Completely Unwarranted Model 98 Project

[Calvin]

I now have two Tippman 98s broken down into parts. I have a direction I think I want to go, but want to get some feedback from members before pouring cash into what is, in fact, a completely unnecessary project being completed solely for the sake of nostalgia.

Air:
I have decided that it might be a good idea to have a high output tank for the sake of my Pro Carbines, and this 98. I really don't want to go down the rabbit hole of low pressure mods for a blowback. I would prefer to give it the pressures it likes best. To that end, I plan on purchasing this cheap 1200 psi output Chinesium regulator on Ebay:


and this 36/4500 tank:


My calculations are that this tank combo should be a good size for mounting directly into a vert ASA, and give me 2 pods and a hopper in any of my Tippmanns. Has anyone used one of these high output cheapo regs? Is this tank sufficiently large to give me 2 pods and a hopper from a clean Pro-Carbine or 98?


98 Parts:

I am going to go with this body since it uses the old style valve, but is molded for any of the accessory options should I desire to experiment later.

I don't think I am going to use the RT to start. I want to get a stone cold reliable marker first. I will be using an LTR on this, so I am ditching the ACT parts as well. The original bolts are both fooked from sitting in paint for years, so I will need something new there as well. I propose the following parts:

Has anyone had any experiences with the Warrior aluminum powertube/bolt combo? Looks pretty straight forward to me, and the price is right.

This leads to the hammer and valve section. The springing of these blowbacks is a dark art that I have not yet mastered. I would love to use the hammer from the Tippmann LPK in this build:

If I use a lightened hammer and spring, I assume I would need to use the matching lightened valve spring and rear seat as well. I would use the standard valve body, cup seal/stem, and front seat so the air volumes are appropriate to high pressure operation. Would those lighter springs in the valve and hammer function at that 1200psi operating pressure? Is it simply a matter of try it and hope for the best? How do other lightened hammers like the Techt handle springing at full pressure? I don't want to have to add an HPR as I want the tank directly into the vert ASA.

I'm hoping that this setup and the .685 CP barrel will make a fun and reliable setup that I can pickup on occasion and enjoy. I play a lot as a lone walk on with rental groups at one of my local fields, so this would be nice when playing with them and their largely 98/BT based rentals. Please feel free to point out any errors/stupidity/insanity in my plan so that I can make one purchase and end up with a decent rig. I think the air system is the most important question since 3 guns will be depending on it.

[FlightMedic938]

I know I’m probably going to be in the minority here, and that’s ok, but low pressure is the way to go when running HPA. You will get better efficiency and consistency. You already have all the parts too, right? What tank regs do you have?

You don’t have to deep dive right away with it all. Clean it all up, polish the internals, fresh seals, etc and then slap the LPK in.

To balance it, wrap your stock velocity adjustment screw with Teflon, and turn it all the way in. This is going to maximize blowback. Turn your inline up, starting at zero, until it recocks consistently under rapid trigger pull. Then go up another 40-50psi. Then back your velocity adjustment screw out until you reach velocity. If you back the velocity adjuster out too much you can create a cavity in the powertube which air will hit and flow into which can hurt velocity. It’ll look like a “pothole” when looking down the powertube. The velocity screw shouldn’t ever be backed out this far. “Wide open” is when the screw looks smooth and flush with the ID of the powertube. Just shine a flashlight down there to !safely! check occasionally while tuning to make sure it doesn’t go past that point.

If you can’t reach velocity with the screw wide open then you have to start increasing pressure until you do. More than likely you will have to.

I’ve been doing this for a couple years now with various Tippmanns and made lots of mistakes. I think the biggest one was the obsession of getting the lowest operating pressure. Going too low really hurts efficiency even if you are shooting at velocity. The best OP is around 340 to even 500psi depending on what else is done.

if you are dead set on using super high pressure and the lightened hammer I wouldn’t use the lightened valve spring. Use the stock valve internals (spring, seat, and plug) but I would still use the LPK valve pin because it decreases blowback and I don’t think you’ll need a bunch of blowback at 1200psi to recock the lightened hammer. If the pin decreases it too much you can try turning your velocity adjustment screw in to increase blowback until it does reliably. I never tried that but I imagine at 1200psi, and without an inline regulator, you shouldn’t have a problem. If you can’t get it to recock reliably and reach velocity then throw the stock pin in and you should be good.

The Warrior tube and bolt are really good but you have to be careful of the Chinese knock offs. ANS is legit though. The Chinese ones don’t have the internal front bolt o ring. With any aftermarket part always polish it, inspect it, and remove burrs. These things are never machined great by any company but can be made to work really well if polished up.

I don’t own a .685 CP one piece but make sure the bore relief for the front bolt will allow the front bolt to move freely or you’ll get bolt slap or stick. The front bolts that seal in the breech are a lot better with a tighter or non existent bore relief. I literally just solved this problem for myself yesterday because I bought a Python compression kit and was getting bad bolt slap with several different aftermarket front bolts until I put in a aluminum RAP4 that had the o ring located further back on the bolt.

[FlightMedic938]

At 1000psi I still wouldn’t use the lightened hammer or valve spring. Yeah it might shoot but any smoothness is going to be erased by the high operating pressure slamming it back.

[Calvin]

Sounds like I should put the brakes on purchasing the 36/4500 until I can sit down by a chrono on a nice day and run field paint through all 3 of these Tippmanns. If I can't get above 270 on them, I might need a higher psi reg. If they all get into the 280-290 range, I can just buy one pre built with a standard reg from ANS. Meanwhile, I will polish the shit out of the 98 body and clean up all the parts. I will re-seal the stock valve, and buy a new stock main spring. I can swap out the stock hammer and the LPK hammer when I am chrono testing and see the effects there. Thanks for the sounding board help!

[Buff_phroggie]

I agree on the 500ish psi. I have an ebolt with a homemade lpk that runs in the 550ish range

[Buff_phroggie]

E-bolt and LPK are hard to find and expensive. The lpk can be made yourself. I reccomend finding a 3d printed center feed too. Feel free to DM and i can help with the parts for the homemade lpk

[Calvin]

Very cool setup! I already have the full LPK in my possession, but I want to keep the rig simple, reliable, and as cheap as possible. I don't want to go low pressure, but do LOVE the hammer from that kit. if I can make that work in a high pressure setup, I think it would be a smoother shooting gun than a stock hammer would be. I love the printed center feed. If that's your model, and you would be willing to send it to me, I would be happy to give it a whirl on my printer. What material did you print it from?

[Buff_phroggie]

I didn't print it, i bought the print. There are a couple guys printing them in the 98 groups on FB

[nak81783]

General rule of thumb for older markers is 10 shots per ci for 3000psi tanks and 15 shots per ci for 4500psi tanks. A hopper and 2 pods should be possible on a 36/4500 IF you get a full fill.

I’ve gone back to 68/4500 after trying 15, 17, and 48/4500 tanks for a few reasons.

1. 68/4500 just shoulders better for me. Not an issue for you if you’re putting the tank in the vertical ASA.
2. I don’t always get a true 4500psi fill. Even when I do, it usually cools to 4200 or less, and I don’t always have time to top it off.
3. We usually play 4-6 games before heading back up for air and paint. The smaller tanks don’t support that.

[Calvin]

Thank you for that info! I play at commercial fields locally. It's invariably one game and back to the table for a bit. Playing with classic Mags with 4 pods on me, I have gotten to the last pod once, but still had a full hopper and about half the pod at the end of that game. Most games a full LTR and 2 pods is more than I shoot, and I still feel like I'm being plenty aggressive.

[William the Third]

That reg won't work on that tank. That reg is Metric threaded M18x1.5, and the tank (as well as pretty much all paintball specific tanks) is threaded SAE threaded 5/8-18. That said, you can find that same Chinesium reg with the correct SAE 5/8-18 threads if you look around.

[Calvin]

Good catch! TY!!! I will find that. THIS is why I posted here before buying.

[Magmoormaster]

I think a 1200 PSI reg is a mistake. There is nothing to gain from such a high output pressure on a 98, and I'd imagine you'll have problems reaching legal velocity with it that high. If you're already ordering from ANSgear, just grab a standard tank reg from HK Army, PMI, or any of the others at a standard 850 PSI. It'll be the same price.

In almost all cases, the stock powertube and bolt are better than upgrades. I think the only time this wasn't the case was Orange bolts from way back in the day. I'd say clean the old ones (soak them in dawn dish soap, old paint should come off fairly easily after a few hours) or buy replacement factory parts.

RE: lightened hammers, yeah the TechT Zero Kick hammers were made for high pressure not low pressure (though they work just fine for that too). You shouldn't need a lighter valve spring to get that working. They were designed to drop into a standard high pressure 98, everything you need to make it work will be included. I will say they tend to be finicky, so if your goal is reliability and not max performance I'd say skip it.

Personal preference, but I think 14 inches is too long for a 98. It appears I took too long to get a 10 inch CP barrel, they're no longer a thing. But IMO 12 inches would still be better than 14, even if it is only available in 693. It's a 98, so bore size won't really do much for you.

Other than that, like others have said just polish up the internals (including the hammer and linkage arm), maybe throw in a lighter trigger spring (cut down pen spring) and you should be good to go.

[Calvin]

Thank you for the info. While searching for a 5/8-18 reg, I found one with 1000psi output. Is that more inline with what a 98 or Pro-Carbine would run perfectly with? I have read of people having issues getting them to shoot to full velocity on 850psi tanks, which is why I wanted to dedicate a tank to running them. I don't want to have to polish everything to glasslike smoothness and bore every air passage to get to velocity.

[COB]

Just my two cents. I think part of the problem with the reg output discussion is the two different markers you are planning to use it on. As others have mentioned, the 98 is fine with an 850 psi tank, because the valve was designed for HPA and CO2. The Pro Carbine has a different valve and handles HPA differently. I have found different valves in the hoard of carbines and pro carbines that have passed through the Arsenal. They have each produced different FPS outputs using the same air tank. So, you may need to view their needs separately.

[Magmoormaster]

Calvin I can't speak to the pro carbine, but a 98 will reach velocity on 850 PSI no problem. 1000 PSI should be ok, but IMO it's still a bit high. Others will have to weigh in on that.

Polishing the internals is not to get the guns up to velocity, it's just to make them shoot better. And you certainly don't have to go to a mirror finish. In fact, true mirror finishes are bad but that's a whole different discussion. It's far from a necessary step, but it's highly recommended simply because it's relatively easy (just takes time) and provides a decent benefit.

[nak81783]

Just one data point. I had to shim my tank reg to 900psi to get a Tippmann Gryphon in the 280-300fps range using a 14” J&J (well more like 13” after I rethreaded it for the Tippmann).

[gnarlynick]

I have the aluminum power tube and use the Core Anti Chop Bolt also from ANS instead of the delrin bolt. I would say it doesn't really provide much over the OEM power tube but I mainly got it because I figured screwing the banjo fitting into the plastic power tube would eventually strip the threads. The anti-chop bolt is milled back a bit far where the linkage arm connects it to the rear bolt; had to add a drop of hot glue in the slot to let the front bolt clear the breach when it's open so a paintball can reliably feed into it.

After all that, it works really nice and haven't had any notable degradation to the ROF or reliability of the marker. I've also got the BT vertical adapter, this picture is a bit old and had my original Tippmann vertical adapter that I later found had a pinhole leak in the transfer tube.

[Calvin]

Excellent info. Thank you! The aluminum threads on the RT air transfer port were one plus that drew me to the aluminum power tube. I figure that I could easily add in the RT later once the gun was running well and take it out again without issue if I didnt like it. I will research that anti chop bolt as well.

[Trbo323]

First off, why are you doing all this work and not polishing the internals?

Honestly I've had more negative experiences with the aluminum power tubes than positive. The last aluminum bolt I had wouldn't make velocity and I ended up taking it back out and going for plastic

Sent from my motorola edge 2024 using Tapatalk

[Calvin]

I will be sanding and steel wooling the bolt, connection rod, and hammer areas in the body halves. Maybe some dremel time with a polishing bit at the end. I just don't plan on freaking out about it. 30 min of time is likely to be slated for the effort.

[Calvin]

Due to the wide variation in opinions on various parts, I have ordered a wide variety of stock and aftermarket parts. I will end up with the ability to mix and match bits until I have a runner that I like. Also got the large ID RT hose kit in case I decide to try out the RT. I have held off on the tank purchase for now pending eventual chrono results. Also not doing any anti chop bolts of any kind. I am confident the LTR will do it's job well. Sitting down now to sand action areas inside body halves. Thank you all for the input!

[gnarlynick]

My RT has the smaller 1/16 ID hose and works fine on 850 psi source pressure. It wasn't until I tee'd it to a cyclone feed that I started having feed issues on the cyclone. In that case, the 1/8 ID hose would probably be most beneficial.

[FlightMedic938]

Good to hear. The 1/8 fittings and hoses really open it up and make it much easier to tune. The anti chop bolt is not very good at all, same with the ACT stuff. I can pop off a full hopper at 18-20bps with shitty paint and not get a single chop using a CTRL

[Calvin]

Well, that was an hour of hell. I had no idea that an industrial process could create such an un-uniform surface. Spraying finish into the channels was a bonus they gave me. 120-320-600-1000-1200-2000-0000 steelwool. It's good enough for government work.

[gnarlynick]

Ouu, shiny

[FlightMedic938]

Polishing the sear area will help some, especially if you end up using the lighter hammer. Looks good 👍

[Calvin]

Good catch. I totally didnt think about the trigger. Ugh. Back to the sandpaper😪

[Calvin]

I avoided sanding the trigger areas of the body by playing around with making my own bolt. Looking through this thread and other older threads, a pattern of what works seems to emerge. I did this with the LPK since my non-ACT stock hammer hasn't arrived. First I did a simple bolt without orings. I put a 3.5mm long subtle campher on the tip to help with chops.
It worked well, so I placed an oring in the model so it seals right as the valve ping is at max compression.

Feels frictionless in the action. I will probably find an oring that fits the powertube properly and make another one with that oring internal at the back of the bolt, just to see how it works. I have also seen Carbine stock bolts modified with a V cut to make a ramp for the ball. I will try that as well. I still have to sand the damn trigger area.

[FlightMedic938]

I like it. Looks really good. The size of the internal o rings are 14 70 but I’ve had better results with 14 75 Viton.

The only thing I can see is that the part where the linkage arm is going in might be a little too tall. It shouldn’t touch the bottom of the linkage arm channel. Probably no big deal at all but it could create unnecessary friction.

If you get the internal o ring in and it looks good I’d definitely buy one from you to try out. I know Myrkul ramps his bolts to help with small paint but I haven’t tried that yet. You get that done and you got the best front bolt nobody made

Chamfer front to help with bolt stick
Recessed o ring to help with bolt stick and efficiency
Inner o ring to help with efficiency
And V ramp to help reduce chops

[FlightMedic938]

Calvin You’re doing some really cool stuff here and I’d hate to let a rough powertube ruin it. The old tubes weren’t made with aftermarket bolts in mind so they are pretty rough on inner o rings. It needs to be sand and polished or it’ll chew them up. Probably the last thing you want to hear lol more sanding and polishing.

Much later on Tippmann made some high quality tubes that were very smooth. No plastic burrs or rough seams.

[Calvin]

Thanks for the oring info! Should make it quicker to grab them tomorrow.

That power tube won't be there. Its the old one, and I'm using it just to test fit the bolt. I have a new Tippmann stock plastic, and the Warrior aluminum on the way. One of those will be used, and will be prepped accordingly.

[Calvin]

Ball ramped bolt is on the build plate .

[Calvin]

This one is a winner.

I put an elbow on it and a hopper so I could work balls through the detent one at a time and watch/feel. lt works very well. There is no resistance from the bolt pushing through the stack at all. I will try the inner oring, but I'm pretty sure this would be just fine as is.

[Myrkul]

This looks incredible.