7 Mag Question

tailchasers · Oct 16, 2015

The 7 mag is my go to caliber of choice and since we moved to the Rockies I have introduced my wife and 2 sons to big hunting as well. Both my boys shoot a 30/06 while the wife uses a 270 win and they have flat out laid the animals down. I on the other hand have had some issues...

We all shoot handloaded accubonds and are not at max loads but near. I shoot 140 grains, the 270 uses 140 grains, and the 30/06 is 180 grains. Over the years I have paid close attention to all three of the calibers and have seen the 30/06 and the 270 lay the animals down and do more terminal damage than the 7 mag at the same ranges which are typically at 200-400 yards. The 7 mag seems to blow right threw the animal without a large exist wound and terminal damage while also requiring more repeated follow up shots where the 30/06 and 270 do some real damage to the animal with few 2nd shots required still with complete pass through. (BTW I believe if the animal isn't down a follow up shot will be coming real soon).

For a shot out to 400 yards is the 30/06 and 270 more capable with the accubond than the 7 mag by meaning is the 7 mag pushing the bullet to hard and at these ranges ballistically less efficient than the other 2 calibers? My theory is leaning me to believe the slightly slower bullet is better at these ranges.

"Courage is being scared to death but
saddling up anyway."

Zeke · Oct 16, 2015

In a nutshell, NO!

There are too many variables for you to draw the conclusion that the 7mm mag doesn't do the "damage" inside 400 yards that the other two do. Especially with the bullets cited in your example.

Terminal performance is partially based on velocity and bullet construction... along with bullet weight and diameter but your citing is of diameters on either side of .284 and bullets with similar construction.

The faster a bullet impacts an animal, the MORE bullet upset / tissue displacement you'll experience. Not.. faster equals pass-through. The only way you'll experience less tissue damage from a faster projectile is if you blow the peddles off the "mushroom".

I think it's a case of too little cross-section in this study for you to draw a hard and fast conclusion.

There's my 2 cents,
Zeke

sageadvice · Oct 16, 2015

LAST EDITED ON Oct-16-15 AT 12:04PM (MST)[p]One of the main reason's that i switched to Accubonds going back several years now, is because Mtmuley here has had nothing but good to say about them with far more animals taken than the regular poster here.

Once i tried them myself and admittedly only 4-5 animals taken with them, i'm convinced that they are about as good as it gets in a all around bullet and am somewhat perplexed why you are getting great results with the slightly slower 270 and 06' rounds but not as good with your 7 MM Rem Mag.

My 270WSM and 280AL both love Accubonds and they way they core thru animals, flat puts their dik's in the dirt!

Both these cartridges, especially the way i reload for max velocities, are similar if not slightly exceeding your 7MM Rem Mag loadings. They're great for me but maybe not so good for you.

Possibly, if you feel serious about changing bullets, you may want to go to a bullet that opens even more on impact like the Hornady SST or Nosler Ballistic Tip for that 7 of yours. Good hunting!

Edit: Good Morning Zeke, Not trying to be contrary, thought i was the first to respond. I also agree with you, i'd stay with the accubonds. my 2 cents as well.

Joey

"It's all about knowing what your firearms practical limitations are and combining that with your own personal limitations!"

Zeke · Oct 16, 2015

Joey is correct.

I think OP has the right combination too. I'd stick with the AB's in all 3 cartridges too. Maybe go to the 7mm 160 AB for higher SD and BC just for giggles but that's splitting hairs.

The ballistic tip WILL produce more bullet upset and tissue displacement but the risk is lack of penetration on quartering shots on elk size game. I hate fragile bullets on elk!

We used the 150 BT in the 280AI and the 7mm Mag on Rocky bighorn and desert sheep this year with stellar results but the AB is a much better all around bullet and I'd use it on anything in NA, IMHO.

Zeke

mtmuley · Oct 16, 2015

Try the 160 in your 7mm. Some RL-22 should get you about 3000 fps. Kills stuff like crazy. mtmuley

tailchasers · Oct 16, 2015

LAST EDITED ON Oct-16-15 AT 01:13PM (MST)[p]So with what has been stated and after doing some quick research, my present bullet weight is on the lower side of the over all caliber performance scale as compared to the other 2 calibers with respect to weight, BC, and SD. Here are the numbers from Nosler;

7 mag = 140 gr AB, 3250 FPS, BC .485, & SD .248

270 = 140 gr AB, 2800 FPS, BC .496, & SD .261

30/06 = 180 gr AB, 2700 FPS, BC .507, & SD .271

By bumping up to the 160 gr AB the 7 mag bullet drops to 2950 FPS, BC of .531, & SD .283.

If I understand correctly the 160, on paper, appears to be a better choice as suggested offering better over all terminal performance?

So really the slower velocity of the other calibers is a moot point, as pointed out, as the bullet SD and BC are more of a factor and by increasing bullet weight the FPS will drop but with the higher SD and BC the caliber performance will likely improve.

Clear as mud!! LOL

"Courage is being scared to death but
saddling up anyway."

mtmuley · Oct 16, 2015

You can talk SD and BC all day long. Bottom line is on game performance. My close friend and hunting partner has been hammering critters, deer, elk, antelope and black bears with the 160 Accubond in his 7mm since they have been available. I can tell you after being a bystander, the terminal performance is excellent. Get a box. mtmuley

Cahunter805 · Oct 16, 2015

Like others have stated get a box of the 160gr accubonds and work up a load. Rl22 or imr7828 is what I'd start with.

completesportsman · Oct 16, 2015

I've had great luck with the 160gr Acccubond and RL22 in 7mm also, get some!

REDDOG · Oct 16, 2015

LAST EDITED ON Oct-16-15 AT 11:58PM (MST)[p]Cant really take a guy serious that feeds a 7 rem 140's, then talks ballistic tables..

Load some 150BT and shoot something,I bet you will fall in love with them..

The 160 accubond is excellent as well,so is the 160-175 partition. The 160 NP will give explosive results from shedding the front, and penetration from the rear.

If you want to see awe inspiring terminal performance load some 180 scenars.

tailchasers · Oct 17, 2015

You have to take me serious reddog as I am also "that guy" who pushed 110 grainers down the bore for an antelope hunt. Couldn't hit the side of a barn at 300 yards in windy Wyoming. Made for a good show on prairie dogs though on them rare calm days.

"Courage is being scared to death but
saddling up anyway."

Cahunter805 · Oct 18, 2015

Never can understand people's obsession with shooting ultra light bullets in big calibers.

mtmuley · Oct 18, 2015

>Never can understand people's obsession with
>shooting ultra light bullets in
>big calibers. Velocity of course. Speed kills right? mtmuley

tailchasers · Oct 18, 2015

All part of the fun with reloading with sometimes a little experimentation in order and the 110 grain ttsx was just that. Blazing fast and at close ranges did a wonderful job on antelope. I've used most of them loads on prairie dogs and coyote now. Accuracy was the best I have ever experienced with the rifle too out to 200 yards.

"Courage is being scared to death but
saddling up anyway."

Cahunter805 · Oct 18, 2015

>>Never can understand people's obsession with
>>shooting ultra light bullets in
>>big calibers. Velocity of course. Speed kills right? mtmuley

Of course it does! I'd rather shoot a big bullet and I've found most the time heavier bullets shoot more accurate.

DRD · Oct 26, 2015

The best info I have seen on this topic of terminal performance by caliber, bullett, etc, etc is written by a guy named Nathan Foster at Terminal Ballistic Studies. Go there and find more info from a guy who has been there done that 1000's of times. Emailed him personally about a question like yours years ago and he responded as well.

Pre64 · Oct 31, 2015

I agree with those who recommend the heavier ABs. I use 200s for elk and they don't disappoint. When a bullet passes through it takes much of its energy with it. Bullets that splash don't transfer energy to the vitals. Please stay away from ballistic tips, esp in a magnum round.