Help me decide caliber for new build

[Dhughes]

I have a mule deer hunt coming up this fall and I'm thinking about building a new gun for it. I was set on a 7/300 win mag, but talked to my smith and he said he would just go with a 284. So now I can't make up my mind. I don't have anything for the build yet so I can go to any caliber. I was thinking about the 7mm for the high bc bullets and would plan on running the Berger 180 or the 195 when it comes out. Give me some opinions on what you think would be a good round to go with. Here's a few calipers I already have.
30-378 weatherby mark v
260 lrp savage
25-06 700 bdl
6x47 lapua custom
And some 243's

Thanks in advance

 

[barnesuser28]

I have a mule deer hunt coming up this fall and I'm thinking about building a new gun for it. I was set on a 7/300 win mag, but talked to my smith and he said he would just go with a 284. So now I can't make up my mind. I don't have anything for the build yet so I can go to any caliber. I was thinking about the 7mm for the high bc bullets and would plan on running the Berger 180 or the 195 when it comes out. Give me some opinions on what you think would be a good round to go with. Here's a few calipers I already have.
30-378 weatherby mark v
260 lrp savage
25-06 700 bdl
6x47 lapua custom
And some 243's

Thanks in advance

I am building a 284 win right now with a 24" barrel i SHOULD be able to get the 195 berger around 2530 fps max, and 180s at around 2680. But my primary bullet will be the 162 grain A-Max at about 2850 fps. This gun will be used for deer/antelope out to 100 yards. Run the ballistic and decide if these external ballistics meet your needs.

Riley

 

[MudRunner2005]

.280 Ackley Improved 40* gets my vote.

 

[Dhughes]

What will the 280 AI move a 180 at?

 

[barnesuser28]

they are almost ballistic twins, but the 280 A.I. will net you another 50-75 fps. The advantage with the 284 win though is that you are able to seat the 195 berger with the boattail shank junction above where the donut in the case would form and still have about .1" left in the mag of a LA savage 110 weather warrior is my calculations are correct. (they should be fairly close)

 

[MudRunner2005]

What will the 280 AI move a 180 at?

Not sure about the 180's.....I will be shooting 160 Accubonds once I get my build under-way. So far it's just a pipe dream.

 

[Truc]

You def need a 7mm, if the 7/300 Win Mag is what you want go for it, but be ready to buy the reamer. I built a 7 SAUM for myself and had seriously consider the 7/300 but personally I like short actions so.....
Since the 7 SAUM does well at 1000 yd Benchrest I figured it should do well hunting and it will add 100 fps over the 284

 

[Dhughes]

Another thing that the 7/300 had going for it, is that I just traded for 200+ pieces of 300 win brass. That still isn't a deal breaker though, because I would like to build one of them someday too.

 

[Rimfire]

If you want a 7mm, the 7-300 is a great cartridge as is the 7rm. In a short action I would look at the 7 RSAUM.

 

[MudRunner2005]

7mm STW is also an excellent one to look into. I have had mine for 11 years and it is a shooter. You can get some pretty hot and nasty ballistics out of one, too.

I don't have a Chrono, but I loaded up some 180 Berger VLD Match Hunting bullets to see how well they'll group with the loads I loaded up. I have a feeling I will be needing more 180's after I run out of these 12 I have. I will let you know how they shoot once I get a chance to. I wasn't able to last weekend like I had planned, but I should go this weekend. Wish I had a chrono so I could give MV.

 

[Dhughes]

The 7 rem mag was another thought. I would probably just buy one in a sendero and (hopefully) be done with it except bedding. I was also told that some of the local guys never could get there 7/300's to run. What about the 7lrm?

 

[MontanaRifleman]

7 Dakota, the brass is a little spendy but it's good brass and a great cartridge

 

[fmajor]

I've gotta add another vote to the 7mm/300 chambering.

There are so many great reports of this cartridge it's hard to fault. Also, there are many great smiths who post here, i'm *sure* one could get a 7/300 tack-driver all set up for you.

It looks like you have a .30cal hammer in the .30/378 so that's another good reason for a 'middle' caliber.

After using a 300 Win for a few years (plus my 7RM), i've really come to appreciate the 7mm. My 7RM ADL anchored a mid-sized whitetail for me at 520 years ago and i thought going bigger (to 300 WIN) would be better bringing even more hammer to the game. However, i found i never really needed the extra horsepower and sold my 300 WIN....

Bryan Litz wrote an article on 7mm vs .308 right here. It's a great read and has helped my thinking/planning a lot.

Like you, I'm also planning a build and trying to decide btw simply updating my current Rem700 in 7RM or splashing out and buying a donor action, re-barreling and going with the 7mm/300. I have 300+ new Winchester 300WM brass cases so i could be reloading for a lonnnng time w/o buying brass (a convenient savings in this day and age).

Honestly, you have some great horse-power in the stall right now, but it's always fun to add another!

 

[Dhughes]

That was a good read. I've got some more reading to do before I make a decision. I still think that it will take something in a magnum case to do what I want. I don't think a 284 pushing a 180 at 2650 will cut it. I'm thinking the 7/300 the 7 dakota maybe an STW or a lazzeroni. Which ones will I run out of room in a Remington 700 mag action with a detachable bottom metal? I don't want to get something built and have to run it as a single shot to make it shoot.
Thanks for the advice so far and keep it coming.