Help me understand the velocity disparity please

ReloadKy

Beginner
May 13, 2020
234
34
I have two rifle in question here:
Remington 700 in 30-06 with 24 inch barrel
Tikka T3x in 7MM Rem mag with a 24 inch barrel
Powder in question is IMR 4451
I have gotten excellent velocity numbers using 4451 in my 06. Using 58.6 gr of powder and shooting a 165 gr Ballistic Tip or AccuBond I have gotten velocity averages from 2925 to 2948.
For the 7 mag this past weekend I loaded up 60.5 gr of 4451 behind a 140 gr sierra game king and only got a velocity average of 2913.
My brain tells me (no jokes, lol) that more powder and a bullet 25 gr lighter should provide more velocity, but that is not what I saw. Does anyone have any explanation for this? Would it be because I have a lower case fill percentage in the 7 mag, my pressure would be down and therefore decrease velocity?
 

gbflyer

Handloader
Mar 28, 2017
881
40
Something about the hole in the barrel being smaller with the 7mm. You need a slower burning powder for 140’s. Try some Re22.
 

SJB358

Ballistician
Dec 24, 2006
31,254
419
The engine is bigger in the 7 Mag, so it needs more gas to get it moving faster. 4451 is probably good for both, better for the 30-06. Lean into a 7 Mag with H1000, 7828 and others of that burn rate and you’ll see it spread the gap. 3200-3300 with the right powders and a 140 in a 7 Rem isn’t out of the norm.
 

Ridgerunner665

Handloader
Oct 28, 2008
2,432
20
Yep... as stated, need a true magnum powder for the 7mm.

7828, Reloder 26, or any of several others in that burn range.

Sent from my SM-G986U using Tapatalk
 

Dr. Vette

Handloader
Apr 16, 2012
1,313
25
I have three Weatherby Mark V's in 300 Wby that I'm working on .

Same bullet/powder/case/primer/prep routine for all 3.

Do you think I get the same velocity with the same charge in all 3? Not a chance.
And, they all like different charges and different seating depths.
Just an example of how every rifle is different.

In your case, I suspect that bearing surface of the different bullets is also having an effect.
 

mjcmichigan

Handloader
Dec 26, 2016
2,263
21
It’s a combination. All these points are on. Case volume, bearing surface, chamber and throat differences powder burn rates.

Think if the powder like a stage on a rocket. Fast vs slow burn powders choices exist so we can make the powder keep pushing on the bullet.
A heavier bullet needs more time to accelerate, slower burn rates give the bullet time to keep accelerating down the whole barrel. I lighter bullet might exit the barrel before peak pressure is reached.

I’d tell you, probably your 7mm is topping at a lower pressure because it’s still burning when the bullet exits. If you shot near dusk, you might see a burning muzzle flash vs a non burning flash.

Fun to think about all these variables...


Sent from my iPhone using Tapatalk
 

ReloadKy

Beginner
May 13, 2020
234
34
Thanks for the responses. I had stated earlier in a previous post that I wanted to find a powder that could get me to shoot a 150/160 gr around 3100 in the 7 mag. I have since collected some R23, IMR 7977 and Hybrid100V. I have already tried a group with the R23 well below max and pushed that 140 SGK 3100 fps. I do not plan to use the rest of the box of sierra bullets so I was using them to experiment with powders. I guess I need to experiment with powders using a 150/160 gr bullet to get best options.
 

jimbires

Handloader
Aug 16, 2011
2,412
255
7mm rem mag , 160 AccuBond , 26" bbl , chart set to max psi of 61000 , and set to a max case fill of 105%
fast velocities at the top dropping down to slower



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 : 26.0 inch = 660.4 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 61000 psi, or 420 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 !

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 95.8 68.7 4.45 3130 100.0 61000 12010 1.255 !DANGEROUS LOAD-DO NOT USE!
PB Clermont PCL 517 101.7 72.3 4.69 3123 99.8 61000 12411 1.234 !DANGEROUS LOAD-DO NOT USE!
SNPE Vectan SP 12 101.5 72.2 4.68 3122 99.8 61000 12384 1.235 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N560 98.6 67.2 4.35 3119 99.3 61000 12642 1.242 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-25 104.7 69.4 4.50 3116 100.0 61000 11710 1.238 !DANGEROUS LOAD-DO NOT USE!
Norma MRP 96.9 67.4 4.36 3116 100.0 61000 12175 1.249 !DANGEROUS LOAD-DO NOT USE!
Accurate MAGPRO 99.0 70.1 4.54 3112 98.5 61000 12774 1.249 !DANGEROUS LOAD-DO NOT USE!
ReloadSwiss RS 70 94.1 66.8 4.33 3110 100.0 61000 11804 1.232 !DANGEROUS LOAD-DO NOT USE!
IMR 7828 SSC 97.6 66.8 4.33 3109 99.6 61000 12233 1.231 !DANGEROUS LOAD-DO NOT USE!
IMR 7828 103.1 66.8 4.33 3109 99.6 61000 12233 1.231 !DANGEROUS LOAD-DO NOT USE!
ADI AR 2213 98.6 66.4 4.31 3097 99.5 61000 12144 1.228 !DANGEROUS LOAD-DO NOT USE!
ADI AP 2214 102.6 71.0 4.60 3095 99.7 61000 11984 1.226 !DANGEROUS LOAD-DO NOT USE!
Raufoss RA15 98.9 66.6 4.32 3091 99.9 61000 12079 1.248 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-22 98.9 66.6 4.32 3091 99.9 61000 12079 1.248 !DANGEROUS LOAD-DO NOT USE!
Bofors RP5/NP ~approximation 98.9 66.6 4.32 3091 99.9 61000 12079 1.248 !DANGEROUS LOAD-DO NOT USE!
Bofors RP15 101.6 67.0 4.34 3090 99.9 61000 12102 1.248 !DANGEROUS LOAD-DO NOT USE!
Winchester WXR 101.6 67.0 4.34 3090 99.9 61000 12102 1.248 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N570 105.0 73.8 4.78 3087 95.9 54873 13695 1.296 ! Near Maximum !
Ramshot Magnum 98.9 71.8 4.65 3073 100.0 61000 11522 1.243 !DANGEROUS LOAD-DO NOT USE!
Bofors RP30 105.0 70.0 4.53 3067 99.5 57225 12511 1.288 ! Near Maximum !
Norma MRP 2 105.0 70.0 4.53 3067 99.5 57225 12511 1.288 ! Near Maximum !
Bofors RP5 NT ~approximation 102.2 69.5 4.50 3066 98.3 61000 12071 1.231 !DANGEROUS LOAD-DO NOT USE!
ReloadSwiss RS 60 87.7 61.3 3.97 3064 100.0 61000 10810 1.243 !DANGEROUS LOAD-DO NOT USE!
Rottweil R905 100.2 66.3 4.30 3062 99.2 61000 11876 1.247 !DANGEROUS LOAD-DO NOT USE!
ADI AR 2209 95.5 63.3 4.10 3051 99.9 61000 11478 1.236 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-19 96.0 63.9 4.14 3049 99.9 61000 11532 1.244 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-23 101.1 65.9 4.27 3043 100.0 61000 10829 1.259 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-17 86.7 60.6 3.93 3042 100.0 61000 10734 1.250 !DANGEROUS LOAD-DO NOT USE!
Elcho 17 86.7 60.6 3.93 3042 100.0 61000 10734 1.250 !DANGEROUS LOAD-DO NOT USE!
Bofors RP14 ~approximation 96.7 64.4 4.17 3042 99.9 61000 11453 1.244 !DANGEROUS LOAD-DO NOT USE!
PB Clermont PCL 518 92.3 63.5 4.12 3039 100.0 61000 11148 1.251 !DANGEROUS LOAD-DO NOT USE!
PB Clermont PCL 511 88.6 62.9 4.08 3036 100.0 61000 11062 1.251 !DANGEROUS LOAD-DO NOT USE!
Winchester 760 86.5 61.0 3.95 3035 100.0 61000 11103 1.252 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H414 86.5 61.0 3.95 3035 100.0 61000 11103 1.252 !DANGEROUS LOAD-DO NOT USE!
Ramshot Hunter 91.6 63.0 4.08 3034 100.0 61000 11047 1.252 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H4831 101.2 65.6 4.25 3029 99.1 61000 11482 1.241 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H4831 SC 97.3 65.6 4.25 3029 99.1 61000 11482 1.241 !DANGEROUS LOAD-DO NOT USE!
ReloadSwiss RS 62 90.0 62.9 4.07 3029 100.0 61000 10823 1.266 !DANGEROUS LOAD-DO NOT USE!
Norma 204 91.1 62.7 4.06 3027 99.8 61000 11260 1.244 !DANGEROUS LOAD-DO NOT USE!
Bofors RP4 ~approximation 94.1 62.7 4.06 3027 99.8 61000 11260 1.244 !DANGEROUS LOAD-DO NOT USE!
Raufoss RA4 94.1 62.7 4.06 3027 99.8 61000 11260 1.244 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-16 92.9 60.3 3.91 3025 100.0 61000 10593 1.259 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N550 88.5 60.3 3.91 3009 100.0 61000 10707 1.262 !DANGEROUS LOAD-DO NOT USE!
Somchem S385 96.1 64.8 4.20 3008 100.0 61000 10967 1.265 !DANGEROUS LOAD-DO NOT USE!
Norma URP 91.1 60.1 3.89 3008 100.0 61000 10574 1.259 !DANGEROUS LOAD-DO NOT USE!
Bofors RP19 ~approximation 91.1 60.1 3.89 3008 100.0 61000 10571 1.259 !DANGEROUS LOAD-DO NOT USE!
Alliant Reloder-33 105.0 75.9 4.92 3006 95.3 51177 13317 1.340
Somchem S365 92.8 61.5 3.98 3004 100.0 61000 10251 1.267 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H1000 105.0 69.2 4.49 3004 99.2 55336 11775 1.282 ! Near Maximum !
ADI AR 2217 105.0 69.2 4.49 3004 99.2 55336 11775 1.282 ! Near Maximum !
Winchester Supreme 780 94.9 66.7 4.32 3003 99.8 61000 10987 1.251 !DANGEROUS LOAD-DO NOT USE!
Accurate 4350 90.2 60.1 3.90 3002 100.0 61000 10528 1.278 !DANGEROUS LOAD-DO NOT USE!
Rottweil R904 95.0 62.4 4.05 3001 99.4 61000 11039 1.245 !DANGEROUS LOAD-DO NOT USE!
Bofors RP4 NT ~approximation 91.8 62.1 4.03 2998 100.0 61000 10766 1.257 !DANGEROUS LOAD-DO NOT USE!
IMR 4955 Enduron 98.6 63.9 4.14 2995 99.1 61000 11127 1.243 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N165 101.3 66.8 4.33 2994 100.0 61000 10744 1.256 !DANGEROUS LOAD-DO NOT USE!
Lovex S071 104.8 66.0 4.28 2990 100.0 61000 10600 1.282 !DANGEROUS LOAD-DO NOT USE!
Accurate 3100 99.1 66.0 4.28 2990 100.0 61000 10600 1.282 !DANGEROUS LOAD-DO NOT USE!
IMR 4831 95.6 61.0 3.95 2989 100.0 61000 10344 1.268 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori N160 101.4 64.8 4.20 2983 99.4 61000 10843 1.248 !DANGEROUS LOAD-DO NOT USE!
Lovex S070 91.1 60.0 3.89 2982 100.0 61000 10563 1.264 !DANGEROUS LOAD-DO NOT USE!
Somchem S361 94.1 66.8 4.33 2971 99.0 61000 10862 1.256 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H380 84.4 57.5 3.72 2970 100.0 61000 10231 1.264 !DANGEROUS LOAD-DO NOT USE!
Rottweil R907 89.2 58.4 3.78 2967 100.0 61000 10461 1.256 !DANGEROUS LOAD-DO NOT USE!
Bofors RP7 89.2 58.4 3.78 2967 100.0 61000 10461 1.256 !DANGEROUS LOAD-DO NOT USE!
IMR 4007 SSC 86.4 58.4 3.78 2966 100.0 61000 10454 1.256 !DANGEROUS LOAD-DO NOT USE!
Hodgdon Hybrid 100V 93.5 60.3 3.91 2959 100.0 61000 9763 1.261 !DANGEROUS LOAD-DO NOT USE!
ReloadSwiss RS 80 105.0 75.9 4.92 2959 95.2 48607 13151 1.369
Hodgdon Retumbo 105.0 70.4 4.56 2959 100.0 48892 12134 1.360
ADI AR 2225 105.0 70.4 4.56 2959 100.0 48892 12134 1.360
Lovex S065 90.1 58.7 3.81 2956 100.0 61000 10153 1.263 !DANGEROUS LOAD-DO NOT USE!
Bofors RP3 84.4 56.9 3.69 2947 100.0 61000 9841 1.278 !DANGEROUS LOAD-DO NOT USE!
Norma 203 old 84.4 56.9 3.69 2947 100.0 61000 9841 1.278 !DANGEROUS LOAD-DO NOT USE!
SNPE Vectan SP 7 79.8 57.0 3.70 2945 100.0 61000 9894 1.265 !DANGEROUS LOAD-DO NOT USE!
Rottweil R903 86.3 56.9 3.69 2943 100.0 61000 9760 1.278 !DANGEROUS LOAD-DO NOT USE!
ADI AR 2218 105.0 74.5 4.83 2942 93.3 48220 13404 1.361
Somchem S355 86.6 56.5 3.66 2941 100.0 61000 9786 1.270 !DANGEROUS LOAD-DO NOT USE!
IMR 7977 Enduron 103.1 68.0 4.40 2940 93.5 61000 10891 1.246 !DANGEROUS LOAD-DO NOT USE!
Lovex D100 105.0 75.3 4.88 2907 90.8 55710 11377 1.304 ! Near Maximum !
Accurate 2520 78.1 54.9 3.56 2905 100.0 61000 9259 1.282 !DANGEROUS LOAD-DO NOT USE!
Lovex D073.6 79.9 54.9 3.56 2905 100.0 61000 9259 1.282 !DANGEROUS LOAD-DO NOT USE!
Accurate 4064 83.7 54.6 3.54 2893 100.0 61000 9221 1.301 !DANGEROUS LOAD-DO NOT USE!
Vihtavuori 24N41 105.0 74.5 4.83 2887 88.2 50910 11916 1.340
Accurate 2460 75.2 54.0 3.50 2884 100.0 61000 9074 1.281 !DANGEROUS LOAD-DO NOT USE!
Lovex D073.5 75.5 54.0 3.50 2884 100.0 61000 9074 1.281 !DANGEROUS LOAD-DO NOT USE!
Norma 217 105.0 68.9 4.47 2873 99.0 43777 12296 1.449
Rottweil R901 79.8 50.5 3.27 2868 100.0 61000 8944 1.281 !DANGEROUS LOAD-DO NOT USE!
Accurate 2495 78.7 51.3 3.32 2861 100.0 61000 8880 1.308 !DANGEROUS LOAD-DO NOT USE!
Hodgdon H870 105.0 72.3 4.68 2849 94.5 43716 12536 1.445
Vihtavuori N170 105.0 69.2 4.49 2846 93.0 50742 11307 1.374
Alliant Reloder-50 105.0 75.7 4.90 2814 91.3 41677 12849 1.498
Bofors 12,7mmRA NC1214 Lot20115087 105.0 74.0 4.80 2751 83.1 43705 11908 1.499
Hodgdon US 869 105.0 74.5 4.83 2696 84.4 41646 11146 1.483
Hodgdon 50BMG 105.0 71.0 4.60 2694 80.1 41824 11129 1.477
SNPE Vectan SP 13 105.0 71.5 4.63 2644 88.7 38350 10949 1.547
Accurate 8700 105.0 73.0 4.73 2620 87.8 37453 10919 1.552
Vihtavuori 20N29 105.0 75.3 4.88 2598 84.4 36274 10992 1.586
PB Clermont PCL 513/520/9520 105.0 71.5 4.63 2579 85.7 36001 10659 1.590
NC A3502 ,test only 105.0 68.5 4.44 2373 61.2 33121 8417 1.643
TLP A 502(RH) ,test only 105.0 68.5 4.44 2350 65.8 31196 8825 1.687
V1734 7-multiperf ,test only 105.0 68.5 4.44 1686 30.3 17221 4146 2.193
 

jimbires

Handloader
Aug 16, 2011
2,412
255
RL23 will get you about 3050FPS

IMR7977 will get about 2940 FPS

hybrid 100v will get about 2960 FPS
 

SJB358

Ballistician
Dec 24, 2006
31,254
419
ReloadKy":ooyhqm4y said:
Thanks for the responses. I had stated earlier in a previous post that I wanted to find a powder that could get me to shoot a 150/160 gr around 3100 in the 7 mag. I have since collected some R23, IMR 7977 and Hybrid100V. I have already tried a group with the R23 well below max and pushed that 140 SGK 3100 fps. I do not plan to use the rest of the box of sierra bullets so I was using them to experiment with powders. I guess I need to experiment with powders using a 150/160 gr bullet to get best options.

The RL23 and 7977 would be where I look first with 150's myself.
 

mjcmichigan

Handloader
Dec 26, 2016
2,263
21
Don’t forget. You could have a batch of powder that’s plus or minus 10%. All the Quickload projections are assuming on spec. That’s why they caution you. You need to work up to loads always.

If I duplicated someone else’s recipe, there are two big wild cards.

1) not the same barrel
2) probably not the same batch of powder.

BTW, I love that QL report. If you have a goal like 3100 FPS, you can improve your odds of achieving it, with a lot less hunting and pecking for the right combo!


Sent from my iPhone using Tapatalk
 

Songdog

Handloader
Apr 6, 2009
878
2
160s at 3100, out of a 24” barreled 7 Rem Mag..... is definitely pushing it.

I’ve run 160 Accubonds out of the 7 RM at 2975-3025 or so with anything from I4350 to Retumbo.

For what it’s worth..... a 7mm 160 AccuBond at 3000fps, will absolutely hammer just about any big game animal that’s in the same zip-code as you.... I’ve seen it.... more than a few times.

Frankly..... I can’t think of a better all-around NA big game slaying cartridge, than the 7 Rem Mag running 160 Accubonds around 3k.
 

ReloadKy

Beginner
May 13, 2020
234
34
Thanks for the quickload info and all of the comments. I have not been able to find any 160 gr accubonds or partitions. I do have some 162 gr ELDX on the shelf that I do not really plan on hunting with. So I have loaded up some mid range charges with R23 and IMR 7977 to see where I will start. I am hoping that it will give me an idea if I can accomplish my goal with the components I currently have.
 

pharmseller

Handloader
Feb 13, 2012
502
5
ReloadKy":dvaj40or said:
Thanks for the quickload info and all of the comments. I have not been able to find any 160 gr accubonds or partitions. I do have some 162 gr ELDX on the shelf that I do not really plan on hunting with. So I have loaded up some mid range charges with R23 and IMR 7977 to see where I will start. I am hoping that it will give me an idea if I can accomplish my goal with the components I currently have.

My brother and I use R26 with 162 eldx in our Tikka 7mm Rem Mags with great success. Deer and elk die right freaking now. I actually switched from the 160 AB to the 162 eldx. I’m right at 3k FPS.

We also use the 150 eldx in our 7mm-08s at 2790 fps for deer when we want to avoid a kick. Great bullets in my experience.




P
 

ReloadKy

Beginner
May 13, 2020
234
34
Pharm, I actually have some 150 ELDX that I plan to try out in the 7-08. What powder are you burning for the 7-08 load?
 

300WSM

Handloader
Dec 24, 2011
395
0
That seems to be right on the money with that powder.

That's a very uninspiring powder for the 7 mag.. IMO.
 

pharmseller

Handloader
Feb 13, 2012
502
5
ReloadKy":3iqo75dl said:
Pharm, I actually have some 150 ELDX that I plan to try out in the 7-08. What powder are you burning for the 7-08 load?

It’s max, so work up.

R-P brass
150 eldx
46.2 grains Big Game
Winchester Large Rifle Magnum primer

Seating depth tests in 3 Tikkas found screaming accuracy at 2.156” and 2.183” measured using a comparator, from the ogive.

2790 fps, no pressure signs. Deer and elk.



P
 

TXbaldhunter

Handloader
May 12, 2007
271
11
I don't think you put enough powder in the 7mag.I can get 3200fps with 140gr bullets easy in the 7mag.I know around 65.0grs of IMR or Accurate 4350 will.I've done it with the right powder with 150gr bullets.Personally I like Reloader 26 for all bullet weights in the 7mag.This is my go to load.
 

Attachments

  • 7mag 3.jpg
    7mag 3.jpg
    53.7 KB · Views: 471
Top