.300RUM, .338RUM & .338Lapua


Well-Known Member
Jun 25, 2003
Aussie in Italy
I am just thinking, brainstorming or dreaming about another LR rifle, maybe later on next year.

I am partial to Sakos, so the TRG in .338Lapua seemed like a good option. Only that I haven't heard that many good things about it.

I was consdering a Sendero in .300 or .338RUM - what I have come to like in Remingtons are all the aftermarket parts availiable.

Or even reaming the .338RUM out to .338Lapua, if the dimensions will permit.

A friend who has a TRG in .338Lapua tells me he feels the Lapua cartridge would do better with a longer barrel than the stock 26" but I cannot modity this, our laws are very strict here.

So would I do better with a .300RUM and a 26" barrel?

What do you guys think?
.300 RUM vs. .338 RUM
Recoil is almost identical.
Both want 26" or longer barrels.
I've heard good reports about the Sendero's. Fairly accurate out of the box. Most are sub-MOA. Wish I had one myself!

Comparing the performance between the .338 RUM and the .338 Lapua, the gap is considerable narrowed when compared to the .338 Win. Personally I'd go with the .338 and then figure out which one fits my needs the best. If the .338 RUM takes off, brass and ammo will be much more available than the Lapua.

Mark in Utah
Well, where I live the Lapua brass is not so expensive and easily availiable.
I also hate Remington brass due to it's inconsistency.

[ 10-28-2003: Message edited by: EXPRESS ]
I'd go with what Chris said.
The Remington brass for my .338 RUM is surprising good brass for Remington. I'm satisfied with it. Going on 4 reloads with it and so far no problems. May need to anneal the necks on the next reload (5).

Mark in Utah

This is one of those tough questions that there is no clear answer for. In my opinion, the 338 Lapua is a great round but also carries alot of baggage with it, mainly high brass cost($2/brass).

The 300 RUM is my favorite of the group and I have them all and load alot for all of them. As an all around big game round, the 300 is very hard to beat.

The 338 RUM is also a great round also and perhaps for larger game at longer ranges, is a better big game round then the 300 RUM.

Interestingly enough, the last Norma 338 Lapua brass I measured for case capacity had one grain less capacity then my 300 RUM. With this in mind, the 338-300 RUM would have 2-3 grains more case capacity then the Lapua.

Also, it could be chambered in anything you like with a magnum length action plus brass is 1/4 the price of Lapua.

I agree brass quality is not up with the Norma and Lapua brass but with a little bench time and prep work, Rem brass can be made into very good brass.

All in all, for an out of the box extreme range big game rifle, the 338 RUM would be my top choice with the 300 RUM next and then the Lapua.

Good Shooting!!!

I was fixing to start a post on choosing what next big caliber to get.
300WM,300WSM,300RUM OR the


I have heard people talk about the RUM not being around in the next 5 years or so,or not being popular. They say the WSM's are better and will be more popular for a longer period of time. WHat do you think of the 300WSM and the WSM in general?

I just want this for punching paper at long ranges.

I have to wonder about the latest short magnums. The WSM will probably stick around for a while. The WSSM is probably just too far "over the top" to survive. Too many $$$ per shot, and too few rounds in the magazine compared to what it's replacing.

The WSM is still enough of a magnum to make a case for it.

Just my $0.02, but then I may be wrong. Who knows? If I knew for sure I'd make a killing on the stock market!

Mark in Utah
I love the Lapua Mag. Yes I was lucky enough to get the First Batch made in 1993 by Sako. I hear another fellow member is having some problem with 300 gr bullets. His bullet has no grove in them and his barrel is a 1 in 10 twist as opposed to my ORG. 1 in 12 Twist. I use the 210gr. Nosler only and groups are very tite. Yes brass in Canada is $3.00ea., and I've reloaded the first 10 cases believe it or not 10 TIMES. No Problems and the load is really moving out.
Hi there TH and welcome!

Yep,it´s me having some problems, got it narrowed down by now though. 300 MK:s shoot good groups with low ES but there is some vertical drift after the first shot and it´s not heat or clean / fouled issue. I´ll get it figured out, it must be a "plastic" issue.

Lapua brass can take many reloads with no changes. I have used some cases eight times to see how it goes. Just starting with MK:s.
Petander I have concern about vertical drift? Also, your contact in USA should send you a bottle of Sweets 7.62 Cleaning Solvent and clean up that bore. That Red Bore Stuff even indicates in his add that Sweets is better for getting that moly out. Glad to hear your working on the bullet-lapua problem. Lower ES is amazing for the 300gr. bullet.
Hello Express..

It's a no-brainer!!!Go with the 338 Ultramag in a Sendero.Brass is readily available and cheap.The heavier bullits will surpass anything in 30cal.and it will equal the capacity of the Lapua.I've been hunting with this caliber for two years and find it hard too beat.The punch down range is somethng to be witnessed.I also have a 338-378WBY TRR but that is a whole different animal.Just like Lapua brass it's expensive.The only SAKO chambered in 338 Lapua is the TRG-42 or the TRG-S.The TRG-42 is expensive and the TRG-S needs work.
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