IMR 7828SSC in .270 WIN

[highcotton]

I recently picked up a pound of 7828 ssc at Cabelas. Planning to start testing some 150 LRAB's in my .270 WIN. Any pet loads for a starting point? Thanks in advance.

 

[DrMike]

No pet loads, but try this:

Cartridge : .270 Win. (SAAMI)
Bullet : .277, 150, Nosler AccuBond LR 58836 G7
Useable Case Capaci: 58.520 grain H2O = 3.800 cm³
Cartridge O.A.L. L6: 3.340 inch = 84.84 mm
Barrel Length : 22.0 inch = 558.8 mm
Powder : IMR 7828 SSC

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 84 46.56 2311 1778 31600 10379 85.6 1.478
-18.0 86 47.72 2374 1878 33852 10767 87.2 1.438
-16.0 88 48.89 2439 1981 36273 11146 88.8 1.398
-14.0 90 50.05 2503 2088 38880 11513 90.3 1.352
-12.0 92 51.22 2569 2198 41688 11866 91.6 1.308
-10.0 95 52.38 2635 2312 44718 12203 92.9 1.264
-08.0 97 53.54 2701 2429 47990 12522 94.1 1.222
-06.0 99 54.71 2767 2550 51528 12822 95.2 1.182
-04.0 101 55.87 2834 2675 55362 13099 96.2 1.143 ! Near Maximum !
-02.0 103 57.04 2901 2803 59518 13353 97.1 1.105 ! Near Maximum !
+00.0 105 58.20 2968 2934 64033 13580 97.9 1.068 ! Near Maximum !
+02.0 107 59.36 3035 3068 68948 13780 98.6 1.033 !DANGEROUS LOAD-DO NOT USE!
+04.0 109 60.53 3102 3205 74310 13949 99.1 0.999 !DANGEROUS LOAD-DO NOT USE!
+06.0 111 61.69 3169 3346 80170 14088 99.5 0.966 !DANGEROUS LOAD-DO NOT USE!
+08.0 113 62.86 3237 3489 86593 14192 99.8 0.934 !DANGEROUS LOAD-DO NOT USE!
+10.0 116 64.02 3304 3635 93647 14261 100.0 0.903 !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 105 58.20 3124 3251 78159 13281 100.0 0.984 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 105 58.20 2756 2530 51812 13020 90.7 1.177

 

[Ridgerunner665]

If the 7828 doesn't work out...try some Norma MRP...I haven't actually used it in the 270 yet, and may never (she doesn't shoot 150's)but have done some "homework" on it just out of curiosity...I'm pretty sure it will sling those 150 LRAB's accurately...and FAST!

Always good to have speed and accuracy...never liked sacrificing one for the other, lol.

 

[tddeangelo]

I'm running RL22 in my 270 with a 24" barrel and getting 2950 for a 150BT (not an ABLR, but a point of comparison). Accuracy has been around MOA without fiddling with seat depth yet.

From what I've seen in loading data, RL22 and 7828ssc are pretty dang close in performance. If I had 7828, I'd happily use that instead, but I happened to have RL22 on hand.

 

[hubcap]

Not sure what my speed is yet. Accuracy is out standing with 57.2 grains of 7828 ssc. Absolutely no pressure signs at all. The LRAB with 7828 may turn out to be a pet load for me. I loaded up some more with 57.5 and will chrony real soon.

 

[tddeangelo]

Should have included that I'm running 56.5gr RL22 under the 150BT. I have gone up to 57.5 with no pressure signs, but better accuracy was found in my rifle at 56.5gr.

 

[pre6422hornet]

I am hitting 3030-3050 with 56.5 of IMR 7828SSC. No pressure signs. Federal 215 mag primer.

I am reloading a few of these tomorrow to verify accuracy on Wednesday. I will let you know how it shoots.

 

[hubcap]

I am hitting 3030-3050 with 56.5 of IMR 7828SSC. No pressure signs. Federal 215 mag primer.

I am reloading a few of these tomorrow to verify accuracy on Wednesday. I will let you know how it shoots.

Good info: I will load a few up with mag primers and see what happens.

 

[highcotton]

Thanks guys, picked up some info somewhere that the 7828 was working well with the 150LRAB and was able to get some on sale so I grabbed a pound.

 

[pre6422hornet]

Okay.. Sad to report that speeds were very consistent, BUT groups were terrible. 2 bullets within 1/2 inch and the third was three inches away. 3045-3052 over 6 shots.

I know it was not me or the rifle, because 140 gr BT's grouped at 3/4 an inch with same rifle.

 

[hubcap]

Okay.. Sad to report that speeds were very consistent, BUT groups were terrible. 2 bullets within 1/2 inch and the third was three inches away. 3045-3052 over 6 shots.

I know it was not me or the rifle, because 140 gr BT's grouped at 3/4 an inch with same rifle.

Well, dang it then. How much bullet jump ya using. I,m using a whopping .110 with the LRAB. I use a lot less jump with the 140 BT.

 

[NWBlacktail]

The 140 grn AB are truly great. Great BC, can achieve good velocity. Very accurate for the 270 win. The 150 grn LRAB looks cool too, but they also cost quite a bit more.

I haven't tried 7828 yet, but 140 grn AB with 58 grn H4831sc gives me very good accuracy. I have thought about trying 7828 to see if I could get any more velocity. But since I shot my chrono again, I think I'll stick with what I have already developed. :mrgreen:

 

[sask boy]

Hubcap, could you please advise on the OAL on that load for your 270win with 150ABLRs using 57.2 of 7828ssc.
Thanks for your help .

Blessings,
Dan

 

[hubcap]

Yes sir. I,m using 3.410 OAL. So far both IMR-4831 and IMR-7828 are both accurate with the OAL set at 3.410. When I shot H4831 with the same OAL groups were around 2.5 ''. Not so good. I will probably get out next week sometime and chrony the 7828 loads with both cci-200 and Federal 215,s. I,m quite curious about velocity at this point. I really don,t have a velocity goal in mind. Anything from 2900 to 2925 would suit me just fine. Certainly with mag primers I,m going to back off on the charge of 57.2 and run a ladder test and see what speed I,m at. The LRAB is an accurate bullet and I am definitely getting a kick out of working with it.

 

[lhsako]

If the 7828 doesn't work out...try some Norma MRP...I haven't actually used it in the 270 yet, and may never (she doesn't shoot 150's)but have done some "homework" on it just out of curiosity...I'm pretty sure it will sling those 150 LRAB's accurately...and FAST!

Always good to have speed and accuracy...never liked sacrificing one for the other, lol.

>>>>I'd love to see MRP tested here!

 

[Ridgerunner665]

I've got MRP...but don't have any 270 bullets heavier than 130 grains...I use H4350 in her 270 to keep the recoil down a little, and there's not much need in high volume/slow powder loads with 130 grain bullets.

I got the MRP for a 280 Ackley that I won't have for a little while yet.

 

[Oldtrader3]

I have some 130 LRAB's form Scotty and some 7828 SSC. I will have to load some of these bullets with 7828 and Hyb100V as well and see what my Model 70 will do with them?