Dpms a15 .223

[Lilswede1]

Factory magazine is too short for the 2.295" loads that shoot really well in my Browning and Tikka.
Have ordered several new mags from ASC (2.318" +/- .002) that should handle the longer loads just fine.
MSR (more politically correct nomenclature) chambers and shoots longer loads fine but have not experimented with different loads at the range yet.
Question: What different loads have been tried; what were they -- did they different loads affect accuracy?
This is my 1st AR.
After shooting several rounds to fireform case to rifle the shoulder measurement was .005"/.007" longer than factory ammo or my other .223's.
Is this normal?

 

[Metal god]

You will be hard pressed to find any mag that's internal length is longer then 2.270 . Do you have a link to the new mags you ordered ? I'd like to get some if the internal length is in fact 2.290 or longer , man that would be great !

After shooting several rounds to fireform case to rifle the shoulder measurement was .005"/.007" longer than factory ammo or my other .223's.
Is this normal?

It is as common as any other rifle having a longer chamber then another . The thing to be aware of is the way the platform works and how the gas system effects the length of your fire formed cases . It's not uncommon to have very inconsistent fire formed cases when fired from an AR . Because of this you may not want to trust the measurement you get . I have found standard 5.56 NATO ammo tends to give me a more consistent fire formed case then the weaker 223 ammo like PMC 223 or others .

Also be sure to FL size all your cases when loading for a auto feeding rifle . Neck only sizing is not recommended . One reason is you can actually have a fire formed case from your rifle that is actually a couple thousandths longer then your chamber . Or the body has expanded a tad more then the diameter of the chamber causing feeding issues .

 

[Metal god]

Found them

http://www.ammosc.com/223-stainless-steel-30-rd-magazine/

ASC Stainless Steel magazines are an improvement on a classic, with the highest levels of durability and increased longevity, simply the best in the industry! Our magazines are manufactured 100% start to finish in the USA using .020 gauge 410 Stainless Steel Alloy, heat treated for superior strength and lasting endurance. Our magazines are chemically treated for corrosion resistance [ref QQ-P-35] and coated with our proprietary finish, Marlube which is a wear-in not wear-off coating that burnishes into the surface providing self-lubricating properties. The interior dimensions of OAL 2.316” ± .002 are perfect for reloads.

 

[Mobuck]

The difference is in the fabrication of the mags. Space(OAL) is gained by switching the metal lap/weld from the front of the mag to the rear. In my case, the small gain in OAL did not make a significant diff in either function or accuracy.

 

[Metal god]

Mobuck : I'm very interested in this mag . What bullets and amount of testing did you do . I have a NM service rifle I load 77gr smk for and would love to finally do some COAL testing . With the 77's You get what you get as far as COAL .

I'd agree I'd not likely see a difference in a 55gr bullet but I might with the 77's in my 223 Wylde chamber . If you've done a bunch of testing with the 77gr smk and found no benefit then I'll likely pass .