Reloader 26 and Retumbo Burn Rate

[Juggerxxx]

I have been searching for quite sometime now but have not been able to find a burn rate chart with both RL26 and Retumbo on the same chart. If I piece together different charts and numbers they seem to have almost the same burn rates but with Retumbo being ever so slightly slower. I have had great results with RL26 but like most others it seems very hard to get. I have a very good amount of Retumbo so I would like to explore that as a possible replacement to RL26.

Anyone able to find a burn rate chart with both listed or have any experience with using Retumbo as a replacement for RL26?
Thank you.

 

[Bandit320]

I found this one at one time, can’t remember where, and saved it to my phone. It shows Retumbo and RL26 as he same speed.

I found this one

Here:

https://www.reload-swiss.com/en/media/editor_media/reload_swiss/pdf/Burnrate_Chart_dt.pdf

It shows Retumbo slower than RL-26. I’m not sure there is a definite guide. I switched to H1000 when I ran low on RL-26. I’d use what you have available.

Mike

 

[Supersubes]

Maybe it’s just my lot, but 26 is quite a bit faster than h1000. Retumbo, which I dont shoot very much of, is a tick slower than h1000. I would t use retumbo data for r26 in any case, if that’s what you were thinking.

 

[Juggerxxx]

Thank you guys for the confirmation on my thinking. I have loaded up 4 rounds of Retumbo and 4 rounds of RL26 of the same charge and will run them over the Magnetospeed next time I’m out at the range to see how much slower Retumbo is. I’ll report back with the data if anyone is curious.

 

[Cascade Hemi]

Do not use the same load data between the two. RL26 and Retumbo may have similar burn rates but they do not have the same bulk density.

 

[Milo 2.5]

I doubt we will ever see a new complete burn rate chart again, as variables are explored by shooters that was never done in the past.
Just an FYI, you can never compare a high energy powder like RL 26, VV N 500 series to others even if they are in the same burn rate on a chart.
IME with 26, I would say RL 25 is the closest you will come, yet 26 seems faster, but also seems to be way more universal or forgiving if that term could possibly be used.

 

[Juggerxxx]

Do not use the same load data between the two. RL26 and Retumbo may have similar burn rates but they do not have the same bulk density.

I did notice a small amount of crunch when seating the bullet with Retumbo and with RL26 there was basically zero crunch. I backed the charge down 2.0gr (4.8%) from the max I have tested RL26 at. Would you think I need to back it down more?

 

[Cascade Hemi]

What cartridge are you loading? Post the components and lengths.

 

[Juggerxxx]

What cartridge are you loading? Post the components and lengths.

That’s where everyone goes silent or starts beating me up. But anyway here goes nothing.

6.5CM
147gr ELD
Hornady brass with 10 firings.
Base to ogive is 2.160”. Cannot remember COAL off the top of my head.

 

[Cascade Hemi]

I wouldn't use either of those powders for that cartridge combination but that's neither here nor there. Here is the QL for both, I used 2.8" since I don't know your COAL. RL26 is the only of the two powders that looks viable. Start low and work up.

Cartridge : 6.5 Creedmoor Hornady
Bullet : .264, 147, Hornady ELD-M 26333
Useable Case Capaci: 46.246 grain H2O = 3.003 cm³
Cartridge O.A.L. L6: 2.800 inch = 71.12 mm
Barrel Length : 30.0 inch = 762.0 mm
Powder : Alliant Reloder-26 *C

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-10.0 90 41.40 2585 2180 35639 7734 99.1 1.740
-09.0 91 41.86 2614 2231 36898 7793 99.3 1.716
-08.0 92 42.32 2644 2282 38205 7848 99.5 1.689
-07.0 93 42.78 2674 2334 39566 7897 99.7 1.662
-06.0 94 43.24 2704 2386 40984 7942 99.8 1.636
-05.0 95 43.70 2733 2438 42457 7981 99.9 1.610
-04.0 96 44.16 2762 2491 43993 8015 100.0 1.584
-03.0 97 44.62 2792 2543 45590 8043 100.0 1.559
-02.0 98 45.08 2821 2597 47256 8068 100.0 1.534
-01.0 99 45.54 2849 2650 48992 8093 100.0 1.510
+00.0 100 46.00 2878 2704 50801 8117 100.0 1.487
+01.0 101 46.46 2907 2758 52690 8140 100.0 1.464
+02.0 102 46.92 2935 2812 54657 8163 100.0 1.441 ! Near Maximum !
+03.0 103 47.38 2964 2867 56718 8184 100.0 1.418 ! Near Maximum !
+04.0 104 47.84 2992 2921 58869 8205 100.0 1.396 ! Near Maximum !
+05.0 105 48.30 3020 2977 61101 8225 100.0 1.374 ! Near Maximum !

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 100 46.00 3004 2946 64570 7701 100.0 1.364 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 100 46.00 2680 2345 39806 8404 97.4 1.651

Cartridge : 6.5 Creedmoor Hornady
Bullet : .264, 147, Hornady ELD-M 26333
Useable Case Capaci: 46.246 grain H2O = 3.003 cm³
Cartridge O.A.L. L6: 2.800 inch = 71.12 mm
Barrel Length : 30.0 inch = 762.0 mm
Powder : Hodgdon Retumbo

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-10.0 92 39.60 2209 1593 24915 6665 88.8 2.012
-09.0 93 40.04 2237 1634 25678 6778 89.7 1.988
-08.0 94 40.48 2265 1675 26466 6890 90.4 1.963
-07.0 95 40.92 2293 1716 27281 6999 91.2 1.939
-06.0 96 41.36 2321 1759 28126 7105 91.9 1.915
-05.0 98 41.80 2350 1802 28999 7209 92.6 1.891
-04.0 99 42.24 2378 1846 29903 7310 93.3 1.868
-03.0 100 42.68 2407 1891 30840 7407 94.0 1.844
-02.0 101 43.12 2435 1936 31810 7501 94.6 1.821
-01.0 102 43.56 2464 1982 32815 7592 95.2 1.798
+00.0 103 44.00 2493 2028 33856 7679 95.7 1.775
+01.0 104 44.44 2522 2076 34936 7762 96.3 1.753
+02.0 105 44.88 2551 2123 36054 7841 96.8 1.731
+03.0 106 45.32 2580 2172 37217 7915 97.2 1.708
+04.0 107 45.76 2608 2221 38422 7986 97.7 1.682
+05.0 108 46.20 2637 2270 39673 8052 98.0 1.657

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 103 44.00 2676 2337 41122 7641 100.0 1.630
Data for burning rate decreased by 10% relative to nominal value:
-Ba 103 44.00 2258 1664 27642 6926 83.9 1.954

 

[Supersubes]

I haven’t seen anybody try Retumbo in the Creedmoor with a 147. Seems like it will be way too slow, your velocity will be down, and the necks will be sooty as shit.


Edit: Based upon cascade’s data, that’s why nobody tries retumbo. Jugger, if you've loaded those up, just pull the bullets and enjoy RL26.

 

[Juggerxxx]

I wouldn't use either of those powders for that cartridge combination but that's neither here nor there. Here is the QL for both, I used 2.8" since I don't know your COAL. RL26 is the only of the two powders that looks viable. Start low and work up.

Cartridge : 6.5 Creedmoor Hornady
Bullet : .264, 147, Hornady ELD-M 26333
Useable Case Capaci: 46.246 grain H2O = 3.003 cm³
Cartridge O.A.L. L6: 2.800 inch = 71.12 mm
Barrel Length : 30.0 inch = 762.0 mm
Powder : Alliant Reloder-26 *C

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-10.0 90 41.40 2585 2180 35639 7734 99.1 1.740
-09.0 91 41.86 2614 2231 36898 7793 99.3 1.716
-08.0 92 42.32 2644 2282 38205 7848 99.5 1.689
-07.0 93 42.78 2674 2334 39566 7897 99.7 1.662
-06.0 94 43.24 2704 2386 40984 7942 99.8 1.636
-05.0 95 43.70 2733 2438 42457 7981 99.9 1.610
-04.0 96 44.16 2762 2491 43993 8015 100.0 1.584
-03.0 97 44.62 2792 2543 45590 8043 100.0 1.559
-02.0 98 45.08 2821 2597 47256 8068 100.0 1.534
-01.0 99 45.54 2849 2650 48992 8093 100.0 1.510
+00.0 100 46.00 2878 2704 50801 8117 100.0 1.487
+01.0 101 46.46 2907 2758 52690 8140 100.0 1.464
+02.0 102 46.92 2935 2812 54657 8163 100.0 1.441 ! Near Maximum !
+03.0 103 47.38 2964 2867 56718 8184 100.0 1.418 ! Near Maximum !
+04.0 104 47.84 2992 2921 58869 8205 100.0 1.396 ! Near Maximum !
+05.0 105 48.30 3020 2977 61101 8225 100.0 1.374 ! Near Maximum !

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 100 46.00 3004 2946 64570 7701 100.0 1.364 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 100 46.00 2680 2345 39806 8404 97.4 1.651

Cartridge : 6.5 Creedmoor Hornady
Bullet : .264, 147, Hornady ELD-M 26333
Useable Case Capaci: 46.246 grain H2O = 3.003 cm³
Cartridge O.A.L. L6: 2.800 inch = 71.12 mm
Barrel Length : 30.0 inch = 762.0 mm
Powder : Hodgdon Retumbo

Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-10.0 92 39.60 2209 1593 24915 6665 88.8 2.012
-09.0 93 40.04 2237 1634 25678 6778 89.7 1.988
-08.0 94 40.48 2265 1675 26466 6890 90.4 1.963
-07.0 95 40.92 2293 1716 27281 6999 91.2 1.939
-06.0 96 41.36 2321 1759 28126 7105 91.9 1.915
-05.0 98 41.80 2350 1802 28999 7209 92.6 1.891
-04.0 99 42.24 2378 1846 29903 7310 93.3 1.868
-03.0 100 42.68 2407 1891 30840 7407 94.0 1.844
-02.0 101 43.12 2435 1936 31810 7501 94.6 1.821
-01.0 102 43.56 2464 1982 32815 7592 95.2 1.798
+00.0 103 44.00 2493 2028 33856 7679 95.7 1.775
+01.0 104 44.44 2522 2076 34936 7762 96.3 1.753
+02.0 105 44.88 2551 2123 36054 7841 96.8 1.731
+03.0 106 45.32 2580 2172 37217 7915 97.2 1.708
+04.0 107 45.76 2608 2221 38422 7986 97.7 1.682
+05.0 108 46.20 2637 2270 39673 8052 98.0 1.657

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 103 44.00 2676 2337 41122 7641 100.0 1.630
Data for burning rate decreased by 10% relative to nominal value:
-Ba 103 44.00 2258 1664 27642 6926 83.9 1.954

Thank you for the input and thank you for putting the extra effort to put the numbers into quickloads! Your guess for COAl was spot on with 2.800” as mine are ~2.803”. If it helps at all the H2O capacity weight on 3 pieces of brass are 53.9gr, 53.9gr and 54.1gr for the Hornady brass.
According to your data with Retumbo I COULD be fine with 46gr. But again that is a big COULD and One is always safer working from low to high and even then we are all on our own in this unknown world.
I have great success with RL26 and 147gr ELD combo. Here is a link for what I have explored and found http://www.snipershide.com/shooting/threads/147gr-eld-and-reloader-26-test.6894466/ . Looks like Retumbo is much slower then RL26 so I should be on the safer side and the results should not be as desirable as far a speed when compared to RL26.

 

[Juggerxxx]

I haven’t seen anybody try Retumbo in the Creedmoor with a 147. Seems like it will be way too slow, your velocity will be down, and the necks will be sooty as shit.


Edit: Based upon cascade’s data, that’s why nobody tries retumbo. Jugger, if you've loaded those up, just pull the bullets and enjoy RL26.

I agree as I have never seen anyone use Retumbo in a 6.5CM for any projectile. The burn rates look similar and the lack of RL26 is what drove me to ponder the possibility of Retumbo. I’d like to give it a try and see what the results are regardless as long as it is on the safe side.

 

[Cascade Hemi]

You will not get 46gr of Retumbo in that cartridge, maybe 45gr and it'll be pretty compressed. I don't know what barrel length you're using but I left it at the 30" I was previously using. You'll be lucky to get to 38K PSI with a full case, maybe 2350fps with a 24" barrel.

 

[Juggerxxx]

You will not get 46gr of Retumbo in that cartridge, maybe 45gr and it'll be pretty compressed. I don't know what barrel length you're using but I left it at the 30" I was previously using. You'll be lucky to get to 38K PSI with a full case, maybe 2350fps with a 24" barrel.

46gr of Retumbo was very doable when using a funnel with a drop tube and had a slight amount of crush. Its amazing how close your QL numbers are when comparing real data with a 28” barrel.

 

[Supersubes]

It’s gonna be safe from a peak pressure standpoint, but the case may not seal the chamber.

 

[Juggerxxx]

You guys were absolutely correct. Even though the burn rates are very close, Retumbo produced 150fps less speed than the same charge for Reloader 26 from a 20” barrel using the 147eld. You were also correct about not sealing. The entire piece of brass was covered in carbon.

 

[maddazzshooter]

I doubt we will ever see a new complete burn rate chart again, as variables are explored by shooters that was never done in the past.
Just an FYI, you can never compare a high energy powder like RL 26, VV N 500 series to others even if they are in the same burn rate on a chart.
IME with 26, I would say RL 25 is the closest you will come, yet 26 seems faster, but also seems to be way more universal or forgiving if that term could possibly be used.

RL26 is my go to for the 6.5Cm and crazy velocities! It has been my PRS secret hack and I’ve held that “Ace up my sleeve “ for about 6 years…..It’s also the reason why I don’t own a 6.5 PRC …. I started with 48gr worked up to 49.5gr but my starting load was the most accurate @ .442 groups with Berger 144 hybrids,a SD of 4…. Too bad there’s no more Of either on the market

 

[maddazzshooter]

RL26 is my go to for the 6.5Cm and crazy velocities! It has been my PRS secret hack and I’ve held that “Ace up my sleeve “ for about 6 years…..It’s also the reason why I don’t own a 6.5 PRC …. I started with 48gr worked up to 49.5gr but my starting load was the most accurate @ .442 groups with Berger 144 hybrids,a SD of 4…. Too bad there’s no more Of either on the market

P.s. Always use magnum primers or it will look like you’re shooting a muzzle loader!!

 

[BJames]

Are you using a drop tube and a vibrator to fit that much?

Only half kidding