I have been reloading rounds for my 7mm Rem Mag for an upcoming elk hunt. I'm using 160 grain Accubonds, IMR 7828 SSC powder and Federal 215 primers. My rifle is a Tikka T3X with a 24" barrel. The Nosler book indicates a max load of 64 grains of this powder should deliver 3014 fps, but this load only delivers 2900 +/-. I have worked up in .5 grain increments to 65.5 grains and the load is still only delivering a maximum velocity of 2960 fps, according to my chronograph. I am hoping to reach about 3000 fps - mostly just because that is the target velocity that I set for myself, but also because it seems that many agree that this is a good velocity for this bullet. I'm happy with the accuracy of the load at 65.5 grains and probably won't change the load before my hunt, but I would like to know much more powder I can safely add to my load to try and reach my 3000 fps target? It's probably splitting hairs, I know. I'm new to reloading and shooting generally. Thanks for your input.
7mm Rem Mag 160 grain Accubond load
- Thread starter calebnm
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DrMike
Ballistician
- Nov 8, 2006
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Welcome to the forum. That is a great question.
Did you use exactly the components listed in the Nosler recipe? Know that lot-to-lot variation will introduce some variation in muzzle velocity as well. There are other variables introduced in different firing systems that aren't immediately apparent. The difference in velocities will have minimal effect on game for most hunting situations. You can work up to the higher velocity by working in small increments of charge for your powder, watching for signs of excessive pressure. However, only you can determine if the extra propellant and time is worth the effort. Also, as I previously stated, the difference in energy delivered to game will likely prove insignificant.
Did you use exactly the components listed in the Nosler recipe? Know that lot-to-lot variation will introduce some variation in muzzle velocity as well. There are other variables introduced in different firing systems that aren't immediately apparent. The difference in velocities will have minimal effect on game for most hunting situations. You can work up to the higher velocity by working in small increments of charge for your powder, watching for signs of excessive pressure. However, only you can determine if the extra propellant and time is worth the effort. Also, as I previously stated, the difference in energy delivered to game will likely prove insignificant.
Looking for a stable and repeating load is the best goal, whether it’s 2850 or 3100 or anything between. I have to remind myself of this fact!
Never had an issue with those bullets, concerning precision or performance on game.
Do you have a magazine length restriction on your overall cartridge length?
Never had an issue with those bullets, concerning precision or performance on game.
Do you have a magazine length restriction on your overall cartridge length?
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- #4
Thanks for the reply. Is .5 grain too big an increment for a gradual increase, in your opinion? What would you suggest?
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- #6
I believe the magazine length is 3.34". I was setting up my rounds at 3.290", as per the Nosler book.
- Nov 4, 2004
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Taylor the load to your rifle and it's accuracy. The speed doesn't matter. If you are at 2960 fps with acceptable accuracy, call it good and go hunt.
FWIW, my wife shot a bull moose with her 280 AI and a 160 gr PT at 2950 fps. She put 3 into him at 262 yards and dumped him. Two of the three 160 gr PTs blew right through him.
Trust me, you have a powerful load as is.
Welcome to the forum.
JD338
FWIW, my wife shot a bull moose with her 280 AI and a 160 gr PT at 2950 fps. She put 3 into him at 262 yards and dumped him. Two of the three 160 gr PTs blew right through him.
Trust me, you have a powerful load as is.
Welcome to the forum.
JD338
DrMike
Ballistician
- Nov 8, 2006
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This.
I agree with what JD338 said. My normal elk rifle is a .35 Whelen running 225 gr. TSX bullets. I always bring a spare rifle just in cast something goes wrong with my primary rifle. ch was the casr a few years ago and ghe back up rifle was a Mauser custom in 30-06 running 165 gr. Nosler accubobs. Shot just happened to be about one hundred yards but one shot and the work began. Your current load will work just fine. I doubt an extra 100 FPS one way of the other will make any difference. Go forth and slay an elk in confidence.
Paul B.
Paul B.
DrMike
Ballistician
- Nov 8, 2006
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I should think 0.5 grain increments would be safe. Five percent of sixty-five grains is slightly more than three grains At five grains, you're only increasing in seven percent increments. QL projects that you have room to increase your charge.
Code:
Cartridge : 7 mm Rem. Mag.(SAAMI)
Bullet : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 72.299 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 : IMR 7828 SSC
Predicted data by increasing and decreasing the given charge,
incremented in steps of 1.0% 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
-10.0 87 59.85 2719 2626 42982 12213 95.5 1.385
-09.0 88 60.52 2750 2687 44432 12357 96.0 1.364
-08.0 89 61.18 2782 2750 45936 12497 96.5 1.342
-07.0 90 61.85 2814 2813 47492 12631 96.9 1.321
-06.0 91 62.51 2845 2876 49105 12761 97.3 1.301
-05.0 92 63.18 2877 2941 50774 12884 97.7 1.280
-04.0 93 63.84 2909 3006 52507 13003 98.0 1.260 ! Near Maximum !
-03.0 94 64.51 2940 3071 54297 13115 98.4 1.241 ! Near Maximum !
-02.0 95 65.17 2972 3137 56161 13221 98.6 1.222 ! Near Maximum !
-01.0 96 65.84 3003 3204 58093 13321 98.9 1.203 ! Near Maximum !
+00.0 97 66.50 3035 3272 60095 13415 99.2 1.185 ! Near Maximum !
+01.0 98 67.17 3066 3340 62172 13502 99.4 1.166 !DANGEROUS LOAD-DO NOT USE!
+02.0 99 67.83 3097 3408 64323 13583 99.5 1.148 !DANGEROUS LOAD-DO NOT USE!
+03.0 100 68.50 3128 3477 66567 13656 99.7 1.131 !DANGEROUS LOAD-DO NOT USE!
+04.0 101 69.16 3160 3547 68894 13723 99.8 1.114 !DANGEROUS LOAD-DO NOT USE!
+05.0 102 69.83 3191 3617 71311 13782 99.9 1.097 !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 97 66.50 3113 3442 66520 13243 100.0 1.136 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 5% relative to nominal value:
-Ba 97 66.50 2942 3075 54099 13374 97.0 1.240 ! Near Maximum !You won't gain as much velocity as you might imagine. It is impossible to predict whether accuracy will improve or not. As I read your initial post again, I note that you don't state your standard deviation and/or extreme spread, which may give an indication of whether the effort will net you enough potential to justify the effort. As JD338 said, a 160 grain AB at a muzzle velocity of 2950 is a great load. I have taken a number of moose, elk, black bear, mule deer, and whitetail with my 7RM firing at "only" 2900 fps! I don't recall any walking away from a well-placed shot.
- Thread starter
- #11
Thanks for the info! I'll keep the load as is and hopefully shoot an elk next weekend.
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- #12
Thanks!
- Thread starter
- #13
Thanks!
- Nov 4, 2004
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Have confidence in your load. Put the 160 gr AB where it needs to go and you will put an elk in the freezer.
Best of luck to you and post some pictures of your hunt.
JD338
I’m with the others. 160 AB leaving the muzzle over 2800 is well suited for elk to 500 yards if it’s accurate. It’s a great bullet. Many elk have been packed cause if it’s effectiveness for our group.
Matter of fact one of our creep is creeping around Oregon right now with just such a load in his 280 Imp. I have no doubt it’ll work.
Matter of fact one of our creep is creeping around Oregon right now with just such a load in his 280 Imp. I have no doubt it’ll work.
Math Teacher
Beginner
- Jan 31, 2017
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My three friends and I used the 160 grain AccuBond from our 7mm Mags at an average of 2950 fps to take 23 moose. It will certainly work on an elk and has. When IMR7828 first became available, Finn Aagaard wrote an article in the American Rifleman listing loads for the then new to handloaders powder. Remington had been using it in factory loads for a while. I still have that issue. Finn listed the maximum load for the 160 grain in the 7mm mag as 71 grains. I worked up to 70 grains without any apparent excess pressure, but when several sources later listed 64 grains as maximum, I decided the angels had been looking out for a fool and switched to Reloader 22 which gave the desired velocity. I don't try to outguess pressure tested and published data.
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velocity from virgin brass is usually slower than after the brass has been fired and sized to your chamber . it's hard to say how much difference there is . all you can do is use the same load in your fired brass and check the velocity .
if you're pushing the pressure , you will shorten the case life , the primer pockets will get loose in a few shots . unless you are using premium brass that will take the abuse .
if you're pushing the pressure , you will shorten the case life , the primer pockets will get loose in a few shots . unless you are using premium brass that will take the abuse .
CALEBNM,
How did your hunt go? How was the performance of the 160 grain Accubonds? I am eyeing the same exact set-up for an elk hunt. Tikka T3X in 7MM Rem Mag so any information you can share would be appreciated.
Were you achieving sub-MOA accuracy?
I do question this comment. "I don't try to outguess pressure tested and published data." Please, do not misunderstand me. Factory ammo is loaded to a Maximum Average Pressure. (MAP) You can bet your bottom dollar that factory ammo will most of the time not even come close. Just a CYA thing by the ammo companies. Certain cartridges are deliberately underloaded, some because older gun are considered too weak for modern pressures and some by the ammo maker so that certain model guns aren't "overworked by too high pressures. Cases in point, no pun intended, the 7x57 mauser due to old rolloing block rifles and thr 93 and 95 Mausers all being too weak. I'll agree on the rolling block but wonder about those Mausers. I run 7-08 data in three modern 7x57 rifles with great accuracy apparent low pressure and long case life. Then there are the .280 Rem. and .35 Whelen, both loaded to an MAP pressure no greater than the 30-06. Funny thing the pump and auto loaders Remington makes are also chambered to the .270 Win. which runs roughly 10KPSI higher in pressure. So why did Remington handicap the .280 and .35W ???
A few years back I ran a velocity test between the .308 Win. and .30-06. Both rifles had 22" barrels. The .308 was 20 FPS faster than the 30-06. The only time the 30-06 came close to the advertised speed of 2700 FPS was when I ran some through a rifle with a 26" barrel.
It all goes back to the MAP allowed by SAAMI. Remington requested SAAMI to restrict the MAP for those two cartridges for a reason. My thought is it had to do with their pump and seni-auto guns as do several people I know. I load the .280 closer to .270 levels and can run a 160 gr. bullet to 2910 FPS. That's reaching into 7MM Mag territory and case life is very good. Pressures appear normal. I run a 225 gr. bullet from the Whelen at 2700 FPS again with great case life and no pressure problems. In that velocity test I used factory Winchester 180 gr. Power point ammo. I can run a 180 gr. bullet from a Remington M700 to a hair over 2800 FPS with reasonable case life and decent accuracy. Pressure is probably in the realm of the .270.
Remember, SAAMI sets the rules for industry MAP on a cartridge and sometimes ammo makers dictate to SAAMI what they want that MAP to be. Reloading manuals are required to stick to those mandated pressures. Personally, I prefer to experiment to see just what a certain cartridge can do. I do not go about it in a hap hazard way. I use a chronograph and monitor the speed of each individual shot and note any deviation from the normal linear increase in velocity. An abnormality in the increase usually indicates a max has arrived for that particular powder and it's time to back off a bit.
I do not advocate exceeding load data as being a good idea but I am exceedingly curious as to just how much more a cartridge can do, especially with the newer powers and bullets.
Paul B.
