300 HAM'R it might be time

ive been pondering putting together an ar in 300 HAM'R for quite some time. with the slow twist 1-13 seems like an ideal cast boo lit platform
well the stars just may be aligning. I dont have a lot of love for the 300 blackout I put together several years ago when it just campout and I jumped on that band wagon. being on a pretty tight budget I just noticed lee has 300 HAM'R die sets on close out for a $20 and Wilson combat reduced price of 16" stainless barrel 20% down to earth $199.

I'll once again ask for opinions on this caliber in the AR platform. for the cost of two tank fulls of gas in my pickup I could be into a whole new round for my unloved AR

and from Wilson combat a fluted 1-15 twist barrel for $227.
I think I'm going to do this. ordered the dies before they are all gone now have to decide on which barrel seem they are all 20 percent off and there are several options.
I'm sure no AR expert. looking for advice from the experienced here. next I guess I might think about a new mold. ive got several in 30 cal, newest is a limited edition lee in 124 grain plus the tried and true 150 and 170 grainers ive used in 30-30's for decades and of course the old 311299 that the 308 and 30-06 can't live without

Farmbif;
I can’t help, but Sundog has had great things to say about the cartridge.
Tony

I put together a short 300 hamr (11.3"?), and have been very pleased with it. I bought a bunch on 125 speer due to economy and accuracy. At 300 hamr velocities they perform well in the penetration and expansion department, acting more like a game bullet instead of a varmint bullet.

I shot a few hogs with it and then moved on to my 260 remington AR. Nothing but good to say about WC barrels. I have built several ARs using their barrels, maybe 6 or 7 to date.

I shoot a 24 in , 14.5 in, and a 11.5 in. all will handle a 110 gr boolit up to a 180 gr boolit with a velocity around 1600 to 1800 fps with great accuracy using powder in the 5744 to reloader 7 range . definitely worth looking into.
Another good cast boolit shooter is the 277 wolverine from Mad Dog Weapons.

Try and stock up on Speer 130fp if you are gonna hunt it. Its a dandy bullet and Bill Wilson designed the cartridge for its use.

CW

I think I would go with the 350Legend-not a better cartridge, but good enough, and easier to buy or make ammo.

I do not have a 300HMMR, but I did jump on the 300BLK bandwagon. The BLK was a lot of fun in a bolt action, then I put put together an AR and most of the fun target shooting ended; I would rather shoot an AR chambered in 5.56 than in any 30 caliber. The price of ammo, weather cast or FMJ is too expensive for me. If I were using the caliber for only hunting, then the 300HMMR would make sense for me if the 300Legend, 450Bushmaster, 6.8SPC, 6.5Grendel, and 7.62x39 were not already out there with more ammo available.

https://www.gunmann.com/learning/300...-300-blackout/

If you going to punch paper at 200 yards or less, and money is tight, and you already have a .300 BO, spending money on a .300 Hammer does not make sense to me. If you want to hunt, then the Hammer gives you more range if you do not have another hunting caliber.

If starting from scratch, the .300 Hammer is what I would pick. It is a better cartridge.

But I understand that when you have in itch, it is tempting to scratch it even if it does not make a lot of sense.

If you are not using the .300 BO, sell the barrel and get the Hammer.

You cannot use certain projectiles in the 300 hammer. Just about any cast boolit that will stanilize should work/fit. There are a multitude of jacketed bullets that will not fit the 300 hamr coal and magazine limits. 125 grain Nosler ballistic tips are too long of an ogive to fit. And there are severla others.

https://texashuntingforum.com/forum/...mr#Post7506626
Good data here.

i have both. the 300bo has killed deer to 200 yards with the 130 barnes designed just for its velocity. hands down the best hunting bo bullet. but i consider it a 150 yard gun. problem is to seat it deep enough for the hmr the bullet falls into the case. my favorite bullets in it are 130 sierras and speer gold dots and both have been very effective out to 250 yards but thats as far as ill use it. but i believe both those bullets are discontinued or at least hard to get. ive shot some speer hot core sand horn ssts in it too but i cant say how they work on game but the deer and pigs ive shot with it show much more smack, for lack of better words then the bo. i havent bothered with cast in the hmr because ive goy 4 bo's and the hamr is to me a hunting rifle like my grendel. one thing ive found in all three of my bo ars and my american is the seem to have tight chambers. about all my cast shooting is with the rcbs 130 spitz gas check and to chamber reliably i have to size to 307 after pc coating. but the good news is it shoots moa out of my american and my psa 16in gun never shot groups with that bullet and my 2 ar pistols but even with a red dot its minute of 6 inch plate at a 100 yards. honestly ill probably never take a bo back out hunting its to me just i bit to small. my ar hunting will be with the hmr, grendel, beowulf or an ar10. that said id take a bo any day over a 556 for deer out to 200 yards. even more so on bear and hogs.