Home Forums Hunting & Shooting AR and Tactical Rifles 77 grain SMK vs Hornady 75 BTHP?

Is everyone from Orygon an asshat?

Unfortunately that Alliant data is for standard 223. I never messed with AR comp with the 77gr TMK. But i have used it with 75gr ELD-M. I used hornady data for the 80gr Eld-m max was 23.2. I used 23.5gr with the 75gr eld-m. .

You might want to check barrel lengths. This one in particular is with a 24" barrel. So, subtract 100fps for a 20" barrel, 150fps for a 18".

Dang j, usually you and mm are the ar comp users here. I have the latest sierra manual with ar and bolt gun recipes for the tmk. Funny thing is they suggest 1 in 8 twist and faster, but my 1 in 9 savage shot them very well.

Many times, 1-9" can be a wild card as to what they will shoot................if you really want to shoot a 75-77 grain bullet, you really need to try it in a particular barrel to see of if works or not.

I have a M-700, 223, 1-9" that shoots most of them just fine..........depends on the particular bullet too.

MM

I think I'm getting 2650 fps with my 77 grain SMK load of 24.5 grains of TAC in my 16" barrels. I've pulled my 77 loads from my phone notes for some reason but I go by the 5.56 pressured loads, not the 223. Sierra always has been very light on their max loads for an AR.

I do remember the 17" Krieger SPR barrel I had got 2725 fps, same as my 18" Noveske SPR barrel.

But unless I'm shooting steel past 600 yards, I'm shooting 55 grain NBT's at 3100 fps in my 16" guns. I have a silhouette at 400 yards that has a heart flapper and a brain flapper, it's pretty easy to make hits on them. 600 is doable if the wind isn't terrible but past that I need lots of help.

bsa,

Go to the Ramshot reloading data page on their website & look at their data.

They are one of the only data sites I've seen that show separate data for the same powder/bullets for both 223 Rem & 5.56 NATO pressures.

Ramshot Data

You can compare the same bullet/powder combos there & get an idea of how much more typical loads change when one steps up to loading to the 5.56 NATO pressure loads.

IIRC, 223 Rem pressure data max's out at around 55K PSI; NATO, while not a SAAMI round, goes to around 62K PSI.

I have seen no other data listed anywhere for AR-Comp that is anything other than for 223 Rem; if data for that powder was developed & published to 5.56 NATO pressure, the loading's would be higher.

I routinely load AR-Comp with 77 gr SMK & Bergers at 22.8-23.0 gr of powder charge...............and that's about exactly where the guy doing the MK-262 clone testing ended up as well (video that I posted).

I think it was Bob Hagel that once said, somewhere, that you never know where the top is until you get there & then back off....................

MM

Anybody using RL15?

I like RL-15 for several cartridges, & used to use it in the AR loading's but I've phased it out in 223/5.56 in favor of AR-Comp.

AR-Comp is a re-formulated version of RL-15 that is more temp stable, finer grained (flows very well) & as re-formulated, came out just a tad faster than RL-15.

MM

I'm using RL15 on the 75bthp, haven't tried it with 77 grainers yet.

With the 75 bthp and an 18" 7 twist barrel, my best accuracy with RL15 has been at around 2,550 fps. Any hotter and my groups open up.

Some very preliminary loads with leverevolution looked promising with the 75bthp at about 100 fps faster, but more testing is needed. This stupid virus has closed my range down.

For awhile AR-comp was hard to find last year l. So probably why I never messed with it with 77 tmk..

Yes

John,

What’s that load?

Yeah, one of my barrels shot them at 2744 fps avg. Weird because my savage bolt gun wasnt shooting them that fast, even with slightly more powder. I wasnt getting any serious pressure signs in that rifle, but was more than a grain over max listing.

24.5gr of RL15 I used CCI BR primer but probably could use cci 400. Bullet seated to 2.250, in LC brass

thanks brother....

That’s where I got the idea to try LVR from. He has a pile of data on his pages.

I just need to pull the trigger and buy a WOA barrel in 223 Wylde. His accuracy improved tremendously when he made the switch.

I’m sure. I guess if I am replacing barrels I’d go with a Krieger or similar that I’d use in my bolt guns. Do the WOA barrels shoot better than those would?

For the money, they are a great buy.............you probably won't find much in their price range that has been lapped; I have 3 of them.

But the Criterion & the button rifled Rock Creek barrels that Craddock uses are about the same or better for around the same price range, maybe a little bit more. And he is just great to work with of you want something in particular.

MM