Best ammo for DPMS AP4

[JCassidy]

What would be the ideal grain/brand .223 ammo for a DPMS AP4 - 6 grooves, right-hand 1x9 twist?

[Guns4Fun]

Best for what? The best shtf load in my opinion would be good ol federal xm193 55g. Or even the hornady tap 55g. For general plinking, wolf 55g will be fine.

With the 1/9 twist, you want to stay under 70g---but, if you choose a 69 or 75g make sure you shoot it first to see how it works. Some 1/9 twist guns don't mind the heavier bullets---others do.

[pete73]

Do not use Wolf in your DPMS!!! Look in the maunal it will void any warranty. For plinking I use Remington 55 grain umc. Never have an issue with it and it is pretty inexpensive. $9.95 a box of 20 at walmart.

[Guns4Fun]

Do not use Wolf in your DPMS!!! Look in the maunal it will void any warranty. For plinking I use Remington 55 grain umc. Never have an issue with it and it is pretty inexpensive. $9.95 a box of 20 at walmart.

I don't want to argue over shooting wolf---but, if your gun won't shoot wolf---it is a gun problem---not an ammo problem. My AR's have been getting a steady diet of wolf for plinking and all function fine.

How would DPMS ever know what ammo you were using?

[Lcpl Overhiser]

Here are words from DPMS site stating what ammo not to use. DPMS would know if you used this ammo and it would void your weapon. The reason why they would know is that the ammo is of a softer metal that they could trace to the damage of your bore.



"Ammunition Warning

After extensive testing, we have found that only ammunition manufactured to SAAMI (Sporting Arms and Ammunition Manufacturers Institute) specifications is reliable in DPMS rifles. DPMS recommends the use of high quality, domestically produced ammunition for best results and highest accuracy. For plinking and practice, we recommend only domestic, commercially manufactured ammunition. Please note: the use of hand-loaded ammunition voids the factory warranty. The use of all ammunition listed below also voids the warranty.

We have incurred feeding problems with the following:

Israeli ammunition
Korean ammunition
Chilean ammunition
Portugese ammunition
We have reviewed several reports, from several manufacturers', regarding problems using this ammunition. The problem appears to be the bullet contour and the overall length of the cartridge, which is contacting the rifling before firing. This is creating a gas port pressure and chamber pressure higher than recommended, therefore causing feeding and extraction problems due to the increased bolt carrier velocity. In addition, there is accelerated fatigue on internal parts. There are also indications that brass may be out of spec, which could create an unsafe condition.

PMP
South African produced surplus
We have used this ammunition in the past for testing purposes and found the brass is extremely soft and can "flow" into microscopic pores and grooves in the chamber creating "sticky" extraction. This has been reported in many types of rifles, but is more prevalent in semi-automatic weapons.

Lacquer Coated Ammunition or Steel-cased, lacquer coated ammunition
Wolf
Norinco
Silver Bear
Any steel-cased (coated or non-coated) ammunition
The problem with this ammunition is that the lacquer coating on the case. As the barrel heats up, the lacquer turns to a soft, varnish substance and upon cool down, becomes very solid and difficult to remove. This effectively creates an undersized chamber and creates understandable problems.

Your rifle is an investment and it only makes sense to choose quality ammunition for a quality rifle!

Barrel Information
To achieve the best results for accuracy you should clean the chamber and bore after every round for the first 25 rounds and then every 10 rounds up to the 100 rounds. It usually takes about 200 rounds per barrel for optimum accuracy. Please keep in mind that our barrels are production barrels not custom barrels. Accuracy is dependant upon many factors such as bullet weight, powder load, rifling twist, rifling lands, operator technique, etc. Our production barrels have achieved anywhere from 1/8" to 1 ½" M.O.A. Obviously, we would hope that every production barrel would shoot 1/8" M.O.A., but with all of the above factors, we cannot guarantee a specific group size."

[Legion_Prime]

WOW, there is so much FAIL here I don't even begin to know where to start. Oh wait, yeah I do.

"Ammunition Warning

After extensive testing, we have found that only ammunition manufactured to SAAMI (Sporting Arms and Ammunition Manufacturers Institute) specifications is reliable in DPMS rifles. DPMS recommends the use of high quality, domestically produced ammunition for best results and highest accuracy. For plinking and practice, we recommend only domestic, commercially manufactured ammunition. Please note: the use of hand-loaded ammunition voids the factory warranty. The use of all ammunition listed below also voids the warranty.

We have incurred feeding problems with the following:

Israeli ammunition
Korean ammunition
Chilean ammunition
Portugese ammunition
We have reviewed several reports, from several manufacturers', regarding problems using this ammunition. The problem appears to be the bullet contour and the overall length of the cartridge, which is contacting the rifling before firing. This is creating a gas port pressure and chamber pressure higher than recommended, therefore causing feeding and extraction problems due to the increased bolt carrier velocity. In addition, there is accelerated fatigue on internal parts. There are also indications that brass may be out of spec, which could create an unsafe condition.

Hmmm, this could easily be solved by cutting a 5.56 chamber rather than a .223 chamber. But to cut .223 and then go around running your suck about "experiencing problems" with 5.56 NATO/MilSpec ammo is just flat out asshattery of the highest order.

PMP
South African produced surplus
We have used this ammunition in the past for testing purposes and found the brass is extremely soft and can "flow" into microscopic pores and grooves in the chamber creating "sticky" extraction. This has been reported in many types of rifles, but is more prevalent in semi-automatic weapons.

Hmmmmmm, the ductility of brass which is the reason why brass is used to make case cartridges somehow makes them not run in you rifles? Sounds more like a timing issue to me. However despite the fact that quality rifles run this stuff with no issues, in your rifles the ammo magically becomes problematic. Obviously the ammo is at fault.

Lacquer Coated Ammunition or Steel-cased, lacquer coated ammunition
Wolf
Norinco
Silver Bear
Any steel-cased (coated or non-coated) ammunition
The problem with this ammunition is that the lacquer coating on the case. As the barrel heats up, the lacquer turns to a soft, varnish substance and upon cool down, becomes very solid and difficult to remove. This effectively creates an undersized chamber and creates understandable problems.

Once again, we have FAIL. The issue is NOT a "lacquer" coating (the coating is not actually lacquer) the issue is obturation. Remember the ductility of brass I mentioned above? the issue is the less ductile steel not forming as tight a seal in the chamber thereby causing combustion gases to blowback into the chamber effectively reducing the chamber's size. I am sure those of you who shoot Wolf a lot have noticed a difference since they switched to their new case coating. Yet despite their insistence that it is the "lacquer" causing the issues they will also void the warranty for using any coated steel case and even UNCOATED ammo? Asshattery seems to be afoot here as well.

Your rifle is an investment and it only makes sense to choose quality ammunition for a quality rifle!

Indeed they are correct, however their definition of "quality ammunition" and "quality rifle" vary greatly from any I have ever heard. "Quality rifle" seems to mean "shit we slapped together the other day at work with some parts we got from some dude" and "quality ammunition" seems to mean ammunition made to specific narrow specs because it's far more cost effective for us to tell you the consumer that you're using the wrong ammunition than it is for us to actually take the time and care to produce a rifle properly."
It's never the Indian, always the arrow.

[Asmodeus6]

Back from the dead?

Fwiw I think I'm at about 75% on the do not shoot list with a track record of 100% so far. In fact... I just shot lacquer, polymer, and silver bear Sunday. About 300 rounds worth...

No issues. Oh some hornady tap too.

DPMS rifle...

[Rundownfid]

You may well find that with a 1-9 twist rate your rifle is not capable of shooting any bullet heavier than 69 gr. accurately. This should not be a problem unless you want to try the really high ballistic coefficient ammo. 55 and 62 gr should shoot accurately with that twist rate, hope you enjoy your rifle.

[USAFSP]

What would be the ideal grain/brand .223 ammo for a DPMS AP4 - 6 grooves, right-hand 1x9 twist?

Define Ideal please.

55 to 69 grain would be your best bet. It may or may not shoot heavier stuff, your just gonna have to try it out.

Get some factory match ammo and go from there.

About the ammo on the ban list..... Pay no mind to it. Research surplus before you buy it to find if its a problem ammo... Wolf will be fine. It might void your warranty, but if it wont run wolf, its a gun problem, and personally, I'd sell it. All my guns run wolf. I shoot CMMG, a custom mega, and a BCM.