Reloder 26

I can't get more than one speed to align with quickload . with everything set to your specs ,

for me to get 69.5 gr to give 2990 FPS I need to set the powder speed ( Ba) to 0.3300

to get 70.0 gr to show 3110 FPS I need to set the ( Ba) to 0.3550

to get 71.5 gr to show 3220 FPS I need to set the (Ba) to 0.371

I'm wondering about your chrony readings .

if you really are getting 3221 FPS at 71.5 gr of RL26 powder you are 72597 PSI . the 7mm rem mag is rated at 61000 psi .


when I adjusted the Ba for my rifle / ammo combo my readings were just about spot on , at any charge weight .
I was wondering about that. 120 fps with a .5 grain change seems like way too much, at least I have never seen it change that much, or evenue close. 110 fps in 1.5 grains I can understand, but that first jump seems like way too much. You may be having chrono issues too.
 
Is there a way to figure the max velocity with this combo that I could shoot for? Alliant's data shows 3050 for this bullet in a 24" barrel. I figure 3100 should be a cake walk in the longer tube. I loaded and fired 5 more rounds of 71.5, velocity was right at 3220 again with an ES of 12 fps. That's a bummer if I gotta back out a bunch.

If your over pressure that much you will be getting signs on your brass, ejector mark, primer pocket expansion, primer flattening and possibly cratering...
 
Is there a way to figure the max velocity with this combo that I could shoot for? Alliant's data shows 3050 for this bullet in a 24" barrel. I figure 3100 should be a cake walk in the longer tube. I loaded and fired 5 more rounds of 71.5, velocity was right at 3220 again with an ES of 12 fps. That's a bummer if I gotta back out a bunch.

Not as big a bummer as a blown primer, gas in the face, low brass life, etc. If you are looking carefully at pressure signs, including measuring the belt and expansion line diameters, and seeing no pressure, it points to the accuracy of your chronograph.
 
After much reading on this unicorn powder I tried it in my 243AI with 105s. With Re22, I was able to get 3250 if I was willing to beat up my brass; I ended up at 3200 to not destroy my cases. 3280 would have been one use only.

With Re26, I am essentially getting 80-100 fps with the same effects on the case. So I can shoot about 3280 with the same brass result as 3200 with Re22.

Compared to the unicorn claims this is a modest difference. Earlier claims in this thread are 3380 for 243AI, mine is a 24" barrel, I hope they are shooting much longer. I guarantee this would blow primers in my rifle. But, this is a significant enough difference that I will transition to Re26 as my routine load.
 
I was wondering about that. 120 fps with a .5 grain change seems like way too much, at least I have never seen it change that much, or evenue close.

(I can't explain this one, perhaps the bore wasn't fouled up enough.of My first shot of 71.5 be only yielded 3178 from a clean, lightly oiled bore.)


110 fps in 1.5 grains I can understand, but that first jump seems like way too much. You may be having chrono issues too.

Chrony issues could be, I'm not lucky enough to be able to use the exact location each outing. One time, not knowing any better I had the chronograph set up on a concrete slab on a bright day; how much pressure does it take to make a 7-mag launch a 162 over 4100 fps?

If your over pressure that much you will be getting signs on your brass, ejector mark, primer pocket expansion, primer flattening and possibly cratering...

I have none of that. But without having an accurate idea of what should be the upper limit in my rifle, I will probably back down to 3100-3120. As far as measuring case expansion like someone else posted, I measured ahead of the belt on unfired cases and after firing. If there is a difference in diameter, it doesn't amount to more than .0005.
 
My apologies, I misstated my first load.
2990 was with 69.0, not 69.5
Once I've got the necessary permissions, I'll post pictures of my brass. The only marks on the head are from primer pocket uniforming which was done with a cordless drill.
 
I guarantee this would blow primers in my rifle.

Keep in mind also, some barrels are faster than others. I had a Remington 700 with a 20" barrel and a Savage with a 20" barrel, both in .308, both rifles would reach very similar pressure at the same charge, and with everything else being the same, the Savage would send the 168 A-MAX about 50-60 fps faster than the Remington. This, in conjunction with a longer barrel could certainly make that much difference. These slower burning powders seem to respond better to longer barrels than some others
 
After much reading on this unicorn powder I tried it in my 243AI with 105s. With Re22, I was able to get 3250 if I was willing to beat up my brass; I ended up at 3200 to not destroy my cases. 3280 would have been one use only.

With Re26, I am essentially getting 80-100 fps with the same effects on the case. So I can shoot about 3280 with the same brass result as 3200 with Re22.

Compared to the unicorn claims this is a modest difference. Earlier claims in this thread are 3380 for 243AI, mine is a 24" barrel, I hope they are shooting much longer. I guarantee this would blow primers in my rifle. But, this is a significant enough difference that I will transition to Re26 as my routine load.

I am running an even 50g of RL26 in my 243 AI, and a 105 Berger. Velocity is 3440.
That is 30rds over the chronograph, not just 10.
The kicker is my 31" bbl.
The load is a top end load and used only for hunting, so the bbl doesn't get heated up.
Should last me several years.
 
I am uncertain about this new format...

However...the poster with the 7mm Mag...I am launching 170s in my 270 Wby @ 3225fps...out of a 28" barrel...basically the same cartridge...Using RL-26

Have fun...
 
here is a chart from Q-load that is set up for your combo . it steps up by 2% powder charges . it'll give you an idea where your at .
it looks like 3080 FPS is max velocity for this combo , at 61143 PSI .

Cartridge : 7 mm Rem. Mag.(SAAMI)
Bullet : .284, 162, Hornady ELD-M 28403 G7
Useable Case Capaci: 78.557 grain H2O = 5.101 cm³
Cartridge O.A.L. L6: 3.465 inch = 88.01 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Alliant Reloder-26 ?, Temperature: 72 °F

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% 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

-20.0 70 54.23 2532 2306 31964 10451 99.8 1.711
-18.0 71 55.59 2590 2413 34183 10627 100.0 1.668
-16.0 73 56.94 2647 2521 36525 10777 100.0 1.626
-14.0 75 58.30 2704 2630 39009 10921 100.0 1.578
-12.0 77 59.66 2760 2739 41644 11061 100.0 1.530
-10.0 78 61.01 2815 2850 44437 11200 100.0 1.484
-08.0 80 62.37 2869 2961 47399 11335 100.0 1.441
-06.0 82 63.72 2923 3072 50539 11467 100.0 1.398
-04.0 84 65.08 2976 3185 53868 11597 100.0 1.358 ! Near Maximum !
-02.0 85 66.43 3028 3298 57398 11723 100.0 1.319 ! Near Maximum !
+00.0 87 67.79 3080 3413 61143 11847 100.0 1.282 !DANGEROUS LOAD-DO NOT USE!
+02.0 89 69.15 3132 3528 65117 11967 100.0 1.247 !DANGEROUS LOAD-DO NOT USE!
+04.0 91 70.50 3183 3645 69335 12084 100.0 1.212 !DANGEROUS LOAD-DO NOT USE!
+06.0 92 71.86 3234 3763 73816 12197 100.0 1.179 !DANGEROUS LOAD-DO NOT USE!
+08.0 94 73.21 3285 3881 78579 12307 100.0 1.147 !DANGEROUS LOAD-DO NOT USE!
+10.0 96 74.57 3335 4002 83644 12414 100.0 1.117 !DANGEROUS LOAD-DO NOT USE!

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 87 67.79 3176 3629 74083 11484 100.0 1.186 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 87 67.79 2935 3098 48150 12376 100.0 1.416
 
you'll see different max loads when you look in different reloading books too . it looks to me like you want to be around 3080 to 3100 FPS max . what max velocity did Alliants data show ?
 
Top