This is a B2k mod I’d never heard of until just now looking through the ICD photo thread. Can someone tell me how, why and why not?
Much appreciated!
Much appreciated!
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Depends which one you’re referring to but the most common was to add an 011 in the rearward stroke of the ram, it pushes the ram forward a hair (helps with smaller paint) and acts as a bumper, there was also people putting it on the ram shaft between the ram housing and the hammer.. basically same results -
With smaller paint rollback can make eyes not detect paint. This just bumps the bolt forward a bit to mitigate this potential issue.Comment
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Gotcha. No gain in non-pds markers then.Comment
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The entire "mod" is a homebrew fix I came up with to help my blind B2k shoot the local 0.675 field paint without clipping it. It's hardly a mod, you litteraly just unscrew the ram cap and drop an additional #011 "o" ring in there so the bolt doesn't go back as far. It really just reduces wiggle room/rollback in the breech. If your paint is larger then 0.682 there will likely be no benefit and if your paint is much larger then 0.684 it may even be determental and cause feeding issues. It is very likely someone else has done this to other older poppet based markers at some point, but I've never actually seen anyone else do it, and don't believe I stole the idea from anyone.
I originally did it on a completely blind marker, but it works fine on markers with PDS too. I have come across a few B2k4s that it was completely unnecessary on, all just kinda depends on the gun and the paint you are shooting. Easy to install or remove depending on the situation.
Details are found here:
Also in that thread is the FAR more effective bolt ramp mod, which is pretty blatantly me just ripping off planet Eclipse's cure bolt and home brewing it onto a B2k. That mod is excellent, I have to be 15 or 20 cases deep into that B2k now and still haven't chopped or clipped a paintball in it. It's been so effective that I've started slapping it in literally anything, Impulses, Spyders, Tippmanns, shockers, cockers, automags Cats, etc. At this point if the bolt is not ramped or beveled, I'm not going to shoot it. It works that well. I specifically recall one day that the paint was running so small, every single person at the field was shooting a blender except me. It feels very good to win a 6 on 1 wielding a 68 carbine in 2023.
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Thanks for the detailed reply. The cure mod looks worth it, though I only have 1 vapor bolt to my name. Who did the cut on that?
Also, not to derail, I’m having a hard time achieving 280 - 300 fps, seems like it doesn’t want to get over 270, ever. Any suggestions on that?Comment
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Increase dwell and/or LPRComment
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KCCockerDoc Did the cut on the bolt. Depending on the size of your field paint you may need to sand it even deeper. I usually wrap a 3/4" dowel with sand paper to get it as deep as possible.Originally posted by TinCan1154 View Post
Swap out your valve spring to something weaker to fix the velocity. I usually like using SLPS autococker valve springs in my B2Ks. My original Bushmaster topped out around 260 with the stock spring but runs 285 with zero issues after changing the spring.Comment
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Thanks for the tips. I'll try the SLPS.
If I take the LPR up above 90psi, velocity increases to a point, but I recall specs being 90 and with the mods I have I would have hoped to be under 90.Comment
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Grabbed a donor spring from an Autococker that was a little lighter. Helped with fps, up to 280'ish now without much messing around. LPR is at 90, which makes the shot a little harsher than I'd like/ remember. SLPS kit should be here Saturday.Comment
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Hell ya!Originally posted by TinCan1154 View Post
The SLPS springs are crazy soft, if it was any softer it would likely have issues sealing up.
Here are some other small things you can do to smooth out and soften the shot and help velocity.
Polish the ram shaft
Be careful with this one, if you are too aggressive and remove too much material you've trashed your ram. That being said I usually go up to 2500 grit sand paper to get mine just as slick and smooth as possible.
While the ram is apart, replace the #010 & #011 "o" rings with quad (or X) "o" rings. It wouldn't make a huge difference, but it's definitely noticable and reduces friction on the ram assembly even more, especially if it's been polished. (Because of minimum order requirements, I have a small pile of extras, just PM me if you want me to send you some.)
Polish the valve pin
Not sure if this actually helps anything but it doesn't hurt and it's shiny and all the polishing stuff is already out anyway from doing the ram shaft.
Sand the bolt.
If you are using the vapor works bolt, it's really best to "polish/sand" those down. The vapor bolt seals at the "o" rings, and should glide on them as well. Use a 400 grit to start and gradually work your way up. Test for smoothness between grits. Not sure where the point of diminishing returns is, but the Nylatron they are made out of gets so freaking smooth and slickery around the 1500 grit mark that it's unreal. You can't polish out the stock bolts since there are no "o" rings on it and the blowby get too excessive.
I also typically use a chain saw sharpener to hand file the detent slot out a just a bit on the vapor bolts to work with the ball bearing style detents and not just the "o" ring style ones. You want the bolt to be able to glide past the detents and not get hung up on them. It only takes a little bit to smooth them out.
DO NOT CHOP THE BOLT TAIL OFF.
I've seen people do this to try and reduce weight, but the weight reduction makes the entire firing assembly too light, and as a result their LPR has to always be set very high just to hit velocity. This is also why the shocktech and bonebreak b2k bolts suck a thick one. I have never once gotten good performance out of a tailless B2k bolt. You can get the tailless bolts to "work" but the shot quality is just absolute garbage afterwards.
Just let me know if you have any questions or issues!Last edited by Myrkul; 07-25-2024, 12:53 PM.Comment
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Ram shaft is polished, not sure on the valve pin, I'll check. I just had the ram apart and I wish I would have known about the x-rings. Damn. I would definitely take some if you're willing to share, but am happy to buy them outright as well. Not happy about having to remove the hammer again.
Bolt is a vapor works, I could work on polishing that and adding a groove for the auto cocker style detent. I hate messing with it if I mess it up, I dont think I can replace it.
Got a set of custom grips coming from ODM as well. Can't wait.Comment
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I totally hear you on not wanting to take apart the ram again. I always just blue loctite mine back together because I hate breaking the torch out. The difference is so small with the quad rings that only one of my 4 B2ks/Defiant's has the quad rings. The other 3 just have standard "o" rings. I have not field tested the Quad rings, but I DID rip two hoppers off the back deck with them and they worked great. Just pm me your address if you want some.Originally posted by TinCan1154 View Post
You likely will not be able to replace the vapor bolt short of buying a whole additional gun that already has one installed. The detent groove is really easy though, it hard to mess up. Just lay the file in the existing trench and go slow. 100% hand tools only. Only focus on the front, anything in or past the "o" ring groove doesn't matter. You just need to widen the front of the existing groove a hair to work with the autococker detents. It's pretty subtle.
If you are nervous, I'd recommend a nice scotch or peated whisky to sip on. That's how I do mine.
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