I know where a Kimber 8400 in 300 WSM is sitting for a good deal. I have a 300 WSM in a Win M70 EW so don't need another. I've always been intrigued by the RCM cartridges. Case head is very similar but the RCM case has a slightly smaller shoulder diameter (0.538 vs 0.515). On the surface it would seem to work. Anyone ever re-barrel a Kimber, or any other WSM based action, to the 338/300 RCM? If so, how did it feed the RCM case?

A 7-7.5 lb 33 caliber rifle would be sweet for chasing elks.

Thanks.

Why not just find a SS ruger compact instead, rifle and scope probably cost much less and weight about the same.

CDNN has a few in stock for cheap

Why not just do the plain old 338/300 WSM since it probably works as is and you could neck up 300-325 stuff pretty easily? Not knocking your plan but the WSM brass is pretty danged easy to get ahold of.

CDNN used to have them for $399! Bought one in 338RCM and sold it like an idiot because I was concerned about finding components. It was a sweet little rifle.

^This. If the Kimber 8400 WSM mag is long enough this route is a no- brainer.

The 338 RCM was designed around the 2.8” Short magazine, and it’s case is shorter than the 300 RCM.

I believe ( but haven’t verified) that the Ruger, Kimber, and M70 short actions are actually a tad longer than 2.8” .

Are you thinking of necking up PRC brass for this cat ?

You could probably try cycling a few rounds of 300RCM or 6.5PRC through the Kimber to see how/if it feeds before committing to one chamber or another.

At one point I considered extending the chamber of a 338RCM to the 338/375 length & slapping it onto a long-action .Didn’t really make sense, even to this loon, as the SS barrel that I had was only 20” . Probably a tad blasty at that length.

Woefully, I don’t have it now, mostly because of ammo availability issues.

The case head above the grooves are .532" for the RCM and .555 for the WSM. I'd stick with the WSM or get a rifle chambered for the RCM from CDNN.

I keep looking at those cdnn 338 rcm.....so far Ive managed to not buy one. The stainless synthetic version with open sights looks like a blast!

To elaborate a bit more on my idea. The goal is to build a rifle that weighs 7.5-7.6 lbs with scope in a cartridge that doesn't recoil as much as a 338 WM. The scope I want to use is a NightForce SHV 2-10x42. I've shot a couple sub 8lb 338 WM and will pass with full power loads. I've considered going the traditional 338 WM route and loading it down.

I also like the Kimber MT platform - it fits me well, stock and action are both solid performers. The Kimber MT WSM platform weighs 6lbs 3 oz bare rifle, NF and Talley 30 mm rings adds 23-24 oz to the mix. Rifle weight ends up being ~ 122 oz or 7.6 lbs. Install a 22" barrel and it comes out right at 7.5 lbs.

The 338 RCM is an oddball no doubt about it. But it has the same capacity as the 338-06 - which means it can push 338 cal bullets to meaningful velocities. I'll chamber a rifle around the 210 Swift Scirrocco and/or 185 TTSX. Both bullets launched from the 338 RCM platform should perform well to at least 400 yards.

I've looked at the Ruger Hawkeyes. I love the Ruger 77 in all its versions and have owned a bunch. The issue is weight. Both the 22" and 20" SS All Weather will weigh right at 8lbs with a Leupold VX-3, 8.5lbs with the NF SHV. The goal of this rifle is elk, backpack and dayhunting. I've dragged enough 8+ lb rifles around at 10,000 ft. I'm 55 and the mountains aren't getting any flatter. I've been using a 270 and 308 the past several years with success but have shot the last 3-4 elk at less than 50 yards in the timber and not broadside. I like 2 holes in animals and have test loads with various Barnes bullets for my 308 and 338 Fed to try. If the 338 Fed works out, I likely wouldn't do a 338 RCM. Or maybe I might to have a pair of elk-capable rifles.

Scott - on the 338 WSM, I considered that as well. Where to get a reamer? Could it be as simple as sending my current 300 WSM to JES for a 338 re-bore? Its been sitting in the safe for years. Using a Leup VX-3 I have and aluminium bottom metal, I could get it down to 7.7 lbs give or take an oz which works as well. If recoil gets too stiff, I can load it down a bit. I only have about 500 pcs of 300 WSM brass............

338 Sherman short. Look on Sherman short mag seb site for solid information. He rents dreamers. Good luck

I highly recommend the 338 RCM in Rugers compact platform.I found a left hand version and have been using it for about a year now. So far I've taken a big bull bison, a caribou, and a wolf. I have access to one small sporting goods store and have had zero problems getting brass. I have enough hoarded away now to last as long as I will be hunting. I cant imagine a better all around caliber for big game.

Get the Kimber 300 wsm and hunt it as is. 155 Scenar, 165 Game Changer, etc. If you really want to spend some money, I'd be going smaller in bore diameter into a 7 or 6.5 rather than up.

To Calvin's comments, in the 300WSM, the 150 Barnes TSX or TTSX would be better close range elk bullets than the Scenar or Gamechanger.

Or if you can find them, the Winchester (Combined Technologies) Fail Safe would punch though an elk from any angle. The only one I ever caught out of my 338WM, was diagonally through an 80 yard bull moose on the second shot (I was shooting until it fell over, we had already tracked him 8km measured on the map). The bullet broke the onside hip, went through a full belly, the lungs, offside ribs, shoulder blade and was found under the hide at the front of the shoulder. Outstanding performance.

If I wanted a lightweight 338 I’d build a 338-06 or 338” WM.

While almost no actions handle the WSM’s as well, I have no love for the Kimber 8400 MT.

The 338 RCM is destined for the trash heap of history. For me, I can see no reason to go there, and I’d take the 300 WSM over the 338 RCM every day no matter the platform.

It's obviously all a matter of opinion. Hornady has a habit of supporting their offerings. It could very well be the opposite, that the 300 WSM (like all the other WSMs) will be in the trash and the 338 RCM will go on. I doubt anyone here will be around long enough to find out.

B, my opinion is send it off to Jess and let him do his work to the rifle. You’ll be into it 225 bucks and a set of dies. Anneal the brass and shoot it.

I’d be prepared to lap the barrel decently and DBC it but that’s about it. JES will find the reamer for it. I’m betting it will just be a straight rebore though. I think it’s an excellent idea and a butt kicker of an elk rifle.

Seriously?

Universally, the 300 WSM is the most successful new cartridge offering of the last 50+ years...probably only to be eventually eclipsed by the 6.5 Creedmoor.

Agreed....I had a portly feel 300 WSM for a hot minute and just never could warm up to it.


Which is exactly why I went for a 338-06 off the 84L.

Plus then you can put nearly any scope you'd desire and still hit your 7.5 pound goal.

I agree the 300 WSM is here to stay as well. In fact my latest rifle is in such cartridge. It shoots the same weight bullet roughly the same speed as my 338-06 but is a full 1.5 pounds heavier than my 338-06 and 1" more barrel.

No, not really. I fully expect the 300 WSM to do well and hope the RCM becomes more popular as well. It's just that things in life often take the unexpected turn.
Happy hunting!

My 300WSM 8400 Montana is probably my favorite big game rifle. I know some don't like the "belly" the 8400 has, but it seems less pronounced with the WSM.

What issue bothers you Brad? I know you have tried many Montanas in various calibres.

If you want lightweight, and a .338 bullet through an elk at 400, the 338 Fed will likely do that fine with the 160, 185 TTSX or 180 AB as examples.

Lots of truth in this ^ I hunted with the Federal round since it first came out in 06 or thereabouts. Got rid of it last year when I picked up the RCM on a whim. IMO the 338 Federal is one of the best rounds to come along in recent history. I took a big bison with mine at 300 yards so I know it will take elk. I've never liked the WSMs, none that I've owned fed worth a hoot. The RCMs are much better in that respect.

Lots of good thoughts presented here. Its only 287 days till I leave for elk camp, come on elk season...............

I agree 338Rules, be sure the 338 RCM will not have issues in a magazine built for the fatter 300 WSM. If it works and the bolt face fit is not an issue give the 338 RCM a try.

The brass is once again available. Bruno's has it on sale:

http://www.brunoshooters.com/product/9778.html



I own two 338 RCMs. Own the SAMMI spec reamer too.

Built a tang safety SA Ruger in a now discontinuted McMillan Ultralight stock Rick sold me. 22" #2 Lilja. Had magazine lengthened to 3.1" for useful OAL of 3.050". Rifle weighs 7 3/4 lbs with scope. Killed two cow elk with the 225 Accubond velocity 2750 fps.

Recently made a super accurate load for this rifle with the 300 gr Berger:

300 gr berger seated to fit and feed from magazine
54 gr of RL-17 fed 210 standard primer virgin 338 RCM brass
Velocity 2349 fps (3675 ft/lb at muzzle)

I used information from from another site and the Berger's terminal performance on elk worked well as slow as 1966 fps impact velocity.

This makes this load viable out a bit over 600 yds!
@ 7000 ft:
POI Velocity Energy
100 0.5 2286.7 3482.5
125 -0.0 2271.2 3435.5
150 -0.9 2255.8 3389.1
175 -2.3 2240.4 3343.2
200 -4.0 2225.2 3297.7
225 -6.3 2210.0 3252.8
250 -8.9 2194.8 3208.4


=================================================================




For grins I built a 14 lb LA Mark X with 29" 1 in 9 twist barrel in Joel Russo stock. This 338 RCM is long throated to shoot the 300 gr Berger at a mundane 2455 fps using It is a real hoot to shoot and bucks the wind quite well with lots of energy way out there. It can be fired 10 shots in a row and the barrel only gets "warm". Did use it once for a coues wt hunt. Shot a buck at 400 yds. .338 diameter hole through entire animal minimal meat damage.
Load data: fed 210 primer 54.5 gr RL-17 seated .010" into lands

-------------------------------------------------------------------------


Some loads tried with the SA:

all loads use fed 210 primers

225 accubonds: worked up to 61 gr of RL-17 / 2750 fps with Fed 210 match primer.
180 nosler bt: worked up to 64 gr of RL-17/ 3045 fps.
215 sierras: worked up to 55 gr of Varget, most accurate 54 gr/ 2730 fps.
215 sierras: worked up to 64 gr of H4350/ 2865 fps

AZ that's the kind of info I was looking for. Thanks!

Was your Ruger SA just a plain Jane SA - meaning 0.473 case head bolt face?

It was a 243/ .473" bolt face SA tang safety Ruger. I had my gunsmith, Joe Reid at Harry Lawson co here in Tucson, open up the bolt face and lengthen the mag box. No other alterations were necessary to make it feed the 338 RCM.

I really like those old tang safety rifles, have two SAs and one LA all with lengthened mag boxes. Two have timney triggers, one to go.

The 8400 stock handles the WSM's recoil about as well as any stock can, but I just don't like the way the stock "feels"... it's "chubby and clubby" all around. I dislike a no.1 barrel contour, especially on a rifle with the recoil of the 300 WSM, and would prefer a no.2 contour for more weight out front.

I’m still drooling over that rebored 84L 338’06. What barrel length did you end up with ?

21" barrel. 6.75 pounds on the nose with a SWFA 3-9 on it.

Alaska_lanche, what FPS do you think it would shoot 210 Partitions?

Not lanche, but my 22” bbl’d 338-06 would go in the mid 2,700’s with the 210 NP.

Thanks. It occurred to me I never reloaded the 210 Partition in my 22” 338-06. Mostly 225s, and it seemed to be rather slow.

The 210 NP was my favorite bullet in all the 338 WM’s I had, and is the only bullet I ever used on the elk I killed with the 338. To me, the 210 Partition in the 33’s is like the 130 NP in the 270 Win in that it kills all out of proportion to its size.

Without a doubt. It hammers elk and penetrates likecrazy. It’s very accurate in my 338 as well and pretty easy to get up to the 2950-3000 mark without issues. Like Brad mentioned, it should’nt perform as great as it does.

I couldn't get the 210 NPTs to shoot as well as the 210 Sciroccos so I focused on the latter more. Final load was 2800+ fps with the 210 Scirocco. 225 Accubonds were at 2690 fps as well. I will be working up a 230 ELDX load as well. But for my brown bear tag on Kodiak this spring I will be using the 210 Sciroccos likely even though the 250 A Frames at 2550 grouped well too...the weight renetion on the couple 210s I have recovered were excellent and I am not worried about not making it to the vitals by anymeans.

Thanks! IIRC I was getting low 2600s with 225 ABs and Partitions using H4350 and RL17. Wish I would have tried 210 Partitions.

2730fps from my 22 inch barrel.

It's essentially the same speed as a 180 from a 30-06, 165 from a 308, 150 from a 7-08, or 140 from a 6.5 Creedmoor.

But we all know the Creedmoor is better

Take it from someone who actually owns a 338 RCM.

The RCM is not destined for the trash heap, not by a long shot. Hornady makes brass and it will be around for a long time as a niche cartridge for those who really know what it can do.

It is the equivalent of the 338-06 Imp, but in a shorter overall rifle.

My 22" Ruger 338 RCM weighs just a bit over 8 lbs with a Leupold VXR scope.

Burning RL16 61.0 grains I am twisting 250 AB's at 2,615 average.
RL17 61.0 grains will push 225 AB's at just under 2,800 mv.

It's a great cartridge and would rather be able to buy 338 RCM brass than neck or form 338-06.

Not to take away from what you say regarding the 338 RCM being a "338-06 Improved" (it has approx 3.5 gr's more water capacity), but necking 338-06 brass from cheap and available 30-06 brass is the simplest thing in the reloading world... and if you want 338-06 A-Square brass, it's available.

I still am confident the 338 RCM will be in the trash heap of cartridges long-term... heck, even short term.

It will always be in my closet and that is what matters. IF it goes down the road that matters not to me. I'm just glad to have one.

.338 RCM?...hell you will join the ilk of those that have weird obsolete trash pile schit like .284wins and 9,3x64 Brennekes.
and are enjoying them very much...

or go 'extra weird' - neck 300rcm to .338 cause its got 72.7 grains water cap. vs 338 RCM 70.1 grs.

338 RCM baby!! I got enough brass for as long as I'll be around. Shot my deer with one last year.

I am not sure I care so much about whats going to be around for how long. I have two 338 RCM's and have enough enough brass to shoot out at least one of the barrels if not both. if you want off the shelf ammo neither 33806 or 338 RCM would be on my list although there is 338 RCM on the shelves at the two shops I visit regularly, haven't checked for 338-06. If you want off the self ammo I would stick to30.06 or 338wm or if you have to have a short mag 300wsm.


While I like the ballistics of the 338 RCM or 338-06, one of the beauties of the original 338 RCM was the nifty little package Ruger put it in. If I wanted a LW 338RCM I might hunt down one of those and put it in a LW stock.

Anyone have one of those compact 338rcm or 338-06's laying around they want to get rid of?
I don't want anyone's trash heap getting to tall.....but seriously though
James


Also, if CDNN has the 338rcm, will someone send me a link. I can't find them

I haven't seen them on CNN in some time.
Keep an eye out on gunbroker or post a WTB in the classifieds here.

Sorry that should be CDNN, you can slap me now.

Not to hijack the thread, but I'm looking for a starting...or accurate load using RL15 and a 210 grain bullet. Info seems scarce...just bought one of the 20" barrel rugers. I'm presuming roughly 50-53 grains...but found someone online who was up to 58 grains...seems on the hot side. Any info would be appreciated. Have a bunch of Swift Scirocccos I want to play with.