Does anyone have experience with this cartridge as to velocities for 250 grain, 200 grain bullets and actual accuracy? I know it's like a 340 Weatherby without the belt but I'm curious about actual velocities and accuracy in the Remington 700. Thanks. 470 Mbogo

i think youll find it to be a little more than the 340.saeed is working on some loads.

470MBOGO- Seems like we have very similar interests. I've played with the .338 RUM alot. My best loads were 87grs of Rl-22,Fed 215 with either the 250gr Lapua scenar or the 250gr sierra SPBT. These loads went 2960 to 3060 in my two .338 Ultras. Both shot <1 inch 5 shot groups. I've got a box stock SS BDL 26 inch barrel and a homebrew M-21 varient in SS witha 28 inch barrel. Either gun will shoot this load <1 inch. I tried a heck of alot of other loads that went pretty fast but didn't deliver the accuracy level I demand. From what I can tell the 28 inch barrel is far more efficient and I can get nearly 100fps more from it with the same load. The ultramags in general seem to want more barrel length.-Rob

Robgunbuilder; I am very interested in the other fast loads that you are referring to. Do you safely get 3000 FPS from the .338 ULTRA ???????? Thanks MD

I am thinking of having a P17 made in the .338 RUM. How is the recoil? I am sure it is excessive, but how bad is it?

If I get my gun built on this I will be sure to get a 27" or 28" barrel.

Basically, the .338RUM is nearly identical to the old ABE EXPRESS. I found this cartridge in a book on wildcats along with a series of starting loads. Can't remember the name of the book. In my case, I obtained good hunting accuracy i.e. <1.5 inches at 100yrds with either Nosler 200gr BT or 210gr partitions over about 95-99grs of RL-22 which went over 3300fps,nearly 3400 FPS with only moderate signs of pressure ( flattened primers, but no ejector marks or sticky bolt lift). I was really after 250 gr loads and found the best accuracy in my guns with the Sierra HPBT and Lapua Scenar bullets. Interestingly, at one point I made two barrels both 28 inches long one made in ChromeMoly(shilen) and the other in Stainless Steel (Shilen)using the same reamer and lathe set-up. The ChromeMoly barrel demonstrated poorer accuracy and Much Much more copper fouling as compared to the SS barrel even after a thorough break-in.. I don't know why, but in .338, I've seen this phenomenon more than once ( this caliber seems to copper foul more than others). Velocities were identical and since this was a switch barrel gun other variables were eliminated. Nevertheless, in my opinion in .338 SS barrels are the way to go and 28-30 inches seem optimum for the .338 RUM. As far as recoil goes, I did not put brakes on these rifles due to the long barrel length and they really don't need them. They Kick but it's far from painful. The use of a P14 action to build one of these on should be fine although to my mind a Rem 700 is really the way to go. However, for comforts sake I'd get the weight of the gun up or put on a good muzzle brake if you are going to shoot it from the bench alot. For hunting I'd keep it light as you will never notice the recoil.-Rob

Robgunbuilder; What about those loads for the 250 gr. bullets???? Thanks Mad dog..

[QUOTE]Originally posted by Robgunbuilder:
Hi Rob,
I'm interested in the 338 Ulta Mag in a gun that will weigh about 8.75 to 9 lbs. with a Leupold 2.5 to 8. My buddy Chris and I talked about this a lot while on our hunting trip in Northern B.C. The twenty six in barrel is fine for me as the velocities they get with it are perfect. The gun we talked about would be a Remington 700 in an H-S presicion stock with a triple X magnum pad (imagine that) and no muzzle brake. I think this set up would be a perfect all around North American set up for anything from deer with downloaded 200 grain bullets to a strong 250 for hunting Moose and Elk in Grizzly country when you may just get that visit. I shot Chris's 375 Weatherby with an MPI stock on a Bruno 602 action with the Triple X pad and it was a pussy cat. It was a pound to a pound and a half more than either he or I wanted to be climbing in the mountains with but pushed out a 300 grain Nosler partition at 2800 fps. I would compare the recoil to a 300 Winchester with 180 grain bullets at 2900 fps.I think the Ultra Mag recoil would feel in the same neighborhood but the trajectory and sectional density would be awsome. 470 Mbogo

I have a 338 RUM in a Mod 700 Sendero SSSF w/ a 26" barrel without a brake. It has a Leupold Mk 4 16X scope mount with Badger rings and base for a total weight of 12.5 pounds. I have only worked up loads for the 300 Sierra MK using several powders, R25, H1000, R22 and H870. Top velocities are 2638 fps w/89.0 gns of R25 and 2688 fps w/89.0 gns of H1000. These loads are one grain below where I get pressure signs starting show. Best five shot group has been .120"@100yds. Worst five shot group 1.110"@100yds (the load was 91.0 gns of R25 - too hot). Average group size from 52 five round group aggregates (every round that has been fired on paper)is .456"@100yds. It seems to be a very accurate rifle/caliber combination. I have not had trouble with copper fouling, but I keep it clean.
I also own a 340 Wby in a Mod 70 w/ a 24" barrel. The 338 RUM has far more recoil than my 340 even with three pounds of difference between the rifles. If this rifle was a light as my 340 Wby (9 lbs w/ three rounds and sling) it would difficult to shoot much off the bench for me. Recoil is HEAVY.
This weekend I will be working on loads for the 250 Sierra SPBT so if you are still interested I will post that info also. I am expecting to see 2950-3000 fps with that bullet. That would be almost 200 fps faster than my 340 Wby (the 340 Wby is long throated w/ a 24" barrel).
My favorite bullet for hunting everything in the 340 Wby has been the 210 Nosler Partition. It shoots around 1"-1.5"@100yds at 3100 fps. We have always had good success with this bullet, especially on elk.
Hope this helps out a little.

Interesting results with the 300 gr Sierra and Rl-25. I briefly played with the 300 gr Sierra and found mediocre velocities, reduced accuracy and heavy recoil. I thought the twist on my barrel was not fast enough for the 300gr bullets and stopped working on them. I will try your loads as perhaps I was too hasty. As for the 250 gr Sierra HPBT or 250 gr Lapuas, 87-90 grs of Rl-22 gave <1 inch groups at 2980-3050 in my 28 in barrel and about 2950 in the 26 incher. This is a super cartridge and frankly beats any 340 WBY I've ever shot in every aspect except amount of powder burned and Who cares about that. The only thing I still can't figure out is why Remington didn't use the full length 300 RUM case. This would have made a bigger difference in velocities as the case gains an additional 5% volume. The only rational I can come up with is that by shortening the case they could still crimp a .338 bullet and get it to feed through the std. mag magazine.
I wouldn't hesitate to use the .338 RUM on anything in North America and like 470 MBOGO originally thought about using this thing on Griz. in Alaska. The Rem 700 SS BDL is nice and light to carry all day. I'm sure it would be more than enough for them as well as everything in Africa except for Buff and Ele.-Rob

[QUOTE]Originally posted by Robgunbuilder:
Hi Rob,
I just read through an article on the 338 Ultra Mag. the reason they thought that they shortened the case was to allow for seating of long 338 bullets without having to push them deep into the powder portion of the case and still retain the OAL. I guess one other reason would be to keep someone(I don't know who) from sticking a 300 Ultra Mag in by mistake. The 375 wouldn't chamber in either because of the bullet diameter getting stuck in the throat so it remained full length.

Guy
I would be very interested in your results with the 250 grain bullets. I'm thinking of the Swift A-Frames in 250 grain for most everything. Next choice is the Noslers if the accuracy part doesn't work out. 470 Mbogo

Rob is right, the 338 RUM is more powerful than the 340 Wby and is a "close?" copy of the 338 Abe Express. I have (or had) a copy of that article written by Bob Hagel around 1981 in Handloader magazine. I'm still looking for it because it has a lot of good starting data.
A gunsmith here in Colorado told me that he has a reamer for the original 338 RUM with the shoulder lengthened and the OAL matching the 300 RUM. This cartridge would use 300 RUM brass and might boost velocities another 100 fps or so. My rifle shoots too good at this point to change it, but it is really tempting. The real reason I haven't had him rechamber it, is because it already knocks the snot out of me.

Rob- for the Sierra 300 MK, R25 and H1000 are the only two powders that I was able to attain 2600 fps. R22, H4831 and H870 were much slower with pressure signs. FYI, last night I was reloading and the cases that I had fired the load with the 300 MK and 89.0gns of H1000 at 2688fps, showed slight ejector marks from firing them last week. Every case, 20 total, had a very faint mark on it. The temp was 80-85 degrees F that day, so that load is too hot. I will back down to 88gns which was giving an average of 2611 fps and a S/D of 18. My cartridge overall length for the 300 MK is 3.775". This is .005" off the lands and the cartridge does not fit in the magazine box.

470 - I have some 250 Nosler Partitions, I will be dropping powder and bullets in the cases tonight. I have several powders to choose from R25, R22, H4831, MR-3100, IMR-4350, H4831, H1000 and H870. If you have a powder preference from the above, let me know today and I will load it tonight and post the results for you on Monday.

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I have a few questions for you .338 RUM fans. I have a P17 action that I want to rebuild and am thinking about getting it in a "elk and larger" caliber. All the local people have been saying to get the .338-06, but I don't know about that. I have been looking at the .338 or .338 RUM.

1. What do you feel is the advantage of the .338 RUM vs the .338 win mag? I don't care about powder, I am more interested in recoil and velocity differences.

2. Is there enough advantage in velocity and power to warrant having the extra work done on the action?

3. If I do get this gun made in .338 RUM, what barrel make and size do you recommend? I am thinking about 28" but don't know about brand.

Any other advice you would have would be great. Just so you know my old P17 is now in 30-06, so another consideration would be if I have enough room to open up the bolt face for the larger case size.

Thanks

monyhunter, I hunt with many people who have 338 caliber rifles.
My friend shoots a 338-06 with 210 Nosler Partitions @2865fps from his older Ruger 77 with a Shilen 24" barrel.
My father shoots a 338 Win Mag with 210 Nosler Partitions @2980fps from his stock Win Mod 70 with a 24" factory barrel.
I shoot a Win Mod 70 in 340 Wby with 210 Partitions @3110fps with the factory 24" barrel re-chambered from a 338 Win Mag. I also have the 338 RUM but I have not tried anything but the 300 Sierra MK in it. I would assume it could get close to 3200 fps with the 210 Nosler.
All of us combined have taken almost 30 head of elk, ranging from 6x6 bulls to cows with these 338's. All the rifles have performed similar shooting elk in the timber, at close range and on public lands. We all agree that there has been no differences between the calibers in killing power with ranges out to 200 yds. We have not lost an elk while shooting these calibers. More often than not the elk dropped where they were shot. Maybe a handful of times they ran a short distance before dying after the shot.
The only advantage for me to use the 338 RUM is the extra velocity for target shooting at 1000+ yards. This was the reason for me to buy it. The recoil is more than my 340 Wby and my dads 338 Win but I'm using 300 gn bullets too.
Every time we discuss these calibers, the consensus is the "little" 338-06 is most impressive in the situations where it is used - heavy timber, close shots on moving elk.
Your questions:
1. Only velocity - the difference in killing power would be hard for us to see where we hunt elk and deer.
2. No - we don't think the smaller 338's give up much killing power to the larger 338's unless you were to shoot at longer ranges.
3. I have a friend who owns a custom 338 RUM with a 28" Lilja SS barrel. His velocities run about 80-90fps faster than my 26" factory barrel with the 300 Sierra MK. His load with the 300 MK is 90.0 gns of R25 for 2736fps.

The 338-06 maybe something to consider with regards to re-barreling your current rifle. We honestly haven't seen much difference between all the calibers under the conditions in which we hunt. The 338-06 might be your best choice. I would not hesitate to use one.

Guy- Thanks for the information and your results with the 300gr bullets are extremely interesting. I had only a small supply of them ( free gift from Sierra-Wonderful People) and thus never got very far with load development. I tried Rl-22 and H4831 and saw exactly the same pressure signs you described. At the time the .338RUM was very new and I did not have any RL-25 so Quit when I could neither get the velocity nor the accuracy levels I wanted. I also really wanted a hunting load as I was considering taking the .338RUM to Tanzania. Instead I took a .300 RUM and had absolutely fabulous results with it on everything up to Zebra.
I've not done a systematic study of the penetration of the various .338's but from first hand knowledge on game either the 338Win Mag, 340WBY, .338 Lapua or the .338RUM should be incredible. I once shot through a zebra lengthwise witha .338 Win Mag handload using a Nosler Partition and you can't ask for more than that. I suspect with a good bullet the .338 RUM would be even more effective.
The other interest I have in the .338 RUM is for 1000yrd matches. Many of my friends in FCSA who shoot these matches competatively report .5 to .6 MOA groups out of custom .338 Lapua bench rifles using the 300 gr bullet and Guy ,I wonder if you have tried the .338RUM with the 300 gr Sierra's at 500-1000yrds. My guess is that it will be very competative as the brass for the .338 RUM is much much cheaper, and the powder capacity should be nearly the same.-Rob

Rob- you're welcome. Long range shooting was the reason that I became interested in the 338 RUM. The Lapua would have been a "dream" to afford to buy it and then shoot it. The 338 RUM in a Mod 700 Sendero was easier on the pocketbook to get started with a long range 338. My 700 holds .5 moa out to 225 yds on paper with the 300 MK. My son and I have been shooting long distance as a hobbie for the past year with a 300 Win Mag. It has been fun and we can consistantly shoot to 1050yds with the 300 Win. It is holding a tad more than 1 moa accuracy out to 1000 yds but it falls off after 1200 yds.
With the 338 RUM the farthest "first round on target" hit we have scored is 1610 yds. It hits much harder than the 300 and is less effected by the wind. But I must qualify my shooting after last week. With the wind, recoil, a flinch and the finicky Shooting Gods, I couldn't hit the broadside of a barn. It was one of those days where you hope you are smart enough to learn something when nothing goes right. A very humbling day.

My friend who also has a 338 RUM, shoots with a guy who owns a 338 Lapua. He told me last week, that the 338 Lapua was shooting the 300 MK close to 2900 fps - impressive. The Lapua also has a brake on it too. Steve also said the Lapua was not as accurate as his custom Mod 700 w/ a Lilja barrel. Something to consider. Steve's 338 RUM will consitantly shoot the 300 MK over 2700 fps into .300" to .400" five round groups at 100 yds.

As for the RUM brass, I'm hearing that the 300 RUM isn't doing that good in the 1000 yard matches because of the brass quality. I don't know for sure as I don't compete. What have you heard?

Guy- Thanks again for the info. My 1000yrd shooting is basically limited to a HomeBrew .50 BMG shooting 850gr Bore Riders at 2700fps. So far its shot .6 MOA in Matches at Reno into some fierce wind. Skip Talbot the current 1000yrd champ with 2.66 incher at 1000yrds tells me that the .338 Lapua does really well although I've heard 2700 is max with the 300 MKG. I'd really like to see the brass on a .338 Lapua shooting a 300 gr MK at 2900 fps. Thats got to be a smoking load! Skip knows what shoots and I listen to him very carefully. He also noted the brass consistency issue with the .338 Lapua and also commented on the strength of the brass and I'm not suprised that it shows up at 1000yrds. Seems like really small differences really show up when you push the envelope. I've not heard of anyone using the .338RUM or its full size varients and being really competitive yet, but I would not be suprised either if someone got it to work.
My .50 BMG is built on a Mcmillan action and I have two spare bolts for it( .378 WBY bolt face and .404 Jeffry bolt face) just in case Dianne Feinstein succeeds in outlawing the .50BMG. I've been thinking of making two barrels in .338RUM Full size and .338 Lapua and comparing them at 1000yrds. I have a hunch that the full size .338RUM will seriously out perform the .338 Lapua.

[QUOTE]Originally posted by Guy:
Guy,
I don't know if I'm too late or not but the powders that I would be interested in are in order H1000, RL 22 and RL25. I'm up in Vernon right now but will check in when I get back home. Thanks again. 470 Mbogo

470 - you're not too late as I had to do "other" things last night. I'll use those powders for the 250 Nosler. I also have some 210 Noslers Partitions and 180 Nosler BT's that I will load. I will post for you on Monday(if the weather holds and I live through the recoil!).
Rob - I am envious of your .50 BMG. I have wanted one for awhile now. I think I would settle on just shooting one at distance. It has to be fun rippin' a big 'ol bullet loose.
It sounds like you have experience shooting in LR competitions. I have something going on with my 338 RUM that I see when the ranges get past 900 yds. It seems the rifle is dumping rounds to the right and low, consistently more as the range increases. I have been told that this is "spin drift" from the 1-10" twist of the barrel. Do you have any ideas?
Darryl Cassel has also expressed similar views about the Ultra series and shooting them at distance. But it's only a matter of time before someone shakes the bugs out and gets them competitive.
I talked with my friend Steve this morning and he corrected me. His friends Lapua is shooting the 300MK in the 2780's fps range and not close to 2900 fps as I had said. Sorry. It is a custom Sako with a Pac-Nor or Kreiger 29" barrel. He wasn't for sure on the barrel manufacturer. He feels his rifle is a little more accurate although slower in velocity.
My mind keeps thinking about the full size 338 RUM too. If I would do it, I think it would be better to re-barrel the rifle as opposed to just re-chambering the factory barrel. I think a brake would be mandatory too!

Take care. Guy

What is a FULL SIZE .338 RUM.. Thanks MD

Maddog - that was Rob's way of referencing a 338 RUM case that has the same overall length and shoulder length that the rest of the Ultra series have. There has been discussion as to why Remington shorten the 338 RUM and left the rest of the Ultra line longer. Apparently there are reamers available to chamber this "longer" version of the 338 RUM.

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Guy/470MBOGO- Thanks for the info, I was up till 12:00 last night trying to figure out if there was any safe way to get 2900 fps out of a .338 Lapua using the 300MKgs. I found a Layne Simpson article on the .338 Lapua that seemed to indicate that all he was able to get out of it was 2850 with the 250gr bullets. That jives more with my experience.
As far as the spin-drift, I suspect and have for awhile that a 1-10 twist for the 300gr bullet is too slow. I would love to see what happens with a 1-9 or 1-8 twist. I suspect it's a stabilization problem. I don't know what twist Accuracy international is using in their rifles, do you? I've built a 22-6mm improved that shoots 80 gr VLD's really really well at 1000yrds. It uses a 1-7 twist and I found that I got much better groups by speeding up the twist with long bullets and driving them very fast ( 3700 fps). I wonder if you have tried the 250gr Lapua scenar.338 bullets at long range? I think they may perform better than anything else with a 1-10 twist barrel.
470MBOGO- good hunting and I will look up and post what data I have with those powders and bullets tonight.By the way I ordered your reamer from JGS and I'll probably see it in 2 months.-Rob

I have been working with loads for my brothers 338 RUM--nothing worth mentioning yet. The thing worth mentioning is the acccuracy of this rifle--It clover leafs at 100 yards right out of the box! I'm ordering one tomorrow a SF, my dealer says it could take up to six months to get--hot item. If one had the reamer for the chamber for the "long version" what kind of tooling would be necessary for a 300 RUM brass to be flared out to .338? If this long version will outshoot a Lapua I'm doing it. Keep us updated guys.----MOA

How much advantage is there to a FULL SIZE 338 RUM over the standard one from Remington??? Is there much increase in velocity?? I did find dies for it, and information from Z-hat guns on the web. MD

[This message has been edited by MADDOG (edited 09-30-2001).]

The full size .338 RUM should be able to make another 100fps or so over the current Rem version all things being equal. However, it isn't as simple as it looks.Because the 250 gr .338 bullets are real long, you can't seat them into the case far enough on a .338 long RUM to still fit the standard magazine and have enough grip on the bullet due to the shape of the ogive. This is why Remington probably shortened the case in the first place. Both My 300 RUM and stock .338 RUM will take a cartridge in the mag of 3.675 inches max. It looks to me like you will need to lengthen the Rem Mag box about .050 to .075 to get the longer cartridge to work and be able to seat the 250grs out far enough. I'd probably mill out this amount of metal from the rear of the remington action so that the longer magazine box would fit and feed reliably. The floor plate would also have to be altered so that the longer cartridge would feed reliably. Now combine this with a 30 inch barrel and I'll bet you can get a 250 gr .338 to fly about 3200fps or more. This would be a absolutely killer combo in a Ruger #1 and would be the cheapest way to go All you would need is the barrel and reamer. I understand JGS has the Full length reamer in stock or I'm sure Fred at Z-hat could easily do the job
Fireforming std 300 RUM cases in the full length .338 chamber would not be a problem and reloading dies could be easily made from std .300 RUM dies although I'd probably just get a blank and make a set with the chambering reamer. With that said, I don't know why a std .338 RUM die set would not work with the appropriate spacers ie. .38special/357 mag dies.-Rob

I promised 470M some data on the 338 RUM today. I loaded one round each, increasing one grain of powder for each bullet weight and powder to find the approx max load. I was then going to load three rounds of each promising bullet/powder combination and then recheck the velocities and accuracy. Unfortunately the weather didn't hold and we were pelted with a good hail storm. I still have some info:

Remington Mod 700 Sendero SS fluted 26"barrel
The rifle is stock except for working the trigger down to 3 lbs.
Leupold Mark IV M1-16x scope
Remington 338 RUM cases/neck turned/trimmed/once fired.
Federal 215M Gold Medal primers
Conditions (constant all day, until the end!)
60 degrees F
Mostly cloudy
8700' altitude
No wind

250 Nosler Partition - COL 3.600"
H1000
All five rounds grouped into .920"@100yds.
95 gns - 2807 fps
96 gns - 2818 fps
97 gns - 2879 fps
98 gns - 2898 fps
99 gns - 2911 fps (faint ejector mark)

250 Sierra Boattail - COL 3.650"
Reloader 22
First four rounds went into .430"/all five into .650"@100 yds.
85 gns - 2879 fps
86 gns - 2892 fps
87 gns - 2927 fps
88 gns - 2979 fps
89 gns - 3017 fps (no pressure signs)

210 Nosler Partition - COL 3.550"
Reloader 22
First four went into .980"@100yds, the last two printed 1.5" higher for a two round group of .640"@100yds.
90 gns - 3009 fps
91 gns - 3079 fps
92 gns - 3100 fps
93 gns - 3137 fps
94 gns - 3174 fps
95 gns - 3205 fps (no pressure signs)

180 Nosler Ballistic tip - COL 3.670"
Reloader 22
I had loaded rounds from 92 gns to 99 gns. We could see the weather coming in so I quickly shot these two rounds. Group size - .640" horizontal group @100yds into heavy cross wind from 3 o'clock.
96 gns - 3358 fps
97 gns - 3375 fps (faint ejector mark)

For comparison:
Winchester Mod 70 340 Weatherby Mag 24" factory barrel
210 Nosler Partition - COL 3.550"
91.0 gns Reloader 22 (same lot as above)
Fed 215M primer
Weatherby once fired & prepped cases.
Two rounds into .750"@100yds fired to confirm zero
3115 fps
3122 fps

The 250 Noslers definitely showed pressure signs with 99 gns of H1000. The 250 Sierra's w/ Reloader 22 could probably be boosted a little faster and still be safe. It seemed R22 was a better powder than H1000 for the 250 gn bullets, but I would need more data to confirm. My gut feeling is H1000 is too slow in my gun for the 250's. The 210 Noslers could handle more powder and still be safe. My guess would be they could go a grain or two higher and safely be around 3250-3280 fps. The 180 Nosler BT's are fun to shoot as they don't kick as hard. I think that was the max velocity for those bullets.
We didn't get to shoot any Reloader 25 because of the weather. I'm thinking it may show slower velocities than R22 but again, I will have to shoot to find.
We will be going back up again this weekend so hopefully I can get more data.

Guy

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MOA - Sportsmans Warehouse here in Loveland, CO still have two Senderos and one BDL in 338 RUM. All the rifles are in stainless steel. Good luck.

Guy- Excellent results with the 250 gr sierra. Your results and mine are essentially identical. Interestingly, Norma MRP might be an even better powder in the .338 RUM than RL-22. While there is alot of controvery about MRP ( some claim its the same powder as RL-22) I think it is subtly different. When they tested the .338 Abe Express, they found that MRP delivered the highest velocities. I have a few pounds of MRP and may try it this weekend. Anytime you can drive a 250 gr bullet over 3000fps with no pressure signs ( hopefully no primer pocket loosening after 5 reloads) its a good day!

[QUOTE]Originally posted by Guy:
Thanks a lot for the information Guy. My buddy just bought his 338 Ultr Mag but hasn't shot it yet. I'll copy out the information for him and I'll be playing with his 338 for a while before I pick up mine. 470 Mbogo

Guy, just an observation. Please note that I am not a reloader, so my opinion is unqualified. But the Weatherby looks a little more efficient. 91 grains of powder on the 210 grain Nosler (3115 fps vs 3079 fps). The Weatherby is using a 24" barrel vs a 26" barrel. This could possibly add another 100 fps to the Weatherby.

I'm probably wrong, but your tests seem to reflect these findings.

I just located a sendero--now I need scope and rings. I'm gonna get a badger base with 20 MOA built inand a 4.5-14 LRT leupold. Does anyoneknow if I can get away with medium badger rings, or will I have to get the highs. Anyone using this set up?

I have been using the 300 grain Sierra MatchKing and get 2775 from a 27.5 inch Pac-Nor barreled Rem 700. The load is 90 grains of RL25 which I will decrease to 89 grains on my next load session.

With the 250 Sierra SPBT I easily get 3000 fps and have test loads to 3156 fps (too hot) using RL25.

I tried RL22 and got good results but prefer the RL25.

I've got MOA sized groups out to 1197 yards with the 300 Sierra and have shot to 1730 yards where the big 300 grain bullets are still supersonic.

ALL loads have produced sub 1 MOA accuracy at 100 yards.

Much of the load data is posted on the www.longrangehunting.com website.

MOA - I have the same Badger rings and base that you are wanting, on my Sendero. I changed to the Leupold MKIVx40mm recently and it has about .100" Clarence between the bell and the barrel. If the scope you are wanting to mount to your rifle has a 50mm lens it may be close. Call Premier Reticles in VA they should know. Good luck with your new rifle, I'm sure you will like it.

Longbob - that was the first time that I had used the lighter bullet weights in my 338 RUM and I noted the same trend too. You are probably right with regards to efficiency between the calibers. I think the 338 RUM will better the 340 Weatherby velocities with the heavier bullet weights though. My 340 will only shoot the 250 Nosler to a velocity of 2795 fps and that is a stiff load for that gun. And in all fairness here, the 210 Nosler/340 Wby load at 91.0 gns of R22 for 3115 fps is a stiff load also. That same velocity in the 338 RUM was easily matched with no pressure signs. Adding two inches of barrel to the 340 will help too. I guess that's why this is such a fun hobby, an infinite amount of variables to play with.

Rob - if you try MRP in your 338 let me know what you find. In the 1970's that was the powder of choice for the 340 Wby. Bob Hagel wrote many articles about MRP and the 340 Wby, that I still enjoy reading today. Times change and I miss his insights on hunting.

What I can tell you is that Remington go the idea for this cartridge from Aubrey White of North American Shooting Systems in Osoyoos BC Canada. I shoot one of his 7mm Imperial Magnum Rifles, and it is almost identical to the 7mm Ultramag, so close that I use Ultramag Brass, both 7mm and 300, funny thing is I bought this gun 12 years ago. I know he was trying to sell his idea to Remington, but they decided to "invent" their own design, and changed the shoulder angle by 2 degrees, now that is what I call inventing.

slavex

quote:

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Originally posted by 470 Mbogo:
Does anyone have experience with this cartridge as to velocities for 250 grain, 200 grain bullets and actual accuracy? I know it's like a 340 Weatherby without the belt but I'm curious about actual velocities and accuracy in the Remington 700. Thanks. 470 Mbogo

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Slavex, Nice to see someone else who is shooting the Imperial Magnum cartridges.I agree with you completely. I had a 338 Imperial built several years ago; before the Ultra mags were "invented". Shot a nice 5x5 elk in Arizona with it last fall. 97 grains of RL-25 produces 3150 fps with a 250 grain Sierra in a 28" barrel. Wonderful cartridge.

What is the closest thing to a Imperial that I can compare to? Would it be a full length size .338 ultra?? MD

Maddog,

You are right. The Imperial is a virtually full length .404 case,in fact, I form my cases out of Norma 404 brass; they are trimmed slightly.The 338 Ultra mag case is 3.76" long and the Imperial is 3.83" The Imperial case holds about 5 grains more water than the 338 Ultra mag. This may or may not be significant.I was disappointed when Remington introduced its 338 in a slightly shorter version. So much for a low priced source of cases. I suppose cases could be formed from the 300 Ultra, but for now I will just stick with the Norma brass. The quality is superb.

Paul S- Could the 338 imperial be built on a 700 action? safely. And did you get the 3100+ vel with the 250 gr. bullet, safely?Thanks MD
P.S. I know my Questions are elementary but I wasn't to be sure that I am understanding fully, and sometimes the simple questions fill the bill..Thanks again MD

[QUOTE]Originally posted by 470 Mbogo:
I went to the range with my buddy Chris and his new 338 Ulta Mag. It's in an H-S Precission stock and with the factory ammo in 250 grain loads I thought it was a pretty soft shooter for the ballistics it has. We didn't have a scope installed at this point so the rifle weighed under 8lbs. Due to no scope and limited time we didn't chronograph any loads. Personally I think with bullets ranging from 180 grains through to 300 grains this could be a candidate for the one gun for all North America. 470 Mbogo

470 - Have you been able to work up any loads in the 338 yet?