Earlier this spring I built a 338 RUM on a Mk V action. After some testing I found 2 loads to try. I am shooting the 300Berger EOL out of a 30 inch Jury barrel. My 2 loads that look good are 91.5grns of N570 and 97.0grns of RL 33. Both are seated at 3.915 with Fed 215 primers and Bertram brass. The N570 gives me 2844 with an ES of 6and SD of 3. RL 33 gives me 2888 and an ES of 10 and an SD of 4.4. N570 gave me .527 and RL 33 >392. Both really good which load would you guys choose given the info.. One other thing when I tested loads I used Fed 215s but I think I used Rem 9.5 when I chrono'd will that change velocity much.
Chronograph my 338 RUM today.
- Thread starter WildBillG
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MagnumManiac
Well-Known Member
Both powders are hard on barrels.
I'm running either Retumbo or H50BMG in my large (RUM or Rigby) based 338's.
Throat erosion is by far less, but I also run HBN coated boolits in those. Sold my Edge last year, just wasn't doing it for me.
I always go for accuracy, velocity is good only when it comes with accuracy for me.
Cheers.
I'm running either Retumbo or H50BMG in my large (RUM or Rigby) based 338's.
Throat erosion is by far less, but I also run HBN coated boolits in those. Sold my Edge last year, just wasn't doing it for me.
I always go for accuracy, velocity is good only when it comes with accuracy for me.
Cheers.
So many reloaders think that bullets wear out barrels when they are shot at high speeds. I'm glad to see others that know that barrel wear comes from the hot gasses of powder burning rates. Certain powders burn excessively hotter than others and N570 has an excessively hotter burning rate than most others.
I am kind of leaning toward using the RL 33 over the N570 for that very reason. The RL 33 load was a little more accurate too. Although both powders ran pretty close in just about every way. N570 used 5.5 grains less powder but every thing else was close. Now I just need to find some more RL 33.
MagnumManiac
Well-Known Member
Actually, primer choice is the least impact changing variable, it still matters but not as much as you think.
Honestly, Retumbo is by far the best powder I used in my RUM cases, is only bettered by H50BMG once you get into Rigby size cases.
Cheers.
Honestly, Retumbo is by far the best powder I used in my RUM cases, is only bettered by H50BMG once you get into Rigby size cases.
Cheers.
I have had great results with H-1000 in all 6 of my 338's . Now I'm going to test the Rl-26 , Nv570 , Rl-33 in a new 338 Rum Build . It's not put together yet .
My findings so far with Identical builds, 338 Edge and 338 Rum both with Remington brass , cci 250 mag primers and the 300 gr berger produced 2884 and 2883 ft.per.sec with a 30 " carbon barrels.
Amazing accuracy!
My heavey 338 Edge with a 29" Kreiger barrel produced 3 in the same hole at 100 yards and 3 shots at 3027 yards in a 26 3/4" group. It was pushing the 300 gr Otm berger at 2849 . Es and sd both in the single digits . Lots of testing to get them diled in.
Ps. I'm no pro at this just a dedicated shooter /reloader!!
My powder charges were 90.4 to 92 gr. All different in each 338 .
Please work up .
Rum Man
My findings so far with Identical builds, 338 Edge and 338 Rum both with Remington brass , cci 250 mag primers and the 300 gr berger produced 2884 and 2883 ft.per.sec with a 30 " carbon barrels.
Amazing accuracy!
My heavey 338 Edge with a 29" Kreiger barrel produced 3 in the same hole at 100 yards and 3 shots at 3027 yards in a 26 3/4" group. It was pushing the 300 gr Otm berger at 2849 . Es and sd both in the single digits . Lots of testing to get them diled in.
Ps. I'm no pro at this just a dedicated shooter /reloader!!
My powder charges were 90.4 to 92 gr. All different in each 338 .
Please work up .
Rum Man
Going to be following your load development with various powders Rum Man as I have a new CA MPR in 338LM(NF 7-35 ATACR sfp,TT Diamond trigger @1 lb.,Terminator T4 brake,Atlas Cal Gen II bipod,and just added a Long Shot Precision Adjustable Bag Rider).I only have 60 rounds of Berger factory 300 gr. OTM's through it so far(bought 100 when I bought the rifle,3 shot groups average 1/2")and still have 40 to go before I start reloading.Luckily I bought equipment(Redding T-7 turret press,Redding Comp. die set,etc.,etc.,etc.)and components when they were available(10 lbs. H1000,5 of RL33,5 of N570,5 of RL26,750 Berger 300 gr. OTM's,200 Lapua 250 gr. Scenar's,3000 Federal 210 and 215M primers[also have a CA BA Tactical in 300WM I'll be sharing primers and powder with],100 pcs. of new Lapua brass,etc.).Will have to start researching some starting loads,etc. with the various powder charges and bullet wts.,and from everything I've read from your posts over the past year I figure you're the go to 338 man so may start bugging you from time to time for information and advice.
Thanks brother,
Jeff
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you apparently have never used US869
MagnumManiac
Well-Known Member
Apparently you haven't seen my other posts.
I have used US869, however, it is no longer available in Australia, if it was, I would be using it.
Very good powder, but H50BMG is about on par with it and made just up the road, so I have a never ending supply.
Cheers.
MagnumManiac
Well-Known Member
It is more temp sensitive than RE25 in my experience.
I wouldn't work up loads in 70° weather and then expect it to be the same at 90°-100°.
It's also pretty dirty even at complete burn in a 32" barrel.
It always left fluffy powder residue for me, and if left to sit is hard to clean.
Cheers.
I wouldn't work up loads in 70° weather and then expect it to be the same at 90°-100°.
It's also pretty dirty even at complete burn in a 32" barrel.
It always left fluffy powder residue for me, and if left to sit is hard to clean.
Cheers.
Magnummania Most of my shooting will be in temps colder tan 70 degrees. Usually temps I hunt in are around 32 to 0 degrees farenhiet.
Rum man N570 and RL 33 both gave me velocities over 2800fps. I may try Retumbo in my rifle as it burns cooler than N570. N570 heats up barrels faster then any other powder I have used. That said it give good velocity and accuracy just take your time between shots. I should maybe try RL 26 as I have a bunch of it.
Piratediverjeff I have a Decom Grizzly gun works brake and a Cadex brake on 2 of my rifles and am very pleased with them. Niether brake is contoured to match a barrel diameter but they both kill recoil. I would give a slight edge to the Defcon because it eliminates muzzle jump. The Cadex is a nicer looking brake but has a less effective muzzle jump system. It does basically allow you to stay on target during the shot though. These 2 brakes really changed my out look on muzzle brakes. The Grizzly brake are made in Canada and he ships to the US. That probably means what a US citizen would pay would be less then the advertised price.
Rum man N570 and RL 33 both gave me velocities over 2800fps. I may try Retumbo in my rifle as it burns cooler than N570. N570 heats up barrels faster then any other powder I have used. That said it give good velocity and accuracy just take your time between shots. I should maybe try RL 26 as I have a bunch of it.
Piratediverjeff I have a Decom Grizzly gun works brake and a Cadex brake on 2 of my rifles and am very pleased with them. Niether brake is contoured to match a barrel diameter but they both kill recoil. I would give a slight edge to the Defcon because it eliminates muzzle jump. The Cadex is a nicer looking brake but has a less effective muzzle jump system. It does basically allow you to stay on target during the shot though. These 2 brakes really changed my out look on muzzle brakes. The Grizzly brake are made in Canada and he ships to the US. That probably means what a US citizen would pay would be less then the advertised price.
