Heavy for caliber .308 loads

[Orcon]

Hey fellas, a friend who started loading his 30-378 WBY with 220gr ELD-X bullets wants me to try them in my .308. I laughed when he suggested it but he seems more than willing to let me shoot his bullets, so I'll give it a crack. I'm expecting pretty low MV outta the 20 inch barrel, maybe 2400 fps. I know MV isn't always as important as velocity retention at longer ranges but at some point there's got to be some diminishing returns, right?

Do any of you have experience with heavy pills in 308?

 

[Bart B.]

I shot a few Sierra 220-gr. HPMK's out of a 26" 1:10 twist barrel from .308 Win cases with IMR4350 producing sub MOA accuracy. Doubt their muzzle velocity was over 2500 fps as when I chronoed 200's in the same barrel at 2580 to 2600. I think I used 45 grains of IMR4350 under the 220's but 48 grains was standard for the 200's.

Your 20" barrel will shoot 220's pretty slow, but such bullets from 30-40 Krags dropped many an elk. Gotta get close to them to do well. Sneak up quietly then do it.

 

[Orcon]

Thanks for the info, Bart! I doubt I'll ever use these for hunting but who knows, I've always wanted an Alaskan moose hunt! This is mostly just for paper punching and to see how it does. Like I said, I am not paying for these bullets so what's a few primers and a couple ounces of powder?

 

[redbullitt]

Nothing wrong with 2400 or 2500 FPS. If they shoot well I would try it. I have chucked a few 208 amaxs. Always been happy with those at the expense of velocity. My 16 inch 308 does very well with them, and I prefer them to a 178 class bullet in the slow guns and/or short barrels.

There has been a bit done using slow powders like RL17 with the heavy bullets in 308. I believe the guy's handle is "montanamarine" over on snipers hide. A search should turn it up. He got surprising velocity out of the heavies. Not sure on the barrel length though. Definitely worth a look.

Yeah there are diminishing returns as with anything, but if you can deal with the drop it may do better in the wind. I have a feeling you might be pretty close to that point...

Maybe this will help.

2650fps 178 ELD 100yd 0
-59 inch 500 yd 10mph full cross wind 19 inch
-374.5 1000 yd 90 inch wind


2400 FPS 220 ELD 100 yd 0.
-70 inch 500 yd 10mph full cross wind 17 inch
-419 inch 1000 yd 81 inch wind

The heavier bullet is super sonic longer by a bit, but both are easily super sonic at 1050 yards still. The 220 does beat the wind a bit better the further out you go, but you would have to decide if it is enough.

I doubt the 220s would be worth the cost difference for me FWIW. Shoot up the free ones and get load data though! You never know if it could come in handy.

 

[Orcon]

Thanks for the info! I honestly would have no use for anything over 180 or maybe 190 grain match. I only reload for 308 and 300 wsm at the moment and I like way the 165 and 180s shoot. May save the data for a short range big game load though.

 

[jmr40]

I think the 220's are just a bit much for 308, especially with the longer bullets A shorter 220 gr RN wouldn't take up as much powder space. I have some 200's that I'm going to try and the 212's have the better BC's.

That said I read a post on another forum several months ago where a guy loaded some 215 gr Bergers to 2600 fps for a 22" 308. His load must have been well off the charts and bullets had to be loaded directly into the chamber they were so long. But he was shooting them at 1800 yards. The load didn't drop below 1500 ft lbs until 800 yards.

With the high BC's of that bullet you'd still have 1300 fps at 1000 yards if you CAN start them at 2400 fps. You'd still have 1500 ft lbs of energy to almost 550 yards. I'm just not sure 2400 fps is do able from a 20" barrel.

At any rate it wouldn't just be a short range load even if you come up a little short of 2400 fps. That is far more energy (200-300 extra ft lbs) than you'd get with 180's at that range. Bullet drop would be about 10" more ( around 70" vs 60" with a 100 yard zero). But nothing that couldn't be accounted for with a long range scope with dials.