QL Request 280AI MRP 140AB's

[MAinAR]

Having tested both 4831's and RL 26 and still not as accurate as I would like I am thinking on MRP as I have 2lbs of it sitting here. Could someone run QL on this for me? Thank YOU

Any help on speed to look for would help, thought on using RL 22 data but see a slight difference in VMD and speed tho probably close enuff to start. Just need to see what the added barrel length shows.

280 AI SAAMI
Nosler Brass
Fed 210 Primer
OAL 3.33
27" Barrel
140 AB

 

[JD338]

62.0 grs MRP should get you where you want to be. Max load is 64.0 grs.

JD338

 

[MAinAR]

62.0 grs MRP should get you where you want to be. Max load is 64.0 grs.

JD338

Any idea what speed to expect to see from 27" barrel?

 

[Dwh7271]

This is showing over the max listed load so I was a little hesitant to post it but here goes.
I'd be really careful with it a work up slow, but you know that. :grin:
Run a couple lower weight loads over a chrono and I'll set it up for whatever you're actually seeing if you would like.

Cartridge          : .280 Ack Imp
Bullet             : .284, 140, Nosler AccuBond 59992
Useable Case Capaci: 66.211 grain H2O = 4.299 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length      : 27.0 inch = 685.8 mm
Powder             : Norma MRP

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.155% 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

-01.6  103    65.83   3293    3370   60580  11315     99.8    1.190  ! Near Maximum !
-01.4  104    65.93   3298    3381   60932  11323     99.8    1.187  ! Near Maximum !
-01.2  104    66.04   3303    3392   61288  11331     99.9    1.184  ! Near Maximum !
-01.1  104    66.14   3309    3403   61646  11339     99.9    1.181  ! Near Maximum !
-00.9  104    66.25   3314    3414   62008  11346     99.9    1.178  ! Near Maximum !
-00.8  104    66.35   3319    3425   62370  11353     99.9    1.175  ! Near Maximum !
-00.6  104    66.45   3325    3436   62737  11360     99.9    1.172  ! Near Maximum !
-00.5  105    66.56   3330    3447   63105  11368     99.9    1.169  ! Near Maximum !
-00.3  105    66.66   3336    3459   63474  11374     99.9    1.166  ! Near Maximum !
-00.2  105    66.77   3341    3470   63848  11381     99.9    1.163  ! Near Maximum !
+00.0  105    66.87   3346    3481   64223  11387    100.0    1.160  ! Near Maximum !
+00.2  105    66.97   3352    3492   64602  11394    100.0    1.157  !DANGEROUS LOAD-DO NOT USE!
+00.3  105    67.08   3357    3503   64983  11400    100.0    1.154  !DANGEROUS LOAD-DO NOT USE!
+00.5  105    67.18   3362    3514   65359  11406    100.0    1.151  !DANGEROUS LOAD-DO NOT USE!
+00.6  106    67.29   3368    3526   65747  11411    100.0    1.148  !DANGEROUS LOAD-DO NOT USE!
+00.8  106    67.39   3373    3537   66137  11417    100.0    1.145  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 5% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 5% relative to nominal value:
+Ba    105    66.87   3427    3650   71805  11115    100.0    1.111  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba    105    66.87   3247    3278   57094  11528     98.8    1.217  ! Near Maximum !

Ran a second one down a little lower for you.

Cartridge          : .280 Ack Imp
Bullet             : .284, 140, Nosler AccuBond 59992
Useable Case Capaci: 66.211 grain H2O = 4.299 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length      : 27.0 inch = 685.8 mm
Powder             : Norma MRP

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.163% 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

-01.6   98    62.65   3126    3039   50801  10991     98.9    1.287
-01.5   99    62.75   3132    3049   51092  11004     98.9    1.284
-01.3   99    62.86   3137    3060   51383  11017     99.0    1.281
-01.1   99    62.96   3143    3071   51678  11030     99.0    1.277
-01.0   99    63.07   3148    3081   51972  11042     99.0    1.274
-00.8   99    63.17   3154    3092   52271  11054     99.1    1.271
-00.7   99    63.27   3159    3103   52569  11067     99.1    1.267
-00.5  100    63.38   3165    3113   52872  11079     99.2    1.264
-00.3  100    63.48   3170    3124   53175  11091     99.2    1.261
-00.2  100    63.59   3176    3135   53481  11102     99.2    1.258
+00.0  100    63.69   3181    3146   53788  11114     99.3    1.254
+00.2  100    63.79   3186    3156   54097  11125     99.3    1.251
+00.3  100    63.90   3192    3167   54408  11136     99.3    1.248
+00.5  100    64.00   3197    3178   54722  11147     99.4    1.245
+00.7  101    64.11   3203    3189   55038  11158     99.4    1.242
+00.8  101    64.21   3208    3200   55355  11169     99.4    1.239  ! Near Maximum !

Results caused by ± 5% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 5% relative to nominal value:
+Ba    100    63.69   3269    3322   60162  10942    100.0    1.199  ! Near Maximum !
Data for burning rate decreased by 5% relative to nominal value:
-Ba    100    63.69   3076    2941   47978  11090     97.1    1.317

 

[JD338]

62.0 grs MRP should get you where you want to be. Max load is 64.0 grs.

JD338

Any idea what speed to expect to see from 27" barrel?

I would think you would be around 3200 fps.

Dewey,
That's smokin'. STW speeds, be careful.

JD338

 

[Dwh7271]

Yep, I agree. That burn on MRP has to be off. Even with 140 s that's zooming. That's why I stuck that second one under there. :grin:

 

[MAinAR]

Will do, on the careful part. Will run 62grains across magento speed in the morning with 215GM instead of 210 primer first and get us a speed to see just what the long barrel has to offer.

Thanks guys, will post soon as I know.

 

[SJB358]

3200 with a good 140 would be a good one. That's elk sorta loads right there.

 

[Ackley Shooter]

Based on the group it just shot we'll need a target as big as an elk to hit anything... Shot about 1.8" at 200