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

[Pellgunfun]

Hey Keith,

I like your shot string analyzer.  Where did ya get it?

[Sfttailrdr46]

  Ok shot my first string over the chrony 786 to 789fps from 3000 psi fill I have not opened the air  restrictor all the way it is still at the factory setting with the screw backed all the way open what can i expect to see for velocity increase the SSG rom WAR is set to his recommended pre set. also installed the WAR NBH so I am seeing 46 FPE as is but I would like to get closer to 900 FPS is that realistic or not? Also like the accuracy from these JSB Match Diablo 33.95 Heavy pellets

Right now I am looking for some advice from the Mavens

[triggertreat]

Finalized my internal DIY SSG build.  I find this one to be the best setup and really works well.  For more details, look me up on the MarauderAirRifle.com forum under 22 cal Internal DIY SSG/FFH thread (22synrodn).

[Buldawg76]

Finalized my internal DIY SSG build.  I find this one to be the best setup and really works well.  For more details, look me up on the MarauderAirRifle.com forum under 22 cal Internal DIY SSG/FFH thread (22synrodn).

Keith

How long is the 1/4-20 SS bolt you are using in the SSG. Why did you cut a groove in the nylon washer that fit inside hammer and is it a radial groove for the spring or actually slots to prevent spring from rotating in nylon bushing for adjusting.

I like the idea and execution of design.

Mike

[triggertreat]

Finalized my internal DIY SSG build.  I find this one to be the best setup and really works well.  For more details, look me up on the MarauderAirRifle.com forum under 22 cal Internal DIY SSG/FFH thread (22synrodn).

Keith

How long is the 1/4-20 SS bolt you are using in the SSG. Why did you cut a groove in the nylon washer that fit inside hammer and is it a radial groove for the spring or actually slots to prevent spring from rotating in nylon bushing for adjusting.

I like the idea and execution of design.

Mike

Thanks Mike.  The bolt is 2.5" long.  The grooves were cut in the nylon spacer with the edge of a file so the spring would grip it when adjusting the spring tension.  This eliminates the o-ring needed in the previous design and also the steel sleeve.  I did bend the end of the spring out a little to ensure it grips good.  Works really well.  Make the grooves prior to inserting into the hammer because the spacer is a tight fit.  Make sure the hole in the spacer has a close tolerance to the bolt.  I used a used 1/4" drill bit and checked before inserting it.  I used the head of the bolt with a nut on the end to protect it when hammering it in.





I threaded in a nylon bolt into the head of the bolt to reduce the noise of the metal bolt hitting the valve stem.  I've shot close to 300 rounds with it and it's holding up very well with no signs of damage.

[Buldawg76]

Keith
I like a lot and of all the different versions I have seen in this thread I like yours the best for the Mrods and I shoot field target with my 177 mrod amnd this is the perfect mod to lower my 20 fps spread and increase my shot count as well.

I think I can get under 10 fps spread and over 50 shots per fill easy since I have it set now at 20 fps spread and 45 shots per fill from 3000 psi down to 2200 psi .

Got a big match in June and will have it installed and tuned by then for sure.

Thanks Mike

[mobilemail]

If you can get sub-10fps across a flat 50-shot string, that would be a great option to the expense of a regulator. My NBH Mrod .177 is shooting 17fpe, 67 shots within 3% (about 25fps).

[triggertreat]

Keith
I like a lot and of all the different versions I have seen in this thread I like yours the best for the Mrods and I shoot field target with my 177 mrod amnd this is the perfect mod to lower my 20 fps spread and increase my shot count as well.

I think I can get under 10 fps spread and over 50 shots per fill easy since I have it set now at 20 fps spread and 45 shots per fill from 3000 psi down to 2200 psi .

Got a big match in June and will have it installed and tuned by then for sure.

Thanks Mike

Thanks Mike!  Sorry to have put you and others through all the different versions, but I wanted to test all the ideas I had in my head some I never posted about.  The ACE spring, although it worked, was causing me grief and I did not want any o-rings to worry about.  This version should hold up for a very long time.

[triggertreat]

If you can get sub-10fps across a flat 50-shot string, that would be a great option to the expense of a regulator. My NBH Mrod .177 is shooting 17fpe, 67 shots within 3% (about 25fps).

Sub-10fps could be possible, but I want make any claims.  I tune for hunting and the higher fps you go the less likely you'll get sub-10 fps, but still should be very decent.  With a low powered tune you just may be able to if everything in the gun is slick and consistent.

I just finished putting triple oil on my deck (shooting platform) and once it is ready for traffic and I get a break, I'll be able to do a proper tune and will post on how well it does.  Preliminary test looks real good.  My goal is 30-40 shots with a 850 fps average and as low an ES as it will give me.  Stay tuned...

[Buldawg76]

If you can get sub-10fps across a flat 50-shot string, that would be a great option to the expense of a regulator. My NBH Mrod .177 is shooting 17fpe, 67 shots within 3% (about 25fps).

Mark
Right now I am shooting JSB 10.34s at 880 to 900 fps/18.5 fpe for 45 shots with every once in a while if the wind is calm I can get another 5 to hit the same POI. I think the SSG will allow me to tighten the spread up at least 10 fps and likely go over the 50 shots I am after and if I get close to the 67 you are getting even better.

Our monthly matches are 48 shots so wanting to shoot a match without having to fill and we have a sanctioned match in June that will be 60 shots per day so if I can get that on one fill as well would be a big plus indeed.

Does sound promising.

Mike

[Buldawg76]

If you can get sub-10fps across a flat 50-shot string, that would be a great option to the expense of a regulator. My NBH Mrod .177 is shooting 17fpe, 67 shots within 3% (about 25fps).

Sub-10fps could be possible, but I want make any claims.  I tune for hunting and the higher fps you go the less likely you'll get sub-10 fps, but still should be very decent.  With a low powered tune you just may be able to if everything in the gun is slick and consistent.

I just finished putting triple oil on my deck (shooting platform) and once it is ready for traffic and I get a break, I'll be able to do a proper tune and will post on how well it does.  Preliminary test looks real good.  My goal is 30-40 shots with a 850 fps average and as low an ES as it will give me.  Stay tuned...

Keith

I have my 22 and 25 for hunting so my 177 is for field target work so I am after average of 890 fps with as close to that for a 60 shot string at minimum and more if better using JSB 10.34s. I am tuned for 880 to 900 fps now with it for 45 good shots and 50 on good days so I think the SSG will give me that extra ten plus shots as well as tighten up the spread.

Got the parts list ready to go shopping tomorrow so will soon see how it does.

Mike

[triggertreat]

Keith
I like a lot and of all the different versions I have seen in this thread I like yours the best for the Mrods and I shoot field target with my 177 mrod amnd this is the perfect mod to lower my 20 fps spread and increase my shot count as well.

I think I can get under 10 fps spread and over 50 shots per fill easy since I have it set now at 20 fps spread and 45 shots per fill from 3000 psi down to 2200 psi .

Got a big match in June and will have it installed and tuned by then for sure.

Thanks Mike

[triggertreat]

If you can get sub-10fps across a flat 50-shot string, that would be a great option to the expense of a regulator. My NBH Mrod .177 is shooting 17fpe, 67 shots within 3% (about 25fps).

Sub-10fps could be possible, but I want make any claims.  I tune for hunting and the higher fps you go the less likely you'll get sub-10 fps, but still should be very decent.  With a low powered tune you just may be able to if everything in the gun is slick and consistent.

I just finished putting triple oil on my deck (shooting platform) and once it is ready for traffic and I get a break, I'll be able to do a proper tune and will post on how well it does.  Preliminary test looks real good.  My goal is 30-40 shots with a 850 fps average and as low an ES as it will give me.  Stay tuned...

Keith

I have my 22 and 25 for hunting so my 177 is for field target work so I am after average of 890 fps with as close to that for a 60 shot string at minimum and more if better using JSB 10.34s. I am tuned for 880 to 900 fps now with it for 45 good shots and 50 on good days so I think the SSG will give me that extra ten plus shots as well as tighten up the spread.

Got the parts list ready to go shopping tomorrow so will soon see how it does.

Mike

Mike, that's some impressive numbers for a guy like me.  I only shoot the H&N Barracuda Match 21.14gn pellets.  I would run out of air way before I hit those numbers and shot count Lol.  If your gun is shooting efficiently the SSG wont do to much, but if not the SSG will expose the inefficiency.  Good luck and would love to see a post of your before and after results.  You should hear a reduction in the report with the SSG if your wasting air now.

[triggertreat]

Trigger fixed and new tune done.  I lowered the peak down to 860 fps as mentioned previously.  I was able to gain more shots within 4% ES.  This is the comparison from the last string H&N 09:



This is an analysis with 40 shots.  I like the 2.32% ES for 40 shots with a 2900 psi fill better:





And here is the string analyzed for 4%:



No sub-10, but works for me.  This was the first tune with the new and finalized SSG build which includes a new hammer and parts.  I'm hopeful that after a break in period it may even get better.

Just to be clear, this is the DIY SSG build that was used for these strings:

[Buldawg76]

Keith
That 20 fps spread in test 10 is nothing to complain about and 40 shots is doing real good in 22 caliber as you have to remember you are using at least 1/3 more air per shot than my 177 is so I think you have it doing very well and would be more than happy with those numbers. You may want play with the air screw adjustment to see if you can tighten the spread up a bit closer and still stay in the velocity range your at and should gain a few more shots as well since you will be using a bit les air per shot.

It only takes an 1/8 of a turn on the air screw to make a big difference and wide open is five turns out from fully seated lightly so you have a range of five turns from fully closed to fully open to play with. My 177 is at 1 7/8 turn out from fully seated and five turns in on hammer spring preload with the stroke adjustment at fully CCW or maximum hammer travel.

Mike

[triggertreat]

Thanks Mike, I do have the VMS at full open (6 turns out).  I also have the TP drilled out to 0.141.  If I put the stock TP back in that might do the trick as well, but will try to close the VMS down some without lowering the peak.

[Buldawg76]

Keith
The nice thing is you can always go back to where you have it now so it does not hurt to adjust and see what you get. You say you drilled out the TP port to .141" and  that's the same size as a 25 caliber TP port and if so did you open the port in the valve itself to the same size and the barrel as well. If not then you are just creating a expansion chamber of sorts in the TP port as it still get choked at the barrel.

The 177s and 22 share the same TP sizes as well as valves and barrel ports so the bigger TP port could be creating some turbulence and issues in air flow. I don't think it would be enough to make much difference though and you should see a difference with the VMS adjustments.

Mike

[triggertreat]

Keith
The nice thing is you can always go back to where you have it now so it does not hurt to adjust and see what you get. You say you drilled out the TP port to .141" and  that's the same size as a 25 caliber TP port and if so did you open the port in the valve itself to the same size and the barrel as well. If not then you are just creating a expansion chamber of sorts in the TP port as it still get choked at the barrel.

The 177s and 22 share the same TP sizes as well as valves and barrel ports so the bigger TP port could be creating some turbulence and issues in air flow. I don't think it would be enough to make much difference though and you should see a difference with the VMS adjustments.

Mike

No I only drilled the sleeve.  The valve and barrel remain stock.  I was thinking the sleeve was causing some restriction itself based on some forum reading.  I ordered a spare sleeve to drill so I still have the stock sleeve.  I've thought about the turbulence issue but wasn't sure.  Thanks for the input.

[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

[triggertreat]

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.