33XC Load Development: Efficient Load Testing for High-Performance ELR Rifles
In this firsthand 33XC load development article, we explore efficient load testing for high-performance rifle cartridges with relatively short barrel life, where getting it right early matters. We shall show some project high performance cartridges we have worked on mainly in 33XC for competition and for hunting. Typically all of this is done overseas so whether we do it for us or for a client, we are typically bound by a tight time window when we have to deliver the result. Everyone can get it right eventually if they’re testing hundreds of rounds. With these cartridges, it’s simply not possible because the barrel life maybe 500-700 rounds of 1/3 MOA performance. Our aim was to develop a promising 33XC competition load in about 30–40 rounds. This firsthand 33XC load testing journey takes us across Malta, Italy and France: we began testing in Italy, then evaluated the ammunition in France at Wolf Consulting with Chris Battison from DESA. The article documents our testing process and results rather than presenting universal 33XC load data.
This was the firing line at the Ko1M in France with a cold bore at 765m, the 33XC delivered that smacking impact on the first round! Oh yeah it was a blast to shoot. I knew the rifle could do it. 
The work starts in the reloading room. Below i’m setting up to load for the 416Barrett and the new 33XC barrel. My reloading room is my peaceful place where machinery and projects come together. 
Rifletalks.com has a softspot for high performance cartridges and it’s understandable, many of our audience including me, are into long range leaning into the ultra long range and ELR matches where these calibers are meant to exploit their full capabilities. Below you can see Rusty Newton’s Alamo built 416 Hell Fire. Rusty is the King of 2 Miles 2026 Global finals winner. We have interviewed him to learn how he does it. 
This 50BMG Match round from Jordan Congon’s ammo case doesn’t eat barrels fast as a 33XC yet still it consumes over 240gr of ammo. At that amount of powder, you want to be testing rounds in an effective and efficient way. 
Today I discuss efficient load development for high performance rifle cartridges – cartridges that will smoke that barrel by the time most shooters have started to get familiar with their rifle. In a world where barrel life may be 5-700 match rounds, 50 rounds of load testing is nearly 10% gone. Sure the remaining 450 is many matches and if you flip between different match rifles and barrels that may lessen the concern. Ultimately even if you do barrel-hop, you’re still investing in a new rig. You got to find time to do it and then you still want to do it efficiently. So let’s find out how we can shorten our load development to useable precision. For this article and purpose, I will use this new RPA 33XC bartlein barrel I have on shown below. It’s a 33″ Bartlein 1.9 R twist barrel with a Warner Tool Company MOAB Brake, if you ask me, one of the most beautifully crafted muzzlebrakes in the industry distributed in europe by SSDguns.com. I have two identical barrels for it. I topped it up with a 16x Leupold mk4 the original one that served for many years on numerous tactical rifles, it still does the job. I was going to shoot mainly at 300m with this for load development. This setup is good for some 2500meters if the conditions are right and you can spot your misses. I love the bolt on these rifles, it closes like Fort Knox.
For me that’s a 1″ group at 300m of 3-5 rounds. I can’t read wind better than 1MOA at best. That sort of group with an Extreme Spread of 10-12 fts (difference between highest and lowest velocity) or less is competitive enough to keep you inside the plate – with the right spotter behind you I may add.
▶ Watch the 33XC long-range shooting video on Instagram (open video)
Watch the 33XC long-range video on Instagram
As we stretch distance we enter into the last bit of the supersonic range and transonic range of the cartridge/bullet combo before going subsonic. At those distances everything matters. Even the type of ground and angle you’re shooting at will make a difference. Wet ground produces poor signature. Hard dry ground leaves little signature. Performance by ELR KO2M 2026, 2 Mile champion, Rusty Newton such as this below at 3119 yards, shows mastery of equipment and superior load development for ELR.
▶ Watch Rusty Newton’s ELR shooting video on Instagram (open video)
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I use to put chalk around the targets for my big Match to help increase the signature and it needs to be done the night before the match to keep it dry. Hard stone areas will give off very little signature as you increase distance. Solid copper bullets may just drill through leaving your spotter wondering where it actually went even at 550grains of a ballistic ELR behemoth. Is high performance handloading only needed for ELR? No, high performance is not for ELR only. Hunters are also pushing the limits on cartridge performance, because they have 1 shot and if that happens to be in the mountains and they’re carrying a 33XC like this Fanzoj 33XC like this: then they may just be able to take that shot at 500m in high winds on the Mid Asian Kyrgyzstan Ibex where everything may look uncertain. When I did load development for my friend mark’s 300RUM which he took to Kyrgyzstan to hunt Ibex, performance was important but also the reliability of it feeding well, of having the adequate neck tension for the purpose and also to stay within 1MOA at 600 yards. Now back to the 33XC load development. 
Mind you, I spent 5 years organising and running Extreme Shot Italia, from when I started it as a small match during covid to its peak in 2025 when I grew it to 230 teams from 32 nations with 30 partners. [I’m no longer involved in the replicated ‘V2’ version] Only a very small percentage of shooters under 15% can hit a 1MOA target cold bore at 600m, that’s statistic with a 338LM in match conditions with some of the best shooters in the world. ______________________ Last year while visiting the UK, I had my RPA 300Norma Mag rebarrelled, I fixed a Desert Tech SRS A2 33XC extension with a new one and had two 33XC barrels made for my new Rpa Rangemaster as well as completing a 2nd barrel for my 416Barrett custom build that was a project rifle for years… i went to my friend Mik Maksimovic. He had to fix a Bat bolt that was damaged at a proof house, and check a new one that Bat sent me. While we were there we went through a few other jobs to make the long trip worthwhile. Paperwork and permits had taken a good 8 months plus on this so the wait was long. RPA RANGEMASTER 33XC /300Norma Twin Below: Top 33XC RPA Range Master and it’s exact equivalent in 300Norma Mag. The former gives around 500-800 rounds of match performance while the 300NM provides a good 1000-1500 rounds depends how hard and fast you run it. For the purpose of this article, most shooters are running 15 round strings. If you’re hunting, the longevity of the barrel will probably be longer as you’re not shooting strings with the rifle. 
RPA Rangemaster rifles was a brand that was very popular in the UK building rifles for target, military contracts abroad and also some hunting rifles. To me they are my preferred rifle, i bought two that were made 2 weeks apart with serial numbers almost identical originally in 338LM. When I can find one, i’ll buy it firstly coz i believe in the system and secondly cause I can use their parts which I bought. The only thing I dont like is the folding stock mechanism that doesnt have a hold close latch to keep the stock securely folded. Once you open it in shooting position, it’s right and firm. They are built simple, tough, and over engineered to last in conditions which are not ideal. They simply work, functional and always go bang. I bought a few spare bits and bobs from their servicing department which is still run by Sid Hawkins a knowledgeable, dedicated armourer from times gone by. After a few rifle builds i’ve done over the years, I value dependability/ reliability first, then practicality, precision and performance in that order. I have always travelled overseas to practice rifle shooting so a rifle not working to me means money down the drain – time off work, travel miles lost and frustration on the way back. Practical means not being larger than it needs to be and compact enough to carry in a plane not a 16ft+ pickup. RPA does what it said on the tin and generally this is where I pivot these days. Mik Maksimovic from Dolphin Gun Company jokingly tells me they’re not refined. Today their legacy continues as Steelcore rifles in the UK adopting pretty much the same design. I have BATs too, theyre lovely but like a Cartier watch, you gotta look after it carefully. 33XC Fanzoj hunting Rifle in kipplauf formatThis is an example of a high performance hunting rifle built by Johann Fanzoj for which me and Harry loaded ammo for it in Austria. When loading ammo to test such a rifle build, you want to make sure you can get to the sweet node in as little amount of shots possible. Johann Fanzoj have been building custom rifles since 1790. 
I’ve handled and reviewed some stellar rifles including bespoke ones from Johann Fanzoj: Luxury 338LM Johann Fanzoj but even those came with function first as they are dangerous game rifles built on trusted mauser actions. Celebrated hunters like Ammon Ammon had their rifles built by them. We even interviewed Ammon Ammon. 
This rifle Range in Austria is a 300 year old range, one of the oldest in Ferlach where Johann Fanzoj has tested rifles for centuries before building their own, on-site range. 
Back to the 33XC load development and testing. Load development for some is a compelling exercise. In some countries where ranges are limited, travelling can often take a few days especially to find ranges beyond 300 meters. It took me 2 ferry trips to load development at 300m and then test them at 600-1200m. That’s €1500 in load development. My friend Chris Battison from Dynamic Evolution Academy (UULRand tactical Training academy in Switzerland/France) had his competition 33XC stiller Tac338 rifle and his PGM precision military sniper rifle in 338LM with a new match barrel with him. The firing pin broke on his stiller competition rifle that came all the way from Texas to France and he had to go back to his 338LM PGM precision. We couldn’t locate a firing pin fast enough. Below you can see Chris’s 33XC rifle during zeroing at WolfConsulting in France. 
33XC Testing in the Wild at wold consulting France.
33XC ammo testing in the wild with Chris Battison as a spotter guiding me to put rounds on target way out there past 2400meters with that 33XC. 
Steiner IFS 4-28×56 shown below on my 416 Barrett at wolf consulting. 
Out came his French made PGM Precision in 338LM. I compare this to the RPA Range Master in the UK in terms of durability and build quality. Simple and effective, always delivers. 
12th Place at KO2M France
We finished in Finals with that PGM mini hecate Rifle, 12th position at Ko2m France, made hits to 2200m in training at Wolf consulting south of France see images below and it shot lights out. Chris and Jay shoot often together, the two flying between the US and France to team up for matches. 
I was like damn this thing shoots and is tough to withstand operational duty too. Chris added a rear bag rider, a tuner with muzzlebreak, and a relatively light profiled 338LM barrel which i think is 0.9″ at muzzle. Chris is a former squaddie, and weapons are tools for him. For me they’re projects I had built. I dont like to abuse my kit but his can take that too. He wasn’t even going to shoot the match and in all sorts of French i tried convincing him to do so while driving from Wolf consulting to our lovely base camp hotel in the French country side. I drove a right hand drive car and chris found himself caught out at times lookig the wrong way. 😂 
Eventually we had a few beers and were glad he did, we shot first time together and we were going to finals 🤣 Chris is metodical, I enjoyed shooting with him, he speaks French and English with equal proficiency and a distinct accent. We had a good laugh after the match and the adrenaline was pumping hard.
PREPARING THE RPA 33XC load for ko1M 🇫🇷
For that trip, i had 1 weekend to get my rifles ready, between my cybersecurity work, a construction project underway the brand new rifles sat in my reloading room begging for load development. What a pity I thought. Let’s do it! I called up my friend in southern Sicily that has a 300m range and is always happy to host visitors. I put an old leupold mk4 16x, and loaded up a few charges in 0.3gr increment of n570. I typically load 4 rounds of the first load, this was 110gr N570 to get the rifle on paper with, I may do this at 25m to ensure I dont waste rounds. I loaded the rounds to be just about 0.015″ off the lands. I typically take one of the fired cases used by the proof house, size them without the bushing so I don’t touch the neck. This way a bullet can slide in easy. I wrap a small piece of paper around the bearing surface of the bullet and slide it in the case. This gives enough neck tension to hold the bullet while allowing it to slide inside the case after the bullet contacts the lands. I do this a few times then come off 0.015″ off tha measurement. You can see an example below. 
For actual loads, I use about 0.0025″ neck tension. I typically buy 3 or 4 bushings to ensure that I can get this, I never change the bushing whilst doing load development, otherwise you induce another factor – neck tension. I don’t waste ammo zeroing the rifle precisely, I just want to make sure the loads go on paper. Typically a bore sight before I leave home against a pole some 100m away and it will tell me if the bore and optics are inline. If you don’t do this, you may waste ammo. I was already planning not to push this load hard, I wanted somewhere between 3030-3080ft/s with 300gr Berger OTM. I have already run a 33XC barrel hard at 3280ft/s and smoked that pipe im under 400 rounds.
33XC Ammo Testing Method
Vince Bottomley from Target Shooter magazine Uk had taught me this back when I travelled to Bisley England to shoot for some 10 years and he taught me alot, he got me hooked! Amazing man and mentor with passion for introducing new guys to the sport and got me started on a FTR 308win built on a surgeon XL and then a 284win built on a Nesika K action in a barrel block chassis. That was some 18 yrs ago or so. I will prepare the ladder test loads around 12 to 15 rounds in 0.3gr increment. 1 round of each. It has saved me alot of ammo. The idea behind this load development method here is to:
- Identify the velocity spread of the loads as you increase powder charge.
- Find a node in which the speed doesn’t change even if the load increases.
- More importantly, find 2 or more loads that impact the same spot at 300m.
I will then load those charges again: x3 rounds each and maybe also the loads in between that powder charge. No change in bullet seating depth. The already loaded rounds expedite that process. I will also prepare about 10 cases with a base charge of 110gr and the bullet upside down so I can adjust the charge, seat them on the range and retest them. These I will use to confirm a load that I find very promising. 
33XC Ladder Test results
Here you can see the result from that initial string of fire with varying 0.3gr loads. Below shooting at 300m shows us a point of impact change of 2.9cm or just over an inch at 300m with 2.4 grains of powder charge difference!
The 300 meter test below of the 33XC was relatively short. I shot 3x load of 110gr, it had a larger spread than i like. I then shot the 110.3 Gr load and this closed in 3 shots into one ragged touching group at 300m. I was happy with that so I stopped, I didn’t fire the other rounds. Instead I loaded another 6 rounds of 110.3gr N570 so I could get some trajectory verification of my load before I head out to France. I shot a 3 round group on the 700m IPSC target in the head. and then picked a stone just over 1020m. 
I seat with a David Tubb die in 33xc and size using a TPM Balle (french made dies) for sizing that come with their own bushings. I use the same die for 37XC sizing as well. I measure the rounds base to O-give using a hornady bullet comparator in 30cal for all my reloading for 30cal or larger and a 6.5mm one for the 6.5mm bullets since the 30 cal would be too big. 
Watch the ELR shooting video on Instagram
The supertrickler below loads all my high performance ammo fast coupled with a A&D FX120-i Scales, this thing can drop 33XC loads in under 10s each. 
I load on a Prazi Press made in Germany by Turban CNC, it’s a single ram, one station press, it’s the 150mm model that can load up to 14.5mm cartridges. It makes short work of the 33XC and 416Barrett case sizing. In my opinion the best Press for your reloading office. It’s heavy about 10kg / 21 lbs with a 7/8”x14, 1-1/4×12 thread. Equipped with standard 7/8″-14 die threads, this press is universally compatible with dies from virtually all major manufacturers. 
Eventually i replaced that leupold scope with a short 3-24×42 March which is really light under 700gr and 120MOA of elevation. I love this scope. Light, repeatable, reliable and I can use it for any rifle. _______ Sponsored insertion. Steiner M7Xi 4-28X56 IFS 
I really wanted to try this scope on this rifle, this scope has an Integrated ballistic calculator, you dial the turret and it gives you the distance readout for your cartridge. If you’re using Steiners range finder like the Steiners M830r mil range finder, you can connect it to it and get the laser read out on the scope’s HUD. It reads past 5000m woth surgical precision, has a reticle in Mils and can give you also angle to target and its a binos. What i like even better is the wind clock feature inside the scopes HUD, fast to set up from behind the scope, you can set wind speed and direction and it gives you an initial correction. What i found it handy for is to quickly see what a wind direction change would do to your windage. Read full write up here. I eventually mounted it on my 416Barrett. This review model has the CW turrets but it can be ordered with CCW turrets too which would be my preference. ___________
33XC Load testing Method
I loaded 10 charges to be exact including 4 of the same starting load to zero and setup rifle. 14 Rounds of 33xc ELR ready missiles. Why? I want to see the velocity as i increase the charge, find a window where the velocity doesnt change much as I increase the charge, and then also groups under an inch at 300M. Typically there will be 2-3 shots that will go in that spec. with 2.4grains of difference in the load, it shot a group slightly larger than an inch at 300m. What is also telling is that I had 3 shots touching and another 2 touching. That’s a good start for this barrel. Also the velocities where right about where I wanted them to be. If you read my article on load testing for the 6.5creedmoor which is more forgiving, i adopt the same approach. I’ve been using this method time and time again to extract the best from these barrels, handloading equipment and custom rifles. I will shortly post another experience about tuning my 416 Barrett load to shoot under 1″ at 300m. 
In all the things I have tried in the last 20 years, the powder charge remains the most important factor to find your sweet node. Time and time again my tests have shown me that with the right powder charge, your custom rifle will land those shots touching at 300 meters. If your rounds are not touching at 300m with a custom rifle and these high end components, you don’t have the best charge for your barrel and equipment or you can’t shoot your rifle to its full potential.
What else can you do to improve your load development?
- You can change seating depth next by 0.005″,
- Change the neck tension,
- Sort your brass by weight or by Internal spirit volume
- Sort bullets by base to O-give length and weight
- Weigh primers etc.
I dont shoot further from that load, these big rounds get pricey fast. In the link below we load test the 416Barrett in the same manner. https://www.instagram.com/reel/DX04TOkIkq-/?stkn=OGpzanN1YXZnNnEz The 416Barrett in europe is about €15-20 worth a shot or the price of a pizza per trigger squeeze. Zeroing it is €45. Barrel wear is €3.75 /shot here for your ELR economics. Not even a powerful PWC will burn that €15 as fast. Mik prepared two identical 1.8 twist bartleins on at 33″. I placed the beautiful WTC MOAB muzzlebrake on this which was on my 37XC DT barrel made by Solid Solution Designs in the Netherlands. Warner tool company makes some amazing muzzlebreaks with a mirror finish as well as custom inline seating dies. I got my dies from ARC Ballistics in England, Chris does beautiful work but can be hard to reach while in his shop. The 33XC rifle looked amazing, matte black finish through out. I fitted my trusted Accu-tac bipod with the Jay Dvorsky *Railfeet which helps it recoil as the rifle goes back parallel to the firing position making it easy to go back on target and track smoother and keep vertical stringing to a minimum. There’s no real increase in felt recoil, you see it slide backward smoothly and on target.
How does today’s 33XC compare with other tests i have done?
I have 3 rifles in 33XC, one on a desert tech SRS A2 that has had two 33XC barrels and this one on a RPA rangemaster rifle. The Desert tech does not like to go hot on the 33XC loads ideally under 3050ft/s, it actually is better suited in the 338LM version than in 33XC, i think it must be the pressures at which the 33XC works.
The 33XC can easily push a 300grain over 3300FT/s if you don’t care about barrel life or you’re only shooting 1 round at a go like in hunting. We had done this for the Johann Fanzoj 33XC kipplauf rifle (break barrel single shot luxury hunting rifle) 
This 33XC load shot exactly what my 87.2gr load had done in my RPA 300NM, so good I framed it. Write it down – when the powder charge is the right one, the rifle will put them in one hole repeatadly. On the left you can see the 300m group of my 300NM during load development. The picture with the red box as an aimpoint is the load testing of the 6.5creedmoor in the desert tech barrel. Those are 3 groups at 300meters. 
It also did that with my Desert tech in 300NM at 83.9gr. This load funnily enough shot the same size group in my rebarrelled RPA 300NM WITHOUT any load development on that barrel. The original load i Had in my other RPA was over pressure in the new barrel, so much so i couldn’t open the bolt after that first shot! I can’t realistically shoot much better than that so if it can do that it’s good enough for the elr matches if the extreme spread is also under 10-12 ft/s. With my 416Barrett, I managed to get the 1inch group at 300m but I didnt manage to keep the ES under 15fts. Thats for another article in this series of efficient load development. I may need to work more on the brass sorting on the 416Barrett. I’ll tell you more about preparing the 416Barrett for Ko2M. Its at 130 rounds through the barrel so far with the 20N29 and 550CE. Meanwhile we also went to the US for King of 2 Miles in September so we’ll tell you more on that shortly!
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Shoot straight, Rod Formosa
