Australian Long Range Shooter Magazine

 The online magazine for the precision rifle shooting enthusiast

                                              For information and advertising Contact  wadcutter@optusnet.com.au

 

Home

Forum

News

Articles

Reviews

Contact 

Handloading the .338 Edge

 
The .338 Edge is fast becoming a popular long range cartridge in Australia. While only a few short years ago it was unknown, it now has a strong and growing following. Based on a .300 RUM case necked up to .338 calibre it is a simple wildcat to make.

The .300 RUM case has about 8% more powder capacity than the .338 RUM and this gives the .338 Edge wildcat a slight "edge" over the standard .338 RUM. Powder charges vary from about 90 grains up to over 100 grains depending upon bullet weight.

All you have to do to make .338 Edge brass is to single pass .300 RUM brass through a custom set of .338 Edge dies.  Or you can even get away with using .338 RUM dies backed out 0.200" above the shell holder for the first firing.

To neck up the brass from .308" to .338, I like to use a K&M neck expanding mandrel. This expands the necks gently and leaves them the correct size should you wish to do any neck turning.

 

The .338 Edge is designed for long range shooting out of single shot match grade rifles. In this configuration the bullet can be seated out to maximize case capacity. Due to its long length it is not the best case for magazine fed rifles although there are plenty of repeaters out there.

There are many excellent bullets to use in a .338 Edge but by far the most popular is the 300 grain Sierra Matchking (SMK) projectile. This match grade bullet has an excellent B.C. and is readily available in Australia. It is excellent for both target shooting and hunting.

Berger has just release the 300 grain Generation II Hybrid projectile into Australia. This projectile is now available from BRT in Queensland. This projectile has the highest B.C. of any .338 calibre bullet. It has now eclipsed the SMK in long range performance due to its higher B.C. Time will tell if it will end up being a better all round bullet but my initial testing has shown it to be excellent.

Although there are plenty of .338 calibre projectiles available in Australia, the 300 grain Berger and Sierra SMK are the most popular for the simple reason that they have much less wind drift than other projectiles. 

I have shot bullets weighing 225 grains, 250 grains and 300 grains out of my Edge and the 300gn bullet weight is the king for long range shooting. Having said that there are a number of situations where a shooter may opt for a different bullet weight projectile in order to maximise certain performance requirements.

This may be for extreme range target shooting where a 250 grain bullet may offer better stability through the transonic barrier or in a hunting situation where a 225 grain bullet "may" provide more suitable expansion on game. There are plenty of bullet choices, but only a few of them are really suitable for long range shooting.

Of the commonly available projectiles, these are some that might be worth a try. I have tried some but not all. Some are good for hunting, some are only good for target shooting and a couple are good for both. If you try some, come back and share your results.

225gn Hornady Interbond, 225gn and 250gn Nosler Accubonds, 250gn and 285gn Hornady BTHP Match, 250gn and 300gn Sierra SMK, 250gn and 300gn Lapua Scenar. I don't recommend any monolithic projectiles "at this stage" due to the poor performance that I have experienced.

There are two good Australia powders to use in the .338 Edge and they are AR2217 and AR2225. These powders are the best choice because of the fact that they offer excellent velocity and accuracy and are not temperature sensitive.

Temperature sensitivity is the downfall of most imported powders. In long range shooting you want your velocity to stay constant regardless of the temperature. Even a small change in velocity can greatly effect your trajectory at long range.

These two ADI powders are the ones to use with AR2217 being the most popular due to its lower powder charge, lower recoil and excellent velocity. AR 2225 however may be more accurate in some rifles with the 300gn SMK.

The primer that I use is the CCI 250 Magnum primer. 

Powder charges with the 300gn SMK range from 88gn to 94gn of AR2217 in most rifles. I use a charge of 93gn to get a velocity of 2840 fps, and find that I get case life of about six shots before I retire the cases with loose primer pockets. 

All powder charges should be accurately and individually weighed to within 0.1 grain of your chosen charge weight. Velocity variations will result in vertical stringing of groups at long range if this is not done. The aim is to maintain vertical distribution of your three shot groups to less than 1 MOA at 1000 yards in "Good shooting conditions".

One tip that I recommend for you follow, is to buy your powder in large lots with "the same batch number". Just a small change in the burning rate of your powder will have an effect on your long range trajectory. So unless you want to waste ammo validating your trajectory each time you buy powder, just buy one large lot that will last you a few years.

Remington and Nosler make brass for the .300 RUM and I find the Nosler brass to be too soft. Cases last much longer with Remington brass.  Primer pockets are a weak point on these cases. Even with medium loads they will quickly become loose.

One of the common things that most people find with the .338 Edge is that it has a sweet spot for accuracy when using the 300gn SMK. The best accuracy is usually to be found in the 2780fps to 2850fps range. Even with different chambers with long throats it seems to make no difference to this sweet spot. 

The reason for this may have more to do with the rifle than the bullet, as a Remington 700 size action is under a lot of stress with a .338 Edge load producing over 2850 fps. A stronger action with less flex, may enable accuracy at higher velocities in some of the larger chambers with long cut throats etc.

So when deciding on what is the appropriate throat length. I would suggest that you make a decision on which bullet weight that you are most likely to shoot. Then set the chamber up to shoot that particular bullet.

As a guide, the 300gn SMK can easily reach the accuracy node of 2800 to 2840 fps with a standard length throat, so an extra long throat is not needed.

When I set up my throat length, I did so with the 250 grain SMK projectile seated with the base of its bearing surface level with the bottom of the case neck. This way the 300 grain SMK was seated to be down into the powder column slightly.

The 300gn Berger Hybrid does seem to be able to take advantage of a longer throat with AR2225 powder.

Alternatively you may wish to have your throat cut so as to be able to load to magazine length. This is personal decision.

Warning

The .338 Edge is generally considered a simple cartridge to chamber and load for. However you should choose your Gunsmith carefully as not all of them know what they are doing or take the care and effort to produce a quality product.

The photo on the left shows a properly formed .338 Edge case and what one looked like after it was extracted from a bad chamber after firing.

The chamber headspace was cut way too long and this could have resulted in severe  injury to myself had the case ruptured, I was lucky and survived the incident. You need to be careful with such large capacity cartridges.

The rifle had to be returned to the gunsmith to have the barrel set back and the chamber re-cut. I will not use him again!

All serious long range shooters know that your ammunition needs to be absolutely consistent from shot to shot in order for the rifle to shoot tight groups at long range. The extreme spread of velocity should be less than 20 fps. If you can get it below 10 fps then that is ideal but few chronographs can read that well to reliably determine this.

This means that care should be taken to ensure that all cases are the same weight, length and of the correct length for your chamber.

Neck turning is not always needed and my rifle shoots slightly better without the necks being turned, even though I have a chamber neck of 0.370" diameter. Even the removal of 0.001" has a negative effect on accuracy in my rifle but this may be different for other rifles.

 
Consistent neck tension is very important for long range accuracy.

As my chamber neck is 0.370" in diameter and loaded rounds have a neck diameter of 0.367" this leaves 0.003" of clearance between the brass neck of a loaded round and the chamber neck.

On the photo to the left, you can see the mark left on the neck from the Redding "S" series sizing bushing. I use a 0.364" size bushing. This means that I have 0.003" of neck tension on a loaded round.

This amount of tension is just about ideal for a rifle that is to be used under field conditions. By using different size bushings you can alter the amount of neck tension holding the bullet in place. This may improve accuracy so is worth getting right. 

After the cases have been fired a few times the brass in the necks becomes work hardened. This will increase neck tension so you may want to anneal your cases to maintain a consistent bullet release.

When preparing your brass. Primer pockets and flash holes should be uniformed.

This entails using a primer pocket uniform tool to square up the shape of the primer pocket and ensure a uniform seating depth for the primer.

Flash holes should be opened up to a uniform size. On the inside of Remington brass there is usually a clump of brass around flash hole left from the factory punch that forms the hole. This remnant should be removed at the same time that the flash hole is uniformed. 

Throw out any cases that have the flash hole punched off centre. The purpose of all this case preparation is to get the most consistent ignition from shot to shot. This will aid long range accuracy.

 

Fire forming your brass is another important step. The first time that you load up new brass it will be a different size and shape to your chamber. Not only is this not good for best accuracy, but you may also find that the muzzle velocity is slightly different to that obtained using fire formed brass. This is even though you are using the same powder charge. 

I am unsure of the reason why this is the case but it is an observation that I have made that is backed up by the fact that when using new brass, it has a point of impact about 1 MOA lower on the target at 1000 yards than fire formed brass. Group sizes are also about 25% larger with new brass at the same distance.

This fact needs to be taken into account when validating your trajectory. Only use match grade ammo, with fire formed brass to do your trajectory validation.

When developing a load for your .338 Edge it is important to check for signs of high pressure.

Traditional signs that most reloaders look for are flattened and cratered primers. Or round ejector marks on the fired case head.

These signs may be unreliable with the Ultra magnum case. The reason for this is that there cartridges run at such high pressure that these signs may be evident even with standard safe loads. 

To check for pressure, I measure the expansion of the top of the case web on a number of fired cases using mild loads. I then use this measurement as a base line for future testing. If this diameter expands by 0.001" on hotter loads then I know that pressure is high and primer pockets will only last two or three firings.  This is also pushing a Remington 700 action to its limit.

Hand loading Rocky Mountain Bullets.

I found that these 300 grain bullets produce 120 fps higher velocity with the same 93 grain charge of AR2217. This may be due to the bullets being a slightly larger diameter than a 300gn SMK. Reduce your powder charge when working up loads for these bullets.

The B.C. of these bullets as is printed on the box that they come in is quite a bit optimistic, so use with caution.   

For further information on these bullets, including my field tested derived B.C. data, see my article on Rocky Mountain bullets. Here

 

 

Hand Loading BERGER 300gn Hybrid Bullets

I found that these 300 grain bullets produce slightly higher velocity with the same charge of AR2217 and AR2225 compared to similar loads using the Sierra 300gn SMK. There was not a big difference in velocity but it was consistent. 

The Hybrid bullets measured true .338 diameter with a slight taper toward the front.  Pressure signs were similar to the SMK but the bullets could be seated further out to a longer COAL. This increases powder volume slightly enabling the shooter to take advantage of the slower burning rate of AR2225.

It is possible to obtain higher velocity with AR2225 than AR2217 while still maintaining good case life and excellent accuracy.

The G1 and G7 B.C.'s of these bullets as is printed on the box that they come in. This advertised data seems to be accurate from my field testing.   

For further information on these bullets, including my field test data, see my article on The BERGER 300gn Hybrid.  Here 

After extensive test I was able to settle on a very accurate load for my .338 Edge using the 300 grain Berger Hybrid OTM bullet. 

The group shown to the right was shot at 867 yards and measured about 2.5 inches.

This load consisted of the 300 grain Hybred being seated 0.015" into the lands with 96 grains of AR2225 (Retumbo), Remington brass and CCI 250M primer.   For a velocity of 2890 fps.

This load has a cartridge overall length of 4.108" with the extended throat of my rifle chamber.

For ELR  G7 B.C. numbers, Email me at the above address.

Some numbers to play with......... Warning :- Use all data with caution. Start 5% below and work up.

300gn BERGER Hybrid test loads. Note :- Custom cut chamber with extra long throat. COAL = 4.050"

Load 1 ...... 300 grain Berger Hybrid, Remington cases, CCI 250 Mag primer, 91 grains AR2217, Velocity 2820 fps from 30 inch, 1 : 10 twist Lilja Barrel.

Load 2 ...... 300 grain Berger Hybrid, Remington cases, CCI 250 Mag primer, 93 grains AR2217, Velocity 2845 fps from 30 inch, 1 : 10 twist Lilja Barrel. MAX LOAD

Load 3 ...... 300 grain Berger Hybrid, Remington cases, CCI 250 Mag primer, 94 grains AR2225, Velocity 2857 fps from 30 inch, 1 : 10 twist Lilja Barrel.

Load 4 ...... 300 grain Berger Hybrid, Remington cases, CCI 250 Mag primer, 96 grains AR2225, Velocity 2890 fps from 30 inch, 1 : 10 twist Lilja Barrel. MAX LOAD

 

300gn SIERRA SMK test loads. 

Standard COAL with 300 grain SMK  = 3.785" with +0.050 throat. COAL can vary considerably from chamber to chamber.

Custom cut chamber. COAL with 300 grain SMK = 3.920". COAL can vary considerably from chamber to chamber.

Standard COAL with 250 grain SMK  = 3.685 with +0.050" throat. COAL can vary considerably from chamber to chamber.

Load 1 ...... 300 grain SMK, Remington cases, CCI 250 Mag primer, 88 grains AR2217 Velocity 2640 fps from 30 inch, 1 : 10 twist Lilja Barrel.

Load 2 .......300 grain SMK, Remington cases, CCI 250 Mag primer, 92 grains AR2217 Velocity 2815 fps from 30 inch, 1 : 10 twist Lilja Barrel.

Load 3 ...... 300 grain SMK, Remington cases, CCI 250 Mag primer, 92.7 grains AR2217 Velocity 2827 fps from 30 inch, 1 : 10 twist Lilja Barrel.

Load 4 ...... 300 grain SMK, Remington cases, CCI 250 Mag primer, 93 grains AR2217 Velocity 2835 fps from 30 inch, 1 : 10 twist Lilja Barrel.

Load 5 ...... 300 grain SMK, Remington cases, CCI 250 Mag primer, 95 grains AR2217 Velocity 2852 fps from 30 inch, 1 : 10 twist Lilja Barrel. MAX LOAD

Load 6 ...... 300 grain SMK, Remington cases, CCI 250 M primer, 95.5 grains AR2217 Velocity 2869 fps from 30 inch, 1 : 10 twist Lilja Barrel. MAX LOAD

Load 7 ...... 300 grain SMK, Remington cases, CCI 250 Mag primer, 96 grains AR2217 Velocity 2890 fps from 30 inch, 1 : 10 twist Lilja Barrel. MAX LOAD

Note : this bullet dids not survive the transonic barrier when tested in this rifle. But excellent accuracy to 1500 yards.

250 grain Hornady BTHP match loads. COAL 3.840" Special long cut throat. 0.020" off the lands.

Load 1 .... 250 grain Hornady BTHP Match, Remington cases, CCI 250 M primer, 98 grains AR2217 Velocity 3046 fps from 30 inch, 1 : 10 twist Lilja Barrel.

Load 2 ... 250 grain Hornady BTHP Match, Remington cases, CCI 250 M primer, 99 grains AR2217 Velocity 3115 fps from 30 inch, 1 : 10 twist Lilja Barrel.

Note : This bullet is excellent at surviving the transonic barrier. Tested to 2300 yards with a reasonable level of accuracy.

225 grain Hornady Interbond loads. COAL 3.810" Special long cut throat. 0.090" off the lands.

Load 1 ...... 225 grain Hornady Interbond, Remington cases, CCI 250 M primer, 100 grains AR2217 Velocity 3232 fps from 30 inch, 1 : 10 twist Lilja Barrel.

Load 2 ...... 225 grain Hornady Interbond, Remington cases, CCI 250 M primer, 101 grains AR2217 Velocity 3257 fps from 30 inch, 1 : 10 twist Lilja Barrel.

Load 3 ...... 225 grain Hornady Interbond, Remington cases, CCI 250 M primer, 102 grains AR2217 Velocity 3289 fps from 30 inch, 1 : 10 twist Lilja Barrel.

 Note : large changes in COAL can have a significant effect on velocity with this load. Not tested to transonic yet but excellent accuracy to 1300 yards.

235 grain Predator Monolithic projectile.

Load 1 ...... 235 grain Predator Monolithic, Remington cases, CCI 250 Mag primer, 99 grains AR2217 Velocity 3164 fps from 30 inch, 1 : 10 twist Lilja Barrel. Note :  Derived G7 B.C. of 0.285 for this projectile from field testing. Accuracy good but B.C. poor. These projectiles did not survive the transonic barrier when tested in this rifle.

Rocky Mountain 300 grain bullet.

Load 1 ...... 300 grain Rocky Mountain Bullet. Remington cases, CCI 250 Mag primer, 93 grains AR2217 Velocity 2940 fps from 30 inch, 1 : 10 twist Lilja Barrel. Note :  Caution HOT LOAD Reduce powder charge. Derived G7 B.C. of 0.37 and G1 B.C of 0.73 for this projectile from field testing. Accuracy good but not as good as 300 grain SMK. B.C. is less that advertised. These projectiles are designed for hunting.

Load 2 .... 300 grain Rocky Mountain Bullet. Remington cases, CCI 250 Mag primer, 91 grains AR2217 Velocity 2820 fps from 30 inch, 1 : 10 twist Lilja Barrel. Note :  Derived G7 B.C. of 0.37 and G1 B.C of 0.73 for this projectile from field testing. Accuracy good but not as good as 300 grain SMK. B.C. is less than advertised. These projectiles are designed for hunting. 

Load 3 ..... 275 grain Rocky Mountain Bullet bullet. Remington cases, CCI 250 Mag primer, 95 grains AR2217 Velocity 3010 fps from 30 inch, 1 : 10 twist Lilja Barrel. Note :  Derived G7 B.C of 0.34 and a G1 B.C of 0.67 is from a limited small sample of tested bullets.

 

Copyright austargets.com 2012