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Load data for .300 Rem. Ultra Mag + .308 | 125gr Hornady ECX

Recommended Powder(s): Accurate 4350, Alliant Reloder-16, Ramshot Hunter, ReloadSwiss RS 62, ReloadSwiss RS 70

.300 Rem. Ultra Mag + .308 | 125gr Hornady ECX

Load Specifications

(Use the Personalized Load Calculator below to adjust )

Bullet:
.308 | 125gr Hornady ECX
Manufacturer SKU:
301944
Bullet Weight:
125gr | 8.1g
Bullet Diameter:
0.308" | 7.82mm
Bullet Length:
1.040" | 26.4mm
Caliber:
.300 Rem. Ultra Mag load data
Case Length (l3):
2.850" | 72.4mm
Cartridge Length (C.O.L.):
3.238" | 82.3mm
Seated Depth:
0.652" | 16.6mm
Shank Seated Depth:
0.652" | 16.6mm
Case Capacity:
112.5 Grains of Water | 7.30 cm³
Primer Size:
Large Rifle Magnum (LRM)
Max. allowed Pressure:
64977 psi | 4480 bar
LID:
LID_B1381_C374
Last updated:
2025-01-01

Load data for 148 loads in caliber .300 Rem. Ultra Mag with .308 | 125gr Hornady ECX bullet and 74 powders such as Accurate 4350, Alliant Reloder-16, Ramshot Hunter, ReloadSwiss RS 62, ReloadSwiss RS 70. The key underlying parameters are shown in the table above.

  • Important Notice: DO NOT go below Minimum Charge or above Maximum Charge unless there are reasons. Since xxlreloading.com has no control over the equipment and components used by the customer and the data used in connection with the website, any responsibility and liability for the results achieved is rejected. Also see our Terms of Service

    Questions regarding the load data: Please read the information in the next tab "Explanations".

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  • We recommend you limit powder range to relevant brands to speed up re-calculation of results

    Use the Personalized Load Calculator to customize loads to your own specific requirements. Find more details in the help section.

    Our default view only displays powders/loads that fulfill certain criteria: Max pressure of a load <=90% of Max. Standardized Pressure. Fill Rate (Min FR): >80% and <100% for rife loads,  >60% and <100% for pistol loads. Min. Propellant Combustion (Min z): >90% for rifle loads , >80% for pistol/revolver loads. Relax these criteria at your own risk to potentially get more powders shown in the load tables.

    .

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Click on the desired row in the tables below to add a specific load / powder to your Diary and manage there.

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2208
<<locked>>
86%
58233
90%
**51
100%
ADI AR 2209
<<locked>>
96%
58349
90%
**17
98%
ADI AR 2213
<<locked>>
97%
54375
84%
**71
96%
[ADI AR 2225]*
<<locked>>
97%
35563
55%
**64
93%
Accurate 2700
<<locked>>
86%
58204
90%
**89
99%
Accurate 3100
<<locked>>
97%
53911
83%
**73
99%
Accurate 4064
<<locked>>
83%
58378
90%
**19
100%
Accurate 4350 👍
<<locked>>
90%
58436
90%
**97
100%
[Accurate MAGPRO]*
<<locked>>
97%
53476
82%
**41
94%
Alliant Reloder- TS 15.5
<<locked>>
85%
57914
89%
**51
100%
Alliant Reloder-16 👍
<<locked>>
92%
58117
89%
**37
100%
Alliant Reloder-17
<<locked>>
87%
58131
89%
**33
100%
Alliant Reloder-19
<<locked>>
96%
58305
90%
**10
98%
Alliant Reloder-22
<<locked>>
97%
53998
83%
**68
97%
Alliant Reloder-23
<<locked>>
97%
50865
78%
**99
100%
Alliant Reloder-25
<<locked>>
97%
44164
68%
**00
98%
Alliant Reloder-26
<<locked>>
96%
57841
89%
**76
100%
Hodgdon H380
<<locked>>
84%
58102
89%
**68
100%
Hodgdon H414
<<locked>>
86%
57957
89%
**01
99%
Hodgdon H4350
<<locked>>
94%
58450
90%
**51
99%
[Hodgdon H4831]*
<<locked>>
97%
50038
77%
**33
94%
Hodgdon H4831 SC
<<locked>>
97%
57261
88%
**58
96%
Hodgdon Hybrid 100V
<<locked>>
94%
58175
90%
**48
100%
Hodgdon LVR
<<locked>>
89%
58407
90%
**04
100%
[Hodgdon Retumbo]*
<<locked>>
97%
35563
55%
**64
93%
Hodgdon Superperformance
<<locked>>
89%
58102
89%
**20
99%
Hodgdon VARGET
<<locked>>
86%
58233
90%
**51
100%
Hodgdon TrailBoss
<<locked>>
97%
34867
54%
**23
100%
IMR 4064
<<locked>>
86%
58291
90%
**41
100%
IMR 4166 Enduron
<<locked>>
87%
58030
89%
**32
99%
IMR 4350
<<locked>>
92%
57957
89%
**45
99%
IMR 4451 Enduron
<<locked>>
88%
58088
89%
**45
99%
IMR 4831
<<locked>>
96%
58204
90%
**68
100%
IMR 4955 Enduron
<<locked>>
97%
55724
86%
**05
96%
IMR 7828 SSC
<<locked>>
97%
56391
87%
**04
97%
Lovex S062
<<locked>>
84%
58436
90%
**38
100%
Lovex S065
<<locked>>
90%
58291
90%
**38
100%
Lovex S070
<<locked>>
90%
57899
89%
**51
99%
Lovex S071
<<locked>>
97%
45208
70%
**22
98%
Norma 204
<<locked>>
91%
58030
89%
**84
98%
Norma MRP
<<locked>>
97%
58189
90%
**63
99%
Norma URP
<<locked>>
91%
58189
90%
**91
100%
Ramshot Hunter 👍
<<locked>>
92%
58450
90%
**10
100%
Ramshot Magnum
<<locked>>
97%
53505
82%
**25
98%
ReloadSwiss RS 14
<<locked>>
97%
35491
55%
**72
100%
ReloadSwiss RS 50
<<locked>>
84%
58436
90%
**45
99%
ReloadSwiss RS 60
<<locked>>
88%
57986
89%
**66
100%
ReloadSwiss RS 62 👍
<<locked>>
90%
58276
90%
**97
100%
ReloadSwiss RS 70 👍
<<locked>>
91%
57928
89%
**56
100%
ReloadSwiss RS 76
<<locked>>
97%
43685
67%
**20
97%
Rottweil R 903
<<locked>>
86%
58059
89%
**41
100%
Rottweil R 904
<<locked>>
95%
58044
89%
**45
97%
Rottweil R 905
<<locked>>
96%
58392
90%
**10
98%
Rottweil R 907
<<locked>>
88%
57885
89%
**48
99%
SNPE Vectan SP 11
<<locked>>
85%
58450
90%
**87
100%
SNPE Vectan Tubal 5000
<<locked>>
86%
58189
90%
**23
100%
SNPE Vectan Tubal 7000
<<locked>>
90%
58204
90%
**89
99%
Shooters World Long Rifle
<<locked>>
90%
58291
90%
**38
100%
Shooters World Precision
<<locked>>
84%
58436
90%
**38
100%
Somchem S355
<<locked>>
86%
58102
89%
**41
100%
Somchem S361
<<locked>>
94%
58015
89%
**02
96%
Somchem S365
<<locked>>
93%
57943
89%
**97
100%
Somchem S385
<<locked>>
96%
58102
89%
**64
99%
Vihtavuori N135
<<locked>>
88%
58146
89%
**66
100%
Vihtavuori N150
<<locked>>
91%
58305
90%
**05
100%
Vihtavuori N160
<<locked>>
89%
57841
89%
**41
100%
Vihtavuori N165
<<locked>>
97%
50256
77%
**10
97%
Vihtavuori N550
<<locked>>
88%
58001
89%
**01
100%
Vihtavuori N555
<<locked>>
97%
56884
88%
**91
100%
Vihtavuori N560
<<locked>>
97%
54099
83%
**78
96%
[Vihtavuori N565]*
<<locked>>
97%
46412
71%
**10
94%
Winchester 6.5 StaBALL
<<locked>>
90%
58436
90%
**09
100%
Winchester 760
<<locked>>
86%
57957
89%
**01
99%
Winchester StaBALL HD
<<locked>>
97%
47137
73%
**58
100%

Max Load - Barrel Length: 23.60''

Powder
Charge
FR
MaxP
%
V(0)
z
ADI AR 2208
<<locked>>
81%
50560
78%
**30
100%
[ADI AR 2209]*
<<locked>>
81%
35114
54%
**22
90%
[ADI AR 2213]*
<<locked>>
87%
39030
60%
**40
90%
[ADI AR 2225]*
<<locked>>
94%
32314
50%
**69
90%
Accurate 2700
<<locked>>
81%
48965
75%
**28
97%
[Accurate 3100]*
<<locked>>
81%
30835
47%
**80
92%
Accurate 4064
<<locked>>
81%
54099
83%
**59
100%
Accurate 4350
<<locked>>
81%
41843
64%
**99
98%
[Accurate MAGPRO]*
<<locked>>
91%
42844
66%
**41
90%
Alliant Reloder- TS 15.5
<<locked>>
81%
51256
79%
**53
100%
Alliant Reloder-16
<<locked>>
81%
40074
62%
**02
98%
Alliant Reloder-17
<<locked>>
81%
46586
72%
**46
100%
[Alliant Reloder-19]*
<<locked>>
81%
35143
54%
**31
91%
[Alliant Reloder-22]*
<<locked>>
84%
34272
53%
**41
90%
Alliant Reloder-23
<<locked>>
81%
29747
46%
**23
96%
[Alliant Reloder-25]*
<<locked>>
84%
28456
44%
**71
90%
[Alliant Reloder-26]*
<<locked>>
81%
32227
50%
**28
94%
Hodgdon H380
<<locked>>
81%
52518
81%
**82
100%
Hodgdon H414
<<locked>>
81%
47848
74%
**30
97%
[Hodgdon H4350]*
<<locked>>
81%
38914
60%
**81
94%
[Hodgdon H4831]*
<<locked>>
90%
39784
61%
**10
90%
[Hodgdon H4831 SC]*
<<locked>>
87%
39885
61%
**20
90%
Hodgdon Hybrid 100V
<<locked>>
81%
37681
58%
**87
99%
Hodgdon LVR
<<locked>>
81%
44324
68%
**48
98%
[Hodgdon Retumbo]*
<<locked>>
94%
32314
50%
**69
90%
Hodgdon Superperformance
<<locked>>
81%
43410
67%
**61
96%
Hodgdon VARGET
<<locked>>
81%
49908
77%
**17
100%
Hodgdon TrailBoss
<<locked>>
81%
27543
42%
**52
100%
IMR 4064
<<locked>>
81%
49371
76%
**04
100%
IMR 4166 Enduron
<<locked>>
81%
48138
74%
**58
97%
IMR 4350
<<locked>>
81%
40756
63%
**20
95%
IMR 4451 Enduron
<<locked>>
81%
46789
72%
**48
97%
IMR 4831
<<locked>>
81%
35998
55%
**48
97%
[IMR 4955 Enduron]*
<<locked>>
86%
39102
60%
**67
90%
[IMR 7828 SSC]*
<<locked>>
86%
38899
60%
**46
90%
Lovex S062
<<locked>>
81%
53461
82%
**56
100%
Lovex S065
<<locked>>
81%
44469
68%
**02
98%
Lovex S070
<<locked>>
81%
42598
66%
**76
96%
[Lovex S071]*
<<locked>>
83%
28326
44%
**12
90%
[Norma 204]*
<<locked>>
81%
40683
63%
**49
93%
[Norma MRP]*
<<locked>>
81%
32285
50%
**99
91%
Norma URP
<<locked>>
81%
41350
64%
**95
98%
Ramshot Hunter
<<locked>>
81%
40292
62%
**69
96%
[Ramshot Magnum]*
<<locked>>
84%
32721
50%
**59
90%
ReloadSwiss RS 14
<<locked>>
81%
28224
43%
**01
100%
ReloadSwiss RS 50
<<locked>>
81%
52402
81%
**46
99%
ReloadSwiss RS 60
<<locked>>
81%
44802
69%
**43
100%
ReloadSwiss RS 62
<<locked>>
81%
41756
64%
**05
98%
ReloadSwiss RS 70
<<locked>>
81%
40611
62%
**22
97%
[ReloadSwiss RS 76]*
<<locked>>
89%
32576
50%
**08
90%
Rottweil R 903
<<locked>>
81%
49081
76%
**07
100%
[Rottweil R 904]*
<<locked>>
82%
37434
58%
**48
90%
[Rottweil R 905]*
<<locked>>
81%
34026
52%
**02
90%
Rottweil R 907
<<locked>>
81%
45368
70%
**22
96%
SNPE Vectan SP 11
<<locked>>
81%
50415
78%
**56
100%
SNPE Vectan Tubal 5000
<<locked>>
81%
49763
77%
**12
100%
SNPE Vectan Tubal 7000
<<locked>>
81%
43555
67%
**27
96%
Shooters World Long Rifle
<<locked>>
81%
44469
68%
**02
98%
Shooters World Precision
<<locked>>
81%
53461
82%
**56
100%
Somchem S355
<<locked>>
81%
49255
76%
**07
100%
[Somchem S361]*
<<locked>>
82%
39247
60%
**41
90%
Somchem S365
<<locked>>
81%
37666
58%
**33
100%
[Somchem S385]*
<<locked>>
81%
34925
54%
**99
92%
Vihtavuori N135
<<locked>>
81%
47471
73%
**18
100%
Vihtavuori N150
<<locked>>
81%
42076
65%
**33
100%
Vihtavuori N160
<<locked>>
81%
44599
69%
**22
99%
[Vihtavuori N165]*
<<locked>>
84%
32764
50%
**23
90%
Vihtavuori N550
<<locked>>
81%
45440
70%
**71
99%
Vihtavuori N555
<<locked>>
81%
33025
51%
**12
96%
[Vihtavuori N560]*
<<locked>>
88%
39624
61%
**76
90%
[Vihtavuori N565]*
<<locked>>
91%
38000
58%
**23
90%
Winchester 6.5 StaBALL
<<locked>>
81%
42134
65%
**49
100%
Winchester 760
<<locked>>
81%
47848
74%
**30
97%
[Winchester StaBALL HD]*
<<locked>>
81%
23699
36%
**64
94%

Start Load - Barrel Length: 23.60''

Any powder missing? Then click here.

FR ... fill rate of the cartridge in percent

MaxP ... max. pressure of load in psi or bar

% ... max. pressure of load in percent of the maximum allowed pressure for this caliber 

V(0) ... muzzle velocity in feet per second (fps) or  meters per second (m/s)

z ... powder burnt in percent

[...] *... not dangerous but load has suboptimal powder burnt with possible characteristics such as extensive muzzle flash or inaccurate loads.

[...] ²... fill rate low - you might want to consider using a filler to ensure proper ignition.

[...] ᴾ... possible press load - work up slowly to this load while watching for signs of excessive pressure.

👍  ... recommended powder/load for this caliber and bullet combination based on its ballistic performance.

<<locked>>... you need to buy an access license to unlock the data

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