2nd the 350 legend

You could turn it into a 300 HAMR with a barrel change. And the gas block and tube. Everything else you could keep including the mags. I'm about to start testing mine with 150 gr. Hornady SSTs.

https://www.wilsoncombat.com/300-hamr/

"...Terminal performance testing on over 200 Texas feral hogs has proven it to kill much more effectively than the 6.5 Grendel, 6.8 SPC, 7.62×39 or 300 Blackout..."

The pigs were deader with the 300ham'r.

I believe Mad Dog Weapons Systems is your answer. There are a couple cartridges there that are extremely interesting if you reload. I'm a reloading newb and i think i can handle these. Their 6mm mongoose seems awesome and totally reasonable.

https://www.maddogweapons.com/

I have a home built 6.5 grendel and absolutely love it. I also think 6mm grendel would be a great choice.

This claim to fame has always made me giggle.

If your choice has to have factory ammo available the 6.8 is my choice. If not there are numerous wildcats on the market.

I just bought one of these in 7mm-08.

https://www.wilsoncombat.com/recon-tactical/

Put an Eotech Vudu scope on it.

I've had no problem ordering all the ammo I want from Wilson Combat. Very good prices no more expensive than the SSTs I order for my 6.8.

After a bit of study, I’ll look into a 6.5 Grendel.

One of my favorite calibers, even had a semi custom bolt action built in it on a CZ Mini Mauser action.

More energy at 400 yards than a 243 and trajectory about like a 308 with 165s. Look at some of Double Naught Spy's videos in the hog forum here. It works for sure. If yuo really want to see it shine on deer and hogs try some 129gr Accubond Long range bullets in it.

Some are switching from the 6.5 Grendel to the a couple wild cats off the same case, 22 AR and 6mm Grendel but for those you have to reload but for 603 we know that is not an issue.

Top 5 most capable AR-15 cartridges in my opinion.

I didn't know that there were 5 ar-15 cartridges

223/556
7.62x39
300BLK
6.5G
450Bushmaster
458Socom
6.8SPC
350 Legend
50Beuwulf (sp?)
300 HAM’R

I’m sure I’m missing some main stream and there are several more wildcats.

Well, there's not...

I'm sure it is effective. I just laugh at the "our stuff kills 'em deader" advertising.

I totally agree that it’s hilarious hype and as I look at these rounds like 6mm Mongoose and you have to laugh.
There is almost no performance improvement over the standard 6/223 that’s been around for 35 years ....but they do offer expensive brass and dies. It’s simpler just to neck up or down the 6.8 SPC and get same or better results which folks have been doing since the 6.8 came out.
Now that the 22 Nosler and Valkyrie are here I am sure the wildcatters will have some fun with them as well.
It’ s all good by me as that’s the American way of building a better mouse trap but when it’s hyped that way then it’s usually just that mostly hype.

.22 Nosler
.224 Valkyrie

It’s basically just a magnum 300BLK that needs a longer barrel to achieve the advantages over the 300BLK

Goes back to pretty much every cartridge. It will shoot X bullet at Y velocity, simple as that.

Then we look at what primer does it run, what case head size does it have, is the case geometry efficient, how is the brass life, do you have to fire form to get there?

Oh good grief......Run the Grendel. You’ll love it and won’t be happier.

AR's suk

I love it. Let's turn this into AR's vs AK's.

I ran an M4A1 through well over 5k rounds in about a week and a half and never cleaned it one time. Sand, dirt, grass, you name it. Not bench shooting by any means, about every kind of drill you can think of, couple of rainy days. Only malfunction in one instance- three times right in a row- until I realized I was covering the ejection port with my fingers, shooting prone. Out to 400 yards a man size silhouette is a given hit, 500 No problem, and can do it out to 600 pretty regular. Have hit further than that but you wouldnt believe me. Using nothing but regular 62 grain ball. Lets see a 7.62x39 or 5.45x39 AK do that at the same distance. Even the very best ak's can't touch it unless you step up to a much more potent cartridge.

This was with a "made by the cheapest bidder" service rifle...

But crap talk and jokes aside, better get you an ak or ar or something while the getting is good. The laws they are trying to pass have got me anticipating the worst. I'm looking to get an ar or ak pistol myself.

What I meant by factory ammo is something that one can get from most hunting/sporting goods stores. You can not walk in a store and buy 300 hamr ammunition.