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338 Lapua vs. 338 RUM
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After reading a recent post on long range cartridges, I started thinking about how the Lapua 338 has become so popular as a tactical long range round. I was looking up some load info in the Swift manual and noticed that the Remington ultra mag runs neck and neck with the Lapua. If you were thinking of building a long range rifle, which cartridge would make the most sense from a practical standpoint? It would seem that the RUM would have cheaper, more available brass. Any other advantages/deficiencies? This would be a Toy gun, not necessarily for hunting.


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Posts: 2276 | Location: Texas | Registered: 18 May 2004Reply With Quote
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case capacity is nearly identical (Lapau is actually 1 grain more in water capacity: 114 vs. 113 grains)

However, standard max loadings are higher PSI for the RUM at 65,000 PSI vs. 60,916 for the Lapua, with the Lapua being the stronger case even.

250 at 2860 fps RUM
250 at 2940-3000 fps LAPUA
 
Posts: 2852 | Location: Michigan | Registered: 02 September 2001Reply With Quote
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338 lapua needs a big action, as a sako trg.
 
Posts: 3611 | Location: Sweden | Registered: 02 May 2009Reply With Quote
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By case design,faster powders can be loaded in the Lapua case.
Cost of Lapua brass is 2-3/4 times the price compared to Rem Ultra brass.
Production barrels chambered in Lapua are normally 1-2" longer than Ultra barrels.

Showing up as the sleeper/underdog,I like 338 RUM loading 90gr of RL25 behind a 300SMK & pushing them out of a 26" Rem Bbl @ 2750fps.

The rifle won't drive itself!!!!
Call your shot.


Keep'em in the X ring,
DAN

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Posts: 430 | Location: Fairbanks,AK. | Registered: 30 October 2008Reply With Quote
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quote:
Originally posted by lee440:
After reading a recent post on long range cartridges, I started thinking about how the Lapua 338 has become so popular as a tactical long range round. I was looking up some load info in the Swift manual and noticed that the Remington ultra mag runs neck and neck with the Lapua. If you were thinking of building a long range rifle, which cartridge would make the most sense from a practical standpoint? It would seem that the RUM would have cheaper, more available brass. Any other advantages/deficiencies? This would be a Toy gun, not necessarily for hunting.



Well the bolt face is larger for the 338 Lapua. My gunsmith has been building afew 338 Edge just the 300 RUM case necked up. If I was going to build one I'd do the 338 Edge.


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Posts: 1098 | Location: usa | Registered: 16 March 2001Reply With Quote
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They are both 338/378 Weatherby wannabees.


Free men should not be subjected to permits, paperwork and taxation in order to carry any firearm. NRA Benefactor
 
Posts: 1652 | Location: Deer Park, Texas | Registered: 08 June 2005Reply With Quote
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By case design,faster powders can be loaded in the Lapua case.


I'd love to hear an elabaration on this rather unusual statement.
 
Posts: 13266 | Location: Henly, TX, USA | Registered: 04 April 2001Reply With Quote
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I have a little experience with the Lapua version. I was asked to do load development for a really nicely set up custom .338 Lapua with the Barrett BORS system mounted on the Leupold Mark VI.









The rifle had a 32" Brux barrel and was fitted with a muzzle brake. It was a pleasure to shoot. The owner wanted to shoot the 300 gr SMK as well and I surmized that a very slow powder would be the ticket. I came up with a good load at .030" off the lands with Hodgdon US-869 that had only 2" of vertical at 1000 yards. With the 250 gr Lapua Scenar, I had it shooting 1.5" groups at 300 yards.

Some of my friends play with both the RUM and the Lapua and say the ballistics are so similar that they are negligible.

A note if you are going to have one built. Most of the chambers will be reamed with a long throat. This will make it impossible to seat any closer to the lands than about .080" at magazine length. It was tough to find accuracy at such a jump. The best loads I came up with were at .030" off the rifling.

I would build it with an extra long magazine if it is possible so that it is possible to seat to the lands..
 
Posts: 3427 | Registered: 05 August 2008Reply With Quote
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Here we gooo.....

All that's been talked about so far is "internal" ballistics. If you're trying to compare the RUM to The .338 LM cartridge, it's not even debatable which cartridge maintains a more consistent set of LR/ extended range "external" ballistics. The flow path and surface "tangent" between the ogive and bearing surface of the .338 LM (300 Gr. SMK) are so far superior to any .30 Cal match grade bullet that testing beyond 1100 yards is futile. Add a little directional wind factor and you can forget it past a 1000 yards. There is also dimensional case properties that have proven to be more effective in "center burn" that has proven to aid in concentricity stabilization when not jammed into the lands etc.. Been there done that, 1988 Y.P.G. LRAPR (long rang anti-personnel round) .338 Lapua Magnum. 16,000 rounds down range. 1998 Y.P.G. LRAPR Terminal ballistics analysis .338 Lapua Magnum. Wink
 
Posts: 542 | Location: So. Cal | Registered: 31 December 2009Reply With Quote
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Posted 21 January 2011 23:54 Hide Post
Here we gooo.....

All that's been talked about so far is "internal" ballistics. If you're trying to compare the RUM to The .338 LM cartridge, it's not even debatable which cartridge maintains a more consistent set of LR/ extended range "external" ballistics. The flow path and surface "tangent" between the ogive and bearing surface of the .338 LM (300 Gr. SMK) are so far superior to any .30 Cal match grade bullet that testing beyond 1100 yards is futile. Add a little directional wind factor and you can forget it past a 1000 yards. There is also dimensional case properties that have proven to be more effective in "center burn" that has proven to aid in concentricity stabilization when not jammed into the lands etc.. Been there done that, 1988 Y.P.G. LRAPR (long rang anti-personnel round) .338 Lapua Magnum. 16,000 rounds down range. 1998 Y.P.G. LRAPR Terminal ballistics analysis .338 Lapua Magnum.

Post is comparing .338 LM to .338 RUM so there is no difference in external ballistics as you can use the same projectiles...???
 
Posts: 354 | Location: MD | Registered: 11 August 2009Reply With Quote
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WhatThe, check the header, we are not discussing the 300 RUM, we are discussing the 338RUM and comparisons to the 338 Lapua. This also is not a military grade Sniper rifle, but a semi-sporter, say not over 12 lbs. in weight and with probably no more than a 26" barrel. To me, it would appear that the 338 RUM would be cheaper to build and feed than the lapua, I never noticed that the Lapua had a bigger bolt face requirement, my bad! I guess I am theorizing on how to get similar performance without the high price of the Lapua. Any advice appreciated! Lee.
RCamuglia, that is an impressive rifle! Thanks for the advice on the freebore issue.


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Posts: 2276 | Location: Texas | Registered: 18 May 2004Reply With Quote
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quote:
Originally posted by lee440:
WhatThe, check the header, we are not discussing the 300 RUM, we are discussing the 338RUM and comparisons to the 338 Lapua. This also is not a military grade Sniper rifle, but a semi-sporter, say not over 12 lbs. in weight and with probably no more than a 26" barrel. To me, it would appear that the 338 RUM would be cheaper to build and feed than the lapua, I never noticed that the Lapua had a bigger bolt face requirement, my bad! I guess I am theorizing on how to get similar performance without the high price of the Lapua. Any advice appreciated! Lee.
RCamuglia, that is an impressive rifle! Thanks for the advice on the freebore issue.



Ohhh.....ohhhh....oh, my bad. Absolutely a wise choice (.338 RUM)! You're also right on the load and over-all cost of feeding it. It does share external data to be in the same class as the Lapua and even the 338/378 Weatherby. I have never done any work with the .338 RUM, it is too new but the case dimensions suggest that it will have good burn and "neutral" balance characteristics. Although the Weatherby has a bit more huevos, it's a burn out past 900 yards and even with heavy test receivers and head-barrels it's lacking in the Int. ballistic department to be an effective long range threat. I/we did a lot of work with it (.338 Wthrby)when the .338 LM was introduced for MOAP operations in the mid 80's and it stunk the place up. On the other hand, the .338 RUM may have out-performed the Lapua had it been available at the time. I'm sure it will get its turn shortly but I haven't seen it or even its data proposed for mill ops by OMC, RMC or Peters? Good luck with your build. A lot of gun! You must be hunting grizz at 7 or 8 hundred yards away??
 
Posts: 542 | Location: So. Cal | Registered: 31 December 2009Reply With Quote
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I consider the 338RUM the poor mans Lapua. I went that route and am happy as hell. Can find the brass for $90 per 100 and usually you can find a second hand Rem 700 because most cant handle a full box of 20 rounds. She does rattle your teeth!

I was lucky enough to get 2 (I'm a lefty) never fired from an estate sale. I'm about 500 rounds into one. Once I shoot out that barrel she's going to be a 375RUM.

After dropping it into a McMillian and bedding it -- 16oz sniper fill added; I've gotten fantastic groups with 225gr Interbond. 3 shots can be a dime size but 5 shots are quarter size all day long.

There are many others here that report the same type of accuracy with these rifles. I uses RL25 and sometimes RETUMBO.

Good luck! Enjoy.
 
Posts: 969 | Registered: 13 October 2009Reply With Quote
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quote:
Originally posted by lee440:
...If you were thinking of building a long range rifle, which cartridge would make the most sense from a practical standpoint? It would seem that the RUM would have cheaper, more available brass. Any other advantages/deficiencies? This would be a Toy gun, not necessarily for hunting.
Hey Lee, I've shot a whole bunch of the 338RUMs, but no 338Laupas, so I can only comment on the RUMs. The ones I shot were all Factory M700s and everyone of them was MOA - with the excellent Factory Muzzle Brake. So, I'd see no need to build one, unless you just wanted to. Of course, you could build a real HEAVY one and delete the Brake.

The RUMs are relatively easy to locate Cases for and there are plenty of excellent Powders for the various Bullet Weights.

I would find it very difficult not to Hunt with it, unless it was built to HEAVY to tote around.

Nothing at all wrong with the excellent 338-378WbyMag that 30378 mentioned either.

Best of luck with your choice. BOOM
 
Posts: 9920 | Location: Carolinas, USA | Registered: 22 April 2001Reply With Quote
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Originally posted by BISCUT:
I consider the 338RUM the poor mans Lapua. I went that route and am happy as hell. Can find the brass for $90 per 100 and usually you can find a second hand Rem 700 because most cant handle a full box of 20 rounds. She does rattle your teeth!

I was lucky enough to get 2 (I'm a lefty) never fired from an estate sale. I'm about 500 rounds into one. Once I shoot out that barrel she's going to be a 375RUM.

After dropping it into a McMillian and bedding it -- 16oz sniper fill added; I've gotten fantastic groups with 225gr Interbond. 3 shots can be a dime size but 5 shots are quarter size all day long.

There are many others here that report the same type of accuracy with these rifles. I uses RL25 and sometimes RETUMBO.

Good luck! Enjoy.


It would be an interesting build. Perhaps a single stage fluted "BAT" action with a heavy Shilen 26" stainless match grade @ 1:10 all dropped into a Mcmill/AW stock. How can you go wrong there?
 
Posts: 542 | Location: So. Cal | Registered: 31 December 2009Reply With Quote
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One thing not mentioned is if you want to hunt with the rifle, the .338 Lapua will run afoul of some countries' no military ordinance laws, while the .338 RUM is safe from that. Not a big deal in the US, but Mexico or some of Africa might not be so understanding.
 
Posts: 11203 | Location: Minnesota USA | Registered: 15 June 2007Reply With Quote
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Isn't the Lapus a Non-belted case and the RUM is belted???

Either way, here in the next year im going to convert my Sendero 7mm Mag into a 338RUM with a nice barrel. It may have the "poor man's Lapua" nickname...But when I crank a 300grain into that Elk's shoulder at 600+ yrds, I bet he wont know the difference.

BTW, I got my 7mm Mg Sendero for less than $500 with a cheapo Bushnell Banner scope, hardcase, and 120rds of ammo...And to convert it to the 338 chamber will not take much. A new barrel of my choice, Wyatt's magazine deal and a decent smith and about $500 the way I figure it after the cost of the barrel blank.
 
Posts: 468 | Location: Goldsboro, NC. | Registered: 02 August 2009Reply With Quote
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I have one of those older M995 Sakos in 338 lapua. 26" barrel. think the stock is made by McMillan. Really shoots well. Never fooled with an RUM, but I can't see where it is a bad round. I mostly shoot 225 grain hornadys (because when i bought a bunch, they were cheap) and H-1000 powder. Think I used H 4831 with the 250s. Never thought of shooting a 300 grainer. Most of my shots on groundhogs are between 250-350 yards and the 225 is just fine for that application, and deer for that matter.
 
Posts: 831 | Location: Virginia | Registered: 28 January 2005Reply With Quote
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I like the 338-378 weatherby better than both the 338 lapula and the 338 rum.I bought two 338-378s I liked them so much.Mine were both $1000 each no lapula 338 for that.I have shot under an inch at 300 yards many times.My rifle will shoot a 250 gr bullet at 3100 fps with no pressure.It weighs under 10 pounds with a 6.5x20 power scope ,sling and 3 rounds.The 338 rum is about dead these days.Yes the 338 Lapula is awesome but it needs to be in a more afordable package.I have loaded my 338-378 brass up to 17 times.I love to shoot 250 gr Nosler partitions out of my 338-378 they hit like a mack truck.Its silly to have a long range 308.I want to try the 300 gr Serria match king more .It is the best long range 338 bullet.If you find a cheap 338-378 buy it!!!
 
Posts: 2543 | Registered: 21 December 2003Reply With Quote
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Originally posted by dgr416:
I like the 338-378 weatherby better than both the 338 lapula and the 338 rum. I have shot under an inch at 300 yards many times.


Perhaps a 1 shot group?



I couldn't resist..... animal.....Sorry......
 
Posts: 542 | Location: So. Cal | Registered: 31 December 2009Reply With Quote
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Originally posted by Brando:
Isn't the Lapua a Non-belted case and the RUM is belted???


Both are non-belted, the Lapua is based on the 416 Rigby case while the RUM family is based on the 404 Jeffery case
 
Posts: 2124 | Location: Whittemore, MI, USA | Registered: 07 March 2002Reply With Quote
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I have a 338-378KT on the way in, Should be interesting to see what it will do.
GWB
 
Posts: 23752 | Location: Pearland, Tx,, USA | Registered: 10 September 2001Reply With Quote
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I had a 338RUM for a while. I really liked it. The factory 250 gr Swift A Frame chronoed 2900 f p s out of my Rem. 700 stainless. 26" brl. I worked up a load with 275gr Kodiak Bonded cores. They were going 2800 f p s. I finally got some Rl 25 but didn't get any loads developed with it. One friend didn't like it because it was a Rem. 700. He is a crf snob. Another friend wanted it to much for me to keep it. I had a light weight 4x scope on it. It is a great round. And it was a good rifle. I wish that 1friend who is a member here would have not disliked it so much. People often sgaul
and carry on about Rem. 700 actions . But that one functioned and fed flawlessly. I had not a qualm 1 about fighting bears with that rifle and round. I don't think that original factory load of a 250 gr Swift @ 2900 f p s can be improved on for big game hunting with the 338 RUM.


.If it can,t be grown , its gotta be mined ....
 
Posts: 3445 | Location: Copper River Valley , Prudhoe Bay , and other interesting locales | Registered: 19 November 2006Reply With Quote
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Originally posted by WhatThe:
quote:
Originally posted by dgr416:
I like the 338-378 weatherby better than both the 338 lapula and the 338 rum. I have shot under an inch at 300 yards many times.


Perhaps a 1 shot group?



I couldn't resist..... animal.....Sorry......



rotflmo animal
 
Posts: 969 | Registered: 13 October 2009Reply With Quote
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338 Lapua ....... tu2




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