon!!!  Honestly you should make a separate post for this as it deserves its own thread

[triggertreat]

I think this is a marvelous idea...  The only change I can think of is to swap out the steel washer for a brass or even bronze washer....  The lubricity (is that a word???)  of brass or bronze is far better then steel which should smooth it out even more and being the brass is softer only the washer should wear instead of both the washer and tube causing problems further on down the line.... 


I don't have time to test it out right now but you can bet I will very soon!!!  Honestly you should make a separate post for this as it deserves its own thread

Thanks it does work well.  I had someone else recommending those two metals instead on another forum.  Might just have to try those out.  The steel has worked well and slides really smooth and I haven't seen any wear after 1000 shots, but the slicker the better.

Maybe I should create another separate post for this one because it will work on other guns like the Prod or discovery I'm sure.  I just put it here to go along with the DIY SSG I created.  Thanks again and let me know what you think if you try it.

[Royce Hesley]

I'm wondering if the "Old school buttons" sold by Jim Maccari, applied to the hammer, would do the trick without modifying the receiver. I have some I bought years ago when trying to get a Tech Force springer to shoot well. Maybe I'll dig them out and give it a try.

[triggertreat]

I'm wondering if the "Old school buttons" sold by Jim Maccari, applied to the hammer, would do the trick without modifying the receiver. I have some I bought years ago when trying to get a Tech Force springer to shoot well. Maybe I'll dig them out and give it a try.

Not a bad idea if you could get the correct fit.  I've played around with grilling foil with Teflon and thin plastic too, but just briefly.  It's a tight fit.   The F.A.M.E. mod is really working well.  Here's my latest hunting tune with it and the DIY SSG:

[rsterne]

Here is Steve in NC's excuse on the Yellow for changing the name of his SSG to an FFH.... He is reinterpreting what transpired....

http://www.network54.com/Forum/79537/message/1468510266/A+quick+comment+on+the+terms+%26quot%3BSSG%26quot%3B+and+%26quot%3BFFH.%26quot%3B++In+late+January+of+this+year...

In actual fact, I contacted him regarding the SSG only to request that since he was making a commercial version, and did so without first having the courtesy to ask my permission (which would have been freely given), that he at least continue to acknowledge my pioneering of the idea.... He originally recognized that, but once it went commercial, he no longer even mentioned me.... Never did I ask him not to use the term SSG, I only asked him to continue to acknowledge where he got the concept.... He had already changed the name of his product to the FFH before I ever contacted him.... I would assume so that he could justify ignoring my development of the concept....

There is no question where he got the idea, he freely admitted it.... He has recently begun to mention me again, I have no idea way, perhaps he is getting flack (or feeling guilty) for not recognizing my contribution in developing the SSG.... However, it is unacceptable to try to rewrite history to suit himself, IMO.... I could care less what he calls his commercial version.... but IMO, just changing the name doesn't erase where he got the idea from.... BTW, I never asked for a dime.... and I never implied in any way that I had a copyright over the idea, or the name SSG, or even that I invented it.... All I asked for was recognition for developing the idea into a useful method for increasing the efficiency of PCPs.... I guess this may be his way of doing that, while trying to explain away the name change to FFH.... 

Bob

[ezman604]

Imagine that....not the first time.
GREAT job and contribution Bob.
Too bad some folks can't give the proper respect or credit for other's contributions!!!!

[bnowlin]

Wow guys he's always had ba$$s for that sort of thing,  Bob keep up the GREAT stuff that you put out for us.
Bob The other one