View Full Version : Biggest cal. semi auto rifle.......

May 10, 2007, 05:39 PM
What is the biggest caliber semi auto rifle you know of or have experience with? I know they used to make a Browning BAR in .338 win mag but dont think they do anymore.

May 10, 2007, 05:42 PM
well theres the barret .50bmg

May 10, 2007, 05:48 PM
Isnt that a bolt gun? Im thinking more on the lines of a semi auto bear hunting rifle.

May 10, 2007, 05:51 PM
Biggest cal. semi auto rifle.......

Couple years ago, someone was making an M1 Garand conversion to .458 Win Mag (4 or 5 +1 rounds?). Might be able to find one used. That's your ultimate bear hunter there, IMO, if you want a semi-auto, anyhow.

Remington currently offers the 750 Woodsmaster in .35 Whelen - you can get 10 round mags for it.

And of course, as mentioned, Barrett makes a .50 BMG semi-auto. Don't know the capacity. They're about $6,500 - $7,000 IIRC.

The semi-auto rifle I have is a bigger caliber than any of those, however:



Comes in at .72 cal (18.5mm), with up to 8+1 capacity, as modified, with 2.75s (7+1 with 3.0s). Almost as big a caliber as a 20mm. :)

I believe the BAR can still be had in .338 winmag. If not, there are still plenty on the used market:


May 10, 2007, 06:12 PM
First Freedom good point 12 guage semi auto rifled slug gun.
You had me when I first read that. HUH?! lol

May 10, 2007, 06:22 PM
hee hee. :D

T. O'Heir
May 10, 2007, 08:31 PM
"...a semi auto bear hunting rifle..." You don't need a large calibre rifle for bear hunting. Your deer rifle, if you have one, will do nicely. Whether it's a semi-auto or not doesn't matter. The chances of you getting more than one shot are slim. Yogi is very fast and will disappear if you miss. A .30-06 or a like calibre will do.

May 10, 2007, 08:44 PM
I think in terms of mass production guns, the BAR in .338 Win Mag - still in their catalog last I saw, or FirstFreedom's rifled barrel 12ga are it.

Dave Haven
May 10, 2007, 11:52 PM
Lahti made a 20mm semi-auto anti-tank rifle, as did Steyr-Solothurn. These rifles had over twice the muzzle energy of a .50BMG. They WERE fired from the shoulder.:eek:

May 11, 2007, 06:16 PM
Ouch. And by the way this isnt something Im looking at buying its just info gathering for my files of useless knowledge on the subject. :D So as far as a hunting semi auto it looks like a bar .338 win mag or 12 guage auto slug gun is it. Unless there are anymore?

May 12, 2007, 03:58 AM
well theres the barret .50bmg
Isnt that a bolt gun? Im thinking more on the lines of a semi auto bear hunting rifle

The M82A1, M82A2, and M95 barretts are all semi auto. XM500 is the newest. But here is a link to a .577 rifle being test fired :D (called it a T-Rex)


Edit: I have heard a 12 ga w/rifled barrel used in combination with winchester supreme gold sabots are good for bear (heard a guy talking about taking grizzley's with them too). Somthing about a 385gr round traveling at 2000 fps can really knock down some tough stuff,

May 12, 2007, 10:15 AM
.338 win mag or 12 guage auto slug gun is it. Unless there are anymore?

Now as I mentioned, the Rem 750 Woodsmaster is *currently* offered in .35 Whelen - not a "magnum" round like the .338, but a .357/358 heavier bullet.

May 13, 2007, 05:32 PM
Alexander Arms makes the nifty .50 Beowolf


May 14, 2007, 04:19 PM
Oh yeah the .50 beowulf AR's. Has anyone used these for hunting up north yet? I have heard they are popular hog hunting guns down south.
And the .35 whelen sparked my interest a bit. Hows it rate for taking down dangerous game? I know its a necked up 30-06 so it should have some poop to it. Say compared to a .338 win mag how does the .35 whelen stack up as far as stopping big game such as bears. Any thoughts?

May 14, 2007, 04:45 PM
Don't forget the .500 Phantom, the big brother of the .50 Beowulf, and the ballistic equivalent of the .50 Alaskan (yet another very powerful big bore choice):

(scroll down and click on .500 Phantom - the Ghost from the Machine.


Well, at short-range, the .500 phantom is the ballistic equivalent of .50 Alaskan - at long range it is far superior to the .50 alaskan. And also, unlike the .50 alaskan, the .500 phantom is semi-auto.

I'll get back with ya on .35 whelen vs. .338 winmag....here...here's some reading that may help with that issue (gray area):










My opinion would be that at all normal hunting ranges (out to 300 yards), the .35 whelen would be the better big game stopper..but at some point at loooong range the better ballstics of the .338 winmag overtakes the bigger bullet of the .35 whelen and so at very long (unrealistic in most cases) hunting ranges, the .338 winmag is superior.

May 16, 2007, 06:28 PM
Good to know. Thanks. Now another rifle to add to my want list. sheesh. :)

May 17, 2007, 01:27 AM
30MM full auto! Don't mess with the Apache!

Hughes M230 Chain Gun

May 17, 2007, 03:03 AM
I didn't see the Benelli R1 mentioned:


It can be had in .300 Win Mag. I don't own one and haven't fired one, so I don't know how reliable or accurate these are.

May 17, 2007, 08:44 AM
Good to know. Thanks. Now another rifle to add to my want list. sheesh

I know the feeling... but do you mean the .500 phantom or the .35 whelen?

May 18, 2007, 01:24 PM
.35 whelen. It makes the most sense to me. I have been reading up on the various calibers mentioned. Also I'm a bit biased because I am already a big 30-06 fan.:D

May 18, 2007, 05:09 PM
Taking a gander at the calibers of my longguns.....

For hunting rifles, the calibers are (with cartridge & action type)...
.729 (12 ga rifled)(semi)
.458 (.45-70 gov't)(lever & single shot)
.366 (9.3x62mm)(turnbolt)
.308 (.30-'06)(turnbolt)
.277 (.270 win)(turnbolt),and
.243 (.243 win)(single shot)

For hunting shotguns, it's:
.729 (12 ga)(semi)
.615 (20 ga)(semi & single shot), and
.451 (isn't .410 bore actually .451"?)(single shot)

For self-defense rifles, it's:
.311 (.303 Brit & 7.62x39mm)(semi & turnbolt)
.308 (.308 win)(semi) and
.224 (5.56x45mm)(semi)

For self-defense shotguns, it's:
.729 (12 ga)(semi)

For Varminter/Target rifles, it's
.243 (.243 Win)(turnbolt)
.224 (.223 Rem)(single shot)
.221 (.22 WMR & .22lr)(semi, turnbolt, pump, & single shot)
.172 (.17 HMR) (single shot), and
.177 (.177 pellet/air)(single shot)

For Purely Recreational/Target rifles, it's:
.308 (7.5x55 swiss)(straight bolt)
.264 (6.5x55 swede, and hopefully soon, will be Savage 12 F Class in 6.5-.284 Norma)(turnbolts)

Oh, and .35 Whelen rocks - I got a caliber extremely similar to it, the 9.3x62mm, even though I wanted a .35 Whelen, since I wanted the CZ 550 FS so badly, and it came in 9.3x62 but not .35 Whelen. You can find Rem 700s (new & used), Rem 750s (new), Rem 7600s (used), and other rifles in .35 Whelen. Not quite the trajectory of .30-06 with 200+ grainers; not quite the knockdown power of the .45-70, but a good compromise between the two for very large game.

May 22, 2007, 11:14 PM
Sweet thanks. And nice collection!