GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Nvreloader on December 25, 2018, 01:15:57 PM
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Guys
I am starting this post for those that may choose to use these flat wire springs for SSG use.
If you use a spring of this type, please include the OEM spec's of your spring,
so we can have a data base for use, for other that follow etc.
Flat Wire springs.
Brand name: Sig Sauer, sp#1911033-R
OEM overall length: 5-7/8" with 35 coils,
Spring Outside diameter: .418"
Spring Inside diameter: .265"
Wire size: 0.026" thick by 0.072" wide
OEM Poundage rating: 18#'s
Brand name: Wilson unk number, lost OEM package,
OEM overall length: 5-3/4" with 36 coils,
Spring Outside diameter: .430"
Spring Inside diameter: .250"
Wire size: 0.028" thick by 0.074" wide
Coil bound at 1.030"
OEM Poundage rating: 17,18 & 20 #'s
SSG design: From this posts info by Bob,
https://www.gatewaytoairguns.org/GTA/index.php?topic=102095.340, (https://www.gatewaytoairguns.org/GTA/index.php?topic=102095.340,)
See post #355 for designs, or your own designed SSG etc.
Your information on how this spring worked, good, bad or otherwise, in your build,
please include make/model,caliber of the air rifle used, and operating spec's etc.
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QB-79 22 cal, 1500 psi Reg set point, 3000psi tethered,
5 shot av,
14.3 gr = 1007 fps av,
15.8 gr = 984 fps av,
18.1 gr = 947 fps av,
21.1 gr = 901 fps av,
25.3 gr = 846 fps av,
Specs/info on my setup,
81 cc plenum (cut down Disco tube, 18-5/8" long),
Valve intake hole - .210" dia, valve exhaust hole - .203" dia, Receiver TP hole -.203", bbl TP hole -.170" dia,
.310" dia, Delron poppet head tapered w/flat faced poppet face/seat, OEM poppet spring.
Poly hose TP seal .225" O/S x .200" I/S x .230" long, 20" bbl.
Jason Mini valve, cut down to within .050" of the washer, sides milled flat and opened to .375" slots.
OEM hammer, total weight+cocking pin =725.0 grains.
SSG set at max, Gippeto's style of SSG, #4,
Flat hammer spring rated at 18#'s, length of 4.250" long, .430" O/S dia with a .250" I/S hole dia,
Reg SP 1500 psi, tethered 3000 psi.
I sure do like the very light cocking effort of this 18# flat spring,
it does provide a great latitude for tuning, with more power than the OEM set up etc.
Don
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Specs on two flat wire handgun recoil springs used for SSGs:
Wilson Combat - 1911 Flat-Wire Recoil Spring - 5" Full-Size - 24LB (using recoil spring method of measure)
OD: 0.415"
ID: 0.268"
Wire size: 0.028" thick by 0.074" wide
Number of coils: 36
Free Length: 6.95"
Coil bind length: 1.01"
Spring rate: 3.5 lb/inch
Note: after being cocked 20 times the length set to 6.45 and the spring rate dropped to 3.4 lb/inch
Glock Compacts G19, 23, 32, 38 Flat-Wire Recoil Spring - 22LB (using recoil spring method of measure)
OD: 0.415"
ID: 0.268"
Wire size: 0.028" thick by 0.074" wide
Number of coils: 30
Free Length: 5.75"
Coil bind length: 0.84"
Spring rate: 4.1 lb/inch
Note: after being cocked 20 times the length set to 5.41 and the spring rate dropped to 4.0 lb/inch
The above springs worked great on an SSG in a Big Bore QB 357 build. the Glock spring was cut in half and used in combination with the full length 1911 spring - combined free spring length was 9.4" compressed into 2.7" on the SSG. This allows a high initial cocking force (15 lbs) without having too high of a final force (17 lb) at the end of the cocking stroke. The result is a high average force during the 1.0" hammer stroke to enable this 200 ft-lb Big Bore.
Specs on the Big Bore build: QB78 starter rifle, 24" TJs .357 cal 1:26" twist barrel, 3000 psi custom tube, 0.28" porting, 188 cc plenum, N.O.E. 360-152-SWC (cast weight is 152 grains), 3+1 hunting tune is 784-782-770 fps for an average of 205 ft-lb at 2% ES (starting pressure is 2900 psi).
When using the flat wire springs as discussed above, the overall cocking effort was reduced from 28 lb for round music-wire springs to 17 lbs using the flat wire spring. A large reduction in stress on the trigger/sear assembly and the cocking finger!
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I am copying my post from another thread for those that are considering using a handgun recoil spring for an SSG. Hope this helps:
One thing I initially found confusing was the method used to describe spring stiffness by the handgun community. The "pound" rating used for automatic handgun recoil springs is different than the "spring rate" used by spring manufactures.
Handgun recoil springs are measured by the pound force generated when the spring is compressed into the full recoil position for a particular model of handgun. For example: the full recoil position for a Colt 1911 G.M. is about 1.6", so the recoil spring for this model is measured when the spring is compressed to a height of 1.6". The rating is specific to each model of automatic handgun.
On the other hand, spring manufactures rate springs by pounds of forces generated per length of compression. So that a 10 lb/in spring gains 10 pounds of force for every inch the spring is compressed.
The result is that if you typically order springs by "spring rate" from say Century or Grainger, and you order a handgun recoil spring thinking that the "pound" stated is a typical "spring rate", you will get a very different spring. For example: the 24 pound Colt 1911 G.M. recoil spring that I just used in an SSG had a spring rate 3.5 lb/in - which turned out perfect in an SSG because the spring length was 7".
One other note: handgun recoil springs come in round and flat wire. If you want flat wire, make sure it is in the description or contact seller to confirm.
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OK, so I'll bite...
I ordered a Wilson Combat spring, the 5" full sized 24lb spring.
I would like to replace a QB78 hammer spring that is used in my Type 4 SSG. It is in a .25 Gauntlet and currently tuned for 57fpe.
Here is a pic of the Wilson Combat spring, my SSG and a spare QB hammer spring.
(http://i68.tinypic.com/dwdy84.jpg)
The way the SSG works is preload is adjusted by turning the nylon locknut. Gap is adjusted by loosening the rear jam nut and screwing the threaded rod/spring guide in/out of the 10/32 threaded rod coupler, which is attached to the end cap. The brass tube is serving as a bushing, yielding almost a press fit into the Crosman end cap. A short 8/32 setscrew is in the bottom of one of the 8/32 holes in the end cap, and screws against a dimple machined in the 10/32 threaded rod coupler, firmly retaining the SSG in the end cap.
This SSG is a variation of my KISS SSG, but without any external adjustment capability.
The current spring is .0470 wire and .3410 OD. it is 2.3" long at rest. Currently it is preloaded to 1.685". This, coupled with a 35gram hammer/pin assembly and about a .080 gap is yielding 57fpe.
I would like to replace the coil spring with the flat spring so I can see what all the rage is and so I can share in the information base.
My question is how many coils of Wilson Combat 28lb spring should I start with?
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I ended up going with 16 coils, approximately 3" as this was a little longer than my spring guide and required a bit of compression to get the preload nut started. I dialed max preload, which with the coil spring wasn't possible due to coil bind. Test shots were well over 900fps. So plenty of preload capability for this tune. I dialed it back to 875fps and ended up with a 1.6" compressed length.
I have to admit that it is a bit easier to cock significantly easier to cock with the flat spring.
Helpful hint to anyone wanting to try this----start with much longer spring than you think you will need. I initially started with a spring equal in length to my QB spring and it was nowhere near enough preload. If I had it to do over again I would likely start with at least 4" of uncompressed spring.
(http://i63.tinypic.com/352g2ro.jpg)
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Thread information is inaccurate. I ordered a flat wire spring to test next to my current 5 lb spring. You need to use the thickest wire of the spring to determine these spring ratings there is absolutely no way these springs are 3 to 5 lbs an inch even full length. Cutting them down to any decreased length increases rating. FWIW my calculations put the 22 lb glock spring right at 22lbs.
Next to a 15 lb spring the glock recoil spring is much harder to compress. Also at full length it takes the calculated 22 plus lbs to compress the spring 1 inch.
I'll have to just resell this glock spring or offer it for free to another member to confirm my findings. I got the flat wire glock gl 22lb. PM me if you wanna try it and are willing to measure rating and contribute to this thread.
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Thread information is inaccurate. I ordered a flat wire spring to test next to my current 5 lb spring. You need to use the thickest wire of the spring to determine these spring ratings there is absolutely no way these springs are 3 to 5 lbs an inch even full length. Cutting them down to any decreased length increases rating. FWIW my calculations put the 22 lb glock spring right at 22lbs.
Next to a 15 lb spring the glock recoil spring is much harder to compress. Also at full length it takes the calculated 22 plus lbs to compress the spring 1 inch.
I'll have to just resell this glock spring or offer it for free to another member to confirm my findings. I got the flat wire glock gl 22lb. PM me if you wanna try it and are willing to measure rating and contribute to this thread.
Can you please clarify your blanket statement of "thread information is inaccurate"?
The results I posted above are simply a report out of my experience in this one application.
I will also add after a few dozen rounds I would like to amend my statement from "a bit easier to cock" to "significantly easier to cock."
I have one more 50fpe+ gun that will get this same hammer spring.
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How I calculated spring wire od. Spring wire od width + spring wire od height * spring od width to height ratio which is generally 70% on flatwire which puts the spring wire od average at .069", with that number I get 22 lbs an inch. Fwiw
If I am wrong I apologize but my calculations and tests on the spring in hand both conclude the same.
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How I calculated spring wire od. Spring wire od width + spring wire od height * spring od width to height ratio which is generally 70% on flatwire which puts the spring wire od average at .069", with that number I get 22 lbs an inch. Fwiw
If I am wrong I apologize but my calculations and tests on the spring in hand both conclude the same.
I see what you are saying. I have no idea on the calculations. Thank you for the clarification.
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Guys
On the 1911 recoil system, it is rated via the spring pressure rating, ie; 11 thru 24 #'s,
this is the amount of force required to arrest the slide after full recoil, from whatever load, and not batter the frame etc,
and still slam the slide forward to feed the rounds for the mags, and lock up securely,
and is tuned to the recoil level of the loads being used etc.
I do know that if you use a too strong a recoil spring in a 1911 type system,
you will have a single shot, with the casing still in the chamber or smoke stacked,
as I learned from my 3 Coonan 357 Mag pistols.
When I was tuning these pistols, Wolf brand recoil spring, made a Vari-Rate springs,
was soft (poundage wise) and then got harder (poundage wise) with more compression etc.
I do not know if they are still available.
FWIW,
I used Wilson 17 & 18 # flat wire spring on my QB with the #4 SSG, (Gippeto's design),
after testing, both springs came out to 4-1/4" long, uncompressed.
These full length springs go coil bound around 1.030".....
The reason is the OEM 79 QB round coil spring is rated at approximately 17 #'s.
IMHO, I would start with the longest length possible that would not go coil bound,
for the length you can use on/with the SSG design, you are using, as there is several designs,
since these flat springs have an I/S diameter of .250/.260", my rod diameter was .240" polished etc.
You can always cut shorter, but not make longer, without using a new spring. LOL
I have not calculated the poundage of these flat springs, so I am unsure of the results etc.
YMMV,
Tia,
Don
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I'm just referring to sbrowers spring rating calculation. The springs ratings are correct in the first post NVR. I wanted to make the spring rating clear before anyone else made the same mistake as me thinking these were 3.5 to 4lb/in springs. To my knowledge no 4 lb spring exists with a max load over 17 lbs.
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Thanks Guys
I am not sure how to test these springs etc.
I was hoping that Bob would jump in here and educate me,
as I am still learning the ropes for air rifle tuning etc. ;D
What I have learned so far,
is start as long as possible, then clip a couple of coils and retry etc, with these flat springs.
And the end result is better, IMHO.
Just one more step to a better mouse trap. LOL
Tia,
Don
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Mike
I would check that flat spring and see where it goes coil bound at.
From that length, you can come real close to the length needed for your SSG, as a starting point,
I would error on the long side, and then cut a couple of coils and do a dry test, repeat until the end results are feeling/looking good.
I have never used a 24/28# spring, just the lighter weights and started longer and worked shorter.
Sorry, I don't have a correct/good answer for you, YOU are the Ginny Pig, now. LOL
Tia,
Don
OK, so I'll bite...
I ordered a Wilson Combat spring, the 5" full sized 24lb spring.
I would like to replace a QB78 hammer spring that is used in my Type 4 SSG. It is in a .25 Gauntlet and currently tuned for 57fpe.
Here is a pic of the Wilson Combat spring, my SSG and a spare QB hammer spring.
(http://i68.tinypic.com/dwdy84.jpg)
The way the SSG works is preload is adjusted by turning the nylon locknut. Gap is adjusted by loosening the rear jam nut and screwing the threaded rod/spring guide in/out of the 10/32 threaded rod coupler, which is attached to the end cap. The brass tube is serving as a bushing, yielding almost a press fit into the Crosman end cap. A short 8/32 setscrew is in the bottom of one of the 8/32 holes in the end cap, and screws against a dimple machined in the 10/32 threaded rod coupler, firmly retaining the SSG in the end cap.
This SSG is a variation of my KISS SSG, but without any external adjustment capability.
The current spring is .0470 wire and .3410 OD. it is 2.3" long at rest. Currently it is preloaded to 1.685". This, coupled with a 35gram hammer/pin assembly and about a .080 gap is yielding 57fpe.
I would like to replace the coil spring with the flat spring so I can see what all the rage is and so I can share in the information base.
My question is how many coils of Wilson Combat 28lb spring should I start with?
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Mike
I would check that flat spring and see where it goes coil bound at.
From that length, you can come real close to the length needed for your SSG, as a starting point,
I would error on the long side, and then cut a couple of coils and do a dry test, repeat until the end results are feeling/looking good.
I have never used a 24/28# spring, just the lighter weights and started longer and worked shorter.
Sorry, I don't have a correct/good answer for you, YOU are the Ginny Pig, now. LOL
Tia,
Don
OK, so I'll bite...
I ordered a Wilson Combat spring, the 5" full sized 24lb spring.
I would like to replace a QB78 hammer spring that is used in my Type 4 SSG. It is in a .25 Gauntlet and currently tuned for 57fpe.
Here is a pic of the Wilson Combat spring, my SSG and a spare QB hammer spring.
(http://i68.tinypic.com/dwdy84.jpg)
The way the SSG works is preload is adjusted by turning the nylon locknut. Gap is adjusted by loosening the rear jam nut and screwing the threaded rod/spring guide in/out of the 10/32 threaded rod coupler, which is attached to the end cap. The brass tube is serving as a bushing, yielding almost a press fit into the Crosman end cap. A short 8/32 setscrew is in the bottom of one of the 8/32 holes in the end cap, and screws against a dimple machined in the 10/32 threaded rod coupler, firmly retaining the SSG in the end cap.
This SSG is a variation of my KISS SSG, but without any external adjustment capability.
The current spring is .0470 wire and .3410 OD. it is 2.3" long at rest. Currently it is preloaded to 1.685". This, coupled with a 35gram hammer/pin assembly and about a .080 gap is yielding 57fpe.
I would like to replace the coil spring with the flat spring so I can see what all the rage is and so I can share in the information base.
My question is how many coils of Wilson Combat 28lb spring should I start with?
As often happens, I didn't wait for an answer...I cut it too short, then cut again and it worked, but again almost too short LOL....
Thank you for promoting this type of spring, it definitely helps with reducing cocking effort on my 50+fpe guns.
I only wish they made a flat spring that was smaller OD, but still 15+lb....
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Mike
Check the flat spring selections for the different models/makes of pistols,
then ask the supplier the spec's of the springs, they should reply back,
there is a lot of different makes/models of pistols.
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2505460.m570.l1311.R3.TR5.TRC0.A0.H1.Xflat%20spring.TRS0&_nkw=flat%20wire%20recoil%20spring&_sacat=0#item25e315f88e (https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2505460.m570.l1311.R3.TR5.TRC0.A0.H1.Xflat%20spring.TRS0&_nkw=flat%20wire%20recoil%20spring&_sacat=0#item25e315f88e)
As for cutting too short, just add a thin flat washer between the cut off coils.........LOL
Don't ask how I know and you second behind me.......... ;)
My googlefu is not strong.......LOL
HTH's,
Tia,
Don
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Thread information is inaccurate. I ordered a flat wire spring to test next to my current 5 lb spring. You need to use the thickest wire of the spring to determine these spring ratings there is absolutely no way these springs are 3 to 5 lbs an inch even full length. Cutting them down to any decreased length increases rating. FWIW my calculations put the 22 lb glock spring right at 22lbs.
Next to a 15 lb spring the glock recoil spring is much harder to compress. Also at full length it takes the calculated 22 plus lbs to compress the spring 1 inch.
I'll have to just resell this glock spring or offer it for free to another member to confirm my findings. I got the flat wire glock gl 22lb. PM me if you wanna try it and are willing to measure rating and contribute to this thread.
Negatory ghost rider, no way you got 22lbs out of one inch of compression. But if you did ill be more than happy to take it off your hands and give it a go
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PikeP, I apologize if my description (reply #1) of spring rate for the flat wire handgun recoil springs was not helpful. The posted spring rates were measured, not calculated. The spring rate was measured by compressing the spring one inch and measuring the pound-force with a digital scale.
I do not want to distract from the practical information that Nvreloader is posting on how to use these springs in an SSG but will provide an example of the difference between conventional spring rate (lb/in) and spring poundage as used for handgun recoil springs.
Heres an example with round numbers so the math is easy: a 20# recoil spring intended to be installed in a handgun at a full recoil length of 2 inches, it has a free length of 6 inches. The spring rate in lb/in can be directly measured by compressing the spring one inch on a digital scale. The scale should read 5 pounds at this point (one inch of compression). It is a 5 lb/in spring.
Continue to compress the spring on the scale. At 2 inches the scale should read 10 lb. (2 inches x 5 lb/in), at 3 inches it should read 15 pounds, and at 4 inches it should read 20 pounds. This recoil spring would be described as a 20# spring, because that is the force required to compress the spring 4 inches (6-inch free length, compressed into full recoil position at 2 inches).
Knowing the actual spring rate was critical for my QB big-bore build I was trying to cram as much spring energy as I could into a limit space, while trying to reduce peak cocking effort. The long flat-wire spring was just the ticket.
If your build is more typical to a 22/25 cal., then the instructions provided above by Nvreloader/Mackeral5 are great, dont worry about the spring rate, just start long and slowly trim length while testing in the gun to be sure you do not over trim.
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Sbrower
Thank you for that info,
If I can ask, can you give the spec's of your big bore build, SSG type, hammer spec's, flat spring used, psi that you are running etc.
I am sure this info could help others following behind, using the QB system etc.
I was thinking about a way to measure these flat wire springs rates, so I could provide more useful info,
I may have come up with a system that is fairly simple to use and make, except the digital measuring part.
It is basically a 1/2" diameter copper pipe, with a set of several different lengths, as needed.
Which depends the inside available space, plus the distance to the poppet shaft end.
On the OEM hammer, the total overall length is approx 2" and the inside depth about 1-1/2",
and SSG design you are using, for spring pressure, with the #4 design.
On one end there is a handle with a rod attached into the handle, about 1" long, this rod is approximately .240" diameter,
or what ever size to fit the inside of the flat spring being tested etc.
To use, just slip the spring over the rod, then choose the length of the pipe needed,
place pipe/spring on a scale re zero/balance the scale to read zero.
Place spring inside the pipe and push down on the spring, until handles touches the pipe end, read the results etc.
I don't know if this system will work, have to find a digital scale first.
I do know that these flat springs do work in all aspects with a SSG system #4 design.
I started with an 18# spring rate, then changed to a 17# spring and produced great results for me,
and have lots of room for adjustments for tuning.
I DO NOT know the results of using lighter or heavier spring rates, ultra lite hammers etc,
as that info and results has yet to be tested etc.
(Mackeral5) Mike, is doing a lot of work with a Guantlet, which is very close to the QB,
so I am sure his work and info will be very useful.
The OEM stock spring rate for the QB's are around 17#'s, per Bob's info, and that was my reason for starting with these rates of springs.
On my SSG, the tapped hole thru the end cap is 7/16" x 20 tpi, which is just large enough,
that I can unscrew the center adjustment cap with the adjusting rod/spring,
then take out the adjust rod and change springs etc.
HTH's,
Tia,
Don
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Nvreloader,
Yes, I will give the specs for my QB big bore build in a following post. But first, it looks like we were heading in a similar direction for measuring spring rates.
These pics show the simple setup that I use for compressing a spring on a digital scale, allowing a direct reading of the spring rate in lb/in. I load the spring into the white piece of PEX 1/2 tube. The spring is held inside by the PVC threaded end cap. The 7/16 wooden dowel is then slipped in until touching the spring. A pencil mark is made on the dowel to show 1 inch of compression. Pushing the dowel down on the scale to the 1-inch mark compresses the spring and allows a direct reading of spring rate.
If the spring rate is low enough, I will compress to 2 inches and divide the scale reading by 2. My scale only goes to 11 pounds, so this is not always possible.
I use this same setup to load long springs onto the SSG. The SSG guide rod is slipped into the spring ID and then the spring/SSG are placed into the PEX tube. The dowel is then used to safely compress the spring until the SSG guide rod sticks out through the slot in the PVC end-cap ready for a retaining nut of some sort.
Safety note: whenever working with springs (or any stored energy) always use appropriate protective gear. I use safety glasses or a face shield when compressing springs. Note that the ½ PVC end-cap is too large to thread onto the PEX tube (if you use ½ PVC pipe instead, smaller springs will buckle). I wrap duct tape around the end to increase the OD so that the threads get a bite. Because of this, I do not push on the tube alone, just grip the end-cap when compressing the spring.
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That is exactly how you measure spring rate.
Spring rate is linear as long as wire diameter doesn't change with in the spring and or the ID/OD is different like a progressive spring (cone). So, you can compress it 1/8" and multiply that number by 8 and get Lb/s per inch or a 1/4" and multiply by 4 for Lbs per inch.
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Tim
Here is some info for you, on Vari-rate recoil springs, ;)
From the Wolff Gunsprings site,
https://www.gunsprings.com/index.php?page=FAQ (https://www.gunsprings.com/index.php?page=FAQ)
1. What is the difference between conventional and variable recoil springs?
The difference is both physical and operational. With a conventional spring, all the coils are spaced equally apart, except for the closed ends. In a variable recoil spring the space varies between coils with less space between coils at one end and more space between coils at the other end.
The way the two springs store energy is also different. For example if a conventional recoil spring is compressed 1/2", it might store 1 pound of energy. For every additional 1/2" this spring is compressed it would then store 1 additional pound of energy. When a variable recoil spring is compressed 1/2", it might store 1/4 pound of energy. The next half inch of compression might store 1/2 pound, the next half inch might store 3/4 pound and so on. In other words, a conventional spring stores energy on a straight line and a variable spring stores energy on a curve. If both springs are rated at 16 pounds, they will both store 16 pounds when compressed to the same working length, but the way they get to 16 pounds is different.
Sbrower
Thanks, looks like we are felling our way along this dark rabbit hole, ;)
gives me an Idea....
Tia,
Don
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Nvreloader, Here are the specs you asked about on my QB big bore build as they relate to SSGs and flat wire springs. Sorry for the long post:
General specs: QB78 starter rifle, 24" TJs .357 cal 1:26" twist barrel, 3000 psi custom tube with 188 cc plenum, PEEK poppet, 0.28" port, 0.313 valve throat. With 2900 psi starting fill and 152 grain cast bullets, the 3+1 hunting tune is 784-782-770 fps for an average of 205 ft-lb at 2% ES.
This build is intended for hunting but was initially tuned to a 2100 psi fill because I was hand pumping. At a 2100 psi fill, the rifle produced around 135 ft-lb. This low-pressure setup used the factory hammer (bumped up in weight to 67 grams), and an SSG with conventional 0.049 round music wire. The SSG produced a hammer strike of around 10 in-lb for this low-pressure tune.
The design energy level of this rifle is +200 ft-lb at a 3000 psi fill, so more hammer strike was needed. A heavier custom hammer was made that weighed 116 grams and has a stroke of 1.01. No fancy calcs for this hammer, just the largest one that would fit into the 4.4 of space between the valve stem and the rear tube cap in a QB. The hammer is 0.74 diameter by 3 long. It has a 0.438 diameter by 1.43 deep hole drilled in the end to receive the SSG. When cocked, the forward (muzzle) end of the SSG protrudes into a clearance hole in the hammer that is 0.313 diameter by 1.20 deep. The sliding end of the SSG rides against the shoulder between the smaller and larger diameter holes. The SSG for this hammer has a compressed spring length of 2.7 and a gap 0.025. Pics of the two hammers are show below, factory hammer is the lower one.
I initially used a conventional round music wire spring in the SSG: 0.055 wire, 3.15 long, 18 lb/in spring rate. Crunching the numbers shows this SSG/spring combo yields a hammer strike of about 16 in-lb which was enough for the 3000 psi fill. However, the 26 lb peak cocking force was uncomfortable and the spring began to take a set which cause the rifles energy fall off. When I tried longer, smaller wire springs to reduce the peak cocking force, they became coil bound or did not delivery the needed energy. Enter the flat wire spring.
The flat wire spring allows a long spring to compress into a much smaller stack of coils compared to a round wire spring. This allows a very long spring at a lower spring rate to be compressed on to the SSG without going coil bound. The result in a couple of things: 1) A higher initial cocking force - because a 6 inch spring is being crammed onto a 2.7 SSG, and 2) A lower peak cocking force - because we are only compressing the spring another inch during cocking.
The first flat wire spring tried in this build was for a Glock model 19. The spring was designated as 22# at full recoil (using the handgun rating method). This spring was about 6 long and had a spring rate of 4 lb/in. Crunching the math yields a hammer strike of 12 in-lb, which enabled a fill pressure of 2500 psi. Next a Colt 1911 G.M. spring was tried (24# at full recoil), which turned out to be the same wire as the Glock spring. This Colt spring was 7 long and had a spring rate of 3.5 lb/in. Crunching the math showed that I needed 9.5 of spring to yield the desired energy. So the Glock spring was chopped and added to the SSG along with the full length Colt spring. Total combined length was 9.4 and the spring rate was 2.5 lb/in. This gave the 15 in-lb needed to enable a 3000 psi fill. Peak cocking force is a comfortable 18 lb, a noticable reduction from the 26 lb peak of the equivalent round wire spring.
The assembled SSG is shown in a photo below. Note how many coils were used without the SSG going coil bound. The sliding spring spacer is to keep the two springs from winding into one another.
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Nvreloader, Here are the specs you asked about on my QB big bore build as they relate to SSGs and flat wire springs. Sorry for the long post:
General specs: QB78 starter rifle, 24" TJs .357 cal 1:26" twist barrel, 3000 psi custom tube with 188 cc plenum, PEEK poppet, 0.28" port, 0.313 valve throat. With 2900 psi starting fill and 152 grain cast bullets, the 3+1 hunting tune is 784-782-770 fps for an average of 205 ft-lb at 2% ES.
This build is intended for hunting but was initially tuned to a 2100 psi fill because I was hand pumping. At a 2100 psi fill, the rifle produced around 135 ft-lb. This low-pressure setup used the factory hammer (bumped up in weight to 67 grams), and an SSG with conventional 0.049 round music wire. The SSG produced a hammer strike of around 10 in-lb for this low-pressure tune.
The design energy level of this rifle is +200 ft-lb at a 3000 psi fill, so more hammer strike was needed. A heavier custom hammer was made that weighed 116 grams and has a stroke of 1.01. No fancy calcs for this hammer, just the largest one that would fit into the 4.4 of space between the valve stem and the rear tube cap in a QB. The hammer is 0.74 diameter by 3 long. It has a 0.438 diameter by 1.43 deep hole drilled in the end to receive the SSG. When cocked, the forward (muzzle) end of the SSG protrudes into a clearance hole in the hammer that is 0.313 diameter by 1.20 deep. The sliding end of the SSG rides against the shoulder between the smaller and larger diameter holes. The SSG for this hammer has a compressed spring length of 2.7 and a gap 0.025. Pics of the two hammers are show below, factory hammer is the lower one.
I initially used a conventional round music wire spring in the SSG: 0.055 wire, 3.15 long, 18 lb/in spring rate. Crunching the numbers shows this SSG/spring combo yields a hammer strike of about 16 in-lb which was enough for the 3000 psi fill. However, the 26 lb peak cocking force was uncomfortable and the spring began to take a set which cause the rifles energy fall off. When I tried longer, smaller wire springs to reduce the peak cocking force, they became coil bound or did not delivery the needed energy. Enter the flat wire spring.
The flat wire spring allows a long spring to compress into a much smaller stack of coils compared to a round wire spring. This allows a very long spring at a lower spring rate to be compressed on to the SSG without going coil bound. The result in a couple of things: 1) A higher initial cocking force - because a 6 inch spring is being crammed onto a 2.7 SSG, and 2) A lower peak cocking force - because we are only compressing the spring another inch during cocking.
The first flat wire spring tried in this build was for a Glock model 19. The spring was designated as 22# at full recoil (using the handgun rating method). This spring was about 6 long and had a spring rate of 4 lb/in. Crunching the math yields a hammer strike of 12 in-lb, which enabled a fill pressure of 2500 psi. Next a Colt 1911 G.M. spring was tried (24# at full recoil), which turned out to be the same wire as the Glock spring. This Colt spring was 7 long and had a spring rate of 3.5 lb/in. Crunching the math showed that I needed 9.5 of spring to yield the desired energy. So the Glock spring was chopped and added to the SSG along with the full length Colt spring. Total combined length was 9.4 and the spring rate was 2.5 lb/in. This gave the 15 in-lb needed to enable a 3000 psi fill. Peak cocking force is a comfortable 18 lb, a noticable reduction from the 26 lb peak of the equivalent round wire spring.
The assembled SSG is shown in a photo below. Note how many coils were used without the SSG going coil bound. The sliding spring spacer is to keep the two springs from winding into one another.
Very cool build, thanks for sharing.
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Sbrower
Don't worry about being long winded, it provided lots of info and the photo's were great.
Thank you for providing it.
Questions for you,
What SSG/flat spring adjustment levels did you try, or did you try for max only,
with the OEM or your new hammer?
What do you think of the flat springs for your application?
Would you use them again, if they fit what you are doing using an SSG type 4 design?
Wolff brand 1911 recoil springs have a Vari-rating's, in several rates, might provide other options.
I have used lots of them for my Coonan 357 Mag 1911 style pistols,
with very good results, but they are round coil wire types.
Thanks,
Don
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Don,
Sorry for the delayed reply, but I am winter camping in Arizona and do not have regular internet access. Just a note: Arizona is awesome for air gun hunting!
I did not try to build an adjustable SSG for this QB357. I was struggling to get enough hammer strike, so I built an SSG that utilized all of the available room in the QBs rear tube area - leaving maximum space for the spring so that it did not go coil bound. If I had needed some additional preload, I still had a little space to shim the SSG, but did not end up needing to.
If I were to do the project over, I would change the sear engagement location on the custom hammer to provide a longer cocking stroke. This would allow an even lower peak cocking force for a given hammer/cocking energy.
This QB357 required more hammer strike than could be achieved using conventional round wire springs (at reasonable cocking forces anyway). The flat wire spring used on the SSG as described in the earlier post was the only spring configuration that could store enough energy without becoming coil bound. I will definitively use these flat wire springs in future high-energy builds, or whenever a long spring with a relatively low spring rate is desired to reduce peak cocking force.
Hope this helps...
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Just bringing this post/info back up to the top, and hopefully others will add more info etc.
Since I have a new 22 cal Gauntlet, I'll be using a flat wire spring on the SSG,
I plan to install in it, from the info I have received, the Gauntlet is just a refined QB.
The cocking force on this Gauntlet is Rude, Crude and Sociably unacceptable , or just plain horrible,
it is just about all I can do, to cock it with my bum right hand/wrist,
as soon as the newness wears off, it will get a complete make over, with a SSG installed etc.
Tia,
Don
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Looking forward to your findings Don, and will then STEAL it for my BNM modded Maximus. LOL!!! ;D
Knife
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Knife
You don't have to steal it, I'll give it to you free.......... ;)
From the diagrams I have seen so far,
I think I can get a #4 type SSG in the Gauntlet,
It is getting up enough nerve to tear it apart and my the conversions etc.
So far for the Gauntlet 22 cal, is really showing her stuff,
starling at 40 yds+ are a gimme shot > 1S1K for far, the HOSP are running about 50% hits.
I think, I need to do some accuracy work to improve it overall.
Tia,
Don
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No common house sparrows here, but I've Been giving the cow birds a hard time. I think the bullets are a bit of overkill. ;D
Made a single shot tray from a mag bumper. Well, what I think was a .380 mag. bumper that I found on the range. Works perfectly. LOL. Fit the mag slot with no mod's and was rubbery, so holds itself. Just had to shave off the top and add a trouft.
Mike
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Adding an update to my flat wire spring experience.... The 1911 recoil spring seemed ok for a while, but lock speed was a bit sluggish compared to my normal setup---to the point of effecting accuracy at 100 yards.
Cocking effort was reduced with the 1911 spring, however it just didn't suit my needs. I switched back to a QB78 spring in my SSG. This spring with considerable preload and a bit more SSG gap results in a much more snappy shot cycle.
Your mileage may vary....
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I'll just offer an opinion here on progressive springs for use as hammer springs.... This applies regardless of whether they are round or flat wire....
The "bad" part of cocking a PCP occurs during the last part of the cocking stroke, when the force is the highest.... A SSG allows a higher initial cocking force, so for the same AVERAGE force, and therefore the same hammer energy and momentum, the force required at the end of the cocking stroke is less.... That is one of the primary advantages of the SSG, provided the proper longer, softer spring is chosen.... It can open a given valve with less peak force required at the end of the stroke....
Why is the end of the stroke the most important part?.... That is the force you must overcome to get the hammer to engage the sear.... If the force required rises suddenly in the last part of the movement (like it does with a stiff spring with a gap to the hammer, an SSS), you are more likely to not QUITE pull it back far enough to cock the gun.... This is particularly bad if the gun is a repeater, because when you pull it back a second time, you may double load pellets.... Conversely, if you have a significant preload on the spring (like you do with a properly designed SSG), your muscles have to develop more force just to start the bolt moving back.... Since the spring rate is lower, the force rises less quickly (starting from a higher base), and you don't notice it as much.... making it more likely that you will complete the cocking stroke.... The PERCEIVED peak cocking force is also less, because you don't have that quick increase that you see with a spring with a high spring rate....
Considering all of the above.... WHY in heaven's name would you want a progressive spring that requires more force at the end of its stroke to develop a given hammer energy and momentum?.... That seems completely the WRONG way to go.... :o
On the other hand, using a flat wire spring would seem to be a good solution for an SSG, as it will fit in a shorter space.... On the other hand, it will, of course, require more space between the ID of the tube (or hammer) and the SSG limiting rod running through the middle of it.... because the "thickness" of the flat wire spring (difference between ID and OD) is greater for the same force.... You are simply arranging the steel in the spring wire into a wider but thinner (and therefore shorter) space.... 8)
Bob
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I'll just offer an opinion here on progressive springs for use as hammer springs.... This applies regardless of whether they are round or flat wire....
"On the other hand, it will, of course, require more space between the ID of the tube (or hammer) and the SSG limiting rod running through the middle of it"....
"because the "thickness" of the flat wire spring (difference between ID and OD) is greater for the same force....
You are simply arranging the steel in the spring wire into a wider but thinner (and therefore shorter) space.... 8)
Bob
Bob
I am not sure, I am following you on the above information about the flat wire spring, (underlined)? ???
Help me to understand............... ::)
Most of these flat wire springs are made to fit inside the spring tunnels of the major brands of semi auto pistols, among other applications,
which run about .420" inside diameter and have spring rod guides diameters from .250" to .320" +/-.
The inside diameter of the QB/Gantlet hammer hole is around .375/.380", with an Outside hammer diameter of .740" +/-,
so yes, the spring and other parts would have to fit on the end of the hammer, but would not be any larger than 1/2" diameter etc.
I do not know what the dimensions of other AG's hammers/tubes are etc.
Tia,
Don
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It seems pretty obvious to me that to be of nearly equal force, the wire in a flat wire spring must be wider if it is thinner.... The wire in the two springs you mentioned in your OP were 0.072" and 0.074" wide.... Since it is wider, that means that the difference between the ID and the OD is greater.... That may or may not be a problem, but for example the SSG I use in my 2260 HPA fits over a 1/4" guide and inside a 3/8" hole in the hammer.... That leaves only 1/16" of clearance between the two, so a flat spring where the wire is wider than 0.060" would bind on either the inside of the hammer or the guide rod....
The spring in a 22XX/Disco or a QB sits inside the hammer.... having it sit behind the hammer only would mean that the tube is too short.... Just an example.... It may be a problem on some guns and not on others....
Bob
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OOPPSS Please Delete.