SL 68 II main spring

[VintageZoomer]

Hey folks,

So a few weeks ago, my brother bought an SL 68 II on eBay that I'd spotted for a good price. He bought a CCI/EV 12g changer to go with it.

Well, we put it to a chronograph and we're getting some serious velocity swings. First couple shots start strong around 270, then we see a couple around 240, then a few more still hovering around 200, and then it goes downhill from there.

From what I can find on the web, it seems that the likely culprit is a worn main spring.

I tried stretching the main spring and making a detent in the barrel with electrical tape, which briefly helped, but then back to the same issue.

I understand that a phantom spring won't work due to the odd size of the sl spring, so I'm wondering if anyone has dealt with this issue, and what spring they used to fix it.

I'm somewhat worried that we won't be able to fix the issue, but it doesn't seem like the sl is a complicated marker, either.

[Fossilhead]

Found some on bacci

https://baccipaintball.com/tip108.html

[VintageZoomer]

Well, I ended up getting a new main spring from tippman parts as a backup option if I couldn't find anything in town (I wasn't sure if it would ship in time). It seemed to help initially, but the velocity still drops rapidly. Is the SL just not good with 12g? Or am I just cursed? I have a phantom doing a similar thing where it can't get above 260 and drops rapidly.

[markdem]

How long are you waiting between shots? Also, you should get better 12g performance in summer.

I have used my sl68 with 12 grams in winter. I dont have actual numbers but i can tell you that i was struggling to get 10 usable shots. Summer, i get about 15 usable shots if i waited at least 30 seconds between shots

[VintageZoomer]

2 or 3 seconds, I'd guess. I knew that 12g aren't good at rapid fire, but I thought that was enough spacing. I'll try that. In the mean time, do you think a high output HPA tank would help? The consistency would be there, but from what I'm reading it sounds like the SL doesn't like HPA, even at 850 psi.

[RAZRBAKK]

2 or 3 seconds, I'd guess. I knew that 12g aren't good at rapid fire, but I thought that was enough spacing. I'll try that. In the mean time, do you think a high output HPA tank would help? The consistency would be there, but from what I'm reading it sounds like the SL doesn't like HPA, even at 850 psi.

I'm not very familiar with SL68s in particular, but most Nelsons are geared for Co2, and your issue is more than likely a spring imbalance. High output shouldn't be necessary.

[markdem]

My sl68 works just fine with hpa. Ive heard some people dont have such luck. If your gun doesnt like hpa, you can bump up the velocity with a tighter fitting barrel.

[VintageZoomer]

Yeah, I went ahead and ordered a couple 13 ci tanks. After watching my phantom indecisively hunt around 220-240 and then randomly spike to 300+, I'm in no mood to keep tuning for CO2. I'll get them running with HPA and stop messing with it.

Edit: I should say I do realize both markers likely have a spring issue, I'm just trying to eliminate a big variable to chase.

[markdem]

Dont worry about a 20fps fluctuation - thats pretty standard. Has more to do with the paintballs than the gun

[VintageZoomer]

For sure, the paint isn't like I remember it as a kid 15 years ago. I'd rather just be in the 260-280 range, and preferably without spiking over 300. I don't want to hurt someone.

[Dennis]

The barrel on the SL-68 is also on the larger side, and the modern paint is pretty small so depending on the ball, it can let more air blow by the in the barrel causing the inconsistency. Out of curiosity, did the grips on the SL-68 have yellow paint and did it come with an old Camo Hopper? If it did, it was an old rental marker from Orion Paintball, a field that ran from 1989-1996 in Rhode Island.

[VintageZoomer]

That's true, we had some paint that swelled a bit, and it shot consistently around 275. No yellow paint or hopper came with it.

[Sniperfan]

Late to the party, but I just figured out 1911 recoil springs are a perfect fit on the SL-68 series, just trim to fit. You can buy them in a range of weights from Midway or Brownells. Unscientific but I'd place the stock one on the 20# range.

[Funsi00]

https://www.deadlywind.com/fibur-x-cf-barrel-fibur-x-thread-adapter

deadly wind sells barrel adapter for SL-68ll. Need a fibur x barrel and 5” freak inserts. That will help with velocity and or rollouts