so if your friend was looking at having a custom rifle built but couldn't decide on a caliber, what caliber would you recommend? he is a 90% whitetail deer hunter, his shots range from 100-350 yards and would like it to also be able to handle elk if he got the opportunity to go. he is torn between a .270 or 300WSM.

The easiest way is to work the problem backwards. Start with the bullet/bullet weight you want to shoot, and how fast you want it going. Then select the cartridge based on that. You also have to consider the rifle and magazine system to make sure the desired bullet will fit and feed in the rifle you are building with adequate barrel twist. The options are too wind open to list for one choice. There are many good ones.

I would go in the middle with a 270 wsm

Of those, I'd go 300.

I have a 270 wsm. It shoots great and seems like a hard hitter. But finding brass or ammo is more difficult from what I can tell.

Taking the time and making the investment to build a custom rifle begs for something he'll get the most use out of. You say he's torn between the .270 (I assume Winchester) and the .300 WSM...ok, since you say he's a "90% whitetail hunter", he might ask himself which of his two preferred options makes a better "90% whitetail" cartridge. I'd say that's the .270...

So what about the "10% or less" elk hunting? That same .270 will do just fine with a good bullet in a good spot...not at all unlike a whole lot of other calibers.

But since building is a "want to" and not a "need to" endeavor, he ought to build whatever blows his skirt up.

My two cents anyway...free advice usually being worth what you paid for it!

Mark

Both would do fine for what he is wanting. If I only had to choose between those I would go with .270 mainly because I like to have the extra round in the magazine. If I was having one built I would pick something in 7mm.

If he was my friend, I'd tell him to get a 308 Win.

Hard to beat the 7 Rem Mag. If he goes with a lightweight rifle, put a brake or suppressor on it and/or shoot reduced power loads for the whitetails. Another question that needs to be asked is does he plan to shoot factory or handloads? Handloads open up a lot more options IMO.

Custom rifle with that application, I'd look at 6.5 PRC, 7mm-08 AI, 7mm WSM, .280/AI, maybe .270 WSM. If you can afford a custom rifle, you can afford the ammo. Have Chad or FJG build a load for it and buy enough components to load at least 100, maybe 200 rounds.

If I had a friend that was into rifles enough to build a custom, I'd tell him I can't make that decision for him. Selecting a caliber and parts for a custom is like deciding to propose to a girl. That's something you do for yourself and it does matter what anyone says about it.
I have a friend with a 284WIN in a long action. He pushes 175grs quite nicely. That would kill his 90% deer, elk, and pretty much whatever else he wants to hunt. Then again, there's 50-150 others that do the same thing. Personally, I'd use my 708AI. I'm confident hunting to 600 yards with a 162gr. Elk, deer, hogs at 300-400 yards, no problem. I think practice is more important than caliber selection.

7mm-08 A.I. Magnums are not necessary for whitetail. But, if he had to have a short mag, 7mm WSM. As you can tell I'm a big 7mm fan, they do everything well.

And has been said, get a load worked up, and commit to 200 rounds minimum. Ammo made for that rifle is a third of the equation.

.300 WSM

I’m a fan of the 270, even though I don’t use mine much anymore. It’s always a good choice for a custom rifle, but being a reloader I’d go for something more uncommon, with an uncommon name. How about a 256 Newton? Or maybe look around in PO Ackley’s books and pick something interesting. Lots to choose from.

But...the 270 would be a good choice.

If he’s only gonna have one rifle, the 300WSM is not necessarily a bad choice. He can load light 150 grain loads (At .308 velocities) for deer and step up to 180 grain loads for elk.

280 ackley

Fireman built me a .280AI - best dang rifle I ever shot! I also have a 7-08AI he worked on. Love that one as well!

.280 A.I. is a great one between short action and magnum.

Brass shows up already in A.I. form. My notes show George's new 24" barrel had a 162 gr leaving at 2930 fps by the time I got the right load decided upon. It undoubtedly sped up from there. It was another one of those rifles I didn't want to hand over. Best thing there is in a .473" bolt face and long action. (Same action at .30-06 and .270)

If only those 2 I would 300

I used to have a 6mm AI and regret selling it, a 280 AI is high on my list to own.

Do all caliber, is 30’06 if you can’t make up your mind, you don’t need anything special lol!

22CM

Alamo Precision in Hurst built this 6.5 PRC for me and I'll be hunting Muleys with it in New Mexico starting on Saturday. Elk would be no problem with the right kind of bullets!!





3 shots with Chad's (Dallas Reloads) ammo

7Sherman Short Mag. Guys are pushing 168’s at 3000 FPS from a 22 inch barrel, that’s salty. 24’s are hitting 3050-3100fps.

Same 22 inch barrel is seeing 2920-2940 with 180’s

Oh, and it’s shorter than 7SAUM, 180’s easily clear a 300WSM magazine, and it’s a short action

Typical overkill.........7mm08 would be my choice, easily for the criteria you listed.

I’m doing this now....APR is building me a 300 WSM. My use is primarily deer/pigs. My 6.5 Creedmoor rarely exits pigs, so I wanted to step up in caliber/speed to solve the problem.

This is going against the grain for all of the long range guys....but the plan is to push 110-130 TTSX’s at warp speed. I know I’ll get massive terminal damage, a pass-thru & virtually no hold-over out to ~400 yards. Kinda like a souped-up 257 Weatherby with the ability to run heavier bullets if needed.

I could care less about weight, and for 95% of Texas deer blind hunters, I simply don’t understand the fascination with ultra lightweight rigs. I can lug 12-13 lbs 100 yards from the SxS to the blind with ease.

Specifically those two only....270 wide variety of bullets and broad off the shelf availability. They can be loaded to be very explosive or penetrating depending on your preference because they carry speed, especially those ranges.

Having said all of that, there are a ton of great calibers above mentioned but I assume he’s narrowed it down and looked at those...if he hasn’t, he needs to.