TECHNICAL SECTION

This section is dedicated to providing technical information, tips and tricks to help players better understand and fine tune their equipment.

When it comes to modifying, repairing or restoring stock-class markers, there are two basic platforms - Nelson-based and Sheridan-based. Outside of the different types of material used in their construction, the primary distinction between the two is their valve train design. Please note that the title of each topic below will indicate if it applies specifically to either Nelson-based or Sheridan-based markers. If the title doesn’t indicate a specific platform, then it is generic information applicable to both.

Our goal is to update this section as often as possible, so be sure to check back in for new info.

Selecting The Best Grade of Paint for Stock-Class

One of the most commonly asked questions when getting into stock-class is “What is the best grade paint I should use in my stock-class marker?”

The vast majority of stock-class markers use older style valve systems that were originally designed to operate exclusively on CO2. These markers also required manual cocking which can be extremely tough of paint. Because of this, the paintballs that were manufactured at that time had a larger diameter, and a much thicker-shell. As the drive to create faster shooting markers with higher-capacity, assisted feeds became the norm, paintball manufacturers reformulated their product to perform to this new standard.

So, today we have paint that is considerable smaller in diameter and has a much thinner shell than the paint made decades ago which was designed to work best in CO2-based, pump-action markers. Given all this, stock-class payers today must contend with pellets breaking in the barrel, breaking in the breech during heavy cocking and roll-outs.

At playing fields that offer different grades of paint, we have found that selecting a mid-grade paint works best. You never want to select the lowest grade paint, as that is usually sold to the renters and will obviously be the worst quality. You also don’t want the highest grade paint, as that will usually have an extremely fragile shell and very small diameter. The mid-grade (i.e. GI Sportz 2-star or 3-star) paint normally has a thicker shell, is often a little larger in diameter and performs best with stock-class markers. Bonus: it’s usually less expensive too!

Always remember to inspect your paint closely before you buy it. Check to make sure the paint is as round as possible. If the paint is dimpled, has flat spots from sitting too long or is obviously out-of-round, then that’s going to cause accuracy problems - that is if the paint even makes it out of your barrel. You also never want to buy a bag of paint that looks wet. Tiny drops of moisture on the inside of the bag, or ”sweating” paint is an immediate indication the entire bag is crap. Do not buy that paint!

Bottom line: You want your paint to be as dry and as round as possible with the thickest shell you can get. If the paint has a small diameter (usually anything under .686 to .684), then you’ll need to compensate with barrel inserts or a sized barrel that matches the size pellets you have.

Play safe and be a good port,
Slim

“What’s the best brand of 12-gram CO2 cartridge to use”?

Question (from an online post):
“What 12g's do you suggest running? Off Daisy 12g's from Walmart I got around 37 average shots (just doing math, ball consumption vs 12g consumption throughout the day). I'm using a Phantom”

Answer:
We have found that the one of the best quality 12-gram brands to use is Leland. However, it's important to note that 12-gram efficiency has little to nothing to do with the brand of cartridge that you are using. Caveat: some brands of 12-grams have been known to have "short fills" or add extra oil (to act as a lubricant) to their fills. Lelands have been consistently reliable, and don't seem to have extra oil added to their fills, which is why we recommend them.

The most economical way to purchase 12-grams is in bulk directly from the manufacturer.

Leland Website: Leland

12-gram CO2 Efficiency in Nelson-Based Markers

The topic of 12-gram efficiency has been one of the most frequently discussed topics over the years among stock-class players. Because of this, and the abundance of complete misinformation surrounding the topic, it’s going to be one of the top tech articles we cover.

This topic is broken into three sections. The first section will address the basic principles of how CO2 works (don’t worry, I kept it comparatively short). The second section will address the theoretical application of maximizing efficiency from a 12-gram cartridge over a chrono. The third section will address the practical application of 12-gram efficiency during actual game play.

Section 1 - How CO2 Works (If you don’t understand the basics, then you’ll never understand efficiency):

Unfortunately, the internet is rife with misinformation regarding 12-gram CO2 efficiency. The primary reason for this seems to stem from a total lack of understanding of the basic principles of CO2. I have read all sorts of wild claims by players alleging they get 50+ or 60+ usable shots from a single 12-gram on a Nelson-based gun. Some claim that using some sort of “devolumizing” method like sticking a plastic stir rod in a hardline works wonders. Or that using a “bobbed” valve body (*see more below on “bobbed” valve bodies) is the way to go. Or that aftermarket spring kits, lightened hammers, polished internals, or larger I.D. valve tubes make all the difference. However, at no point have I ever seen any evidence to prove these claims true. Ever. Any one of these gimmicks may yield marginal gains in efficiency, but given the inherent nature of CO2, it’s safe to say that none of them will produce the type of significant performance gains that players are looking for.

It’s All About The Temperature
12-gram CO2 efficiency is affected by a multitude of variables, but the most important thing to understand is that CO2 is a complicated element that can exist as a gas, solid or a liquid depending on what the temperature is. CO2 pressure is determined by temperature first, and then the volume-to-fill / volume-to-size ratio of the vessel it is contained within. So, keeping in mind that temperature is the most important factor, let’s look at some examples of how it effects 12-gram efficiency.

As most of us already know, hotter temperatures raise CO2 pressure. Colder temps lower CO2 pressure. At 80 degrees CO2 pressure will be around 969 psi (in a 100% filled vessel of any size). It is not uncommon to get between 32 to 37 usable shots from a 12-gram in warmer 76° F to 80° F weather. Note that these numbers also factor in using high quality (round, no dimples, no residue) paint and a good paint-to-bore match barrel. "Usable" means any shot over 220/200 FPS, as anything under 200FPS probably won't break. If the temperature is lower - say 35°/40° F, then you will get far fewer shots per 12-gram (at 40° F CO2 pressure will be around 567 psi). If the temperature is higher - say 95°/100° F, (at 100° F CO2 pressure will be north of 1,200 psi) then you will get more shots - very likely, over 40 per 12-gram. If you live in an area where the temperature fluctuates throughout the course of the day, then efficiency (and velocity) will vary accordingly unless a regulator or stabilizer is used (see more on regulators/stabilizers in a separate section below).

Section 2 - Maximizing Efficiency From a 12-gram Cartridge Over a Chrono:

Because CO2 pressure is determined by temperature, it’s important to understand that the number of shots you will get while at the chrono, will be completely different than how many shots you get during actual game play because the rate of how fast the gun is fired effects CO2 pressure (and thereby efficiency). When the gun is fired rapidly, the quick release of CO2 chills down the entire system. When the gun’s air system is colder, the CO2 pressure will not be as high as it would be if the gun was at a warmer (ambient) temperature. Most players don’t rapid fire over a chrono, but will often do so during game play. This can have a noticeable impact on overall efficiency. If you take your time in between shots during game play, and allow the air system to warm back up to the ambient temperature, this will help maximize CO2 efficiency. However, controlling your fire rate on the field isn’t just about trigger discipline as game play dictates how fast you’ll be firing. Because game play dictates how fast you fire, then it stands to reason that each game will produce slightly different results as far as efficiency is concerned.

Paint-to-Bore Match and “Blow By”
The second biggest factor in 12-gram efficiency is paint quality and the paint-to-bore match of your barrel. While these are technically two separate variables, they are connected in this matter. Using either barrel inserts or a sized barrel that matches the size paint you are using prevents gas from blowing by the pellet as it travels down the barrel. This maximizes efficiency. Using out-of-round paint, or a barrel that is bigger in diameter than the paint you are using allows CO2 to travel past the pellet (known as "blow by"), which wastes the potential energy of the propellant, and decreases efficiency. It should also be noted here that while sizing rings and detents may prevent roll-outs, they do nothing to prevent blow by.

Springs
Spring kits can certainly affect velocity, but may not always impact efficiency in a positive way. The harder the main spring in a Nelson-based gun is, the longer the valve stays open (known as “dwell”). The longer the valve stays open, the more CO2 is released. This can have an adverse effect on efficiency. The main spring and valve spring must be paired to work in unison effectively in order to maximize performance. Overall, springs play a tertiary role as far as efficiency goes.

Don’t Believe The Hype
While there are certainly other lesser variables to the overall equation of maximizing 12-gram efficiency, temperature, paint quality and paint-to-bore match are the three biggest factors. I’ve read numerous online posts from players intent on maximizing efficiency who focus on a lesser variable and ignore the primary ones in the hope that it will create a “magic bullet”. However, their efforts never seem to yield results that can be verified, or defy how temperature impacts CO2 pressure. Despite what unverified opinions you may read online, I can say definitively that polished internals or a plastic stir rod in a hardline do absolutely nothing as far as improving efficiency (and I truly regret verifying these claims as the amount of 12-grams I wasted was significant).

Section 3 - 12-gram efficiency during actual game play:

Personal Perspective on “Performance Tuning”
Over the past 35 years I have devoted countless hours to efficiency testing and trying to maximize every last drop of CO2 out of a 12-gram. Looking back, I can honestly say that I wasted a lot of time focusing on an aspect of “performance tuning” that really isn’t that complicated. If you are playing in warmer temps using the best paint-to-bore match barrel or insert as you can with decent quality paint, then expect good 12-gram efficiency. If you are playing in colder temps with poor quality paint and a larger bore barrel that the paint you are using, expect poor 12-gram efficiency.

The Reality of Efficiency During Game Play (a.k.a. “Tactical Reloading”)
I think it’s important to start off by saying that I use my chrono to set my initial average velocity, not provide a definitive assessment of my 12-gram efficiency. While I believe a string of results over the chrono will be representative of in-game efficiency to a degree, I also know that long pauses between shots when it’s hot, or rapid firing when it’s cold during a game can result in significantly different efficiency results.

In all my years of playing I have NEVER come off the field thinking to myself “Damnit! I’m SO mad that my 12-gram efficiency was off by three shots!”. For that matter, I have never, EVER heard any other player complaining about their efficiency being up or down by a few shots after a game either. Why? Probably because we’re all too focused on game play and not our shot counts. Trying to eek out every last drop of CO2 from each 12-gram during actual game play would be foolish because doing so could leave the player in a vulnerable position at a critical point in the game. The vast majority of players I know practice “tactical reloading” and immediately dump their 12-grams the second they get a chance in order to have a full charge - whether the cartridge is spent or not. Given that fact, stressing about whether your gun will get 38 shots instead of 35 seems pretty silly.

Bottom Line
• Consider the climate you will be playing in. Understand that as far as efficiency goes, the hotter the temp, the more shots you will get per 12-gram. In colder temps, your efficiency will go down.

• Consider how your gun is configured. Guns with the 12-gram located closer to the valve body may provide slightly better efficiency than guns configured with the 12-gram located farther away.

• Using 275 FPS as your max velocity at the chrono, ensure that you are using high quality paint and have the best paint-to-bore match barrel or insert you can. Don’t forget that poor quality paint will often negate any efficiency upgrades you have.

• Remember that rapid firing at the chrono or during game play chills the system and lowers pressure, which negatively affects efficiency.

• For Nelson-based guns, experimenting with springs may offer some gains. A lighter main spring combined with a standard valve spring is usually recommended.

• In addition to changing spring tension, some players experiment with larger inner diameter valve tubes. Lapco (as of 2023) still sells #4 size valve tubes (which is not a larger size) for about $22 each. Remember that increasing the valve tube size means velocity will go up, so you’ll need to adjust your velocity accordingly. This is also true when experimenting with springs. Depending on how the gun is configured, it is always possible that using these methods to increase velocity can have a negative impact on efficiency, so diligent testing is required.

12-gram efficiency in stock-class play is an important consideration, but there are far too many variables involved for it to be attributed to any one factor or modification. Don’t get too hung up on trying to achieve some magical shot count at the chrono. If you’re getting over 30 usable shots from a single 12-gram, then you’re doing fine. Just get your gun set up as best you can, and then go have some fun.

Be safe, and be a good sport,
Slim

*Addendum: The “Bobbed Valve” Craze
A “Bobbed” Valve body (usually when referencing a CCI Phantom or similar Nelson-based gun) means the valve body of the gun has been cut down in length. The common misconception is that these valve bodies were cut down to decrease the volume of air inside the valve chamber. This is demonstrably untrue. In reality, all a “bobbed” valve body means is that excess solid metal from the back of the valve has been removed. The valve chamber itself is normally left untouched. If the valve body is cut down too close to the valve chamber, the wall thickness can be compromised which could result in catastrophic failure under pressure. As this modification is purely for aesthetics, can be potentially dangerous and provides zero performance gains, it is not something that is recommended.

Are Regulators and Stabilizers On Nelson-Based Guns Helpful In Stock-Class Play?

Many players who enjoy stock-class play love to tinker with their equipment in the hope of either maximizing performance or just making something look cool. One accessory players have considered for their Nelson-based marker is either a regulator or stabilizer. One common misconception is that a "reg" or "stab" will increase their marker's efficiency. This is not the case. The primary function of a regulator/stabilizer is to regulate/stabilize the pressure that is entering into the valve body. While regulating the pressure coming into the valve body can help provide a more consistent FPS reading at the chrono during a string of shots, it does not guarantee an increase in co2 efficiency (see 12-gram efficiency article above for more info).

Some players have insisted that it also helps vaporize liquid CO2 into a gaseous state (which theoretically will improve efficiency), I'm not convinced this is true. This claim is called into question because the physical state of CO2 is predicated upon the temperature and not by any mechanical means. While I may be unaware of a mechanical method to help facilitate this transition, I have never seen any documentation that proves this claim to be true.

When it comes to regulators, and more specifically stabilizers on stock-class equipment, here is all you really need to know. Most units are high-quality, well-built, easy to maintain and do provide the luxury of stabilizing the output pressure during dramatic shifts in temperature throughout the day. During the spring and fall in a region like the northeast United States, mornings can start off in the low 30°s F to 40°s F, and end up in the high 80°s F during the afternoon. When using 12-grams, this means paying close attention to chono readings throughout the day so you're not chronoing at 350FPS at 3:30PM in the afternoon when you originally chrono'd at 265FPS six hours earlier. The use of a stabilizer simply means that it's less likely you'll need to adjust your gun for these wider temperature shifts. That's it.

Any gains realized in efficiency or even shot consistency may be marginal at best. At least I haven't witnessed any huge performance boosts and I've been using stabilizers on my CCI Phantoms for almost 20 years.

Two important things to note in regard to the Palmer's Pursuit Shop (PPS) Phantom Stabilizer... first, on my guns I had to use a higher tension red spring from CCI with the PPS Phantom stab. I do not know why. All I know is that the stronger spring created optimal performance for the gun I was using it on. Others may have had different experiences. Second, the PPS Phantom stab has both a micro gauge (what I call a "ballpark" gauge given how inaccurate these things are), as well as an external velocity adjustment. It's been my experience that this external velocity adjustment can actually "fine tune" your FPS far better than the factory CCI internal velocity adjustment. Like a LOT better and far easier! In my mind, it's been a great feature and helps justify the price tag (or at least that's what I like to tell myself after spending the $150 on the unit).

Note: As of May, 2023, it is not clear if Palmer’s Pursuit Shop is still in operation. Call before placing any orders online.

Bottomline: A reg or stab provides a luxury feature at a comparatively high price point. Yes, they are nice to have, but unless you've got a lot of cash burning a hole in your wallet, it may not be worth the investment. If you don't live in a region that experiences large temperature shifts, then it's not going to be much help. And even if you do, you can certainly get by just fine without a reg or stab by simply chronoing and adjusting your gun throughout the day as the temps fluctuate.

How To Prevent Losing Your Nelson-based Piercing Pin Seal

You're in the middle of a game and the action is getting pretty heavy. You're trading shots with multiple opponents, and really putting out some paint. In the heat of the moment, you forget how many shots you've used off of your 12-gram. "Have I fired 20 shots yet?" You decide not to risk running low, and unscrew your bucket changer. Apparently, you had quite a bit of CO2 left. Oh well. As you twist in a fresh 12 gram into your bucket changer you hear the familiar hiss that signifies a pretty big leak. Figuring the CO2 didn't seat correctly, you dump it and put in a fresh one. Same thing - a big leak. "WTF? The gun wasn't leaking a minute ago! Why is this happening now?!" Just as you are about to curse the Gods... Pop! You're hit in the leg and are now eliminated.

Sound familiar?

So what happened? Most players know that the 12-gram piercing pin seal must have fallen out at some point, but don't know why, or how to prevent it from happening again. When you rapidly dump a 12-gram that still has a fair amount of CO2 in it, the rapid expulsion of freezing CO2 gas shrinks the seal and blows it out of the pin assembly. Note that this will hold true for any Nelson-based gun (Nel-Spots, CCI Phantoms, Lapco Gray Ghosts, Carter Comps, RTR Gargoyles, etc.), and for a variety of 12-gram changers that utilize the factory piercing pin assembly. So, how can you prevent it?

When you realize you need to change 12-grams, simply back off the 12-gram from the piercing pin by a quarter turn. Do this as S-L-O-W-L-Y as you can. This prevents the seal from blowing out of the assembly. Once the remaining gas is expelled, quickly tighten the empty 12-gram back into the piercing pin. This re-seats the seal in the assembly if it has come loose. Now you can safely remove the used 12-gram and replace it with a fresh one.

That’s it.

Understandably, this sounds like a very time consuming process that could result in your elimination. The truth is, with enough practice, the additional time it takes to re-seat the 12-gram is only about a second or two. Sure, every second counts, but this technique is far better than losing a piercing pin seal in the middle of game play which will result in a non-functional gun. This technique has been proven to work for any twist-off 12-gram changers (Bucket changers, speed wheels, drop-outs, etc.).

Play safe and be a good sport!
Slim

How To Prevent "Roll Outs" In Your Stock-Class Gun

A popular complaint of many stock-class players is that their paintballs will roll out of the barrel of their gun before they have a chance to aim and fire. The reason this occurs is because paintball manufacturers are producing smaller caliber paintballs that will feed better in the high-end semi/full auto markers.

Smaller caliber paintballs aren't a huge issue for the mainstream mechanical and electronic markers as there are a wide variety of smaller bore barrels for these guns, as well as barrel bore insert kits that will prevent roll outs. Unfortunately, older stock-class guns like the Nel-Spot and PMI/Sheridan guns have fixed barrels with bores that are quite a bit larger than the paint that is currently being produced. Owners of newer stock-class guns like the CCI Phantom, and the Lapco Grey Ghost also have bigger bore sizes, and experience the frustrations of roll outs as well.

One solution is to try and find manufacturers who produce larger size paint, but that only works for players who are able to use their own paint. As many fields are Field Paint Only (FPO), players are forced to find different options.

Many players mistakenly believe that paintballs are made in .68 caliber, or pretty close to that. The truth is paintballs have ranged in size from over .690 down to .670. These tiny tolerances may seem insignificant, but I assure you they are not. Here in the Northeast the "larger" brand paint we use can vary from .678 to .685 (with the .685 considered to be “huge” comparatively speaking).

One of the cheapest and easiest solutions is to layer a bead of nail polish on the edge of the barrel that contacts the breech. This gimmick will be harder to perform on older guns with fixed barrels, but can be easily achieved with removable barrels. For Phantom owners with stock barrels, CCI sold an inexpensive detent ring kit with different sized rings that will help prevent roll outs.

Owners of Sheridan-based guns who feature fixed brass barrels can opt for what are called "Wedgits". Wedgits are precise dents placed on the side of the barrel in front of the breech. As far as I know, Palmer's Pursuit Shop is the go-to source for installing wedgits in your Sheridan marker, however turnaround time for work has reported to be quite lengthy to say the least.

Roll outs aren't the only consideration when smaller diameter paintballs are used in larger bore barrels. Even with some sort of detent in place, a small amount of CO2 is wasted when it blows past the smaller paintball as it travels down the larger bore barrel (called “blow by”). The end result is that the player must increase the velocity of the gun, and will get fewer shots per 12 gram CO2. An ideal solution would be to prevent roll outs and maintain CO2 efficiency.

The next best thing to a detent ring would be bore sizing inserts, such as Freak inserts. Note that insert kits will only work on removable barrels. Freak inserts will work with any barrel, but require that your removable barrel be bored out by a skilled machinist to accept the insert. CCI offers what they call a “C’ bore” barrel (counter-bore) that accepts Freak inserts and has become the single best option for Phantoms.

Another option for Phantom owners that is currently available (as of June 2022) is the “ASP Detent Mod” from Air Soldier Products. The ASP Detent Mod uses two tiny o-rings which fit into two precise holes that have been drilled into the Phantom breech to not only prevent roll outs, but stop double feeds as well. Visit https://airsoldier.com/ for more info.

(The TechT iFit kit is no longer in production for the Phantom, but if you can still find one, it makes a decent alternative to the Freak system.) The iFit kit is a screw on sleeve that the sized insert fits into. Their Phantom kit required that you either buy an under-cocking pump (not recommended), or purchase a matching iFit Phantom pump handle. The TechT iFit kit came with 6 inserts (.685, .682, .679, .676, .673, .670).

There are other Phantom-threaded barrels that are designed to be used with Freak inserts such as Deadlywind Carbon Fiber barrel (no longer in production). While insert kits are far superior to detent rings or wedgits, they do allow a marginal amount of CO2 "blowby" compared to a fixed-bore barrel.

The best solution to solve both roll outs and maximize CO2 efficiency is to use a one-piece “fixed bore” or “control-bore” barrel that is the same size (or a hair smaller) than the paint you are using. Currently there are few options for Phantoms. Lapco had a great reputation and made four "Big Shot" barrels for the Phantom in .690, .687, .684 and .681. I have used all and can say they shoot very well. Unfortunately, they are no longer in production and finding a NOS or used one is difficult.

Years ago J&J made 12" and 14" ceramic barrels for the Phantom (size unknown). A newer company from Canada called Flasc made a limited run of ported Phantom barrels in .678, .681 and .702. The Flasc kit originally sold for around $50, but are no longer in production.

Palmer's Pursuit Shop currently (as of June 2022) offers a custom made ported Phantom-threaded barrel in .680, .685 and .690.

The overall lack of options for Phantoms probably have the owners wondering if nail polish or a C-bore barrel is their only hope. The last option I know of is to have a fixed barrel (any make or model) "re-sleeved" with a custom made insert that extends the entire length of the barrel. You may be able to find a machinist online who offers this service, but do your research before committing to this.

The bottom line is that for Phantom owners, sized “control bore” barrels are the most effective way of preventing roll outs, and the most efficient way to maximize CO2 usage. The issue is trying to get a hold of a control-bore one-piece barrel due to the current lack of supply. Currently, the CCI C’ bore barrel (now known as the “Phreak Barrel” at phantomonline.com - which is operated by Extreme Velocity of OR) that accepts Freak inserts is the single best option available.