AR uppers

epl1007 · September 11, 2020, 08:59 PM

I know this might be a dumb question but I need to know anyways. Can I buy a PSA upper and magazine to change calibers to a 450 bushmaster for deer hunting or do I have to get the upper brand my gun is. I have an APF AR and they make uppers but PSA is cheaper by far.

Chipperman · September 11, 2020, 09:02 PM

If it’s mil-spec it should fit

epl1007 · September 11, 2020, 09:06 PM

Thank You

bfoosh006 · September 13, 2020, 07:44 PM

YMMV... you might want to change your buffer weight as well.

But yes a different brand upper should fit your AR lower.

50 shooter · September 13, 2020, 10:48 PM

This mostly applies to AR15 lowers and uppers. You might find a very limited number that have some fitment issues.

When you change to AR10 lowers and uppers, you'll find that a lot have fitment issues. If you plan on buying an upper in a different caliber, buy it from the same company.

This should keep you from having any problems with them fitting together.

stagpanther · September 14, 2020, 05:55 AM

Should work. 450 AR's are a bit of a thumper, a Tubbs flat spring and maybe moving up to heavier buffer may be helpful--but not absolutely necessary as long as you don't mind the possible "pthwack-twang."

bullspotter · September 22, 2020, 12:22 AM

Should be fine, I run a standard buffer and spring in my 450, no issues at all, I do have an adjustable gas block though. Put a small 1-4 leupold on it, shooting 250 grain FTX hand loads. Thing is a hoot!!

September 11, 2020, 08:59 PM	#1
epl1007 Member Join Date: August 28, 2015 Posts: 72	AR uppers I know this might be a dumb question but I need to know anyways. Can I buy a PSA upper and magazine to change calibers to a 450 bushmaster for deer hunting or do I have to get the upper brand my gun is. I have an APF AR and they make uppers but PSA is cheaper by far.

September 13, 2020, 10:48 PM	#5
50 shooter Senior Member Join Date: August 6, 2002 Location: SoCal PRK Posts: 986	This mostly applies to AR15 lowers and uppers. You might find a very limited number that have some fitment issues. When you change to AR10 lowers and uppers, you'll find that a lot have fitment issues. If you plan on buying an upper in a different caliber, buy it from the same company. This should keep you from having any problems with them fitting together. __________________ I see the world thru bloodshot eyes Streets filled with blood from distant lies The dogs of war never compromise, No time for rearranging.

September 14, 2020, 05:55 AM	#6
stagpanther Senior Member Join Date: March 2, 2014 Posts: 11,772	Should work. 450 AR's are a bit of a thumper, a Tubbs flat spring and maybe moving up to heavier buffer may be helpful--but not absolutely necessary as long as you don't mind the possible "pthwack-twang." __________________ "Everyone speaks gun."--Robert O'Neill *I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk!*

September 11, 2020, 09:02 PM	#2
Chipperman Senior Member Join Date: January 31, 2000 Location: Live Free or Die, Baby! Posts: 1,550	If it’s mil-spec it should fit

September 11, 2020, 09:06 PM	#3
epl1007 Member Join Date: August 28, 2015 Posts: 72	Thank You

September 13, 2020, 07:44 PM	#4
bfoosh006 Senior Member Join Date: February 17, 2009 Posts: 1,089	YMMV... you might want to change your buffer weight as well. But yes a different brand upper should fit your AR lower.

September 22, 2020, 12:22 AM	#7
bullspotter Senior Member Join Date: November 2, 2008 Location: Montana Posts: 308	Should be fine, I run a standard buffer and spring in my 450, no issues at all, I do have an adjustable gas block though. Put a small 1-4 leupold on it, shooting 250 grain FTX hand loads. Thing is a hoot!!