Gen II Internal DIY SSG Mod Detailed Build and Instructions

[ackuric]

I have spare 16#'s and I just ordered 11.5# 2" springs that should in my hands by Thursday I hope.

I can send you one or two of each if you'd like, just cover shipping costs (2.60$ w/ tracking).

I'm going to aim for as high of a shot count as possible on the 11.5# spring, hoping for 24-32 shots @ <2% es with 800-815 fps from a .25 cal...I figure I might as well get the most out of my ssg and I don't mind sacrificing a few FPS to do so.

The 16# spring is great but I figure for a 37 fpe/shot count tune its overkill and I can try out the 11.5#. I was able to get 25.4gr pellets up to 880-890 with minimal pre-load on the 16# on a stock valve (no bell curve).

That spacer is the same spacer I used with the I.D of .257, you can definitely feel how smoothly the bolt rides/glides on it.

Another benefit of using a 1/2 inch spacer in the hammer and 2" spring is it requires no cutting of springs, which quite a few others require and can have variation from one cut spring to another. I know its generally emphasized to use a longer lighter spring in ssg's, but I have yet to see any evidence, theoretical or in my applied tests to show a shorter(2") stiffer (16#) spring has any adverse effects, in fact I achieved better results in my tests so far.

[triggertreat]

I have spare 16#'s and I just ordered 11.5# 2" springs that should in my hands by Thursday I hope.

I can send you one or two of each if you'd like, just cover shipping costs (2.60$ w/ tracking).

I'm going to aim for as high of a shot count as possible on the 11.5# spring, hoping for 24-32 shots @ <2% es with 800-815 fps from a .25 cal...I figure I might as well get the most out of my ssg and I don't mind sacrificing a few FPS to do so.

The 16# spring is great but I figure for a 37 fpe/shot count tune its overkill and I can try out the 11.5#. I was able to get 25.4gr pellets up to 880-890 with minimal pre-load on the 16# on a stock valve (no bell curve).

That spacer is the same spacer I used with the I.D of .257, you can definitely feel how smoothly the bolt rides/glides on it.

Another benefit of using a 1/2 inch spacer in the hammer and 2" spring is it requires no cutting of springs, which quite a few others require and can have variation from one cut spring to another. I know its generally emphasized to use a longer lighter spring in ssg's, but I have yet to see any evidence, theoretical or in my applied tests to show a shorter(2") stiffer (16#) spring has any adverse effects, in fact I achieved better results in my tests so far.

Thanks for the offer!  I'll be adding the 2" springs to my next McMaster-Carr order.

Do you have the F.A.M.E. mod installed in your .25 cal?  Do you have a .22 cal with the mods?  I don't have a .25 cal but I like to compare apples-to-apples results with the mods and different configurations with someone that enjoys tinkering as much as shooting like me.

I'm a little concerned about the .257" I.D of the 1/2" spacer.  I've checked it with a 1/4-20 bolt and it does have more play than I care for.  I do have some other 1/2" spacers that require drilling if I find it's an issue.

With the current 14.8lb spring and no spacer/hammer sleeve I'm testing, cocking is still very smooth and very doable.  The F.A.M.E. mod is working very well without the hammer sleeve.  I wouldn't go without the hammer sleeve with no F.A.M.E. mod though for sure.  I do have the spring length at 2.7" and believe that is why the cocking is fairly easy.  My current setup has the spring actually attached to the hammer itself and not just sitting against the hammer.  I've only had time to do a quick test string with this setup, but the results got my attention.  I have been shooting with it a lot while pesting and playing around with it and I like the power, but will probably back off a bit for more shots.

Here are the results of that test and is where I have it tuned to now:



As you can see 30 shots at an average of 31.40 FPE with a 1.68% ES is not bad at all for an unregulated gun.  What got my attention the most was that the VMS adjustments I made on my previous tunes had no effect at there previous settings on this configuration.  I also believe the spring is pulling back on the hammer after the shot and giving me a much better ES average.

When I get caught up on my home projects, I'll do more testing with this setup and also the 2" 16lb and 1/2 hammer sleeve you recommend and see what the differences are between them.

[ackuric]

Yes I have the F.A.M.E mod done, but only have the .25 cal.

FYI when you cut that "14.8#" spring down to 2.7 inches of length roughly...you increase the spring rate to about 19#...so I wouldn't call it a 14.8# spring when you're modifying its length and rate. This is why I told you on the other forum that the 16# spring is easier...by far, than the 14.8# spring cut down, which in reality makes it a 19.X# spring.

[Nickelsig229]

Drilling out the gap adjuster is proving to be difficult.

I snapped five 1/8 drill bits and two 1/16 drill bits. I figured I might have more success drilling a small pilot first.

I just got back from Lowes and purchased 1/8 cobalt drill bit. Hopefully those work better then the standard high speed bits I blasted through. I'll continue in the morning, too frustrated to go on now. If anyone has any tips please let me know. Or else I'm just going to power through with these new bits no matter how many it takes.

[ackuric]

Ohboy...it took me about 2-3 hrs to drill through the gap adjuster by hand using a Cobalt bit...granted towards the end I started using more force and started making faster progress...2 18v batteries later lol

[triggertreat]

Drilling out the gap adjuster is proving to be difficult.

I snapped five 1/8 drill bits and two 1/16 drill bits. I figured I might have more success drilling a small pilot first.

I just got back from Lowes and purchased 1/8 cobalt drill bit. Hopefully those work better then the standard high speed bits I blasted through. I'll continue in the morning, too frustrated to go on now. If anyone has any tips please let me know. Or else I'm just going to power through with these new bits no matter how many it takes.

It took me around 30 minutes to drill mine if my memory is correct.  I used a drill press and cutting oil.  I did use a smaller bit and stepped up to the 1/8" bit.  It was hard material to drill for sure.  I didn't let the bit get too hot and used a medium speed with decent force.  I did use sharp quality bits.  Hope you have better luck today!

[triggertreat]

Yes I have the F.A.M.E mod done, but only have the .25 cal.

FYI when you cut that "14.8#" spring down to 2.7 inches of length roughly...you increase the spring rate to about 19#...so I wouldn't call it a 14.8# spring when you're modifying its length and rate. This is why I told you on the other forum that the 16# spring is easier...by far, than the 14.8# spring cut down, which in reality makes it a 19.X# spring.

Well I won't say you're wrong here because I'm no expert for sure.  I am trying to wrap my head around this though.  The compression length is 1.32" and I'm only cocking it back 1/2" tops.  I only took off .3".  When cocking, it feels about the same as the 12.5lb spring.  However, the 12.5lb spring was being cocked back to near full coil bind and only has a .93" compression length.  I will be testing the 16lb for sure and then I'll see what you are saying first-hand

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[ackuric]

Bob(rsterne) has noted how cutting springs shorter INCREASES their rate (lbs per inch)....

Again, this is just simple math and how springs work.... use a spring rate calculator like I have. You cannot cut a spring shorter and obtain the same spring rate...

Its like people who cut their stock springs on their car for a lower ride...guess what happens, you lose ride quality due to the springs being much stiffer...and they aren't even cutting a full coil!

[triggertreat]

Bob(rsterne) has noted how cutting springs shorter INCREASES their rate (lbs per inch)....

Again, this is just simple math and how springs work.... use a spring rate calculator like I have. You cannot cut a spring shorter and obtain the same spring rate...

Its like people who cut their stock springs on their car for a lower ride...guess what happens, you lose ride quality due to the springs being much stiffer...and they aren't even cutting a full coil!

Thanks!  I ran the spring calculator and do see what you mean.  I came up with 18.3lbs.  Cocking it sure doesn't seem much harder to me than the 12.5lb really, but the cocking is really smooth with the F.A.M.E. mod so it's hard to tell.  I could be wrong.

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[Nickelsig229]

I'm a happy camper today.
 
After a horrible night of failure, I woke up and got to it. It took me about 75 minutes start to finish.

I used 3 cobalt drill bits,  1/32, 1/16, and 1/8. I should have gotten a 11/64 because there is enough room, especially if you watch your depth, to drill the adjuster out without messing with the hex key slots. That would give a lot more room to put your driver in. I drilled down from the cup side, I found it easier to find the center for the bit and it was easier to monitor progress.

The hardest longest part was putting the right amount of pressure on the small bits. They are fragile, but they also cut faster. Once I got through with the 1/32 in about 50 minutes, the 1/16 went through in about 10 or so and the 1/8 in another 10.

I don't see how someone does this without a drill press though. I just can't picture that.

I'm polishing and getting ready for assemble. Really this is a great guide and the gap adjuster the only tough part.

[triggertreat]

Tony, glad to hear you've had some success and hope it continues

One thing I experienced that is worth mentioning is when you change the friction points of the hammer and air tube by adding the DIY SSG build, you may need to take the SSG out and smooth out and clean the hammer, air tube and bolt again after a number of shots.  This really helped when I did this to make it work smoother after the initial install and break-in period.  If you're lucky you may not need to, but not a bad idea anyways.  Just food for thought.

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[LDP]

Do you think the plastic threaded spacer that captures the the spring on the 1/4-20 bolt will fail? That seems like allot of pressure when cocked on a plastic thread. Would it be feasible to make an aluminum piece instead of using the plastic? Shooting season is winding down in MT so I will be doing mods to my .25 Mrod over the winter and this will be one of them.

[triggertreat]

Do you think the plastic threaded spacer that captures the the spring on the 1/4-20 bolt will fail? That seems like allot of pressure when cocked on a plastic thread. Would it be feasible to make an aluminum piece instead of using the plastic? Shooting season is winding down in MT so I will be doing mods to my .25 Mrod over the winter and this will be one of them.

The nylon spring adjuster pictured is the same one I use today and has been in my gun since about February of this year when I first built the mod.  It looks the same as day one and has been removed and installed many times.  It has seen many shots over 900 FPS.  It has held up without issues.

The aluminum may work, but I don't think it will grab the spring and hold it tight when turning CW or CCW when tuning.  You might could attached the spring to it somehow.  It also may spin on the bolt while shooting.  You don't want that.

[LDP]

as long as the nylon holds up I wouldnt be worried. no need to mod it if its gonna work and last.

[triggertreat]

as long as the nylon holds up I wouldnt be worried. no need to mod it if its gonna work and last.

I use it with a 3" 14.8lb spring that has been cut shorter.  That's a pretty good test of it.

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[Nickelsig229]

I wanted to update my progress for others who  are on the fence with doing this.

If you have a drill press and a 1/4-20 tap you can get this project done. I will be making a second in my free time now that I have the experience of the first.

Things I will focus on are smoothing and polishing the drilled out hammer, hammer screw, hammer nylon guide and a cleaner slot for the screw driver as well as buying a screwdriver specifically for adjustments. These are all simple things to do, and will kill the boredom over the winter months.

These are not necessary however. Once you upgrade to this ssg you will soon find that smoothness and less resistance is your friend but by no means do you have to go these extra steps to increase performance with the mod.

On my build, I followed the instructions exactly but used my factory 10lbs spring. I have a regulator on the way so from what I read the extra strength spring isn't necessary. During tuning I had a failure, the spring slid over the nylon spring adjuster. I had turned in the last spring coil and coned the nylon guide but while tuning I cranked the spacer all the way in just to see what the effect was and it slide over the nylon spring adjuster. After closing the spring more and using the same adjuster, it solved all the problems. I will say it is important to have the cone portion and the last coil of the spring mate properly. To wide and it will go over under extreme force, to narrow and it wont grab the spacer which wont allow for tuning as the spring grabbing the nylon is what keeps it from spinning when you turn the hammer screw. I reassembled and put 120 or so flawless pellets through the gun after adjusting the spring to nylon fitment.

I tuned it like the instructions say and finally got solid performance from my gun. This is superior to the FFH I had installed in the gun due to the tune ability and smoother action, though still stiff it's not coarse like the ffh is.

I can't thank TriggerTreat enough for detailing where to get the parts, how to assemble them and how to tune. This really should be the first place people look when they want the add an ssg to their marauder without buying one premade.

[triggertreat]

Thanks for the update Tony!!  Great info for those on the fence.

One thing I did to smooth out the edges of the 1/4" hammer hole was to follow up with a 1/2" bit just to knock the sharp edges off.  That made the bolt slide across the edges smoother.  For the interior edge, you might drop down to the next size bit for easier entry.  I did use a 1/2" bit on both sides, but had to power through the interior side and it was not easy to do.

Glad to hear the instructions are sufficient to accomplish the build and tuning.  I was hopeful that they were and tried to keep them as concise as possible.

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[Gippeto]

Coming to the party late as usual....

Having drilled out more than my share of stripped/rusted in set screws (27yrs repairing oilfield instrumentation)....they are hardened steel, and annealing them first makes drilling quick and easy.

Heat to cherry red then let cool slowly to room temp.

Al

[Nickelsig229]

Thanks for the update Tony!!  Great info for those on the fence.

One thing I did to smooth out the edges of the 1/4" hammer hole was to follow up with a 1/2" bit just to knock the sharp edges off.  That made the bolt slide across the edges smoother.  For the interior edge, you might drop down to the next size bit for easier entry.  I did use a 1/2" bit on both sides, but had to power through the interior side and it was not easy to do.

Glad to hear the instructions are sufficient to accomplish the build and tuning.  I was hopeful that they were and tried to keep them as concise as possible.

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I actually used a dremel polishing stone and it beveled both the interior and exterior of the 1/4 hammer hole. I wish I had a 1/4 inch stone to slide in the whole itself though. I used my worksharp belt sander to make the bolt look like a mirror.

[ackuric]

Reporting back with my findings on the 2" 11# spring, on the .25 cal I could only get 780ish fps max, so I swapped back to the 16# spring which I don't mind at all and am getting my desired 800-820 fps tune, a 845-865fps, and a 895-925 tune if I so desire.

I suppose the 11# spring would work for .177 or .22 cal. The 16# spring is going to be what I settle with for the time being. I may give the 11# spring another go some time who knows.

Also I am not using the F.A.M.E. mod in some of my recent tests as I have noticed its not necessary with the 1/2" spacer in the hammer. I do however still use a 1/4" water line tube on the cocking lug to keep the hammer from wiggling so much.