7mm Magnum powder choices

Dogleg said:
Well; you're not wrong. I only have 40 years of reloading behind me, which is sort of sad in a way. Where did those years go? Don't know; but they sure went fast.

I think it was about '88 when we started playing with STWs. It wasn't like it was something new except the name; there just weren't any powders around to make it work before that. The Rem mag made its reputation with 7828 long before we we could get it and it basically stunk without it or equivilents. Either way, the STWs ate the Rem alive. It was a different era though, every gunwriter in the world said you couldn't match Weatherbys factory velocities with handloads.

I'm not sure if I have a point, except that if you think you are going to get speeds out of 4350 you better be counting on some luck. I wish you good luck; and definitely dont wish you any harm.
Click to expand...

Im similar in timeline to you. Just wanted to add that IF you could find them, Norma MRP and its predecessor would work as well as 7828. And yes, late 80's for the STW. - dan
 
Thanks for all the replies. Choosing a powder is always difficult for me. I think I'll save the 4350 for the 243 and start using the 4831. I see that many guys like Reloader 22 or 25 or 26 and theres also Retumbo and 7828 and H1000. But now many are not available and the ones that's are can be quite expensive. I noticed that my local gun shop now has H1000 for $95/lb. I'd like to try it but for that price I want to start with my 4831.
 
I decided to use this mild, -7° day to try my first few handloads.
I definitely did not get noslers published velocity but I did get much better accuracy than my hornady factory loads. I did not get hornadys listed velocity either with their 139 grain american whitetail load.
I tried 63 and 64 and 65 grains of IMR4831 with 150 grain nosler ballistic tips and federal magnum primers. The largest group was just over an inch and both 63 and 65 grain loads produced a 0.865 inch 3 round group from 100 yards. Average velocity for 65 grains of IMR4831 was 2957 fps and an ES of 29 fps. I may try 66 grains of IMR4831 yet. According to available data this seems to be about the maximum load.
The hornady ammo is terrible in my rifle. I'm getting an average of just under 2 inch groups and an average velocity of 3050 fps with and ES of 92 fps for 3 shots. Listed velocity for this ammo is 3150 fps.
The velocity of my handloads is in line with my Lyman 49th manual. Somehow nosler got 3240 fps in their testing.
 
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If powder aND BULLETS WERE NOT SO EXPENSIVE, i WOULD INVITE YOU TO FIRE 5 SHOTS AT 10 FEET AND THE SAME AT 20 AND SEE THE DIFFERENCE.

Muzzle blast can give false readings. If your set up allows it, back off.
 
IMR 4350 vs IMR 4831 - I used both years ago on my first 7mm, when powder choices seemed a lot simpler. They're almost identical in performance. I think I would of also went with 4831 in the 7mm Mag like you did, unless I didn't have much of it on hand and had lots of 4350

I would jump up your load in 0.6 grain increments (1% of your charge weight) as you look for max load. (65.6, 66.2, 66.8, 67.4grs) I would not push speeds past 3050 fps in your 24.4" Tikka with the IMR 4831 / 150gr Nosler combo
 
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here's a Quickload prediction for fastest powders in a 7mm Rem Mag 24.4" barrel @ 62,000 psi which will be within a whisker of max load. Actual charge weights required to hit this speed could be off by a bit, but the velocity potential will be accurate.

Code: 
Cartridge          : [COLOR=#ff0000][B]7 mm Rem Mag[/B][/COLOR]
Bullet             : .284, [B][COLOR=#ff0000]150, Nosler BalTip[/COLOR][/B] 28150
Useable Case Capaci: 77.698 grain H2O = 5.045 cm³
Cartridge O.A.L. L6: 3.290 inch = 83.57 mm
[B][COLOR=#ff0000]Barrel Length      : 24.4 inch[/COLOR][/B] = 619.8 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 62000 psi, or 427 MPa
or a maximum loading ratio or filling of 104 %
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 !

57 loads produced a Loading Ratio below user-defined minimum of 80%. 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
---------------------------------  -----------------------------------------------------------------
Vihtavuori N570                    103.8     78.4     5.08    3232    96.2    62000   15498   1.150  ! Near Maximum !
Vihtavuori N568                    103.2     77.1     5.00    3194    98.0    62000   14704   1.160  ! Near Maximum !
Alliant Reloder-26                  91.7     70.6     4.57    3181   100.0    62000   13340   1.160  ! Near Maximum !
Alliant Reloder-25                 100.7     71.7     4.65    3176   100.0    62000   13067   1.145  ! Near Maximum !
Norma MRP 2                        102.5     73.4     4.76    3168    99.4    62000   14026   1.170  ! Near Maximum !
Norma MRP                           93.0     69.5     4.50    3165   100.0    62000   13579   1.156  ! Near Maximum !
Vihtavuori N560                     94.9     69.5     4.50    3165    98.7    62000   14047   1.150  ! Near Maximum !
Alliant Reloder-33                 104.0     80.8     5.24    3163    95.8    58785   15093   1.175  ! Near Maximum !
IMR 7828                            99.4     69.2     4.48    3162    99.1    62000   13651   1.138  ! Near Maximum !
IMR 7828SSC                         94.1     69.2     4.48    3162    99.1    62000   13651   1.138  ! Near Maximum !
Accurate MAGPRO                     95.2     72.5     4.70    3154    97.7    62000   14157   1.169  ! Near Maximum !
Hodgdon H1000                      104.0     73.7     4.77    3145    99.3    61492   13351   1.136  ! Near Maximum !
Alliant Reloder-22                  95.2     68.9     4.46    3140    99.7    62000   13466   1.155  ! Near Maximum !
Vihtavuori N565                     99.1     72.9     4.72    3138    98.9    62000   13866   1.180  ! Near Maximum !
Ramshot Magnum                      95.2     74.3     4.81    3124    99.9    62000   12902   1.151  ! Near Maximum !
Hodgdon Retumbo                    104.0     74.9     4.85    3115   100.0    55689   13650   1.180  ! Near Maximum !
Alliant Reloder-16                  88.1     61.5     3.98    3109   100.0    62000   12011   1.146  ! Near Maximum !
Alliant Reloder-17                  83.4     62.6     4.06    3104   100.0    62000   11965   1.155  ! Near Maximum !
Alliant Reloder-19                  92.6     66.4     4.30    3103    99.6    62000   12895   1.152  ! Near Maximum !
Alliant Reloder-23                  96.4     67.5     4.38    3097   100.0    62000   11939   1.164  ! Near Maximum !
Winchester 760                      83.4     63.2     4.09    3092   100.0    62000   12462   1.158  ! Near Maximum !
Hodgdon H414                        83.4     63.2     4.09    3092   100.0    62000   12462   1.158  ! Near Maximum !
Ramshot Hunter                      88.3     65.3     4.23    3091   100.0    62000   12368   1.158  ! Near Maximum !
Vihtavuori N555                     93.1     65.4     4.24    3087   100.0    62000   12092   1.179  ! Near Maximum !
Hodgdon H4831SC                     94.1     68.1     4.41    3082    98.5    62000   12817   1.148  ! Near Maximum !
Hodgdon H4831                       97.9     68.1     4.41    3082    98.5    62000   12817   1.148  ! Near Maximum !
Norma 204                           88.1     65.2     4.22    3082    99.5    62000   12607   1.152  ! Near Maximum !
Ramshot LRT                        104.0     80.3     5.20    3074    88.8    56942   14346   1.181  ! Near Maximum !
Vihtavuori N550                     85.4     62.5     4.05    3068   100.0    62000   11977   1.167  ! Near Maximum !
Norma URP                           87.8     62.2     4.03    3067   100.0    62000   11834   1.163  ! Near Maximum !
Accurate 4350                       86.6     62.0     4.02    3054   100.0    62000   11752   1.180  ! Near Maximum !
IMR 4955 Enduron                    95.6     66.6     4.32    3052    98.7    62000   12458   1.150  ! Near Maximum !
Vihtavuori N165                     97.7     69.2     4.49    3048    99.8    62000   12050   1.162  ! Near Maximum !
[COLOR=#ff0000][B]IMR 4831                            92.0     63.1     4.09    3047   100.0    62000   11576   1.173  ! Near Maximum ![/B][/COLOR]
Hodgdon H4350                       90.8     63.6     4.12    3046    99.9    62000   11926   1.155  ! Near Maximum ![COLOR=#ff0000]
[B]IMR 4350                            89.1     63.5     4.11    3045    99.9    62000   11899   1.155  ! Near Maximum ![/B][/COLOR]
 
Thanks for your input todbartel. I appreciate it. I was hoping of get 3100 fps but 3050 would be good too as long as it still shoots as well as it does now. I might have to try a new powder when the 4831 is gone. If I can find one when the time comes.
 
Hornady loads the 150gr CX ammo to 3000 fps 24" brl - I'm sure they have good access to pressure testing equipment

If you can find RL26 or Viht N568, you'll see some speed out of the 7mm Rem Mag
 
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