Originally Posted By 0uTkAsT:
Great thread!

I was about to pull the trigger on an 11.5, but now you've got me torn between doing a 12.5 instead

Originally Posted By CountryGuy:
There is the light and fast bullet crowd and the slow and heavy bullet crowd, with others in between.  Velocity is not the only important item to consider in bullet performance.  I go from one side to the other depending upon circumstances- typically driven by research of suspected/proven bullet terminal performance and accuracy for the task I have tailored each particular weapon to.  Velocity at a particular distance is just one component of the equation.

My first AR purchase was a Bushmaster 16" pencil barrel back in 2003.  My 10.5" is a recent build and has quickly become my favorite for MY uses, as a quick access, quick pointing all around defensive gun and my primary go to long gun; it is my truck gun (after the revolver.)  It has a Meprolight RDS that is always ready to go, so the usage and parts match the purpose.  It is a short range piece- out to 110 yards.  And of course the shorter barrel has less velocity and less bullet terminal performance at distance, which is why I limit it to 110 yards for my purposes.  Since I built and tested the pistol with tested accuracy as good as my BCM CHF 16" at my distances, I have gotten to the point I see little purpose for my 16" barrels with their reduced velocity.  With experience, if I had things to do over, I would have a 18" or 20" barrel for longer distances from a static position- which is not a priority of mine, and my 10.5" barrel as the primary, short range piece it has become.

I am using GD 55s for my 10.5" for bonded core performance with IMI OTM 77 as secondary.  I have chronoed each, among others and fired for accuracy.  Speer's statement on their LE web site concerning their 223 Gold Dots:  "...Gold Dot rifle bullets are optimized to ensure expansion out of barrels down to 10" at a wide variety of velocities out to 200 yards..."  But they do not state what the velocities are.  I am more conservative on the velocity vs. terminal performance and consider my 10.5" as a 110 yard gun, which is where the velocity drops to 2200 FPS- my minimum standard for GDs and 77 grain Sierra OTM types.  With a 50 yard zero and GD 55s or IMI OTM 77s, point-blank-range (P-B-R) is -2" at 10 yards to +1.25" at 110 yards from the point of aim.  With -+2" at 210 yards. -+2" is exactly what I require as a maximum variation. 

I am using GD 75s for my 16" as a 150 yard gun for the bullet weight and bonded core performance- again as the bullet velocity drops to 2200 FPS.  And GD 55s and IMI OTM 77s out to 200 yards.  P-B-R with GD 55 and IMI OTM 77 is -2" at 10 yards to +1.8" at 135 yards to -1.6" at 200 yards.  For the GD 75 it is -2" at 10 yards to +1.2" at 110 yards to -1.6" at 200 yards.  However, its velocity drops to 2200 FPS at 150 yards.

I do wish Speer would increase the 223 GD velocities.  But there is a potential down side to velocity increases.  In a bonded bullet, increased velocity most likely will cause increased expansion in tissue earlier and cause decreased penetration at shorter distances.  While increasing velocity on an OTM bullet type can cause increased fragmentation earlier and decreased penetration in flesh at shorter distances.  To me it is all a balance of terminal distance and material vs. terminal velocity, bullet construction and impact point, along with momentum for penetration depth.  Velocity is not the do all, end all.

I do hand load hand gun ammunition but quit hand loading defensive bullets since I can't get my hands on flash suppressed powder.  I will start loading 556 this winter when I have time and do have all of the components and equipment to do so, but probably not for defensive purposes.

Originally Posted By QCB:
Very diligent work.  Thanks for sharing.

Two comments.  The 62 grain Barnes TSK shows great velocity and more than 55 graiin.  Was 55 grain ammo 223 or 556 pressure?  I cant tell from photo of boxes you tested.  (Impressive).  

On trajectory, the 62 grain Fusion G1 BC is probably un-realsticaly high compared to other 62 grain bullets.  It was higher than pointed M855.  TSX BC probably alot more in line with small, flat meplat,  

Great work none the less!!

Originally Posted By Storm_Tracker:
@ Eagle_19er

What change if any does the suppressor on the 10.5" bbl velocity data have vs. an unsurpressed 10.5" bbl?

Thank you

Originally Posted By Eagle_19er:


You gain 1-2% velocity with a suppressor, but usually closer to 1%. I haven't done any formal testing of it but it's held true through the few loads I've tried both ways on the same day.

Originally Posted By Storm_Tracker:


So with a theoretical 2,500 fps I would expect about 25 to 50 fps slower without suppresor. Am i understanding you correctly?

And thank you again for your hard work and answering our questions.

Originally Posted By SpyHawk:
There's a newish post on TOS where the 5.56mm 62gr TSX were tested with both the Barnes Vor-TX and Black Hills loadings. The numbers were extremely close to what you posted in the OP, which offers some confirmation as well.

Originally Posted By SpyHawk:
I thought it was considered bad form and frowned upon to provide links to TOS?

Originally Posted By KnifeCollector:
I did a quick look thru the posts and didn't see this mentioned. In the tests the 12.5 always had higher velocity, except for the PPU 55 gr. It shows 2776 in the 12.5 and 2821 in the 11.5.  Is this correct?

Originally Posted By SpyHawk:


Look at this test from 2012, it definitely seems plausible to me.

Originally Posted By mr_h:
how did i miss this? wow, great stuff eagle.

Originally Posted By Saddlerocker:
Another theory is that it was a liability concern. Not wanting issues with 5.56 in .223 guns.

Originally Posted By mitsuman47:
Unfortunately, this is exactly the reason I've heard they discontinued the 5.56.

I may or may not have pulled the projectiles on a couple boxes of the .233 version and given them a little "bump" in velocity*....for science. 

*I do not recommend anyone do this. As with reloading any other projectile/powder/primer combo, Iwas carefully watching for pressure signs. Don't blow your face off. 

Originally Posted By BigMan74:
OP can you enlighten me on how you are adjusting the gas block on the 11.5?

Originally Posted By Eagle_19er:


What exactly are you asking for? It's an SLR Sentry. I had it set to position 9 or 10 (don't quite remember honestly) and it cycled all the rounds tested. Some were a bit gassier than others.

Originally Posted By CountryGuy:
OP:  Yours and my chrono results out of 10.5" barrels have really made me take a hard look at my initial primary and secondary ammunition stock for the short barrel 556.  Your Federal Fusion MSR 62 grain results provide 881 ft. pounds of energy and my Speer GD 55 grain results provide 833 ft. pounds of energy.  Not a lot of difference but in the case of short barrels and some distance- maybe enough, depending.  Online pricing for the Fusion MSR is ~ $1/round plus shipping and I typically purchase no less than 400 rounds of any 223 defensive type ammunition at a time and usually more if I need to test something new- like the Fusion MSR 62 grain, in this case. 

I feel comfortable Fusion MSR will chronograph similarly in my 10.5" barrel as in yours with the results we both have.   My 556 stamped barrels that have been measured and reamed as required to 556 specs, like any quality ammunition I have fed them and shoot reasonably small groups of everything- meaning they are more accurate than I.  Have you compared how the Fusion MSR group on paper vs. 55 grain Gold Dots or anything else?

Since a short barrel firearm is typically for shorter ranges, and in my case 50 yards - 75 yards, I am rearranging my short barrel ammunition stock from 75/77 grains as primary to the GD 55 grain as primary until I can find a good sale on Fusion MSR and test.  Alternatively, I will be comfy with my GD 55s in this case.  For the 16" carbine, my testing confirmed 75 grain GDs and 77 gr. IMI OTM as my primary choices.

Again, great job.  Your data have confirmed my suspicions about a lot of the ammunition I have not purchased/tested and your data will be in my library :-)

Originally Posted By 762AR25:
Anyone running a lot of the Barnes 70gr TSX or any other TSX loads?

Is the copper fouling as bad as some people claim?

Originally Posted By Joker1713:
Great thread!

1. Bump so this stays on the first page as the information available should be read by all visiting this subforum.

2. The data makes me feel good about going with a 12.75" barrel and pairing it with 55 gr Gold Dots.

Originally Posted By SpyHawk:

First, I want to say thank you to the OP again.

Second, where did you get a 12.75"? I want to hear more.

Originally Posted By SpyHawk:
There's a newish post on TOS where the 5.56mm 62gr TSX were tested with both the Barnes Vor-TX and Black Hills loadings. The numbers were extremely close to what you posted in the OP, which offers some confirmation as well.

Originally Posted By urbankaos04:

Was it Molon’s work?

Originally Posted By BMad316:
Any updates with the newer Speer 62gr Gold Dot?  I’m curious to see 10.5” muzzle velocity.

Originally Posted By Eagle_19er:

I've got a box of 62gr and a spare box of 64gr to put up against each other head to head. Just need to find the time to get out there.