Home Forums Hunting & Shooting AR and Tactical Rifles W-W 748 reports of super high velocity shooting 65gr Sierra GK

Hand out that came with current issue of Hand loader magazine listed 27.5grs of W-W 748 produced 3,160FPS out of 20" BBL AR-15.That's 200 fps faster then max load of Varget ? Can any one confirm this?

I know in my AR, 25 gr of Win 748 and the Nosler 55 BT shoots little bitty groups and the last coyote i shot with this rifle and load dropped in it track at around 150 yards.

I did the same think with a 26grs of Bench Mark behind a 55gr V-Max.Shot her from a 20degree angle above hit her just in front of Shoulder plex bullet came out at bottom of neck,dang near took her head off.......... I just think the posted velocity of 3,160 with a big 65gr Bullet is a bit high. Local gun shop had 20 1lb cans of the stuff. I wonder if that high velocity was reported to get us to buy the stuff up ? Because I haven't seen that powder in local gun shop for last 10 months ?All of a sudden they have a bunch ? Maybe I'm thinking too much ?

Saw nothing close on Hogdons site. They now supply winchester's powder and thought they might have changed something up but no word.

Who did the hand out come from?

AR-Tactical loads Brought to you by www.LoadData.com apparently the parent company is Wolfe Publishing Company They publish Rifle magazine and Hand Loader Magazine. When I bought current issue of Hand Loader Magazine it was wrapped in plastic with this 10 page data collection together. It has 6 cartridges load data all chambered in the AR-15 plat form. 223 6.5 Grendel,6.8 SPC .450 Bushmaster,458 SOCOM,.50 Beowulf. I just think they're listing of 3,160 for a 65gr bullet is way to high out of a 20" BBL.

Nosler brass and rem 7.5 small bench rest primers but loaded to saami 52000 pressure... hmmm Don't know about the pressure rating but NATO 62gr is loaded to 60000 and runs close to that with a 20" barrel.

I run 2963fps avg, with a 60gr V-max in a 16" AR-15. Got 3110fps with Nosler 60gr but it was a little warm in a 17" AR-15.

Nato Ammo runs 60,000 ! Is that right ? My gosh Sierra book list loads for AR-15 as lighter then a Bolt action. I have shot Nato stuff and it did seem awfully heavy . What were your loads that got you those high velocities ?

QuickLoad says that load would give a peak pressure of about 77054 psi. Not good!

It might be worth a try working up some. I hope I can find that issue of Handloader, particularly for the Beowulf loads. I don't find much info for the 50 around, except from AA. Lil Gun works pretty good, though. Still, like to see what others are doing. Thanks for the tip!

I have the 50 data in front of me now. What bullet ? They list a Powder and WT of charge then COL but no velocity. They have one bullet called a 530 gr Power Belt DG steel tip Alliant #7 37.7grs. COL of 2,240 Another one is 300 SinterFire Lead free Frangible Lil'gun35.0 COL 2.220 Another one is called a 348 Power Belt Aerotip Lil'gun 35.5 COL 2.160. Hope that helps

I never saw excess speeds when playing with it years ago, and then found out its SUPER temp sensitive as it gets hot so haven't even thought of using it since the late 80s.

25.8 TAC and the 60 NBT got me 3110pfs ina 17" Kreiger tube.
25gr Benchmark and the 60gr V-max got me 2963fps in a 16" Colt tube.

As always these loads should be worked up, yada yada.

about halfway down; http://www.thegunzone.com/556v223.html

here's another source; http://www.6mmbr.com/223rem.html

".223 Remington vs. 5.56x45--Chambering and Throat Considerations
Is the .223 Remington the same as the 5.56x45? The answer is yes and no. There ARE differences between the .223 Remington as shot in civilian rifles and the 5.56x45 in military use. While the external cartridge dimensions are essentially the same, the .223 Remington is built to SAAMI specs, rated to 50,000 CUP max pressure, and normally has a shorter throat. The 5.56x45 is built to NATO specs, rated to 60,000 CUP max pressure, and has a longer throat, optimized to shoot long bullets. That said, there are various .223 Remington match chambers, including the Wylde chamber, that feature longer throats. Military 5.56x45 brass often, but not always, has thicker internal construction, and slightly less capacity than commercial .223 Rem brass."

I don't have a strain gauge and can only go by what I've read from several sources, if you can prove otherwise I'd be interested. And yes there is some reports of different methods of testing but if you ever chronograph real NATO spec ammo (not XM) vs commercial it does run higher velocity or has in what I've seen.

TWR,
A lot of good info in your post. Just purchased a Bushmaster w/16" barrel. I have quit a bit of experience with .223 in my son's Tika T3 shooting 65gr Sierras and after reading these posts it appears I can break out the 748 that hasn't seen much use for years and run it in the new rifle. Looks like starting around 24g and working up with the 65g bullet. Benchmark and Varget are also available to use. What would be your preferred powder and load??
The 65 Sierras work for Whitetail well. I have a box of 60g Noslers available too.


Dave

Like Rost, I come from a highpower background, and in the early days of the AR15 Service Rifle, WW748 was attractive because it showed very good velocities even with the heavy bullets that we were using. The reality like Rost says is that it's a psychotic powder with temps. What was safe when you worked it up in 60 degree temps might blow primers in the summer heat of Camp Perry.

Here's some info regarding 223 pressures vs 5.56 pressures off of Wikipedia;
"NATO EPVAT test barrels made for 5.56 mm NATO measure chamber pressure at the case mouth, as opposed to the location used by the United States civil standards organization SAAMI. The piezoelectric sensors or transducers NATO and SAAMI use to conduct the actual pressure measurements also differ. This difference in measurement method accounts for upwards of 137.9 MPa (20,000 psi) difference in pressure measurements. This means the NATO EPVAT maximum service pressure of 430 MPa (62,366 psi) for 5.56 mm NATO, is reduced by SAAMI to 379.21 MPa (55,000 psi) for .223 Remington.[12] In contrast to SAAMI, the other main civil standards organization C.I.P. defines the maximum service and proof test pressures of the .223 Remington cartridge equal to the 5.56 mm NATO."

I AM set up to run strain pressures on my AR, and I've run pressures on factory 223 as well as USGI M855. I kept scratching my head on why the M855 was no hotter than a lot of the factory 223 I ran. I'd heard that NATO pressures were higher. Rost kept telling me to give him the 60K data. I'd heard the measurement protocols were different. That article was the best explaination of how and why.

Oh yeah...SAAMI max on a 223 is 55K...not 50K or 52K, and contrary to what is out there on the internet...while it certainly holds true for 7.62, most LC 5.56 and other USGI 5.56 brass is not heavier with less internal capacity than commercial brass.

and I still don't think that 60 will get you in trouble... but the unavoidable spikes over 60 could eventually....

Of course I know where I"m at when shooting those loads, and am VERY careful that the ammo is consistent temp, not in the chamber long and such... Never kept a round in the chamber longer than about 20 seconds or so max....

Dave, I like TAC for almost everything 223 but especialy in the heavier bullets.

ChrisF, thanks for the info. I've seen that wik report before and weighed it against what Winchester and all other sources say. I have chronographed M193 that was hotter than any commercial 55 gr I had. But I'll concede as I do not own my own pressure testing equip as you do.

TAC really showed lots of promise when I tested it years back, as it was new, and had I not been totally invested in N540/N550 what we found with rattle battle loads and 77s with TAC was enough that had I kept shooting TAC would have netted a hard test against the N500s...

N540 and N550 good?? Looks like some range time is in order. The 15 year old likes open sights and running clips of 30 at a time instead of target shooting from the bench. Gotta work on him a little. May have to put him to work so he can buy ammo.

Dave

the ONLY reason I run N500s is to boost speeds of things like 90 jlks in competition matches... if I were not shooting to win, I'd be leaning back towards TAC or others generally, as N500 isn't cheap, hard to get sometimes etc... but it does shine for what I use it for.

Just FYI. AND it won't like anything but warm to hot loads generally speaking. I was told that and still started low and was pissed with the groups, but once we got to the max charge area things shrunk and I've won more than a few things going that route match wise, including some nice results in national ocmpetition

Ok so the reported W-W 748 loads might be good for the winter. So if I develop a load in 60 degree heat and shoot it in 35 degree temps . MY POI will change ? That's no good I think I stick with Varget.