Wildcat cartridges, the best PRS caliber, and how to actually improve a rifle’s accuracy: these are three of the questions we get asked the most, so we sat down to answer them straight. Short version: there is no single best PRS caliber. There are tradeoffs, and which ones matter depends on what you’re building the rifle to do.
What Is a Wildcat Cartridge?
A wildcat cartridge is anything that isn’t a SAAMI-spec cartridge you can buy off the shelf, cartridges like 6.5 Creedmoor, .308, or .223 Remington. Wildcats show up constantly in F-Class and PRS. If you’re shooting one, you’re stuck handloading for it, since there’s no factory ammunition to buy.
How a Wildcat Becomes a Standard Cartridge
Every wildcat starts as a standard parent cartridge that already has a SAAMI spec, then gets modified from there. If a wildcat becomes popular enough, a major manufacturer can pick it up. Hornady is the example here: a cartridge gets popular enough that Hornady decides that’s what they’re going to start making. Once that happens, the cartridge becomes SAAMI spec, and that’s really the end of it being a wildcat. You can still handload or reload for it afterward, you just don’t have to modify your own brass to make it work anymore.
A lot of precision shooters choose to shoot wildcats anyway, even knowing it’s more work. In this sport, people tend not to mind making things harder on themselves.
What “AI” Means on a Cartridge Name
One of the most common wildcat modifications is the Ackley Improved case, the “AI” you’ll see on a cartridge name like .223 AI. Making a cartridge Ackley Improved typically increases its velocity, which is exactly why PRS shooters look for wildcats in the first place: more velocity out of a smaller case.
Fire Forming Brass: The Tradeoff for More Velocity
The tradeoff for that extra velocity is that you have to fire form the brass yourself. Fire forming reshapes a parent cartridge’s case, typically changing the shoulder position and sometimes the case length. Going from 6BR to 6 Dasher is a good example: the shoulder gets blown out by roughly .100 inch, and the neck angle changes from 30 degrees to 40 degrees, giving you a flatter shoulder.
Fire forming used to be a real requirement for 6 Dasher, because headstamped 6 Dasher brass didn’t exist yet. Now it does, so you can just buy it directly.
One fire-forming method: load a 6BR case with a primer and a charge of pistol powder, fill the rest of the case with cream of wheat as a filler, and pack the mouth with a piece of tissue or paper towel to hold everything in, with no bullet seated. Fire that in a rifle already chambered for the wildcat you’re forming to, 6 Dasher in this case, and the chamber reshapes the case as it fires. It typically takes two firings to get the case close to perfect, but it’s usable for loading after the first one. From there, you can load and shoot it like standard ammunition.
This process is ridiculously time consuming. Once headstamped 6 Dasher brass became available, more shooters moved to Dasher specifically because they no longer had to fire form their own brass. You still have to handload it, you just skip that one step. Dan Cogan remembers the value of formed brass well enough that he’d dig through grass and dirt at the range rather than lose a fired case that took 20 minutes to produce.
22 Creedmoor: A Wildcat That Made the Jump to Factory Ammo
22 Creedmoor is another wildcat that got picked up commercially. It started with predator hunters necking a 6.5 Creedmoor case down to .22 caliber, and once the industry noticed, Hornady started making factory-loaded 22 Creedmoor ammunition you can buy off the shelf, no handloading required. It’s fast, close to a modern equivalent of .22-250, and it’s the current new hotness in that category.
What’s the Best Caliber for PRS Competition?
This is probably the single most common question 360 Precision gets. When someone says they want to build a custom rifle and asks what caliber to put it in, the honest answer is usually another question: what are you already thinking about? Most people asking aren’t looking for an open recommendation, they’re looking for confirmation of a choice they’ve already made in their head.
Here’s the part that often surprises people: Dan and Braxton’s view is that any rifle built well by a good gunsmith is going to shoot around half MOA. If you have a half-MOA rifle and you’re missing the target, that’s generally not the cartridge’s fault, it’s the shooter’s, or a handloading mistake, like an accidental double powder charge. There’s no single correct caliber answer. Different calibers just have different tradeoffs.
Why PRS Shooters Want Heavy, Low-Recoil Rifles
PRS competitors generally want heavy rifles with low recoil, because they need to be able to spot their own misses on the target. A .308 works perfectly fine in PRS, but it produces more recoil than a 6BR or 6 Creedmoor. Competition rules also place bullet-weight limits on some calibers that affect which class you compete in: the .223 limit discussed is around 77 grains, and a .308 limit was also mentioned, though the exact number wasn’t stated with confidence even by the gunsmiths answering the question. If you’re building around a specific weight limit, the recommended step is to check the current rulebook rather than go by secondhand numbers.
It’s the Shooter, Not the Cartridge
Every competitive season, top shooters tend to gravitate toward whatever cartridge is trending that year, and it changes constantly. In recent years that list has included 6 Dasher, 6BR, 22 GT, and 6 GT, among others.
There’s a Precision Rifle Series blog that tracks which cartridges the top-ranked competitors, roughly the top 100, are actually shooting, with published charts on cartridge usage. But cartridge choice matters less than people think. Dan points to a simple test: hand a top-ranked shooter a 6.5 Creedmoor loaded with standard factory ammunition, and that shooter will still beat him, regardless of what cartridge he’s shooting himself. A cartridge with less recoil can help make someone a somewhat better shooter, but it isn’t what makes them a better shooter overall. Time spent practicing and shooting is what actually improves performance, more than caliber choice does.
Why Some Shooters Never Switch Cartridges
Dan shoots 6BR year after year rather than chasing whatever’s newly popular, and the reason is familiarity. He knows that cartridge well enough to trust his wind holds and dope from memory, down to knowing that at 400 yards he’s dialing around 1.8 mils, even if the true number on a given day is closer to 1.7 because of wind or elevation. He knows most of his distances within roughly a tenth of a mil without having to think about it.
That familiarity has bailed him out before. He once had the wrong ballistic profile programmed into his Kestrel and had written down incorrect dope, but because he knew the cartridge and rifle so well, he was able to self-correct in the field despite the bad data. That’s the whole reason to stick with the same cartridge season over season: you get to know your wind calls and your dope by heart. Some shooters genuinely enjoy switching to a new cartridge every year just for the novelty of it, and that’s a legitimate reason too.
Budget, Recoil, and How Much You Want to Reload
Before picking a cartridge to reload for, it’s worth asking what your budget actually is, since reloading costs both time and money. Dan ran a full season on factory 6 Creedmoor ammunition, Berger, at around $28 a box, a few years back, before the pandemic. Showing up to a match with sealed factory boxes while everyone else had spent the previous night handloading was its own kind of nice. That same ammunition later got harder to find and roughly doubled in price to about $49 a box, which was part of why Dan switched to 6BR the following season, along with wanting less recoil than 6 Creedmoor produces.
The general principle: it’s better to spend time at the range practicing than at the reloading bench, because shooting makes you a better shooter more than reloading does. That said, reloading itself is a genuine hobby for a lot of people, and if you love sitting at the bench, that’s a perfectly good reason to pick a cartridge that requires it.
What Can I Do to Improve My Rifle’s Accuracy?
Say you’re starting with something like a factory Remington 700. There’s real room to improve it. The single biggest change is usually replacing the factory stock with a good chassis or a quality aftermarket stock, something like a McMillan or a Manners. We covered the tradeoffs between stocks and chassis systems in a previous episode.
Stock, Trigger, and Bedding First
Chassis systems don’t need to be bedded. If you’re using a stock instead, bedding the action is another major improvement worth doing. Upgrading the trigger away from a stock factory trigger, often around a 6-pound pull, is another common step. Aftermarket trigger options exist for Remington and Tikka actions. Savage has fewer options, but some exist.
Bedding itself is done with a two-part epoxy compound. A release agent goes on the action, the recoil lug, and any surface that will touch the epoxy, then a light coat of bedding compound goes into the stock where the action sits. The rifle gets reassembled and left to cure overnight. The next day, the action screws come out, the barreled action lifts free, and what’s left is a precise custom mold of that exact action inside the stock.
The point of bedding is to stop the action from shifting inside the stock during handling or transport, so the rifle goes back together the same way every time. It also removes stress between the action and the stock. An un-bedded stock can flex or pull by a few thousandths of an inch when the action screws get torqued down, and that small amount of stress can cause real accuracy problems. Chassis prices vary widely, roughly $500 to $2,000 or more, with brands like Magpul covering a wide range of that spectrum.
Blueprinting the Action
Beyond a stock swap, Braxton walks through a deeper option: blueprinting the action. The factory barrel comes off, then, using a lathe or gunsmith jigs, the front of the action gets re-faced so it’s perfectly true, the receiver threads get recut, and the recoil lug face gets cleaned up. The bore the bolt slides through gets aligned perfectly in the lathe, and the bolt face gets trued the same way, so the action and bolt are both perpendicular to the same centerline. The barrel is then fitted to that trued action. The result is a factory action remade into something that fits and performs the way a purpose-built custom action would. If you want the specific truing and lapping steps a gunsmith runs through on this kind of job, we walked through them in detail in an earlier post.
Accurize It or Buy Custom?
Here’s the tradeoff, in the gunsmiths’ own words: a fully blueprinted, upgraded factory action will shoot as well as a full custom build, but it’s still going to feel like the original factory rifle. Custom actions are now available in roughly the $800 to $1,000 range, which can make building a full custom rifle the more sensible option once you start adding up the cost of heavily upgrading a factory action.
The real reason to accurize instead of replace is sentimental value: a rifle you shot your first whitetail with, or one you want to pass down to a kid. In that case, running it through the blueprint process is worth doing rather than starting over. Dan has been on both sides of this. Early on, before 360 Precision existed, he took a factory Christensen Arms rifle and had it accurized, including lapping the barrel. It ended up shooting well, but it still felt like the same rifle he’d started with, and he concluded it just wasn’t the right tool for what he was actually trying to do.
Why a Broken-In Action Is Worth Keeping
Dan’s first true custom rifle was built by gunsmith Brian Allen, based in Alabama, who he jokingly credits, or blames, for getting him into this business in the first place. That rifle used a Curtis action, since that’s what Brian was using at the time, and Dan deferred nearly every other decision to him. He picked 6 Dasher for the cartridge and earned the nickname “Dasher Dan” as a result, something that stuck for roughly eight years. He doesn’t remember the exact barrel brand or trigger on that build, but he does remember mounting a scope on it and running a Manners stock with the older-style mini chassis. Brian asked whether to bed that rifle, and the answer was no, it wasn’t considered necessary given the stock’s mini chassis design.
Dan eventually sold that rifle, and both he and the buyer have regretted it since. Part of the reason is that an action with thousands of rounds through it gets noticeably smoother from wear, essentially lapped in on itself. That’s why buying a used action can be a genuinely good option, as long as it has no functional problems. Some 10-year-old Defiance actions run so smooth from heavy use that people describe them as buttery. Dan still prefers shooting his own older, broken-in action over a new one, since a new action needs thousands of rounds before it reaches that same smoothness. 360 Precision has rebarreled that particular action multiple times over the years while keeping it in service.
The Bigger Picture: Why These Questions Matter
All three of these questions come back to the same answer: it depends on what you’re building the rifle to do. When someone asks what the best caliber is, the honest response is that it’s the best caliber for you specifically, based on how much you’re willing to reload, how much recoil you want to deal with, and your budget. Dan built a rifle for a friend who doesn’t reload at all and recommended 6 Creedmoor specifically, since quality factory ammunition, Berger, is available for it and ammo cost wasn’t a concern for that particular build. In a heavy rifle, 22 to 23 pounds, 6 Creedmoor produces low enough felt recoil that your shoulder won’t hurt at the end of a match day, and it’s flat and fast enough that Dan has used it to make hits at a mile, which pushes back on the idea that 6 Creedmoor can’t reach out to distance.
Build around what you’re actually capable of reloading, how much recoil you want, and what your budget allows. Everybody’s answer to that is going to be different, and that’s exactly why there isn’t one best caliber, and no single fixed path to a more accurate rifle either.
Ask a Gunsmith FAQ
A wildcat cartridge is any round that isn’t a SAAMI-spec cartridge you can buy off the shelf. It starts as a standard parent cartridge, gets modified, and if it becomes popular enough, a major manufacturer can eventually pick it up and start producing it as a standard round.
“AI” stands for Ackley Improved, a case modification that typically increases velocity. It’s one of the most common ways a wildcat cartridge gets built from a standard parent case.
It started as one. Predator hunters originally necked a 6.5 Creedmoor case down to .22 caliber, and once the cartridge caught on, Hornady began producing factory-loaded 22 Creedmoor ammunition, so it no longer requires handloading the way a true wildcat does.
There isn’t a single best answer. In the gunsmiths’ view, a rifle built well is going to shoot around half MOA, and at that level, a missed target usually comes down to the shooter, not the cartridge. The right caliber depends on how much recoil you want, your budget, and how much you’re willing to reload.
Because they need to spot their own misses. A heavier rifle with a lower-recoil cartridge like 6BR or 6 Creedmoor makes it easier to see where a shot actually landed, compared to a harder-recoiling round like .308.
Yes. Bedding creates a precise, custom-fitted mold of the action inside the stock, which stops the action from shifting during handling and removes stress that builds up when the action screws are torqued down. That stress, even a few thousandths of an inch, can cause real accuracy problems.
It depends on why you’re keeping it. In the gunsmiths’ own words, a fully blueprinted factory action will shoot as well as a custom build, but it will still feel like the original rifle. If there’s no sentimental reason to keep the factory action, a custom action in the $800 to $1,000 range can make more sense once you add up the cost of heavily upgrading a factory gun.
Yes. In a heavy rifle, it produces low felt recoil while staying flat and fast, and it has been used to make hits at a mile. It’s a good option for shooters who want low recoil and don’t want to handload, since quality factory ammunition is available for it.
Have a Gunsmith Question of Your Own?
These are three of the questions we hear most, but they’re far from the only ones. If you’re weighing a caliber choice, deciding whether to accurize a factory rifle or start a custom build, or just want a second opinion on a wildcat cartridge you’re considering, send us your question and we’ll get to it in a future episode.
