H1000 vs Retumbo in 338 LM Results

[barnesuser28]

Today I decided to test H1000 and Retumbo in my 338 LM with the 300 grain Berger OTM. Savage 110 FCP HS 26" barrel. The velocities were measured with a magnetospeed. Lapua brass and fed 215 GM primers were used. I didn't shoot for groups because it was extremely windy out and I wanted to see what velocity I could run the Berger's at.

Here are the results

Retumbo
86 grains 2512 FPS
87 grains 2573 FPS
88 grains 2619 FPS (Velocity has little change between 87-89 grains, may be a great safe accuracy node.)
89 grains 2628 FPS
90 grains 2683 FPS
91 grains 2714 FPS (slightly heavier bolt lift, no ejector mark or flattened primers, safe MAX)
92 grains 2754 FPS (slightly heavier still, but no flattened primers or ejector mark)
93 grains 2782 FPS (Heavy bolt lift, still no flat primers or ejector mark, but bolt lift was more than I like to see.)

H1000
85 grains 2516 FPS
86 grains 2583 FPS
87 grains 2596 FPS (little change in velocity between 86-88 grains, may be a good safe accuracy node)
88 grains 2612 FPS
89 grains 2662 FPS
90 grains 2695 FPS (slightly heavier bolt lift, about the same as 91 grain Retumbo charge, safe MAX)
91 grains 2723 FPS (Heavier bolt lift, but no flat primers or ejector mark.)
92 grains 2750 FPS (Stuck a case in the chamber, flat primer but no ejector mark.)

I would like to use Retumbo as I have quite a bit and want to use the H1000 for another rifle.

Now I have a question, do I load at 88 grains of retumbo and adjust seating depth for ES and accuracy? Or do I load 90 grains and adjust seating depth for ES and accuracy? This rifle and load will be used for 1000-1300 yard antelope-elk hunting. Would the extra 65 FPS be helpful in lessening the effect of wind drift? I think the 88 grain would likely be more accurate.

 

[varmintH8R]

Thanks for posting all the velocities, very interesting to see

If it were me, I wouldn't read too much into accuracy potential based on this amount of data. I'd run a true ladder test (in triplicate) between 86 and your safe max and make further decisions based on the outcome.

My 2C only

 

[sp6x6]

Interesting, Im running 87 gr. retumbo in my 338 Norma w 215 m and getting 2725 in 26 " barrel .I have shot same load in my other norma at targets and rocks but not chrono. Was across oehler 3 screen type.

 

[canderson]

I would start with bullets 0.015 off the lands and try three of each closer to the 91 gr charge. Vary the powder first to get the tightest group then adjust seating depth. When you think you have found the magic load, adjust 0.1 or. 0.2 gr powder either way to confirm. My edge was fairly solid 1/2 MOA gun until I tried the 0.1 gr powder increments after the best group. Now, it shoots closer to 1/4 MOA. Have fun.

 

[Broz]

Riley, there still needs to be some temp testing, but from what I have seen you might want to see if you can locate a pound of RL33. I am pretty sure it will give you some velocity. To only 1300 yards I feel you can deal with temp swings if they are reasonable.

As far as velocity and drift, I think you should try to find out why this rifle is so down on velocity. For example it is not uncommon to run 92 gr or a bit more of H-1000 in a 338 LM. The fact that you stuck a case, but no ejector marks could mean you could need to polish the chamber??

Also, I find that if you run cases with zero head space and a max load in a 338 LM it can stick a case especially on shot 2 or 3. What are you setting the shoulders back to? Were these full sized cases?

How about bumping that shoulder back .003 and try working up toward that max load of H-1000 again?

Jeff

 

[barnesuser28]

Thanks for the replies, I don't have access to a 300 yard range at the moment, so I was hoping I could just take the three best loads with the best ES and shoot them at LR and see which one comes out on top. I have the rounds loaded just short of mag length, about 3.735". Jeff, I do have a pound of RL33 that I forgot about. I will give it a try this week, any ideas on a starting load? I am bumping the shoulders .002" every time, with a redding body die and neck sizing with a bushing die. Powder charges are weighed on my new Gempro 250 scale. I looked closer and I do see a small ejector mark on the 92 grain load. I thought the "to only 1300 yards" comment was kind of funny .

 

[Broz]

Jeff, I do have a pound of RL33 that I forgot about. I will give it a try this week, any ideas on a starting load? I am bumping the shoulders .002" every time, with a redding body die and neck sizing with a bushing die. Powder charges are weighed on my new Gempro 250 scale. I looked closer and I do see a small ejector mark on the 92 grain load. I thought the "to only 1300 yards" comment was kind of funny .

Awesome! sounds like your cases are in tune too. A slight ejector mark at 92 is par.

You get that thing tuned in and you will say the same about 1300 in good conditions. That rifle and bullet will do it with ease.

Don't waste time and components at 100 yards. You need to see what those bullets are doing at 200 + to judge your loads.

Jeff

 

[MontanaRifleman]

Riley,

I haven't seen any threads or posts on the 338 LM and RL33 but there is this thread Kirby started on his 338 AX (338 LM Imp) and RL33. His case is probably about 5 gr more in capacity give or take. He max'd out at 106 gr which was 100% in his case. I thought that seemed to be a low 100% load to me as 33 is a dense powder, but that's where he was.

http://www.longrangehunting.com/forums/f17/338-allen-xpress-rl33-load-development-120353/

Alliant developed this powder specifically for the 338 LM. You could call them for a suggested starting load. My guess is that a 90% capacity starting load wil be more than safe... but that's just my guess.

I went with 90% in my 300 RUM and 230 hybrids for break-in and pressure was very low with MV of about 2700 fps.

Look forward to your results.

 

[barnesuser28]

I was able to test RL33 today, same specs as the above test but this time the bullets were seated .015 off the lands.

I loaded 93-98 grains. Here are the results.

93 grains 2649 FPS (retumbo was at 2719 FPS at this charge)
94 grains 2673 FPS
95 grains 2712 FPS
96 grains 2750 FPS
97 grains 2770 FPS
98 grains 2797 FPS SLIGHTLY heavier bolt lift.

There were no excessive pressure signs, so I ran back to the house and loaded up three more from 99-101. 100 grains was 100% density.

99 grains 2840 FPS Again, slightly heavy bolt lift, about the same as 98 grain load.
100 grains 2850 FPS Bolt lift was just a tad heavier than the last two charges, but not excessive.
101 grains 2866 FPS Bolt lift was a little heavier than I would feel comfortable using in the field in a hunting situation. But no ejector mark or flat primers on any of the above loads.

I am VERY happy with the results, thanks for the suggestion Jeff. I might have to pick up an 8 lb jug. I will load up the 100 grain charge and try to shoot a couple groups before the snow sets in.

 

[Broz]

Great. Look at those results and the gain in MV per grain. I would load some at 99 and some at 100. Shoot groups at 200+ yards and look at the results.

There is only 10 fps between these and I would let accuracy decide. Remember, shoot 3 and let her cool completely.

Also be aware these loads could be over pressure in summer temps. So I favor the 99 gr load if it shoots good.

2840 with that bullet will serve you very well.

Jeff

 

[Bob L.]

I have a 338 edge 30" rock creek 9.3 twist on a rem 700. I originally shot h1000 because it was "the powder" in other guns of this nature. I ended up not getting the accuracy or velocity I wanted or thought the gun should do better. After going back to the drawing board, retumbo produced a 1/4moa load at 2789fps that has been confirmed out to 1670 yards in drops using only 89 grains of retumbo, cci250 primers, and nosler brass. I have shot incredible groups with this combo and the gen 1 300 grain bergers 30 thousands off, for what its worth. This velocity was recorded at 1300ft elevation. I agree on shooting groups farther out, I discovered this 1/4moa group at 377 yards and have seen under 2" of vertical holding 1/4moa at 980 yards with it.
I have several firings on this brass with no bolt click or stiffness. I may have a faster lot of retumbo, hence such a low grain powder charge for me?
Hope this helps, give retumbo a chance.
Bob

 

[marioq]

Here is a good one for ya. My chrono said 93.9 gr retumbo pushed the 300 Berger at 3000 fps. I shot an elk at 700 last weekend and it was low. After reading Riley's post, I see why!!!! Guess I need a new chrono. Heard good things about magneto thing. Might look into that.
Good info Riley. Thanks a bunch!!!

 

[bigngreen]

Ive been playing with the r13 and it is interesting and seems to hold a lot of promise but it does seem to have a different way about it!

 

[MontanaRifleman]

Ive been playing with the r13 and it is interesting and seems to hold a lot of promise but it does seem to have a different way about it!

I'm thinking it might be good for heavies in a 270 WSM