What is the diff. between the two uppers. I am wanting to change the upper on my DPMS LR308
- Thread starter DIESEL758
- Start date
Re: AR 15 A4 vs AR 15 A3 UPPERS
Ok, well... where to start.
First off, a bit of .mil info:
The M16A1 had a simple rear sight called "field sights". The M16A2 had adjustable target like rear sight(among other improvements and changes). The M16A2 was also 3 round burst instead of full auto. Some parts of the military,(more specifically the Navy, wanted a full auto M16A2) so the M16A3 was made. The M16A3 being a full auto A2. Later the M16A4 was adopted, which is an A2 with a flat top railed upper.
Now on to commercial sales. Civilian manufactures made A1 and A2 uppers. When the flat tops came out, instead of calling them A4 uppers, many dealers and manufactures called them A3 uppers.
Now it gets more complicated. The .mil decided on steeper feedramps on the M4 to help feeding with old worn out mags. These steeper feedramps require a deeper cut in the barrel extension and the upper. These are often called "M4 Feedramps"
A barrel with M4 feedramps will work fine in a upper w/o M4 feedramps. However an M4 feedramp cut upper may have issues with a barrel w/o M4 feedramps.
Recall that civilian manufactures were calling their flat top uppers A3 uppers. Now some of these companies as they started offering flat top uppers with M4 feedramps started to call these others uppers A4 uppers.
Awesome naming conventions right?
So whats the difference between an A3 and an A4 upper?
Well that depends on the company and what they mean when that individual company names their product.
And yes, after all that I still haven't answered your question. HA!
Ok, well... where to start.
First off, a bit of .mil info:
The M16A1 had a simple rear sight called "field sights". The M16A2 had adjustable target like rear sight(among other improvements and changes). The M16A2 was also 3 round burst instead of full auto. Some parts of the military,(more specifically the Navy, wanted a full auto M16A2) so the M16A3 was made. The M16A3 being a full auto A2. Later the M16A4 was adopted, which is an A2 with a flat top railed upper.
Now on to commercial sales. Civilian manufactures made A1 and A2 uppers. When the flat tops came out, instead of calling them A4 uppers, many dealers and manufactures called them A3 uppers.
Now it gets more complicated. The .mil decided on steeper feedramps on the M4 to help feeding with old worn out mags. These steeper feedramps require a deeper cut in the barrel extension and the upper. These are often called "M4 Feedramps"
A barrel with M4 feedramps will work fine in a upper w/o M4 feedramps. However an M4 feedramp cut upper may have issues with a barrel w/o M4 feedramps.
Recall that civilian manufactures were calling their flat top uppers A3 uppers. Now some of these companies as they started offering flat top uppers with M4 feedramps started to call these others uppers A4 uppers.
Awesome naming conventions right?
So whats the difference between an A3 and an A4 upper?
Well that depends on the company and what they mean when that individual company names their product.
And yes, after all that I still haven't answered your question. HA!
Re: AR 15 A4 vs AR 15 A3 UPPERS
Damn Postal, you left out the M16 pre-A1 and the SP1.
Damn Postal, you left out the M16 pre-A1 and the SP1.
Re: AR 15 A4 vs AR 15 A3 UPPERS
Yup, to help you more, it would help if we knew what products you were comparing.
As near as I can tell, A3 and A4 "receivers" (note Postal0311's caveat above about feed ramps) are different manufacturer's designations for "mil-spec"-style flat top receivers, "mil-spec"-style being used to differentiate them from billet or slick sided receivers.
Also, you mention your LR308 which doesn't use AR15 receivers at all. With the large-frame AR's you run into compatibility issues: AR-10 (Armalite pattern) LR308 (DPMS pattern) SR-25 (KAC pattern) and LAR-8 (RRA pattern) none of these are fully compatible and you can search to find information regarding the differences. If this is what you need help sorting out there are already tons of posts across the internet about it.
Either way, post back with more information about what you would like to know.
Yup, to help you more, it would help if we knew what products you were comparing.
As near as I can tell, A3 and A4 "receivers" (note Postal0311's caveat above about feed ramps) are different manufacturer's designations for "mil-spec"-style flat top receivers, "mil-spec"-style being used to differentiate them from billet or slick sided receivers.
Also, you mention your LR308 which doesn't use AR15 receivers at all. With the large-frame AR's you run into compatibility issues: AR-10 (Armalite pattern) LR308 (DPMS pattern) SR-25 (KAC pattern) and LAR-8 (RRA pattern) none of these are fully compatible and you can search to find information regarding the differences. If this is what you need help sorting out there are already tons of posts across the internet about it.
Either way, post back with more information about what you would like to know.
Re: AR 15 A4 vs AR 15 A3 UPPERS
Don't worry KClark, pre-A1 M16s and AR15 were upgraded to A1 sights for free. You didn't even have to send it back in, as a Colt rep snuck into your house and took care of it while you were sleeping.
To the OP. I looked into it. I -believe- that DPMS just called their 308 uppers A3 uppers.
A word of cautions, DPMS has produced 3 different heights of rails on their 308 uppers. They recently changed to a new, non standard height. Call Repairs at 1-800-578-3767 to get the info you need.
Ugh, trying to get 100 useful posts in so I can trade some old optics of mine for a Nightforce is gunna be hard.
Don't worry KClark, pre-A1 M16s and AR15 were upgraded to A1 sights for free. You didn't even have to send it back in, as a Colt rep snuck into your house and took care of it while you were sleeping.
To the OP. I looked into it. I -believe- that DPMS just called their 308 uppers A3 uppers.
A word of cautions, DPMS has produced 3 different heights of rails on their 308 uppers. They recently changed to a new, non standard height. Call Repairs at 1-800-578-3767 to get the info you need.
Ugh, trying to get 100 useful posts in so I can trade some old optics of mine for a Nightforce is gunna be hard.
Re: AR 15 A4 vs AR 15 A3 UPPERS
Ok well i was searching for a new upper i want the A3 style upper i currently have what DPMS calls the A2 upper with no assist and dust cover. I would like the flat top rail and assist, dust cover. do i have to buy the one DPMS or can i buy some other one. Does the DPMS A3 upper have M4 cuts. I was looking at the Daniel Defense and the Double Star, Daniel Defense calls there's an A4. I am getting very confused on what to buy. I don't even know if the uppers iam looking at are any good.
Ok well i was searching for a new upper i want the A3 style upper i currently have what DPMS calls the A2 upper with no assist and dust cover. I would like the flat top rail and assist, dust cover. do i have to buy the one DPMS or can i buy some other one. Does the DPMS A3 upper have M4 cuts. I was looking at the Daniel Defense and the Double Star, Daniel Defense calls there's an A4. I am getting very confused on what to buy. I don't even know if the uppers iam looking at are any good.
Re: AR 15 A4 vs AR 15 A3 UPPERS
I almost forgot i also noticed that some say 308 A3 upper, what is the diff.
I almost forgot i also noticed that some say 308 A3 upper, what is the diff.
Re: AR 15 A4 vs AR 15 A3 UPPERS
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DIESEL758</div><div class="ubbcode-body">Ok well i was searching for a new upper <span style="font-weight: bold">i want the A3 style upper i currently have what DPMS calls the A2 upper with no assist and dust cover. I would like the flat top rail and assist, dust cover.</span> do i have to buy the one DPMS or can i buy some other one. Does the DPMS A3 upper have M4 cuts. I was looking at the Daniel Defense and the Double Star, Daniel Defense calls there's an A4. I am getting very confused on what to buy. I don't even know if the uppers iam looking at are any good. </div></div>
Am I clear on what you are looking for? You are looking for an upper identical to what you have presently? .308, flat top, with FA, and dust cover? It sounds like you are trying to find out if there is an alternative to the factory DPMS upper receiver. I make be wrong, but any DMPS pattern upper receiver should work for you. The .308 guns are a little less forgiving than the 5.56 uppers and lowers from what I understand. If you could be a little more specific on what you are trying to do, more help might be available. What lower are you running, and what are you trying to accomplish?
- Loud
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DIESEL758</div><div class="ubbcode-body">Ok well i was searching for a new upper <span style="font-weight: bold">i want the A3 style upper i currently have what DPMS calls the A2 upper with no assist and dust cover. I would like the flat top rail and assist, dust cover.</span> do i have to buy the one DPMS or can i buy some other one. Does the DPMS A3 upper have M4 cuts. I was looking at the Daniel Defense and the Double Star, Daniel Defense calls there's an A4. I am getting very confused on what to buy. I don't even know if the uppers iam looking at are any good. </div></div>
Am I clear on what you are looking for? You are looking for an upper identical to what you have presently? .308, flat top, with FA, and dust cover? It sounds like you are trying to find out if there is an alternative to the factory DPMS upper receiver. I make be wrong, but any DMPS pattern upper receiver should work for you. The .308 guns are a little less forgiving than the 5.56 uppers and lowers from what I understand. If you could be a little more specific on what you are trying to do, more help might be available. What lower are you running, and what are you trying to accomplish?
- Loud
Re: AR 15 A4 vs AR 15 A3 UPPERS
Sorry, the gun came with a A2 style upper it has no assist and no dust cover it is open which i do not like and it has the tall rail, i was just loking for a diff. upper besides the A3 style upper DPMS offers on there website, i have the DPMS lower everything is DPMS i have not changed anything. I would just like to get another upper with assist and dust cover and flat rail. Sorry if i am not asking the right questions i am new to the semi auto game and these type of rifles.
Sorry, the gun came with a A2 style upper it has no assist and no dust cover it is open which i do not like and it has the tall rail, i was just loking for a diff. upper besides the A3 style upper DPMS offers on there website, i have the DPMS lower everything is DPMS i have not changed anything. I would just like to get another upper with assist and dust cover and flat rail. Sorry if i am not asking the right questions i am new to the semi auto game and these type of rifles.
Re: AR 15 A4 vs AR 15 A3 UPPERS
Give JD Machine Tech a call. They are building the matched upper/lower set for the Hide's group buy. The uppers are DPMS pattern, flat top w/ forward assist.
http://www.jdmachinetech.com/
If they can't help you out, let me know and I will see what else I can dig up.
- Loud
Give JD Machine Tech a call. They are building the matched upper/lower set for the Hide's group buy. The uppers are DPMS pattern, flat top w/ forward assist.
http://www.jdmachinetech.com/
If they can't help you out, let me know and I will see what else I can dig up.
- Loud
Re: AR 15 A4 vs AR 15 A3 UPPERS
Thanks Loud i will check them out.
Thanks Loud i will check them out.
Re: AR 15 A4 vs AR 15 A3 UPPERS
Good luck...
- Loud
Good luck...
- Loud
