Savage 12FV in 223 Rem Accuracy Experiences

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THAT'S ALL THE HISTORY TO DATE

On that note my friends, it’s time to up-shift into 3rd gear and pick up some steam as we plan and prepare to see exactly what this rifle can do. Of course, I’ll be covering some really gory details about how I’m preparing, and how I’m loading my ammunition. That should give you a leg up on your loading, whether you are lucky enough to have a Savage 12, or are using another rifle.

Everything you read above is largely my historical experience to date- we are all caught up! From those experiences I learned a lot about my rifle, the quality of my materials, and how to do things better (WAY BETTER). With all that in print, it's time for us to turn the page to the next chapter, where we look to how the world should be using better methods and materials- going forward this is all new for me too.

 

[Grimstod]

FINDING THE RIFLE LANDS THE RIGHT WAY

Rehashing all that mess above got me thinking, it’s probably time I grew up and got a tool that would give me the precise readings I’m looking for. I checked my Cabela’s points, and pleasantly found that I had enough points to get a Hornady OAL Gauge and a 223 cartridge for the gauge with NO CASH out of pocket. That fact turned the tides a bit and flipped the question to:

You: “Why wouldn’t you take a free gauge Slow?”
SlowSqueeze: “Okay, okay, it's for a good cause.”

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So there you go- if I had to do it over again, I’d just have bought this tool from the start. As a side bar, before you spend your money, I just got my RCBS Precision Mic for 223 Rem that also has a tool to measure the lands. I’ll post more details shortly, but the mic enables you to measure OAL, headspace, and the lands for a lower price than all three of the Hornady tools I’ve mentioned- it’s worth a look!

If you want the altamit accuracy in headspace measurements you should get steel headspace gaiges. PremierAccuracy.com sells them. He makes them from steel and the same reamer you chamber with.

These aluminum ones Hornady sells wear and change readings with time.

 

[SlowSqueeze]

If you want the altamit accuracy in headspace measurements you should get steel headspace gaiges. PremierAccuracy.com sells them. He makes them from steel and the same reamer you chamber with.

These aluminum ones Hornady sells wear and change readings with time.

Thanks for the tip- I think I'm set for now with headspace tools but will keep them in mind if I want to get really serious about measuring headspace since they are a bit pricey...

 

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SELECTED CARTRIDGE ROUND MATERIALS

I’m assembling the materials now to continue the study. First off, I don’t plan on using the following combination forever- I am searching for the optimal load for this rifle. If this combination, at a given charge weight, ends up yielding the best then fine, but I doubt I have that random luck. I wanted a good 223 Remington configuration that is well supported by information on the internet and available materials, and these all seemed to be reasonable starting points.



I discuss the selection of each item, and some considerations about them, in greater detail below.

 

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WHY LAPUA BRASS CASES?

First off, Lapua is a premier brass manufacturer- the cases cost more, and Lapua is known for delivering additional quality worth the increased cost. That quality means the following things of note:

1. Drilled flash holes- most manufacturers stamp/press the holes, which is less precise and generally means you have a small lip to remove inside the case to make everything consistent.
2. Necks are all annealed before shipping, so the brass in the neck starts off with the right hardness/softness and isn't over-worked.
3. Tighter tolerances during manufacture means the cases need less work to get them to a high-quality state required for precision shooting.
   

Besides the higher cost, there’s really not much of a down side to the case- they save time and can be reloaded more times than most other cases (upwards of 25 reloads by some accounts). There is some data suggesting that Lapua 223 cases have had some quality issues, but I’ll measure mine fully and get results we can compare to Cal’s over at PrecisionRifleBlog.com

 

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WHY HODGDON H335 BALL POWDER?

In trying to rectify my past powder selection of IMR4064 I did a lot of digging- this is where I came across the 223 Remington guide on AccurateShooter. The write up has great information on powders that perform well in the 223. I also consulted several forums and saw that H335 was always in the discussion (along with H4895 and VV N133) for lighter bullets. From what I read I’ll summarize H335 as a ‘you can’t go wrong’ powder for lighter 223 bullets. I do think the other two, along with Varget might have better accuracy nodes, but I’ll play with those later.

For now the H335, as a great overall powder, will meter well (it’s a ball powder), and should yield better results than IMR4064. The selection was made even easier when MidwayUSA had a sale on 8lbs of H335 in the spring of 2017- and I’ll use every bit of the 8lbs to plow through the shots I need!

 

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WHY CCI 400 PRIMERS AND NOT MAGNUMS?

Primers are strange little beasts for me- when I first started reloading I couldn't believe the amount of attention that was paid to such a (physically) small part of the equation. It wasn’t until I started reading about primers explosive power that it started to make sense. Primers are explosives- they don’t burn like powder does.

So, why did I go with CCI 400’s? First off, I bought 1,000 CCI 400’s when I started reloading, and I have about 450 left, so that’s the first point. Second and more importantly, H335 is rumored to require a magnum primer, which the CCI 400’s are NOT. After doing some reading, including detailed spec sheets from Hodgdon’s site, it appears that the CCI 400’s won’t have a problem igniting the powder, so I’ll use what I have for now.

That being said, I’ll try different primers once I finish with the initial shooting and have identified a load that works well. That should give me good data about the effects that primers actually have on ammunition precision.

 

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WHY HORNADY 52 GR BTHP BULLETS?

When I first started reloading I was fixated on longer ranges of up to 600 yards with the 223. People who shoot that far with a 223 go for longer bullets, and the 69 gr Sierra Matchking (SMK) was regularly touted at the top of the list. It was only natural for me to start with the 69 gr bullets.

After doing the initial shooting however, I realized that all of my time right now is spent at 100 yards (because I’m still learning and developing). As a result I don’t have any need for a heavier bullet and picked something reasonable that would suit my needs at 100 yards. The box of 1,000 52 gr BTHP’s from Hornady were regarded pretty well, and again I found them on sale at MidwayUSA.




All that being said, if I could just pick my bullet and get them in a quantity of a few thousand at a time and not worry about cost, I’d pick the 52gr Hornady ELD Match. It’s got a polymer tip instead of the hollow point that improves the G1 BC to 0.247, which is quite a bit for the same weight bullet. Maybe I’ll test a few of those at the end of the study just to see what happens.

One quick note about Secant ogive bullets- their secant shape gives them hight BCs than Tangent ogives, but they are more sensitive to seating depth changes. As a result, I’ll be spending some time later on testing various seating depths and the effects on my peak loads.

 

[seymour fish]

PEBTAC (PROBLEM EXISTS BETWEEN TRIGGER AND CHAIR)

As I started shooting more seriously by myself, I was getting some reliable statistical results, and I wasn’t really fond of what I was seeing. I thought the results were heavily limited by something between the trigger and chair- what I would call “PEBTAC”: Problem Exists Between Trigger And Chair. As I would soon find however, that wasn’t really true…

With the PEBTAC assumption, the only way I saw to get better was to run some rounds through the rifle and systematically work through my breathing, trigger squeeze, and comfort around the rifle (ergonomics). I focused pretty intently on my shooting technique as I built up a solid baseline of performance to measure where my skills really were with the gun and ammo. Excluding the initial sight in and plinking we did, I put just under 400 rounds through the gun. I’m pretty confident I have stable, yet very humble, results.

9/20/2015: Average MOA: 1.72
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9/26/2015: Average MOA: 1.90
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11/14/2015: Average MOA: 1.35
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11/15/2015: Average MOA: 1.51
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11/22/2015: Average MOA: 1.46
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It’s important to remember that I was using bulk ammo for all these tests, and didn’t really change much in the process outside of my own skills. That being said, I was really unhappy with how things were going at this point of time…

You lost me when you said “AROUND”

 

[drover]

WHY HODGDON H335 BALL POWDER?

In trying to rectify my past powder selection of IMR4064 I did a lot of digging- this is where I came across the 223 Remington guide on AccurateShooter. The write up has great information on powders that perform well in the 223. I also consulted several forums and saw that H335 was always in the discussion (along with H4895 and VV N133) for lighter bullets. From what I read I’ll summarize H335 as a ‘you can’t go wrong’ powder for lighter 223 bullets. I do think the other two, along with Varget might have better accuracy nodes, but I’ll play with those later.

I have had good accuracy from H335, it has always been an easy powder to develop a load with.

However - be cautious about using top end loads on hot days, and if you have been shooting enough that the chamber is hot be especially cautious about letting a case set in the chamber and heat soak. It is the only powder I have had pressure excursions with (up to and including case separation) and in each instance I had let a round set in a hot chamber for a bit before firing.

drover

 

[SlowSqueeze]

You lost me when you said “AROUND”

Ya, not literally 'around' the rifle... LOL. It just takes a while to get used to a rifle: all the little bumps, shapes, and nuances.

I have had good accuracy from H335, it has always been an easy powder to develop a load with.

However - be cautious about using top end loads on hot days, and if you have been shooting enough that the chamber is hot be especially cautious about letting a case set in the chamber and heat soak. It is the only powder I have had pressure excursions with (up to and including case separation) and in each instance I had let a round set in a hot chamber for a bit before firing.
drover

Thanks for the tip!

I will be shooting H335 this summer in the heat, so I'll have to keep an eye on the cases for signs of pressure when I get there. I usually load a round in the chamber with only 15 seconds or so before the pin strikes- I specifically manage my movements to have the chamber open to 'breathe' and let some of the heat out for as long as possible. That's keep the chamber temp more consistent too.

 

[SlowSqueeze]

H335 POWDER CHARGE SPREAD

As mentioned above I’ll be using H335 and Hornady 52 HPBT. I’m looking for a range of charges for the study, and from the Hornady manual, I see that the 52gr (and some 53gr) HPBT bullets are rated at the following charges for a given speed (Feet Per Second, FPS). I also dug up some data from Hodgdon and Nosler via their websites for bullets of similar weight as a contrast. I think it’s pretty clear that Hornady is probably conservative in their load maximums since both Hodgdon and Nosler have higher loads by 0.7 grains.



So I’ll start with 22.3 grains of powder and then go up to 25.3 gr, giving an initial span of charge weights of 3.0 grains (22.3 gr to 25.3 gr). I’ll watch for pressure signs as I’m getting close to the 25.3, and if things are looking good, I will test loads above 25.3 grains through 26.0 grains as long as i don't see pressure signs. In short, we will look at up to a 3.7 grain spread in charge weights.

 

[SlowSqueeze]

MILLER STABILITY FACTOR RANGE

Now that I’ve reviewed my loading stuff, let’s do an absurd analysis to determine the Miller stability factor for the 52gr BTHP in my barrel with a 9.135” twist, moving at the projected muzzle velocities above. If I we’re launching these bullets to variable distances of several hundred yards this would be more useful information, but given that I’m only shooting at 100 yards it’s totally unnecessary. To calculate the stability factor I used the JBM calculator and plugged in the required data:

• Caliber: 0.224”
• Bullet Length: 0.715”
• Bullet Weight: 52 grains
• Plastic Tip: 0”
• Barrel Twist: 9.135”
• Temp: 59 degrees (left the default)
• Pressure: 29.92 & 29.86 in Hg (left default for sea level, and then Denver)

I then plugged in the velocities for the range in the previous post and recorded the following numbers:

 

[SlowSqueeze]

INTERPRETING MILLER STABILITY FOR MY 223 12FV

What does it mean? Not much really- my selected bullet is stable. In fact my bullet is on the high side of stability, which means that gyroscopically it’s pretty locked into the long-axis orientation when it leaves the barrel (more of a factor at long ranges). I have a minor concern that the bullet might be over-stabilized and spin apart, but I’m not too worried at this point. If you want to know more about Miller stability, actually the Miller Twist Rule, you can read the Wiki here (it’s a formula to determine required barrel twist, but once you HAVE a barrel it will tell you how the barrel will stabilize various bullets given the parameters above).

As a general rule you want a Miller stability factor between 1.5 and 2.0. Less than 1.5 is bad and you risk your bullet not being stable (e.g. tumbling). There isn't really a published maximum for the stability factor, and there is debate about the reality of over stabilization as well… Here’s a good summary from a guy named “Fiftydriver”, in thread form over at LongRangeHunting.com, of how I see the issue.

One thing that I did find interesting is that the altitude in Denver didn’t impact the stability as much as I thought it would. Granted, the Miller stability only describes the bullet at the end of the barrel, so whether a bullet is fired at sea level in Miami or the top of Pikes Peak, we are only talking about 20” to 26” of travel to the end of the barrel (depending on your barrel length). Once the bullet is launched however, the barometric pressure has a much larger effect as the bullet travels to it’s target… So I talked myself into it making sense!

 

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EXPERIMENT APPROACH- BRUTE FORCE SAMPLING (MEASURE ALL CHARGE WEIGHTS)

I equate the experiences I’ve had shooting to date as an introduction- I’ve gotten the basics down for shooting, reloading, and maintaining/configuring my equipment. With the completion of that introduction I’m now working on my apprenticeship. The best advice I’ve heard, and will heede, recommends that the best way to get better at shooting is TO SHOOT. Practicing my shooting also means I need to practice reloading (using my tools), and caring for my rifle (logs, cleaning, etc.).

As a perfect excuse to shoot, I’m using a ‘brute force’ approach to determining my optimal load. Doing so gives me several thousand rounds to chew through while improving my skills (shooting and reloading), and learning the nuances of what matters and what doesn’t. In other words, I’m not just doing this to determine the best load- I’m doing this to uncover the best shooter in me!

As an opportunity during my education in shooting, I’ll carefully collect data that enables me to ask very detailed questions about how different things affect my performance- in short, I’ll be able to ask why things are happening, or at least what things are related as they drive precision.

For now I’ll summarize my approach as the ‘long way’ that isn't concerned with determining the best load with the fewest shots fired. Instead I’ll get lots of practice, have lots of fun, and learn lots of stuff.

 

[SlowSqueeze]

VS. AUDETTE LADDER & OPTIMAL CHARGE WEIGHT (OCW) TEST

One thing I’ve always been curious about is whether the Audette Ladder (or Initial Load Development Method, ILDM) and/or Optimal Charge Weight (OCW) can actually help to determine the optimal load with only a few shots. OCW, per request from Dan Newberry, is described here, and has detailed instructions as well. My suspicion is that both of these methods do a great job of finding a good load that is less sensitive to changes, HOWEVER, there are likely more accurate and precise loads that these methods do not identify. These truly optimal loads can only be found by, well, finding them from shooting.

So, as part of my study I’m going to perform both the ILDM and OCW right up-front as I start shooting. Once I’m done with the rest of the study I’ll turn back to the ILDM and OCW results that be able to definitively show if the shorthand methods actually pointed me to the right spot.

Cal Zant did a great job of explaining the use of ILDM and OCW in his (ancient) blogs when he first brought PrecisionRifleBlog.com on-line. I’ve included two links to Cal’s work that provide great background and links to additional materials.

http://precisionrifleblog.com/2012/10/19/7mm-rem-mag-ladder-test-results/
http://precisionrifleblog.com/2012/10/19/7mm-rem-mag-load-dev-part-3-optimal-charge-weight/

What Cal didn’t finish as part of that work was to show us how these methods compare to a brute force determination of optimal load- a fact I plan to resolve in this thread. Of course, Cal was shooting a 7mm Remington Magnum (my favorite long-action caliber!), and would have had to throw his barrel out after the number of rounds I’m about to shoot (perhaps even two barrels). My 223 barrel should still have a lot of life left in her after I’m done here. Besides, it costs about ⅓ as much per round to shoot a 223 than it does to shoot a 7mm RM (fewer bruises too!).

 

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RECORDING RESULTS FOR ANALYSIS

I will collect seven groups, 5 rounds each group, for each charge weight (7x5 = 35 rounds per weight). The following table shows the data I want to collect, which is very similar to the previous table with my initial accuracy results above (way above). Oh, and one thing I didn't mention earlier- I’m using 0.1 grain powder charge increments. That should be VERY fine resolution for the eventual plot of precision!


Filling in the whole table will require 1,330 rounds of ammunition, and about 32,000 grains (4.5+ pounds, @ 7,000 grains per pound) of powder. I know you can’t see it, but I’m sitting here smiling thinking about all the shooting I need to do!

 

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MUZZLE VELOCITY (MV) MEASUREMENTS: MagnetoSpeed V3

One of the things I’ll be doing as I peel the layers back on the drivers of precision is to very carefully record the muzzle velocity of my rounds. Muzzle velocity (MV), or just velocity, is one of the most important factors that determines how a bullet will travel once it leaves the barrel. Variation in muzzle velocity also provides us with a glimpse into the internal ballistics that just ended (when the bullet emerges). MV changes with ambient temperature as well, so knowing how it changes is important when you shoot on a warm summer day at the range vs a cold October hunting day.

To measure the MV of my rounds I’ll make use of my very handy MagnetoSpeed V3. I’ve only used it a handful of times so far, but it’s worked very well and only dropped about 3% of the readings. I’ll post review-ish impressions while I’m shooting to give you more information, but for now, this is a good review of the MagnetoSpeed by Galvin Gear of UltimateReloader.com (shout out to Galvin and UR- his information is great and I have learned quite a bit along the way).

 

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MUZZLE VELOCITY DATA TABLE

I’ll use my Magnetospeed to measure the approximate velocity of the 52 gr bullets 5 times over 10 charge weights. I’ll need for fill out this table, which means another 50 rounds fired...


While I haven’t seen a definitive study saying the MagnetoSpeed doesn’t affect precision, it makes a great deal of common sense that any weight attached to the end of a 26” barrel WILL change barrel harmonics- as you might expect, I’ll check that later on as well. I can use the above data to star answering that question, but I’ll need a few additional groups to be confident.

 

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HOW DOES A CLEAN BARREL IMPACT PRECISION?

We all know you need a foul shot or two after a barrel cleaning to put the barrel into a stable state where you can get precision. I’ve often wondered just how much fouling effects accuracy and precision, and there’s no better time to measure it than when I’m doing all this shooting!

I’m going to mix things up a bit for this mini-study though. I want to know how precise the first foul shot is, how precise the second foul shot is, and so on. That means I’ll have 5 targets that I shoot over five trips to get 5 groups- one group for the first fowl shot, one group for the second, and so on. In other words, after every cleaning, I will shoot five targets with 1 shot each.

For the study I’ll have to pick a charge weight to use, and then compare the groups at that charge weight to the final results of the same charge weight. So I wont know the quantitative results of how fouling effects precision until later on when I’m done shooting the H335. Oh, and because I’m measuring accuracy of the foul shots, I can’t combine the rounds for velocity with fouling because I have not quantified the effects of the MagnetoSpeed yet on accuracy and I don’t want to introduce unknowns.