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Load development for 308Win in under 50 rounds (updated)

Updated 10th April: New Video Content

Load development with a 308Win can be extremely rewarding. In the video below you can see the product of the load development efforts and what such a tuned field rifle can do. Go to the article to understand how to achieve these results.

 

308win ladder test

Surgeon Rifles 308win infront of the watchful eyes of a Swarovski BTX 95mm spotting scope which we reviewed here.

If you want to shoot well and have a great time at the range, load great ammo or buy match ammo.

In the following article we shall develop 20 rounds for our Surgeon Rifles 308Win ladder test to complete load development in under 50 rounds. That’s our objective.

This load is for my 308Win hunting/steel plate rifle so I picked the Hornady 178gr eldx and the aim is to have a load that shoots under 1 MOA at 600m over 10 rounds. As long as I get the velocity I’m after and consistency, I’m happy.

Why 600m? At this distance, I can better see the vertical spread between impacts. Normally with my f-class rifle or ELR rifle, I will start at 600m then carry out another at 1000yds (915m) or further.

surgeon rifles 308Win

On the range with the Surgeon Rifles 308win and Swarovski BTX 95mm bino-spotting scope

Why should you take time to load good 308win ammo?

308win handloads

The 308Win is an excellent round to learn to hand load with and it’s probably still the can do it all rifle (previous article on 308Win). It’s easy to tune and shoot which makes this process rather straight forward. Time not spent well at the reloading table means wasted miles back and forth, gas, time off work, ammo cost, range fees and frustration on the range with your equipment when most probably the faults lies with your processes. Shooters blame their kit before their knowledge or processes. They save money on tuition yet spend it on expensive ammo down range – in vain.

Travelling to shoot and compete in different places in Europe taught me some important lessons which I’m happy to share. I’ve seen shooters come all the way to have their ammo give up on them because the base work was not done well. They thought they’re saving time or money and paid for it later either because their ammo shot like crap or couldn’t even chamber. Once your trip is compromised, your small savings went out of the window.

Get some quality load development tuition

When I started out, I asked for tuition from some of the best guys in the UK Fclass scene. I wanted to travel, load the best ammo from the get-go so my 4 days trips could be maximized. I started with the guys that could teach me that, then practiced, practiced, practiced. First I went to Russell Simmonds (2009 F-TR World Champion) who was running reloading courses back then on his budget 308Win with which he won the worlds championship. Then spent time on the range and reloading bench with Vince Bottomley (editor target shooter magazine) as I developed the load for my FTR rifle. Then I chased Tim Stewart for a few great learning sessions and phone calls and sat with him and James Mc Coosh at the reloading room of the North London Rifle Club among others. These guys tell you what works and what doesn’t so your processes are solid. I thank them for their expertise and time.

NLRC reloading room

Tip: Get to a club reloading room or watch top shooters load at a range. If there’s something that Fclass and benchrest shooters can teach you is how to make the best ammo and most are very happy to discuss with you. Often at bisley, I can see people clean their rifles outside their caravans and many will tell you about their reloading or even show you stuff, just ask.

Let’s get down to hand loading some 308win ammo

I load to my rifle’s chamber specs, it’s a custom rifle so why load standard for it? I started out finding my chamber dimensions so my ammo will be tailor made for that. Reloading manuals are written for safe, generic use. Here we want to be safe and maximize our rifle’s potential. I Loaded up 20 rounds for ladder testing plus 5 foulers for zeroing in, typically I load these 5 rounds at the same charge, you don’t need to have your rifle zeroed for this test, you just want to make sure your rifle will print on paper at 100m so you can then ladder test at 600m. Vince had repeated this to me a few times a few years back, you don’t need a zero for the ladder test, just be on paper so you don’t waste time. Once you had your load, then zero your rifle.

I didn’t even use that ammo for zeroing, I had some lapua 155s to play with and fired off a group of 8 at 100m. Rifle was on and a cloverleaf group put a smile on my face, it recoils nicely. Mik at Dolphin gun company had done a good job.

Ladder test – 308Win

  1. Shoot ammo + rifle to its full ballistic potential, taking velocity readings and being SAFE.
  2. Find out sweet spots in our barrel harmonics that shoot very close to each other at different charge weights.

3. Find the lowest vertical spread of our load in the shortest time possible.

4. Get 10 rounds in less than 1 MOA at 600m – that’s the benchmark I had for this tactical/hunting rifle.

308Win Cartridge Overall length

I needed to know what my cartridge overall length will be so I can plug this data into Quick load and get some numbers for my loads.

We started out finding where the bullet meets the lands and backing off 0.010. For this we removed the spring and firing pin from the bolt to make sure the rifle is safe while removing any sort of pressure exerted on the case head or when working the bolt. Ideally remove the ejector spring as well so there is absolutely no pressure on the case head when closing the bolt on it.

We then seated a bullet further out starting at 2.905” with very light neck tension at 0.001” using a K&M expanding mandrel to ensure the bullet would be easy enough to work with if we need to remove it from the case or when closing the bolt. This will slightly jam the bullet into the lands but it’s good enough to work with. We had a Hornady cam lock bullet puller handy in case we needed to remove the bullet. (best in the business)

I asked AccuracyReloading in Italy to send me a few different collets for each caliber I shoot. Ferruccio gets stuff out to you instantly.

After I chambered this round, it exited the chamber at 2.879”. I did this twice over. I will now seat the bullet in a further 0.003″- 0.005″ inch deeper till I can no longer feel the pressure exerted on the round. When there is no more pressure, there will no longer be that click on the bolt and bullet will be off the lands.

Watch this video to understand better what we are after. ***I meant to say seated the bullet a further 0.003″ not sized!

Watch 308Win Surgeon rifle bolt stops clicking on opening – bullet is off the lands

Next check that these rounds will cycle smoothly from your magazine

Preparing 308Win ladder test

308 ladder test

Here we’re seating bullets using Wilson inline seating dies. I love Wilson inline seating dies, you can load ammo anywhere with them no need of strong benches, just a small arbor press and ready to go. I’ve loaded with these in hotels, pick up trucks, on the range, practically anywhere.

Using the COAL that we had just measured, I plugged in some numbers into Quick load to know where we shall be heading. The numbers using N550 looked interesting with velocities slightly exceeding 30-06 Hornady Precision hunter factory ammo I had used in the Browning Maral 30-06.

308 Win loading Data

This data below is provided by Quickload software. It is intended  to provide us with 308win loading data in 0.3 increments or which ever setting you would like to input. It then returns a table with loading data so you can have a good idea what load you will be looking at.

One way of using this 308Win loading data is to use it as a reference point. Say you have tried a box of Hornady precision Hunter 178eldx ammo and you chronographed that ammo muzzle velocity to 2600ft/s. If that shot well in your rifle, you can then go find that velocity in the chart, read the equivalent powder charge and start 10% lower than that to give you a good idea where you are bound to find a good accuracy node.

308win quickload

I started loading a few rounds at 43 grains to  get the rifle zeroed with then loaded up the rest in a series of increments.

Tip: Another trick to get you done with your 308win load development in a weekend is to get your base charges loaded up before you go to the range. In my case this would be a base charge of 40 grains and placed in plastic tubes. The idea here is to trickle up your charges to the charge that shot best on the range. If I’m flying elsewhere, I typically ask somebody I trust to prepare these for me wherever I am going and pay for it. They don’t have to be 100% accurate as I’m still going to trickle up but it saves me A LOT of time. I should be able to crank off 2 rounds a minute while loading my ammo in the morning before range time.

308win base charges

 Range day with 308Win in Trapani, Sicily

308win ladder test

I met my Sicilian host Vito and Roberto in the winding streets of the city and we headed off for the beautiful country roads which lead to this beautiful shooting complex that stretches out to 1 mile, north west of Siciliy where we also ran our 300 Norma Magnum to 1 mile.

As we had the 300 Normas to get tuned in and dialed, my load testing with the 308win would have to be short, well executed, plotted and meaningful. Vito prepared the setup for me with the Labradar next to it and placed a plank of wood to gain some height as the 600m targets are at a slight incline. I like to keep my bipod as low as possible. I wanted to shoot from the ground not the benches. The Tierone evolution bipod does a good job at having the rifle hanging between the legs of the bipod. It’s carbon fiber making it light for long distance hunts where you carry your kit a long ways. The rifle sports the amazing March 2.5-25×42 MOA/MOA illuminated.

Do you own or interested in a March scope? Checkout our March scopes facebook community.

I had no zero yet with this load but I had a velocity reading from the 100m range. I plugged in the numbers in my trusted kestrel 4500 and dialed in 15MOA of elevation.  I only wanted to print all my ladder test on target and start out hitting sufficiently low that by the time I get to my faster rounds, they would still print on target without having to adjust the scope.

That’s what the ladder test looks like on completion.

308win ladder test completed

We started out at 41.7gr x3 rounds just to make sure we’re on paper. I cranked off 20 rounds steady while Vito thankfully spotted for the impacts on the camera screen and made sure I was looking at the correct bullet hole. I took notes next to each charge shot, I basically mark if I think it’s worth looking into later with a very good sign. By the time I reached 45.3 grains, I had to bring my group down by 2 MOA as the rounds started impacting the top part of the target.

I didn’t adjust for windage, I had a 2 MOA wind dialed in to start with and just cranked on with that. To the right, Roberto watched through the amazing glass of the Swarovski BTX 95mm spotting scope that makes wind reading an enjoyable exercise in itself. You can easily see the bullet holes in paper at 600m and the 3mm circles in the fclass target out to 1 mile when mirage is low. The Swarovski BTX95mm is a true outdoor companion for the serious long range shooter. 40 minutes looking through that spotter and your eyes don’t feel sore so you won’t get a headache in the evening.

600m 308win shoot swarovski BTX 95mm
600m as seen through Swarovski BTX 95mm

308win ladder test results

We started out at 41.7gr of n550 with 2436ft/s and ended our string at 47.2gr with 2782ft/s from a 25inch barrel that’s 346ft/s over the entire string and 5.5grains of powder from the lowest to the highest charge. That’s 6.2ft/s variation per 0.1grain of N550 increment. Past 46.0 grains, the rifle started to recoil a little more than I enjoy on a 20 round string. It’s ok if you’re using it on a hunt where you just crank off a 2-3 rounds max. I will have a kickeez butt pad retrofitted that tames it down to where I like it to be.

Ok now let’s have a look at the chart showing predicted Quickload velocities for 308win vs actual velocities recorded on Labradar. On average, the difference between predicted velocity and actual was just 36ft/s, pretty awesome in my book. Quickload has been my loading companion for years now, worth the money, learn how to use it.

Quickload 308win chart

Day Two of Load Testing 308Win

The next day early morning I woke up to get a few rounds loaded, just trickled up my base charges. I had about 1 hour to get these ready before we headed to the range. A few sweet sicilian pastries kept me good company.

I went with 43.4 grains and 46.2 grains of N550. Regrettably I didn’t try out the 43 grain load again which had shot a nice  3 round group during the ladder test. I thought I wouldn’t have sufficient time and preferably wanted abit more velocity.

308win ammo loading desk

The bottom group was 43.4 grains and the top group 46.2grains. I fired those two shots in the center when I started out with the 46.2 load without adjusting the scope and thought it was better to push the group another MOA up so that they would not print over each other.

308win ladder test

So in conclusion, I have 2 loads that shoot well to 600m over 7-10 rounds. I still need to try out my 43 grain load again however in just under 50 rounds fired, we have a good starting point for the purposes for which I built this rifle. I will probably try out the 43 grain load over 15 rounds and see what that does at 600m.

Does 200ft/s more matter? 

Ballistically how much difference is there between these 3 loads? Let’s call the fastest load our base charge. How much handicap do we incur when we run a slower load assuming it shoots just as good or better? Here is the data.

178eldx at 2710 ft/s (46.2gr N550)

600m

Elevation 15.1MOA

Wind 3.9MOA (10mph Full value)


178eldx at 2546 ft/s (43.4gr)

600m

Elevation 17.6MOA (+2.6MOA)

Wind 4.3MOA (+0.4MOA)  (10mph Full value)


178eldx at 2519 ft/s (43.0gr)

600m

Elevation 18MOA (+3MOA)

Wind 4.4MOA (+0.5MOA)  (10mph Full value)

I’m more concerned with windage because elevation is a given once I know the distance. In a nutshell with the fastest load, for every 2-3mph wind at 600m full value, I have to adjust 1 MOA of windage. Pretty easy to figure out.

Replicating factory 308win loads

308win hornady eldx precision hunter

Naturally anyone that shoots handloaded ammo will also ask himself, how far off is he from the factory loadings? Should you run out of ammo or your ammo not making it to your hunting destination, knowing how close to factory loads you are can be reassuring. Well we decided to acquire a box of 308win rounds shooting the same 178Eldx bullet that we are loading ourselves.  I fired 7 rounds from the Hornady Precision Hunter factory loads over the magneto speed at 600m. This gave an ES of 58ft/s. I didn’t have the opportunity to measure the group but given the size of it on the Fclass target covering the 5 ring, it was about 1MOA or slightly larger.

1 – 2608

2 – 2634

3 – 2623

4 – 2651

5 – 2629

6 – 2593

7 – 2608

I had a look at the ladder test I shot earlier to check what load would bring me close to these velocities. I had a look at the comments I had done during the ladder test process and it was safe to try out. I picked 44.3grains that was equivalent to 2617ft/s. I loaded 10 of these and shot them at 600m. Here is the video of that second string filmed through my Kowa High Lander Spotting scope 82mm.

308Win Eldx

Notice how well you can see the trace of these 30 cal bullets making their way to the target as well as those tiny holes at 600m. I find it really useful being able to digiscope the load development session for reference at a later stage when I’m home looking over the work done over the weekend to find that ultimate load. I feel the rifle shot well all the loads that we fed it, maintaining 1MOA at 600m off the regular bipod is always nice but our most satisfying milestone is to get this field rifle to shoot somewhere under 1/2MOA vertical over 10+ rounds at 600m. This gives an extra level of confidence when engaging small plates during a match or if you have to take an extended shot on a hunt.

Using Digiscoping adapters like these, you may also film your load development session.

Kowa High Lander Digiscoping AdapterKowa high Lander digiscoping

308Win Load Perfected!

On my last trip, we set out to finalize the load for my 308Win. At the same time we also had to start load testing for our new 33XC rifle cartridge by David Tubb.

I had my 44.3grain loads ready, box of 50 with which I planned to give these a go at 600m again, chronograph them and watch out for groups. In parallel I also had a box of 175SMK Federal gold medal as well as another box of factory Hornady Precision Hunter 178eldx ammo.

Here are the results from that weekend as well as the video wrapping up everything we did. Once we knew the load was good to go, we got our kestrel applied ballistics setup and trajectory verified at various distances from 100-800m.

Below is one of the tests I ran at 600m comparing my hunting load to the venerable 175smk match load as well as the clone of my handload which is the Hornady Precision Hunter load with 178eldx. Top impacts in red are my loads, the vertical spread is quite tight around 3inches. Below you can also see the Federal 175smk that shot very well as well and beneath that is the Hornady factory ammo. Same bullet as my load, almost identical.

ladder test 308win

We learnt a few things while doing the trajectory validation with the 308win. Even at 700meters out, the 308win is very loopy, you can see it coming down on to the target in a very distinctive trajectory like a mortar. It still packs a very good punch as you can see, it completely annihilated a 9 inch wide rock which we shot in this video below. However your range input has to be precise! Just 10meter difference between 700m and 710m sees a further drop of 7 inches!

That’s 183 inches of drop at 700m vs 190inches at 710m. 

3″ groups off the bipod with 308Win!

Load testing Weekend Video

Enjoyed this article? Leave your feedback below and share it.

Next time we shall take a look at this beauty from Austria!

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