Came across the ACR results the other day on Small Arms Reviews archive. The ACR Trial put the H&K G11, Steyr ACR, AAI ACR, and Colt ACR up against the M16. Up until now, I do not think the results have ever been published beyond archives.



The basis of the ACR was the use of hyperbursts to achieve increased hit probability by overcoming shooters error (ie a shooter could be 6" off target, and 1 of the 3 rounds would still strike the enemy.)



The ACR results file was found via the bibliography in this Armorers Bench article:

https://armourersbench.com/2018/02/18/advanced-combat-rifle-prototypes/

Small Arms Review does not have a sharable link to the PDF, so I uploaded a shareable version on DocDroid:

https://www.docdroid.net/ffL1XVy/s00440-pdf

Relevant findings:



















So, I was quite shocked by the results.

I had always assumed that the ACR rifles did better then the M16, but had failed to achieve the unrealistically high "100% improvement over the M16."

I had figured they probably did 30-50% better then the M16 - still a great advance, but not enough to convince the beancounters to shell out the $ for that level of incremental improvement.

Well, that turned out to be totally wrong. The M16 (with and without optic) ended up performing better then any of the ACR rifles.

Not only were the ACRs not a 100% improvement, but pretty much across the board they all ended up measurably worse then the M16.

The only increase in performance over the M16 with Irons was found at long range...using the M16 with 4x ACOG, as well as the modified Colt with ACOG.

So, this does help explain the enduring AR forever lifestyle we've found ourselves in.

Mmmmmm Colt ACR

Attached File


Thanks for posting! Chris Bartocci did a great section in Black Rifle II about it. Defiantly a really unique program they were trying

The acr was a fail before it started. I have some misc duplex ammo and they never worked right sacrificing a lot of accuracy at medium distances.

The phase 1 ammo was literally a flat backed bullet butted up to another. The end of phase 2 is when they were starting to put a cone in the back of the rifts round to at least help them fly a little more straight

neat stuff to look at for sure, but I think it should be in the A2 forum, not here in retro

Topic Moved

Interesting that their test showed no significant difference between irons and optics. Obviously that conclusion is in conflict with the modern consensus that comes from real world experiences and subsequent developments. Maybe a lack of familiarity with the optics over iron sights? I've always wondered how optics development would have changed if the Army made the TA01 the general issue optic for the A2 in the 80s, like the Elcan for Canada and the SUSAT for the UK.

Great info, thanks.  I have always been interested in the SPIW and ACR rifle projects, and very little information exists on them so this was a god send!



I found this point interesting too.  You have to remember though that many people back then were very familiar with optics due to hunting rifles, etc (optics for hunting have been the standard for 70+ years).  

The other conclusion is that their results are accurate and there is minimal real world difference between those reticle optics (non red dot) and quality irons at common combat distances.  Remember, they did a lot of testing and analysis in this program.  Optics do have plenty of disadvantages themselves.  As a proponent of iron sights, esp for a SHTF rifle, I am more inclined to lean towards this hypothesis.

Thanks for uploading the pdf OP!

Buckner Range.  That's a name I've not heard in a long time.

Well optics did show some improvement on the Long Range (300-600m) testing over Irons. I suspect the limitation to the improvement is that the targets are pop up, at random distances, and target exposure was only 3,5, or 10 seconds. So the shooter has to see the target appear, draw down on it, aim, and fire, in that time window. Optics would help with the aiming, but not the reaction time.

As for intermediate range (75-225m) not showing improvement, this is also believable, as target exposure is cut to 1.5-3-5 seconds, and also incorporates moving targets.

Just like on the real battlefield!

Is that a Sopmod Beta?  And what's the crazy handguard on the AR?

Back up irons that can be viewed thru the optic.

The handguard on the AR was meant to function like a shotgun rib for quick point shooting at close targets.

This whole program / trial seems like an attempt to make up for a lack of training in marksmanship.

That would be my take as well. Some bean counter thought it might save money not having to train soldiers to be effective marksman? Accurate aimed fire wins firefights.

Probably a realization that the military is never going to thoroughly train most troops in marksmanship, so a technical solution to this problem would be a good thing.