7mm rm slow velocities

[the_kirkwood]

Been happily reloading for my 7mm sako until I can no longer get h1000 at the moment.
Been trying h4831 instead but getting slow velocities.

Load is as follows
160gr AccuBond with 62.5 gr h4831 with cci magnum primer.
I think the load is even slightly over the max load listed on the Hodgson website.
Still not achieving 2800fps.
My 308 shooting 168gr Hornady match is able to do better.

Was able to achieve 3000fps with h1000 at max load.

Anybody have any experience reloading same bullet weight with h4831?

Look forward to any input

Thanks

 

[jimbires]

a 7mm rem mag with a 24 inch bbl using your recipe should get about 2832 FPS , this is at 52445 PSI it's rated at 62366 PSI . your load looks to be a good starting load . MAX would be 66.0 grain , will be at 62369 PSI and should give about 2991 FPS . these specs are from quickload . as always start low and work up to max loads .

 

[DrMike]

Welcome aboard. As Jim says, you have some room to increase your load according to QuickLoad projections.

Cartridge          : 7 mm Rem. Mag.(SAAMI)
Bullet             : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 72.296 grain H2O = 4.694 cm³
Cartridge O.A.L. L6: 3.290 inch = 83.57 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Hodgdon H4831

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   82    52.80   2390    2029   32402   9965     89.7    1.580
-18.0   84    54.12   2450    2132   34589  10290     91.0    1.540
-16.0   86    55.44   2509    2237   36941  10606     92.2    1.501
-14.0   88    56.76   2570    2346   39444  10912     93.3    1.453
-12.0   90    58.08   2630    2457   42123  11207     94.3    1.409
-10.0   92    59.40   2690    2571   44987  11488     95.3    1.366
-08.0   94    60.72   2750    2687   48034  11756     96.2    1.325
-06.0   96    62.04   2811    2806   51267  12008     97.0    1.285
-04.0   98    63.36   2871    2928   54721  12244     97.7    1.246  ! Near Maximum !
-02.0  100    64.68   2931    3052   58415  12462     98.3    1.209  ! Near Maximum !
+00.0  102    66.00   2991    3178   62369  12661     98.8    1.173  ! Near Maximum !
+02.0  104    67.32   3051    3307   66606  12840     99.3    1.139  !DANGEROUS LOAD-DO NOT USE!
+04.0  106    68.64   3111    3438   71151  12997     99.6    1.106  !DANGEROUS LOAD-DO NOT USE!
+06.0  108    69.96   3170    3571   76031  13132     99.8    1.073  !DANGEROUS LOAD-DO NOT USE!
+08.0  110    71.28   3229    3705   81278  13244    100.0    1.042  !DANGEROUS LOAD-DO NOT USE!
+10.0  112    72.60   3288    3842   86930  13331    100.0    1.012  !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    102    66.00   3120    3459   73907  12361    100.0    1.091  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba    102    66.00   2814    2813   51052  12338     93.5    1.281

Work up in one grain increments. This should allow you to achieve velocities very close to what you are seeking.

 

[the_kirkwood]

Ok I will give it a try.
Was just worried as I think 60 grain is the max load listed on the Hodgson site for h4831 and a 160gr Partition.
AccuBond wasn't listed.
Seems very conservative. At 60 grains I was just getting 2700fps.

So I guess work up gradually and check for signs of excess pressure.

 

[DrMike]

Here's a 160 grain Partition with 66.0 grains of H4831 projected by QL.

Cartridge          : 7 mm Rem. Mag.(SAAMI)
Bullet             : .284, 160, Nosler PART SP 16327
Useable Case Capaci: 74.317 grain H2O = 4.825 cm³
Cartridge O.A.L. L6: 3.290 inch = 83.57 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Hodgdon H4831

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   80    53.04   2366    1989   31401  10039     89.3    1.599
-18.0   82    54.37   2425    2089   33491  10371     90.6    1.559
-16.0   84    55.69   2484    2192   35721  10695     91.8    1.521
-14.0   86    57.02   2543    2297   38098  11008     92.9    1.477
-12.0   88    58.34   2602    2406   40634  11312     94.0    1.433
-10.0   90    59.67   2661    2516   43341  11603     95.0    1.390
-08.0   92    61.00   2721    2630   46206  11880     95.9    1.348
-06.0   94    62.32   2780    2746   49243  12144     96.7    1.308
-04.0   96    63.65   2839    2864   52481  12391     97.4    1.270  ! Near Maximum !
-02.0   98    64.97   2899    2985   55936  12622     98.1    1.233  ! Near Maximum !
+00.0  100    66.30   2958    3108   59624  12834     98.6    1.197  ! Near Maximum !
+02.0  102    67.63   3017    3233   63564  13027     99.1    1.162  !DANGEROUS LOAD-DO NOT USE!
+04.0  104    68.95   3076    3361   67779  13200     99.4    1.129  !DANGEROUS LOAD-DO NOT USE!
+06.0  106    70.28   3134    3490   72290  13351     99.7    1.096  !DANGEROUS LOAD-DO NOT USE!
+08.0  108    71.60   3192    3621   77124  13480     99.9    1.065  !DANGEROUS LOAD-DO NOT USE!
+10.0  110    72.93   3251    3754   82311  13585    100.0    1.035  !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    100    66.30   3089    3389   70567  12575    100.0    1.112  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba    100    66.30   2781    2747   48872  12457     93.1    1.307

I do not argue with Hodgdon as their loads are pressure tested. If I run a projection with a 64K psi pressure limit, it allows some latitude.

Cartridge          : 7 mm Rem. Mag.(SAAMI)
Bullet             : .284, 160, Nosler PART SP 16327
Useable Case Capaci: 74.317 grain H2O = 4.825 cm³
Cartridge O.A.L. L6: 3.290 inch = 83.57 mm
Barrel Length      : 24.0 inch = 609.6 mm
Powder             : Hodgdon H4831

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   81    53.84   2401    2049   32646  10240     90.1    1.575
-18.0   83    55.19   2461    2152   34853  10572     91.3    1.535
-16.0   85    56.53   2521    2258   37208  10895     92.5    1.496
-14.0   87    57.88   2581    2367   39724  11206     93.6    1.448
-12.0   89    59.22   2641    2479   42412  11506     94.6    1.404
-10.0   91    60.57   2702    2593   45268  11793     95.6    1.361
-08.0   93    61.92   2762    2710   48293  12065     96.4    1.321
-06.0   95    63.26   2822    2830   51517  12321     97.2    1.281
-04.0   97    64.61   2882    2951   54960  12560     97.9    1.243  ! Near Maximum !
-02.0   99    65.95   2942    3076   58638  12781     98.5    1.206  ! Near Maximum !
+00.0  101    67.30   3002    3202   62571  12982     99.0    1.170  ! Near Maximum !
+02.0  103    68.65   3062    3331   66781  13162     99.4    1.136  !DANGEROUS LOAD-DO NOT USE!
+04.0  105    69.99   3122    3462   71290  13321     99.7    1.103  !DANGEROUS LOAD-DO NOT USE!
+06.0  107    71.34   3181    3594   76127  13456     99.9    1.071  !DANGEROUS LOAD-DO NOT USE!
+08.0  109    72.68   3240    3729   81321  13568    100.0    1.040  !DANGEROUS LOAD-DO NOT USE!
+10.0  111    74.03   3298    3865   86906  13656    100.0    1.010  !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    101    67.30   3130    3481   74026  12660    100.0    1.088  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba    101    67.30   2826    2838   51293  12675     93.8    1.278

Honestly, for 44 fps differential, I don't know that I would go out of my way with the additional grain of H4831.

 

[the_kirkwood]

I'm thinking I should have quickload to reference!!!
Could have saved me a lot of time and effort.

Thanks for the info.
Back to the range again.

 

[DrMike]

I'm thinking I should have quickload to reference!!!
Could have saved me a lot of time and effort.

Thanks for the info.
Back to the range again.

It can be a good investment for the serious hand loader.

 

[Gunner46]

The chart of the 64k pressures almost exactly match what I got out of my 7RM with a 162 Horn SPBT @ 2960fps. Never had any signs of over pressure and could put 10 shots, in a row, inside a tennis ball @ 200yds.

 

[the_kirkwood]

Does quickload account for different COAL?
I'm not familiar with the program but I'm grtting very interested

I was loading before with h1000 and a COAL of 3.435
That gets me about 20 thou off the lands.

 

[jimbires]

yes it does . to really dial in quickload you need the water capacity of your fired brass case , the COAL of your ammo , the bbl length . it's well worth the cost . jim

 

[DrMike]

yes it does . to really dial in quickload you need the water capacity of your fired brass case , the COAL of your ammo , the bbl length . it's well worth the cost . jim

+1

 

[the_kirkwood]

Well I'm sold. Quickload it is.
Thanks for the advice.

This might be a very obvious question.
However, here we go. Regarding water capacity of a fired case.
To obtain this I can just weigh the case, fill with water and weigh again and then subtract to find water capacity? Or is it somewhat more complicated?

 

[DrMike]

You are spot on. QL has a digital manual included that is quite complete.

 

[BF375]

QL is a good reference source but does not take into consideration the characteristics of individual barrels,land/groove configuration and dimensions, throat length etc.

 

[Wyo7200]

QL is a good reference source but does not take into consideration the characteristics of individual barrels,land/groove configuration and dimensions, throat length etc.

Actually, it does. You can make a cartridge and input the diameter of the lands and grooves, how many there are, size of each and if it's polygonal.

 

[DrMike]

QL is a good reference source but does not take into consideration the characteristics of individual barrels,land/groove configuration and dimensions, throat length etc.

Actually, it does. You can make a cartridge and input the diameter of the lands and grooves, how many there are, size of each and if it's polygonal.

Bingo! +1

 

[jimbires]

quickload is reasonable to keep up to date too . I think it's about $20 shipped for an update disc . I haven't bought a reloading book since I bought quickload , I don't see the need . I can't tweek any info I get from using a book only . a book tells you what they used , what they found, and you take their info and use it from there . I'm sounding like a salesman now, so I better say ; I'm not affiliated with quickload in any way , I just like the product . try it , you'll like it ! ha

 

[jimbires]

here is some more info that is easy to gather from quickload . I usually work with powders that give max or close to max velocities . I like a full case of powder , but I try not to use heavily compressed powder charges . here is a list of powders from highest velocity to the slowest velocity that are 105% , or less case fill , and don't go over the 62366 PSI limit . enjoy !



Cartridge : 7 mm Rem. Mag.(CIP)
Bullet : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 72.296 grain H2O = 4.694 cm³
Cartridge O.A.L. L6: 3.290 inch = 83.57 mm
Barrel Length : 24.0 inch = 609.6 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 62366 psi, or 429 MPa
or a maximum loading ratio or filling of 105 %
These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

23 loads produced a Loading Ratio below user-defined minimum of 90%. These powders have been skipped.
Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
Alliant Reloder-26 96.4 69.1 4.48 3089 100.0 62366 13288 1.189 !DANGEROUS LOAD-DO NOT USE!
PB Clermont PCL 517 102.2 72.7 4.71 3081 99.7 62366 13703 1.169 !DANGEROUS LOAD-DO NOT USE!
SNPE Vectan SP 12 102.1 72.6 4.70 3081 99.7 62366 13675 1.169 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N560 99.3 67.6 4.38 3077 99.1 62366 13945 1.176 !DANGEROUS LOAD-DO NOT USE!
Norma MRP 97.5 67.8 4.39 3075 100.0 62366 13467 1.182 !DANGEROUS LOAD-DO NOT USE!
ReloadSwiss RS 70 94.7 67.2 4.36 3070 100.0 62366 13059 1.166 !DANGEROUS LOAD-DO NOT USE!
Accurate MAGPRO 99.6 70.6 4.57 3070 98.1 62366 14074 1.182 !DANGEROUS LOAD-DO NOT USE!
IMR 7828 SSC 98.2 67.2 4.36 3069 99.4 62366 13510 1.165 !DANGEROUS LOAD-DO NOT USE!
IMR 7828 103.8 67.2 4.36 3069 99.4 62366 13510 1.165 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-25 105.0 69.6 4.51 3067 100.0 61670 12937 1.178 !DANGEROUS LOAD-DO NOT USE!
ADI AR 2213 99.3 66.9 4.33 3056 99.3 62366 13399 1.162 !DANGEROUS LOAD-DO NOT USE!
ADI AP 2214 103.2 71.4 4.63 3055 99.5 62366 13235 1.160 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-22 99.6 67.1 4.35 3051 99.8 62366 13346 1.182 !DANGEROUS LOAD-DO NOT USE!
Bofors RP5/NP ~approximation 99.6 67.1 4.35 3051 99.8 62366 13346 1.182 !DANGEROUS LOAD-DO NOT USE!
Raufoss RA15 99.6 67.1 4.35 3051 99.8 62366 13346 1.182 !DANGEROUS LOAD-DO NOT USE!
Winchester WXR 102.3 67.4 4.37 3050 99.8 62366 13368 1.182 !DANGEROUS LOAD-DO NOT USE!
Bofors RP15 102.3 67.4 4.37 3050 99.8 62366 13368 1.182 !DANGEROUS LOAD-DO NOT USE!
Ramshot Magnum 99.5 72.2 4.68 3033 100.0 62366 12750 1.177 !DANGEROUS LOAD-DO NOT USE!
Bofors RP5 NT ~approximation 102.9 69.9 4.53 3026 98.0 62366 13289 1.165 !DANGEROUS LOAD-DO NOT USE!
Rottweil R905 100.9 66.7 4.32 3023 99.0 62366 13105 1.180 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N570 105.0 73.8 4.78 3019 95.0 54873 14942 1.241 ! Near Maximum !
ADI AR 2209 96.2 63.7 4.13 3013 99.8 62366 12680 1.169 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-19 96.6 64.4 4.17 3010 99.8 62366 12739 1.177 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-23 101.8 66.4 4.30 3005 100.0 62366 11979 1.192 !DANGEROUS LOAD-DO NOT USE!
Bofors RP30 105.0 70.0 4.53 3004 99.1 57226 13744 1.233 ! Near Maximum !
Norma MRP 2 105.0 70.0 4.53 3004 99.1 57226 13744 1.233 ! Near Maximum !
Bofors RP14 ~approximation 97.4 64.9 4.20 3004 99.8 62366 12652 1.177 !DANGEROUS LOAD-DO NOT USE!
Ramshot Hunter 92.3 63.5 4.11 2997 100.0 62366 12223 1.184 !DANGEROUS LOAD-DO NOT USE!
ReloadSwiss RS 62 90.7 63.3 4.10 2992 100.0 62366 11985 1.198 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H4831 SC 98.0 66.0 4.28 2991 98.8 62366 12661 1.174 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H4831 101.9 66.0 4.28 2991 98.8 62366 12661 1.174 !DANGEROUS LOAD-DO NOT USE!
Norma 204 91.8 63.2 4.09 2989 99.7 62366 12438 1.176 !DANGEROUS LOAD-DO NOT USE!
Raufoss RA4 94.8 63.2 4.09 2989 99.7 62366 12438 1.176 !DANGEROUS LOAD-DO NOT USE!
Bofors RP4 ~approximation 94.8 63.2 4.09 2989 99.7 62366 12438 1.176 !DANGEROUS LOAD-DO NOT USE!
Norma URP 91.8 60.5 3.92 2972 100.0 62366 11702 1.191 !DANGEROUS LOAD-DO NOT USE!
Bofors RP19 ~approximation 91.8 60.5 3.92 2972 100.0 62366 11699 1.191 !DANGEROUS LOAD-DO NOT USE!
Somchem S385 96.8 65.2 4.23 2971 100.0 62366 12135 1.197 !DANGEROUS LOAD-DO NOT USE!
Somchem S365 93.4 61.9 4.01 2969 100.0 62366 11351 1.199 !DANGEROUS LOAD-DO NOT USE!
Accurate 4350 90.9 60.6 3.93 2966 100.0 62366 11660 1.209 !DANGEROUS LOAD-DO NOT USE!
Winchester Supreme 780 95.5 67.1 4.35 2965 99.7 62366 12132 1.183 !DANGEROUS LOAD-DO NOT USE!
Rottweil R904 95.7 62.9 4.08 2964 99.3 62366 12188 1.176 !DANGEROUS LOAD-DO NOT USE!
Bofors RP4 NT ~approximation 92.5 62.6 4.05 2962 100.0 62366 11914 1.189 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N165 102.0 67.2 4.36 2958 99.9 62366 11885 1.187 !DANGEROUS LOAD-DO NOT USE!
IMR 4831 96.3 61.5 3.98 2953 100.0 62366 11453 1.200 !DANGEROUS LOAD-DO NOT USE!
Accurate 3100 99.7 66.5 4.31 2953 100.0 62366 11733 1.213 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N160 102.2 65.3 4.23 2947 99.2 62366 11972 1.180 !DANGEROUS LOAD-DO NOT USE!
Lovex S070 91.8 60.5 3.92 2946 100.0 62366 11693 1.195 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H1000 105.0 69.2 4.49 2943 98.7 55337 12928 1.226 ! Near Maximum !
ADI AR 2217 105.0 69.2 4.49 2943 98.7 55337 12928 1.226 ! Near Maximum !
Lovex S071 105.0 66.2 4.29 2941 100.0 61468 11713 1.221 ! Near Maximum !
Alliant Reloder-33 105.0 75.9 4.92 2938 94.3 51177 14502 1.284
Somchem S361 94.8 67.3 4.36 2934 98.8 62366 11982 1.188 !DANGEROUS LOAD-DO NOT USE!
Hodgdon Hybrid 100V 94.2 60.7 3.94 2926 100.0 62366 10816 1.192 !DANGEROUS LOAD-DO NOT USE!
Lovex S065 90.8 59.2 3.84 2921 100.0 62366 11238 1.194 !DANGEROUS LOAD-DO NOT USE!
ADI AR 2225 105.0 70.4 4.56 2895 99.8 48893 13357 1.303
Hodgdon Retumbo 105.0 70.4 4.56 2895 99.8 48893 13357 1.303
ReloadSwiss RS 80 105.0 75.9 4.92 2891 94.2 48611 14313 1.312
ADI AR 2218 105.0 74.5 4.83 2872 92.1 48221 14542 1.304
Lovex D100 105.0 75.3 4.88 2847 89.8 55711 12383 1.246 ! Near Maximum !
Vihtavuori 24N41 105.0 74.5 4.83 2824 87.1 50909 12928 1.282
Norma 217 105.0 68.9 4.47 2807 98.5 43777 13470 1.391
Vihtavuori N170 105.0 69.2 4.49 2785 92.1 50743 12307 1.315
Hodgdon H870 105.0 72.3 4.68 2782 93.4 43717 13623 1.385
Alliant Reloder-50 105.0 75.7 4.90 2744 90.0 41678 13919 1.438
Bofors 12,7mmRA NC1214 Lot20115087 105.0 74.0 4.80 2685 81.8 43706 12868 1.438
Hodgdon US 869 105.0 74.5 4.83 2633 83.1 41646 12046 1.421
Hodgdon 50BMG 105.0 71.0 4.60 2631 78.8 41824 12013 1.415
SNPE Vectan SP 13 105.0 71.5 4.63 2581 87.5 38351 11847 1.483
Accurate 8700 105.0 73.0 4.73 2557 86.4 37453 11799 1.488
Vihtavuori 20N29 105.0 75.3 4.88 2533 83.0 36275 11855 1.521
PB Clermont PCL 513/520/9520 105.0 71.5 4.63 2516 84.3 36002 11506 1.525
NC A3502 ,test only 105.0 68.5 4.44 2317 59.8 33121 9019 1.572
TLP A 502(RH) ,test only 105.0 68.5 4.44 2294 64.5 31197 9474 1.616
V1734 7-multiperf ,test only 105.0 68.5 4.44 1647 29.6 17221 4439 2.093

 

[BF375]

Interesting! How close does it come to real life?

 

[the_kirkwood]

Going to order it today.
I'll only be reloading for two calibers however even then there are a number of variables which
Would be nice to investigate before hitting the range.

Thanks for all the advice