.338 differences

[sdkidaho]

I see some guys talking about .338 Edge and .338 Lapau. I looked at ammoguide.com to see what the differences were but then found four or five more .338's - RUM, etc.

Is there one that is more commonly used? If so, why? Major differences or just a preference sort of a thing?

Thanks,
Darby

 

[sp6x6]

This may not be spot on or complete 1958-338win,1962-340 wtby,1988-338-378 wtby,1989-338 lapua,2000-338 rum,338 edge,338ultramax,338 kahn,338 allen-x,2009-338 norma mag, think theirs 2 allens, lazeroni,nawaka? 338 GIBBS,a-sguare,jarrett,dakota,arnold,fedral WOW THE 338 is popular

 

[Long Time Long Ranger]

Just a prefference sort of thing. Slight increases in performance as you go from the blown out improved "06 cases to the 338 winchester, then to the 340 wby which is knocking on the door of the 338 RUM, 338-300 RUM and 338 Lapua which are all three the same thing performance wise. Then a little step up to the 338 Lapua Improved then a slight step up to the 338-378 WBY. Then a slight step up again to the improved 338-378 Wby, 338-416 Rigby and Excalibur size cartridges. Now from the 340 Wby to the improved 338-378 wby and similar class cartridges there is about 300 fps difference. Everything else fits between these except the 338 winchester and improved '06 cases which are below the 340 wby. So in a nutshell there you have it. Just a prefference sort of thing.

 

[Buano]

I see some guys talking about .338 Edge and .338 Lapau. I looked at ammoguide.com to see what the differences were but then found four or five more .338's - RUM, etc.

Is there one that is more commonly used? If so, why? Major differences or just a preference sort of a thing?

Thanks,
Darby

The previous posts covered the history well.

By far the most popular .338 is the .338 win mag, but that's likely mostly because it's been around a long time & it's powerful enough "to get the job done" in most hunting situations. The .340 Weatherby (which is a .338) added more powder to increase the speed of the .338 Win., and is widely considered the best elk round ever created.

The hotter .338 cartridges are more than most can shoot without a muzzle brake and are normally chambered in weapons weighing 12 pounds or more — often weighing much more.

The .338 Federal & .338 Ruger both came about recently to get a .338 into an action too short for a .338 Win mag.

 

[Long Time Long Ranger]

The two you mentioned, the 338 Lapua and 338 Edge, have virtually identical performance. If you wanted to flat out push both to the max the 338 Lapua can be pushed to slightly greater velocity probably because of the much higher pressures the Lapua brass will withstand. The 338 Lapua was developed by Lapua in the late 1980's (about 1989 I think). It became popular during the mid to late 90's in this country primarily as wildcatters like me started improving the case and seeing what we could get out of it. I was in continuous communication with guys around the country and at Sierra Bullets as we all compared notes on what the top improved versions were getting performance wise or basically which ones were the best. The base cartridge is a shortenned 416 Rigby case. The full length parent cartridge improved had been a top wildcat 338 along with the 338-378 wby for many years . I know I started fooling with these during the 1970's and they were already very popular at that time.

The 338 Edge is the 338-300 RUM. It goes by many names however edge seems to work on this site best. The fine gunsmith and strong promoter of the long range hunting sport Shawn Carlock who is on this site started working with it in 2001 and named it edge out of his shop according to his article on it. Overall there are probably more barrels stamped 338-300 RUM than any of the other names. The cartridge began in late 1998 when the specs of the soon to be released 300 RUM were leaked to some and wildcatters went to work. The cartridge became popular with several gunsmiths during 1999 and 2000. It has continued to have a very good following because it can be done on a standard magnum action making it a cheap build with readily available cheap remington brass.

By late 1998 I was doing the 300 RUM necked to 7mm, 8mm, 338 and 358. My primary interest was the 338 version since I had been looking for years for a case that would beat a 340 wby on a standard magnum action. So I immediately jumped all over necking the 300 RUM and many were very impressed by the results. During the 1999 elk season several rifles I had done took elk at long range and recieved glowing reports. To my knowledge an elk taken in October of that year in Colorado was the first to succumb to the 338-300 RUM. The only way anyone could have been doing the cartridge before late 1998 would have to be an insider at remington.

Several shops including me quit doing the 338-300 RUM in 2001 with the introduction of the 338 RUM. Through extensive testing both cartridges deliver basically the same performance. The 338 RUM offered several advantages with cheap RCBS dies and over the counter brass. Being slighty shorter it was easier and cheaper to get it feeding better through standard magnum actions which was the beauty of the cartridge. Like Remington had told us at the 2001 shot show it delivered the same performance as necking the 300 RUM to 338 but fed better through the remington actions with long 338 bullets with less modifications. Some of us just saw no reason after 2001 to continue wildcatting the 338-300 RUM. Both are excellent cartridges with excellent accuracy and capable of killing animals well beyond the capabilities of all but the top marksmen on the planet.

 

[MontanaRifleman]

Thanks guys, good read.

LTLR, Is there a standard 338 LM Imp? Shoulder angle 35*? Shoulder diameter?

 

[sdkidaho]

Thank you! That was what I was looking for in the way of information - much appreciated.

 

[Lapua guy]

The previous posts covered the history well.

By far the most popular .338 is the .338 win mag, but that's likely mostly because it's been around a long time & it's powerful enough "to get the job done" in most hunting situations. The .340 Weatherby (which is a .338) added more powder to increase the speed of the .338 Win., and is widely considered the best elk round ever created.

The hotter .338 cartridges are more than most can shoot without a muzzle brake and are normally chambered in weapons weighing 12 pounds or more — often weighing much more.

The .338 Federal & .338 Ruger both came about recently to get a .338 into an action too short for a .338 Win mag.

Not quite. The 338 Win Mag is a 500 yard gun. Not useful in long range hunting. And the 340 Weatherby is hardly widely considered the best elk round ever created. And the Edge and RUM give up significant amounts of energy and velocity to the LM with 300 grain bullets. They are virtually identical with the 250 and below grainers.

 

[sp6x6]

When I was growing up my father took me to our friends local elk camp.3-4 wall tents and such. No guns allowed inside,large wooden rack outside tent awning. It housed 7mm,30-06,308,308 norma,340 WM,8MMRM,300H&H,375, AND MY little ol 243.Could not wait to get a real elk gun some day.Most guys in the mountains had there 300,s and 338s.Ialways remebered these 2 cowboys hunting the high country with their 340WM, AND talk of shots at 700 yrds, this was all before a 338 lapua or laser existed.The local sporting shop always had a 340, and I longed for one. I have spent quite some time in the mountains now, many a elk I have seen fall, to the 338. Just a couple years ago a buddy and I shot are bulls, side by side , last day, over500 yrds. me325,him 338 win. The 340 got a 27 yr. jump on use over the lapua. The 340 as stated in my old Speer manual,is powerful enough for any Norh American game,less maybe the large brown bears. here is a little case size comp. may not be exact, but most close.h2o 340wm=93,8mmRM=99,338NM=107,300RUM=110,338EDGE=110?,338RUM=113,338LM=114,338-378=137

 

[MontanaRifleman]

Not quite. The 338 Win Mag is a 500 yard gun. Not useful in long range hunting. And the 340 Weatherby is hardly widely considered the best elk round ever created. And the Edge and RUM give up significant amounts of energy and velocity to the LM with 300 grain bullets. They are virtually identical with the 250 and below grainers.

I believe the poster meant the 338 WM was most popular in terms of sales, not LR capability.

I'm also curious why you wold say the EDGE is gives up signicant energy and velocity to the LM as they have almost idenical case capacities? The 338 RUM is a little behind then but not much, not what I would call significant... maybe 50-100fps.

No flame intended at all, just wondered why you would say that? I think the Lapua is a great cartridge and plan to get an Imp 338 LM before long.

-Mark

 

[Lapua guy]

I believe the poster meant the 338 WM was most popular in terms of sales, not LR capability.

I'm also curious why you wold say the EDGE is gives up signicant energy and velocity to the LM as they have almost idenical case capacities? The 338 RUM is a little behind then but not much, not what I would call significant... maybe 50-100fps.

No flame intended at all, just wondered why you would say that? I think the Lapua is a great cartridge and plan to get an Imp 338 LM before long.

-Mark

Brass Quality gives you an advantage more versus the edge, and case capacity isn't totally the same. I would say that 100 FPS with a 300 grainer equates to about 50-100 yards of additional range depending on BC. Probably 50 ft-lbs more of energy too.

They are close though. You are correct. Kind of why they call the Edge a poor man's Lapua.

 

[Long Time Long Ranger]

MontanaRifleman, I doubt there is a standard Lapua improved other than the standard Ackley shoulder and taper for all cartridges. In my opinion that is not the best Lapua improved. When I get all unpacked I can pull out the notes for you from back in the 90's of the ones we all found to be the best. I remember the best one I settled on pushed the shoulder forward and changed the angle to I think 35 degrees with minimum body taper. I don't remember the exact specifics that far back but can find all the specs in my notes which are packed away.

Guys, from all the tests on my 1000 yard range which included numerous rifles in 338 RUM, 338-300 RUM and 338 Laupua, there is just not enough seperation between these three to make a call either is faster. Accuracy loads in all three with 300 grain bullets hit between 2750-2850 fps in probably 90% of all rifles. Either could outshoot the other just depends on the barrel. If you flat out push them the Lapua can be pushed slightly faster. You have to go to the Lapua Improved to begin to get any real seperation from these three. That will give you 100+ fps. I have shot dozens of all these rifles for thousands of rounds. That is what I found.

 

[Lapua guy]

MontanaRifleman, I doubt there is a standard Lapua improved other than the standard Ackley shoulder and taper for all cartridges. In my opinion that is not the best Lapua improved. When I get all unpacked I can pull out the notes for you from back in the 90's of the ones we all found to be the best. I remember the best one I settled on pushed the shoulder forward and changed the angle to I think 35 degrees with minimum body taper. I don't remember the exact specifics that far back but can find all the specs in my notes which are packed away.

Guys, from all the tests on my 1000 yard range which included numerous rifles in 338 RUM, 338-300 RUM and 338 Laupua, there is just not enough seperation between these three to make a call either is faster. Accuracy loads in all three with 300 grain bullets hit between 2750-2850 fps in probably 90% of all rifles. Either could outshoot the other just depends on the barrel. If you flat out push them the Lapua can be pushed slightly faster. You have to go to the Lapua Improved to begin to get any real seperation from these three. That will give you 100+ fps. I have shot dozens of all these rifles for thousands of rounds. That is what I found.

That is all probably fair to say. And yes, the only LM Improved I know of is the standard 40 degree Ackley fireformed shoulder

 

[outlaw45]

If the 338 RUM is so popular now, why does Remington only list one rifle chambered for it?

I'm looking to get a 338 and probably will go with a factory sendero in 300 RUM and eventually re-barrel it to a 338 RUM or Edge. Probably a little cheaper than going full custom.