7mm Mag 139 vs 162 grain

[JShirley]

I was planning on buying 162-grain AMAX for my 7mm Magnum, but I've found a terrific sale on 139 grain poly-tipped BT bullets. How much range will I lose if I go with the 139s instead of the 162s?

Powder and primer suggestions? The only rifle powder I have right now is 8208 XBR.

Thanks,

John

 

[powell&hyde]

Here is an online calculator for trajectories. http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

 

[jwrowland77]

In my 7mm rem mag I use CCI LRPM (I believe it's #250).

As far as powder I like IMR4350, and I have a little bit of IMR7828 I'm going to try. I will probably end up buying more of both he IMR4350 and IMR7828.

 

[Clark]

7mmRM is the champ for hunting in my book.

I zero at 200 yards and do not want to correct more than 8 moa.

That would put the 139 out there at 625 yards and the 162 at 575 yards.

Seeing how I can't hit kill zones with reliability beyond 500 yards, either one would work for me out to 500y.

Both HAVE worked for me.

It is H4350 for me in that cartridge now.

 

[Skyshot]

Are you going to punch paper or shoot critters? My pet hunting load is a 160 grn. Nosler Accubond with IMR7828 seems to do best at around 62.5 to 63 grns. between 2800 and 2900 fps. I can push the 160's over 3000 fps with 7828 but I drives nails at around 63 grns. I couldn't get the 162 Amax to group very good in my model 700 but the 139 grn hornady's shoot great with a charge of 65grns of IMR4831.

 

[JShirley]

Thanks for the responses.

I want to be accurate at distance, which will require a lot of practice. BUT I plan to hunt with the rifle, as well.

 

[JShirley]

P&H, the calculator would only be helpful if I already knew what velocity to expect from each round. And if I already knew that, this thread would be pointless.

 

[helotaxi]

Looking at several reloading manuals will get you an idea of the ballpark velocity that you could expect. Until you load them and shoot then in your rifle you won't have an exact answer.

 

[X-Rap]

IMO the 7mag shines brightest with bullets 160-170 gr. Thats not to say that 139 won't work, a buddy of mine wanted some 139 Balistic Tips loaded for an antelope hunt and they shot very well and he has taken antelope and deer as well with them but when he wants to move up he has to rezero to shoot the heavier bullets.
For distance I think some low drag bullet around 170 would be hard to beat as an all around.

 

[JShirley]

Okay, that helps. It'll be a little easier to get some of this information when I get back to the US.

 

[Zak Smith]

You want the higher BC of the 160+ gr target bullets if you intend to shoot at long range. 0.60 is a good bar to set.

 

[JShirley]

I assumed I did, but you know what they say about assumptions!

Thanks.

 

[helotaxi]

I missed the 8208 part of your original post. You'll need to invest in different powder that is much slower on the burn rate chart. H4831 is a good powder across the spectrum of 7 Mag bullet weights.

FWIW, I keep multiple different bullets on hand and usually have several loads worked up for each rifle. If you've got a line on a good deal on 139gn, I'd pick them up and develop a load for them. You might lose some effective range, but we're talking 500yds+ and they'll drop a deer as far out as you can hit him. The 162s are better in the wind and will carry more energy downrange, but they'll also have a little bit more recoil. The difference in recoil between 160gn Partitions and 140 Ballistic Tips is noticeable with my 7WSM. I have the 140s for deer and the Partitions for elk. I got a good price on a lot of the 140s so I use them for trigger time on the rifle. The fact that they recoil less is an added benefit.

 

[JShirley]

Yeah, at $.18/ea for the polymer tips 139s, I may get both. Doubt I'll be shooting past 400 meters for a while yet.

 

[gamestalker]

I run RL22 under a 139 gr. and it will deffinitely reach out there with plenty of of stopping power. I much prefer the lighter 139's over a 162 simply because they will shoot flatter and still have enough velocity out past 500 yds. to easily punch through a shoulder on deer and elk. Some would argue this statement, but I have used this reloading method for a very long time with the 7mm RM, and all my other pet cartridges with great sucess.

Regarding recoil, I kind of feel it more with the 139's though. I think because they are leaving the barrel at higher velocity might have something to do with the painful thump they give to my shoulder?
GS