I usually use 250 grain nosler partitions in my 338-378 but in am wanting to try it on.whitetail long range .I.think the 300 grain.bullets are too much for deer but I.don't want to go.below 250/so I.don't burn out my.barrel quick .I.am thinking 250 grain nosler accubonds but I.tried them in.My 338 win mag they shot terrible .I.May have to cut the tips off to be able to seat them further out and try again but 3 inch 100 yard groups at 100 yards won't work .I.shot 1 inch groups at 300 yards with partitions with the 338-378 .I missed out on a huge whitetail at 300 yards with my 338 last year my 3.5x10 scope was not big enough for the shot .I bought 4x16x50 scope that will work..The 300 yard shot is a chip shot with the 338-378 .I have not used burger bullets .The Serria 250 grain boattail might be the ticket for 300-500 yards .

I'd just load a 225gn Hornady for that task.
In my .338/378 I used 103gn of H 4831 for 3200fps The 225gn Speer BT by comparison was very soft and made a bloody mess.

The 250gn Hornady also works well over 106gn of IMR 7828 for 3125fps. The same charge using the 250gn Sierra you mentioned dropped to just under 3100fps in my 26" Hart Barrel.
John

Oh boy!!
I made a mistake a few years ago in Az, I had a measly 2.5x8 with an M1 turret shooting a 55 nbt from my .223 at jackrabbits....I killed 3 in a row at 600 yds.....

For deer sized animals at 3 to 500y I would choose something smaller. But if you want to shoot your 338 way past that the 250 gr elite hunters is a very good option. Less recoil than a 300gr with a very good BC.

I use 250gr Sierra's in my 338 RUM at 3,050 FPS. Did a great job on a cow elk at 700 yards.

Your 3.5-10x? Was not big enough for a 300 yard shot? I'm sorry this is one of the funniest things I have read this morning. Guess I have to throw away my 3-10x 42 SHV, 3-10x40 Nikon and 3-10x 44 Sightron Siii and some Leupold 3-10X40's . All have been out to a 1000 yards on 10x10 steel plate.
My friend you need practice not a bigger scope, the tool you have should be more than capable of the task of which you speak. Also not meant to ridicule you in any way just saying.

I don’t shoot the big weatherby but do run a 338 RUM for elk and bears quite often. It has made kills to a shade over 700yds with either the 210 tsx at 3200 of the 250 scenar at 3050. It’s scope is a Leica 2.5-10 and I have never felt it inadequate for those shots.

Sure varmints at that range I would likely want more X’s and I certainly have heavier rifles with over 2 times as much magnification. But that said for hunting to +/- 700yds and steel out to 1k a good clear repeatable 9 or 10x upper end is more then enough to make solid hits.

This ^^^^^Also, not piling on. Practice..

missing that deer had nothign to do with scope and load.... Just saying.. keep shooting what you are, but learn to shoot better.

While I like bigger X on scopes often, 300 yards on a deer I can do with iron sights...

Until you can hit at 300 you have no business trying further.

And for longer shots, I"m going to try the 300 berger in my 338-378 some day....250s are almost on the light side for that round for longer shots.

A 250 grain Berger would do fine. Seat it out long, and you'll be good. If you need help, let me know!

Might also add that I used the 300gn Sierra BT Match bullet in the 2800-2900 range when it was first released.
The powders I used included original surplus 4831, IMR 4831, AR 2213 which is H 4831, AR 2214 which was slower and now discontinued and Reloder 22.

Killed a few animals with it too but a long range bullet isn't always designed for nor always used on game.

John

My Accumark is 10/1 twist same as my TRG 42 designed to stabilize 300 gr bullets Older TRG 42 had 11/1 designed for 250 gr Best to comfirm your rifling ratio. I have 3 rifles shooting 300 gr in 10/1 twist and they dont do so well on the 250 gr. Something too consider. Not painting with a big brush but it applies to those 3 rifles shooting 300 gr SMK bullets in 338 cal.

this Can’t be real. How many sock puppets can a guy have.

Wtf a sock puppet Frederick

youngman: learn to rest your gun on a board in your stand, or if your on the ground maybe a tree branch,fench post, lay down use your pack ,best is lay down if you can and use a bi-pod. but during the off season practice with these methods and other methods too. that 3x10 will do you just fine and believe me we all have missed deer sometimes even closer.good luck,Pete53