7mm mag

[sask boy]

Hi Guys, I have been loading for the 7mm mag for 20 years but have always loaded 160s or there abouts. My nephew has been thinking about some long distance shooting with his. I am using IMR4350 and have 160 AB on top. The load is deadly under 1" moa (just under 3000fps.)
I was wondering if anyone has been playing with the 140gr AB and what kind of performance they are getting.
Would it be better to stick with 160 or try the 140 AB.

Blessings,
Dan

 

[wildgene]

...long range= 400-600, 600-800yds???

...I'd try pushing the 160's a little faster, maybe adj. your seating depth to garner a little more accuracy, but given the BC's of both, the 160's will probably retain better energy, & a flatter trajectory/ less wind drift @ longer ranges than the 140's even tho the 140's start out faster...

 

[sask boy]

wildgene, the accuracy is there as last loads I played with the OAL and we could cover with dime. But according to Nosler I am at max with 60grs of IMR4350.
Distances would likely be 500 yards & up as we have lots of flat land here in the prairies
I was thinking the same as you once you get out aways the heavier bullet would likely retain its BC somewhat better.

Maybe a different powder has anyone used reloader 22 or something that we can get more speed but still maintain reasonable pressure?
Blessings,
Dan

 

[Ridge_Runner]

shooting like that I would stick with that load and change the setup of the rifle, a leupold with a TMR comes to mind and learn how to hold for the longer shots. The load you have is an awesome load, but you can't make a 7 RM shoot as flat as an STW no matter what ya do. with 7RM class of cartridges about 450 yards is max range unless you dial, use a bdc, or some other form of compensation.
RR

 

[wildgene]

...I'd agree w/ RR for starters, but if you want to play I'd try RL-25 for a little more MV & better case fill...

...just what I have in front of me, some numbers comparing 145/ 160/ 175gr. Speer GrandSlams, cause that's what I've shot in my 7mmRM for a long time...

140gr @ MV 3100 500yd V=2000/ E=1291/ BD= -33.5
160gr @ MV 2900 500yd V=1996/ E=1415/ BD= -36.0
175gr @ MV 2800 500yd V=2051/ E=1634/ BD= -36.3

...don't have the windage right handy, but I can guarantee the lesser wind drift of the heavier bullets will more than compensate for the higher BD. Out to 400yds or so BC isn't that critical, as range increases the importance of BC increases. Once you know your loads, trajectory is fairly constant, wind drift is always proceeded by a cuss word...

...I also agree w/ RR about a consistent, repeatable sighting system. Once you start trying to aim @ a point in space above your target, it's almost impossible to shoot consistently...

 

[tyson22250]

When I had my 7mm rem mag, it sported a 26 inch tube, 700 action and price tag that was under 500 bucks, it was a used 700 sps dm :grin: . I worked up to healthy load 70.5 gr of retumbo with a 160 gr nosler AccuBond as well. It was a deer slayer, flat & hard hitting. I Chronied these at 3100 fps with no excess pressure! I Know you will never get stw performance but I wasn't that far off of factory loadings off the stw. I load for my brothers 7mm rem mag as well and it likes hodgon H-1000 and 160 accubonds. I think u could achieve 100 fps more with a slower powder like retumbo or H-1000 with same level of accuracy, plus I like knowing they are temperature stable.

 

[Guy Miner]

Dan, typically the heavier, longer, higher BC bullets are better at truly long range than the lighter faster bullets. This is certainly the case with the 7mm Rem mag. Most of the serious long range 7mm shooters make use of the 168, 175, or even 180 grain bullets.

The reason is really wind drift.

Drop is relatively easy to compensate for - a guy can run the ballistics on a computer anymore and generate useful "come ups" which should of course be verified, and modified if necessary, at the range.

Wind though... Wind is a bugaboo for long range shooters. Very difficult to judge accurately. Even a wind meter only helps so much.

The long, heavy, high BC bullets do a better job in the wind, with less deflection.

Your 160 gr load should actually work real well, even to 600 yards. Much beyond that, I'd recommend something more specialized, like the Berger VLD.

Regards, Guy

 

[JD338]

I agree with the others, I would stay with the 160 gr AB.
Maybe give RL 22 a try for a little more speed.

JD338

 

[sask boy]

Thanks guys, I think I am going to stick with the 160gr and play with RL22.
I will let you know how it works out.

Blessings,
Dan

 

[FOTIS]

You're definitely on the right track.

Let us know how it worked out for you.

 

[SJB358]

I am with the others, you have some speed to gain in the 7RM with a few other powders. Beyond that, it is all dialing from about 400 on out. Good scope would make that current load pretty deadly out to 600 without much hard work.. If you are looking to venture out for targets, the 168gr AMax seems to be a very likeable bullet.. At least in my first runs with it.

 

[Songdog]

162 Amax is the only way to go for LR shooting in the 7mm Rem.... sorry to say on the Nosler board. They'll buy you an extra .100+ in BC (and that's a LOT), and IME you can shoot them a little faster than the AccuBond (3k+ with a couple 26" barreled rifles going 3150). I've seen them kill a bunch of critters... and we've only recovered one bullet... out of a bear that got pole-axed at 500+ yards.

The 160 AccuBond is a good bullet no doubt, and I've seen it kill too... but the 162 Amax is the 160 NBT that every 7mm owner has been clamoring for over the last two decades... plus some.

 

[BK]

'dog, how did the one recovered bullet look? Did it hold together pretty well?

 

[Songdog]

Bear...

Bullet... weighed around 100 grains....

Shot was 500 something out of a 7mm Rem. started around 3k.

 

[baltz526]

The choice i made for my 7mm rem mag Is the 175gr sierra SPBT game king. I had no problem getting near 3000fps out of my 26" match barrel with RL22. Best accuracy was at 2900fps. I can drive a 160gr at 3050fps but the 175gr holds its energy better.