Big Bore Cast AR Deer rifle conversion?

[DonMountain]

About 25 years ago I bought a Colt Delta Match H-Bar AR-15 rifle in 5.56 Nato for target and ground hog shooting on my farm. I never considered using cast lead projectiles in it for this high pressure round since I use it for long range shooting. Now I am seeing a lot of big bore conversions available that may be cast bullet friendly and be large enough for shooting deer at close ranges. Could anyone make suggestions for an appropriate conversion that would fit this rifle and would be large enough for deer hunting in the woods?

[vzerone]

You said AR, AR15 or AR10 which? Lot of big bore AR10 calibers. A dynamite big bore woods whopper for you would be the 45 Raptor in the AR10 and it can even be a lighter carbine as 16 inch barrels are the norm for that round. Here's a link to it:

http://www.45raptor.com/45RAPTOR/

[mcdaniel.mac]

About 25 years ago I bought a Colt Delta Match H-Bar AR-15 rifle in 5.56 Nato for target and ground hog shooting on my farm. I never considered using cast lead projectiles in it for this high pressure round since I use it for long range shooting. Now I am seeing a lot of big bore conversions available that may be cast bullet friendly and be large enough for shooting deer at close ranges. Could anyone make suggestions for an appropriate conversion that would fit this rifle and would be large enough for deer hunting in the woods?

Is you want to go above .30 then I'd point you at the .458 SOCOM

[DougGuy]

Check out the .30 ARX beats 300 blk hands down. Dang near .308 performance out of the AR15 action. Already got a 30 ARX Imp 40, I assume 40gr water capacity compared to the 38gr ARX case, but the 30 Remington AR holds 44 so maybe it might be the baddest .308" boolit you can stick in an AR? They keep re-inventing this platform..

My problem was hunting deer with 150 and 165gr boolits in my .308 and it was tearing meat all to pieces, flecks of lead and gilding metal all through the meat and horrific wounds, so I loaded a 180gr plain base over the same 41.5gr H4895 and it slowed things down enough that I was getting h***ified knockdown power, enough to cartwheel a 100lb buttonhead over backwards the length of an F150 from where it was standing, and not tearing up meat nearly as bad.

I don't know how much success you would have with heavy boolits in any of the 30 caliber AR chamberings unless you can get them to around 2400fps. 180gr boolit at 2400fps is a real sweet spot for deer to 200+ yds.

[Moleman-]

If I didn't like 35's and 44's as much as I do I'd be hunting with a 450 Bushmaster. Quite a few companies make barrels and uppers for it so parts, mags ect are more common.

[Omega]

The .277 Wolverine has enough umph for white tail at longer distances than the 300 blackout and just like the blackout all it needs is a barrel swap. If you stay at 100 yrds or less, and want to go suppressed, then the blackout is a good option.

[dragon813gt]

There are so many wildcats at this point it's ridiculous. You have the likes of the 277 Wolverines and 358 Yeti from Mad Dog Weapons Systems. I could probably spend the next ten minutes listing other wildcat cartridges. For deer if you keep the distances limited there are a lot of cartridges that would work. But when big bore and AR15 are mentioned there are two answers, 458 SoCom and 50 Beowulf. Both are proven cartridges. The wildcats come and go constantly. If you wanted something slightly more than 300 BLK there is 7.62x40wt.

Just be aware that w/ a lot these cartridges the mags have to modified. Or in the case of the real big bores the ejection port opened up slightly.

[popper]

I'm pushing 145gr PB cast to 2100 fps with accuracy in 18" 1:10 BO, just a barrel swap. Not 100% fill, just never tried more powder. 30arx does just a tad better with 50% more powder! My 16" 1:10 308W carbine does 165gr. @ 2400, GCd. Shot a pig carcass with 30/30 185gr @ ~1500 fps, broke the shoulder blade, no exit. Shot again in gut & got a pass through with expansion. Much less P.F. than (275 vs 304) the BO load. Power factor is about the same @ 100 as the 308 @ 200 yds. 308 knocks down steel @ 200 with 2" 3 shot group. I tinkered with the idea of moving the BO shoulder forward for more powder space & same neck length (as Wilson suggested), never did it - another wildcat?
Basically my comment, BO is a very good light weight 100 yd deer gun. I'd rather shoot pigs.

[rockrat]

For something simple, I would go with the 450 bushmaster. I have that, along with a socom,beowulf and 50ae uppers. the bushmaster was ridiculous easy to find an accurate load for it, using cast. Matter of fact, just about everything I tried , shot well.

Smaller caliber uppers, you have the 6.5 Grendel and the 7.62 x 39, the 300 BO and the 7.62 x 40. All good calibers for deer. I shoot all of them , except for the last, the 7.62 x 40.

[vzerone]

Now here's a real thumper with cast bullets. Brass is cheap too, which is a problem with 458 SOCOM.

http://www.375raptor.com/375RAPTOR/

[dragon813gt]

Thought you needed an AR10 for that cartridge?

[Moonie]

Now here's a real thumper with cast bullets. Brass is cheap too, which is a problem with 458 SOCOM.

http://www.375raptor.com/375RAPTOR/

The 375 Raptor looks like a great cartridge but it also appears to be 308 based and as such not a viable candidate for an AR-15.

[dragon813gt]

The 375 Raptor looks like a great cartridge but it also appears to be 308 based and as such not a viable candidate for an AR-15.

It can be w/ a new bolt like the 358 Yeti. But I don't think they found a new supplier since Olympic Arms folded.

[vzerone]

The 375 Raptor looks like a great cartridge but it also appears to be 308 based and as such not a viable candidate for an AR-15.

It's a super round! I fired one and it's a cannon. So is the 45 Raptor a cannon. I like the 375 though. Like I said there are very light AR 10 carbines out there nowadays.

[dragon813gt]

It's a super round! I fired one and it's a cannon. So is the 45 Raptor a cannon. I like the 375 though. Like I said there are very light AR 10 carbines out there nowadays.

The OP is looking to covert this AR15 so that isn't a viable cartridge.

[vzerone]

The OP is looking to covert this AR15 so that isn't a viable cartridge.

Then in that case I wouldn't advise it especially if you are going to rebarrel the Colt upper. Here's my thinking. Colt's are collectable and that would ruin that. If you aren't going to do it that way and you're going to build another upper receiver remember Colt had the odd big pin on the hinged end and I'm not quite sure if your Colt is old enough to have had that. With that said,if it does, then todays uppers won't be a drop in as you'll have to use an off-cam adapter pin to mate the receivers and I'm not fond of that method. To avoid that you could search for another Colt upper receiver that would mate. If you have the money you'd be better off to build another complete rifle.

[Smoke4320]

for the as stated big bore ......458 socom, 450 bushmaster and 50 beowolf all drop in uppers that will use the ar15 lower
I went with the 458 socom for the many many 45-70 bullets and molds .. very very happy with mine
the 458 socom uses the std 223 mags... just makes them a single stack

[rockrat]

Some of the Colt guns (SPS?) used a different hinge pin diameter, but there are many Colt uppers that use the standard pin diameter.
I would also build a different upper, and not use the Colt upper. Probably be cheaper to buy a complete upper than assemble one from parts too.

[vzerone]

Some of the Colt guns (SPS?) used a different hinge pin diameter, but there are many Colt uppers that use the standard pin diameter.
I would also build a different upper, and not use the Colt upper. Probably be cheaper to buy a complete upper than assemble one from parts too.

The different pins models ran I believe up into the early 90's. My cousin has a pre-ban Colt HBAR that he bought in the early 80's and it has the different pins. He had a different upper on it using that off-center bushing, but said he didn't like it especially when hinging it open and close it kind of binded or something like that. He eventually bought a lower for that upper so that problem was solved.

[DonMountain]

Some of the Colt guns (SPS?) used a different hinge pin diameter, but there are many Colt uppers that use the standard pin diameter.
I would also build a different upper, and not use the Colt upper. Probably be cheaper to buy a complete upper than assemble one from parts too.

After doing much research on this subject, especially on the .458 SOCOM that might shoot the various 45-70 cast lead projectiles I have molds for, this whole idea of converting an older Colt AR-15 to a lead shooting caliber seems to have many pitfalls. Besides being particularly expensive to do. I thought initially it would be a couple of hundred dollars and just swapping out the barrel for deer season. But I found it much more complex then that. And especially when most of the conversions might not even work in my Colt rifle. Or would require some modification of my "collectable" Colt rifle. It seems like the people that are successful with all of these conversions have many different AR-15 style rifles, so when one set of parts doesn't fit in one lower, they can just pick one or their other lowers that will work and be successful with the conversion. Where in my case I have just this one, old AR-15 rifle that I was hoping to convert on a temporary basis for deer hunting season. I appreciate all the help from everybody, especially the people that pointed out that my rifle may not be suitable for a conversion. So, I guess I will go deer hunting this year with my Browning 1885 in 45-70 and have to reload fast if I see two or three deer.