The Down Range Forum
Member Section => Tactical Rifle & Carbine => Topic started by: 2HOW on September 04, 2008, 09:03:21 PM
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With so many uppers in different calibers on the market today what do you need to be carefull of when wanting to buy different calibers. What on the lower needs to be switched when you switch calibers?
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You can put any upper on any lower. I've heard that different recoil springs or buffers may help functioning with different calibers but aren't neccesary. I'm hoping someone with experience in more calibers can help. I don't know of any specific changes that need to be made.
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You can put any upper on any lower. I've heard that different recoil springs or buffers may help functioning with different calibers but aren't neccesary. I'm hoping someone with experience in more calibers can help. I don't know of any specific changes that need to be made.
Depends on caliber. 5.56 or comparable rounds, like 6.5 Grendel, .50 Beowulf, or 6.8 SPC are fine with standard lowers. Larger calibers like 7.62x51 (.308) or .50 BMG require special lowers to accommodate the size of the round in the magazine and mag well.
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Okay, AR-10, AR-18, and AR-15, FAL, AK-74, Stoner 63, etc., etc., etc., recievers don't fit together. But different brands and calibers of AR-15s do. I assumed we were talking about one model, the AR-15, and not all rifles ever made. The OP wasn't very specific. It doesn't even say rifles but I made another assumption there. I have to quit doing that. If you switch to a completely different model you need to buy the whole gun. You can't cobble together ANY upper and lower of any rifle or pistol ever made. Within one model like the AR-15 they will fit but Colt used about an 8mm hinge pin for awhile instead of 1/4" like everyone else. A simple adaptor pin makes those uppers and lowers fit standard sized lowers and uppers. I've tried both Colt halves mixed with standard sizes and they work. BTW I have seen several different .50 BMG uppers that use a standard AR-15 lower too. I believe they're all bolt actions.
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Let me get this straight, I can put a 9mm, .308 .6.8 or .50 on a stock lower? without changing anything?
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You can put a pistol caliber or .223 Remington cartridge length upper on an AR-15 and a .308 Winchester cartridge length upper on an AR-10. But you can't put an AR-10 upper on an AR-15 lower or vise vesra.
.22 Long Rifle, 7.62x25mm, 9mm Luger, 40 S&W, 10mm, 45 ACP, .50 AE, .17 Remington, .204 Ruger, 5.45x39mm, .222 Remington, .223 Remington, 5.56x45mm NATO, .223 WSSM, 6mm PPC, 6mm-223 Remington (6x45mm), .243 WSSM, .25 WSSM, 6.5 Grendell, 6.8 SPC, .300 Whisper, 7.62x39mm, .450 Bushmaster, .45 Professional, .458 SOCOM, .499 LWRC, .50 Beowulf, and the .50 BMG bolt-action are just some of the uppers that will fit an AR-15 lower without modification. The pistol calibers have mag-well adaptors that pop in. Everything else is good to go as is.
AR-10s can use any caliber based on .308 Winchester length cartrigdes based on .308 and .284 Wichester as well as some big fat non-belted magnum cases. 6.5-.284 Winchester is just one of the wildcats available for it. Standard calibers include .243 Winchester, .260 Remington, 7mm-08 Remington, .308 Winchester/7.62x51mm, .338 Federal, and .358 Winchester. There are several dozen more possibilities including 6.5mm Creedmoor.
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Excellent!!! thanks JF 8)
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Glad I can help. :) With a .458 SOCOM you can get about 33 rounds in a MWG 90-round drum with no modifications and also use other mags with no modifications. Other than that I would rather have a .450 Bushmaster. The magazine is slightly modified because the round is a little skinnier. It's 250 grain Hornady bullet will take any North American game animal. Factory ammo is easy to get for it unlike some other big-bore AR-15s. I think I'll skip the 6.8mm and go big (~11.25mm) if I get another upper.
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Between .450 Bushmaster and .458 SOCOM, I'd choose the .450 because the Ammo's like $15 cheaper per box than the .458. And I'm sure it can do MOST of what the .458 SOCOM can do. I'd like to get me an AR Lower, and Uppers in 6.8 SPC and .450 Bushmaster for it.
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O.K., so I want to put a 7.62x39 upper on my M&P 15 lower. This may be a stupid question, but can I load that cartridge in a standard 5.56/.223 mag? If not, what kind of 7.62x39 mag will work or where can I find an adapter? Help an idiot out, please.
Swoop
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O.K., so I want to put a 7.62x39 upper on my M&P 15 lower. This may be a stupid question, but can I load that cartridge in a standard 5.56/.223 mag? If not, what kind of 7.62x39 mag will work or where can I find an adapter? Help an idiot out, please.
Swoop
I understand that standard AK mags are the ones to use, I'm not sure that it works with the 5.56 lower.
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Swoop
You'll have to get new mags for 7.62x39 and that's one problem there are scarce and mostly 5 or 10 rounders.
Try CProducts http://www.cproductsllc.com/shop/index.php?cPath=22_36 (http://www.cproductsllc.com/shop/index.php?cPath=22_36) they have developed a 30 round mag but I've heard they have problems.
AK mags will not fit your AR.