338 Rum and 300 gr Bullets

[D.Camilleri]

I recently bought a new Magneto Speed Sportsman chrono and finally got a chance to try it out today. My go to load for my 338 rum has been 300 gr Berger OTM in front of 90 gr of H-1000. I adjusted my velocity to 2775 to make my drops match my ballistics and it has worked well. Neither my pro chrono or chony F-1 chrono gave me that velocity though. I set my loads to a COAL of 3.670. Today my first shot through the Magneto Speed yielded 2774, cool!

My next test loads were one round with a berger 300 gr OTM in front of 101 grs of RL33. It yielded a velocity of 2781. This is a pretty heavily compressed load and it isn't worth the trouble to try and get more powder in.

My next load was a 300 gr accubond in front of 100 grains of RL33 with a COAL of 3.670. It yielded a velocity of 2821 with no visible pressure signs. I might try 101 grs with this bullet, and then check the groups. The added velocity of this load helps the NAB keep up with the higher BC of the berger out to 350 yards and then the berger is only slightly better a keeping the same dial in for moa on drop.

I feel a little better about having the accubond in the chamber when I am hunting in Grizzly country and might have to defend myself.

 

[450hunter]

I tried the 300 grn Berger with RL-33 in my RUM but could never get decent accuracy with it. As a matter of fact I didn't get any good accuracy with Berger 300 grn using H-1000, RL-33, RL-25 or 50BMG so I tried 250 grn Accubonds. I am starting to have some good results with them but it's getting to cold to shoot now. I will try some 300 grn Accubonds when it warms up some and I can find them.

 

[royinidaho]

OP,

Your post got my attention regarding two things.

338 RUM/300 grain velocity and the MagnetoSpeed

The factory Rem 700 in 338 RUM that I had, gave the durn thing away and I miss her, was accurate with any bullet and a wide selection of powders. Beta Chrony velocity hung around 2735. A load of 101.5 grains of 50 BMG gave the 2735 velocity and out of your mind accuracy.

I don't know of a cartridge that I would rather have than the 338 RUM!

Received a MagnetoSpeed V3 from Len a week ago and all I can say is that it's life changing. At least for me.

I've never had this much confidence in velocity data. As you found, my measured velocity now matches the drop chart velocity! That certainly says something about the MagnetoSpeed and Bryan's bc data.

For myself, hunting on the outer edge of grizzly country, I wouldn't have a problem with having a Berger chambered for the "infrequent" grizz encounter. However since I no longer have the 338 RUM I'll just have to trust the 375 AM, but Berger makes no bullets for it.

 

[D.Camilleri]

Roy,

I love my 338 rum and if I had to choose one gun to keep, it would be the ONE. I also shoot a 300 rum, but it just isn't as sexy. I am so happy to actually have confidence in my actual velocity now. Now I have to go through my other loads so that I can update my velocity numbers. Since my purchase of the G-7 rangefinder, it really brings home that good data in equals good data out.

My accuracy with the 300 gr Berger is better than I can shoot. I have to admit that holding to 1/4 inch groups isn't my goal with the big 338. One shot DRT kills is what I am after and I have had close to 90% that meet the criteria with the 338 rum and 225 accubonds and now the 300 gr Bergers. My only non confidence builder with the Berger is consistency of penetration. I only had several exits on deer and elk and this years deer blew up 4 inches of spine, but didn't exit and the largest piece of bullet found was about 1/8 inch. That doesn't instill confidence in stopping a charging grizzly if the bullet doesn't penetrate far enough on a frontal shot to inflict massive damage. I know of a person down here that the exact thing happened to after a grizzly attacked him and he shot her with a 200 gr ballistic tip from a 338 win mag. He lived to tell the story, but the bear got some pieces of him and he and his hunting partner finally killed the bear, but I can't help but wonder if more penetration would have dispatched the bear more quickly. From the Bergers that I have recovered, the bullet resembles a ballistic tip.

My velocity testing was done inside of my shop where I shot into a 30 inch diameter douglas fir log about 18 inches long. The accubond penetrated over 13 inches, the Berger about 8-9 inches. When I get done with inside testing I will split the log and pull out the bullets. I know this isn't a good expansion or penetration media, but it still gives some data. Last elk season I shot a 300 gr Berger into a live pine tree behind my target when checking my zero after my horse dropped my gun and the bullet only penetrated about 4 inches. I have played with some 225 barnes tipped tripple shocks, but my gun doesn't seem to like them and it also doesn't seem to like 225 hornady interbonds.

What I am after right now is being able to have a bullet in the chamber or magazine with the same short range trajectory as my long range 300 gr Berger. So far the drop chart show the 300 gr accubond started 45 fps faster having the same moa dial as the 300 gr Berger out to 1000 yards even though the NAB only has a .720 BC compared to the .818 of the Berger. Now I just need to see if the NAB shoots close to the same zero. Maybe in an hour or two when it warms up a little, I will shoot a few.

I also had a friend pick me up a pound of IMR 7977 to give a try and see how it does, it looks like a promising powder.

 

[HARPERC]

....Your post got my attention regarding two things..........

338 RUM/300 grain velocity and the MagnetoSpeed

I don't know of a cartridge that I would rather have than the 338 RUM!

Received a MagnetoSpeed V3 from Len a week ago and all I can say is that it's life changing. At least for me.................

Love the Magneto Speed, but confess to lusting after the Labradar.

The .338 RUM will run with the "EDGE" or Lapua.

Not a long range bullet, but the Swift 275 A-Frame makes a positive impact on grizzlies.

 

[NYSHUNTER]

HARPERC,

When you say the 338RUM isn't a long range bullet.. May i ask why not ? I only ask cause I'm considering one for long range hunting

 

[7mmShooter]

HARPERC,

When you say the 338RUM isn't a long range bullet.. May i ask why not ? I only ask cause I'm considering one for long range hunting

HAPERC was referring to the 275gr Swift A Frame as not being a long range bullet

 

[royinidaho]

HARPERC,

When you say the 338RUM isn't a long range bullet.. May i ask why not ? I only ask cause I'm considering one for long range hunting

HARPERC Said: "Not a long range bullet, but the Swift 275 A-Frame makes a positive impact on grizzlies." I don't think he meant the 338 RUM is NOT a long range cartridge.

If the Swift 275 A-Frame, with which I have no experience, will open well at lower velocities I'd certainly consider it for LR hunting. The 225 NAB has proven itself at 1K elk shoulder shots more than once out of a 338 RUM class rifle.

D.Camilleri,

When I wanted to impress someone, with out using words, I handed them my factory butt ugly plastic stocked 338 RUM, laid them on the mat and had them shot at least 1 pop can laying end to end @ 300 yards. None of them ever missed there shot and if the not so bad recoil didn't scare them off they usually took two more shots with better than average success. Expressions were from big grin to head scratching.

I hear you on the terminal performance. My first elk, cow @ 157 yards, after 35 years of getting skunked, it it weren't for the 300 Berger I would have lost her.

If I'd have been using bullet of NAB type only one rib would have been broken and she'd still be running around.

When I took the shot, resting on a fence post @ 157 yards, elk facing away at just a bit less than 90 degrees, standing looking to my right. I figured to go in behind the last rib on her left side and exit through the off side shoulder.

I remember, quite vividly , her head beginning to move to the right as I was putting ever increasing pressure on a much too heavy trigger. At the shot her ears dropped which I took as something happened bad to her.

76 layered yards later there she was with two wounds on the left side. My CSI skills, upon reconstructing the crime, indicate she was pretty much exactly 90* away from me upon impact. About half way up the rib cage the Berger broke the hide, cracked a rib, shattered the next rib and cracked the rib ahead of that one. The bullet never entered the chest cavity, really. Entrance and exit were inches apart on the same side of the hide. (It cost me a ton to get the hide tanned to validate my story..)

No harm was done to any vital organs. When I say none I mean not a mark. Not even a bruise.

Having said the above, when upside down the chest cavity was full of blood. After the blood was out of the way the cause of death amazed me.

A full 10 inches of the artery that goes up from the heart to the rear quarters was completely gone. Completely gone! It was pretty much as if that 10" piece of artery was surgically removed.

In more ways than one I was a very luck hunter that day and the elk had a very bad day. (BTW, she was/is the worst tasting piece of meat I have ever attempted to munch on. If I wouldn't have harvested her I wouldn't have eaten so much of her.

Having said the above, leave 76 yards of life in a grizz a fella could be in big trouble!

 

[HARPERC]

HARPERC,

When you say the 338RUM isn't a long range bullet.. May i ask why not ? I only ask cause I'm considering one for long range hunting

The .338 RUM makes a very good long range cartridge. Works well close if it's not handicapped with a 25x scope, on a 16lb rifle.

I think the others cleared up I was just referring to the Swift A-Frame 275 bullet, sorry for any confusion.

Not long range? Maybe I should have said there are better choices. I believe like most Swift bullets it will open well, but have not tested it for a minimal opening velocity.

BC isn't much to write home about, and while i've seen sub-MOA out of it, the Accubonds out shoot it in our rifles. The partition style bullets have never been the most accurate for me.

My partner and I hunted BC for goat and grizzly, he killed a record book bear and it worked very well. Not a lot of post mortem digging around, but blood poured rapidly out both sides. About 200 yards.

If I ever have another grizzly tag, it's what will be in the rifle.

 

[D.Camilleri]

I have given serious consideration to the 275 gr swift A Frame and if I ever get a chance to hunt brown bear, I will probably give it the nod. My current goal is to have two bullets that will shoot to a very similar point of impact. Based on the G-7 ballistic program, it looks like the 300 gr Berger driven at 2775 and the 300 gr Nosler accubond driven at 2820 will have almost identical drops to 1000 yards. If the bullets print the same at 100 it should be a no brainer. If not, it would still probably be close enough for defensive shots under 100 yards on things with teeth and claws.

Roy,

Do you have some photos of that elk carnage? Do you think the shock ruptured that artery? I once read that a high velocity bullet that hits an animal at the exact time that the heart is pumping blood can cause instant death due to exploding the veins in the brain.

 

[royinidaho]

Do you have some photos of that elk carnage? Do you think the shock ruptured that artery? I once read that a high velocity bullet that hits an animal at the exact time that the heart is pumping blood can cause instant death due to exploding the veins in the brain.

I'll have to dig up the pics.

I'm confident that the bullet began fragmenting when it touched the first rib, was completely in pieces by half way through the smashed rib with only a piece of the bullet cracking the next rib then exiting.

Damage to the artery, I think, was by shrapnel and bone frags.

Kind of cool to be able to grab the hide and measure a 8" between entrance and exit.
Entrance it one cal. and exit is maybe half of that.

 

[D.Camilleri]

I got the chance today to shoot 101 grs of RL33 behind the 300 gr Accubond. I warmed up the barrel with my 300 gr bergers and had to make an adjustment on my 100 yard zero since I bedded my recoil lug since the last time I shot. My last shot was an exact bullseye with the berger load. I strapped on the magneto speed and pulled the trigger with the 300 gr accubond load. It hit about 7 inches high and read 2853 fps. Hmm, no pressure warnings. Let's see how it shoots. I told my buddy that this load shot way high with the magneto speed on the barrel. I took it off and told him I would aim for the lowest point of the target center line. I hit the exact point! One more shot and it cut the first! I think I found a good load! I went out to 750 yards and had my buddy spot for me. I saw the hit, but he didn't. ***, oops I aimed at the 700 yard gong and not the 750. One more time and a hit on the 750 but high and at 1 o'clock, most likely me. Time to load more of these. 5400 foot pounds at the muzzle should be a knock out to a self defense grizzly charge. Or maybe better yet they will delist them and I could get a tag..........................

 

[bitbythebug]

I love the 300 gr Berger in my 338 rum with 88 gr's Retumbo and a coal 0f 3.78 running around 2730 and very accurate. I CAN PUSH IT WAY OVER 2800 BUT MY best ACCURACY IS 2725-2750.