.338 Edge

History

The .338 Edge was designed by Shawn Carlock during the interim period between Remington’s release of the .300 RUM and the expectation of a .338 RUM. Carlock set about creating a basic .338-300 RUM wildcat, eager to obtain data and study its potential while expecting the same cartridge to be formalized as a Remington Chambering. However, when Remington did finally release a .338 RUM it differed from Carlocks design, being slightly shorter in the body than a .338-300 RUM wildcat. Carlock then decided to name his version as the .338 Edge so that it could be distinguished from the Remington chambering.
 
The .338 Edge achieved a good deal of hype at the time of its creation and for many it seemed to be the more natural addition to the RUM family rather than a shortened version. Edge rifles were also built with extra long barrels and extended magazine boxes as a means to extract maximum performance and to this end the name ‘Edge’ worked further in its favor.
 
At this time of writing, the .338 Edge is more popular than the .338 RUM while also serving as an economical and logical alternative to the .338 Lapua which requires a unique bolt face due to its overly wide case rim diameter.

 

Performance

The .338 Edge is a well balanced medium bore magnum. This cartridge is potent and effective with enough powder capacity to drive heavy bullets at relatively high speeds, boasting excellent long range performance. Nevertheless many have fallen into a trap when using this cartridge, neglecting the importance of bullet choice, selecting for example, heavy Sierra MatchKing bullets for hunting which have proven ( by Sierra and myself as examples) to produce pin hole wounds should the bullet fail to meet very heavy resistance. Worse still, some of those who use such bullets will not admit to their failures and do not share such experiences for the benefit of others and the animals they hunt. The same occurs with the .338 Lapua.
 
Try always to keep in mind that if the cartridge is to be used for hunting, projectile choice is of primary concern. The BC of a bullet is only one part of the equation. The same can be said of paper energy figures. If the bullet, by it's design, cannot transfer its energy at its target, its energy figures are meaningless.
 
With regards to barrel length. From a 26” barrel the Edge gives similar performance to its kin. Powder charges and velocities are often identical to within a half grain of those used in the Lapua. With a long 30 to 32” barrel, the Edge does have a slight ‘edge’. And while it is obvious that a long barreled .338 Lapua will do the same, one has to understand that .338 Lapua rifles are often bought in factory rifle configuration while the Edge is a custom build.
 
For my own part I quite like a 26” barreled Edge due to its handier configuration. However - extra velocity does help when the wind is at play so I cannot claim that a handier barrel is exclusively ‘better’. 
 
As stated, the Edge requires a long magazine box. It needs a good 96mm (3.78”) and preferably 97mm (3.82”) to allow long bullets to be seated out where they need to be. This maximizes magazine capacity for bulky slow burning powders while allowing projectiles to be seated close to the lands.
 
Like other .338’s of this power, the Edge is best served with a relatively heavy barrel to tame recoil. Without a brake or suppressor, recoil is stout yet by the same token it does not take great effort to take the sting out of this cartridge (even with a medium weight barrel). A side or slightly forwards ported brake is perfectly adequate, a deafening, face slapping rear ported brake is unnecessary unless you really dislike your hunting buddies or your pooch. If using a suppressor on this or the Lapua, the unit must be of sound design, capable of handling a large volume of gas without fear of rupture. For those who do not wish to use any recoil reducing aids, a relatively long and heavy barrel coupled with good shooting technique are the keys to success.

   
 

Hand loading

Brass for the Edge is easy to form from .300 RUM cases. The best powder for this cartridge is H1000 / ADI 2217 and Retumbo / ADI 2225 along with similar burn rates from competing brands.
 
The Edge throat and leade design works well with a wide range of .338 caliber projectiles while being optimized for those with match style ogives. This cartridge is at its very best when loaded with Rocky Mountain or Hornady A-MAX / ELD bullets. From a 26” barrel, extreme accuracy sweet spots for 225 grain bullets occur at around 3100 to 3150fps, 2950 to 3000fps with 250 grain bullets, 2700 to 2750fps with the 285 grain ELD, and around 2650 to 2700fps when using heavy 300 grain bullets. A longer barrel can result in increases of up to 35fps per inch of barrel (depending on powder burn rate).
 
Please see the .338 Lapua text (and kin) for more detailed information on bullet performance. For more detailed notes on long range performance, cartridge OAL length considerations and suitable rifles for the .338 Edge please see my long range book series.

 

Closing comments

In plains terms, the .338 Edge offers .338 Lapua performance without the price tag. The design works without being overly fussy during hand load development.
 
Having spent a great deal of time comparing the extremes of the 7mm Practical to the big .338’s, one thing that has been obvious is that the Practical does cheat wind a good deal more than the .338’s when loaded in an optimal fashion. Put simply, the big seven can be a doddle to use in challenging winds when hunting high country. That said, the fast 7mm lacks the payload of the .338’s, a vital factor when it comes to hunting large bodied game.

 

Suggested loads: .338 Edge					Barrel length: 26”
No	ID		Sectional density	Ballistic coefficient	Observed  MV Fps	ME Ft-lb’s
1	HL	Hornady SF 225gr SST/IB	.281	.515	3150	4956
2	HL	250gr Rocky Mountain	.281	.846	2950	4830
3	HL	285gr Hornady A-MAX / ELD	.356	.820	2750	4785

 

Suggested sight settings and bullet paths
1	Yards	100	150	295	337	375	400
	Bt. path	+3	+3.7	0	-3	-6.6	-9.4
2	Yards	100	150	283	325	350	375	400
	Bt. path	+3	+3.7	0	-3	-5.2	-7.7	-10.5
3	Yards	100	257	300	325	350	375	400
	Bt. path	+3	0	-3	-5.6	-8.3	-11.4	-14.1

 

No	At yards	10mphXwind	Velocity	Ft-lb’s
1	300	5	2600	3398
2	300	3.3	2622	3815
3	300	3.7	2426	3724

 
Note: Barrel length differs to other published data.
 

 

.338 Edge	Imperial	Metric
A	.534	13.59
B	.550	13.97
C	30 Deg
D	.525	13.34
E	.371	9.42
F	2.387	58.32
G	.330	8.38
H	2.850	72.39
Max Case	2.850	72.39
Trim length	2.840	72.1

 
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