To load or not to load 80grain 223

[quigley257]

I have had great results with the Hornady 75gr Match HPBT bullet loaded to mag length. They shoot fantastic in all my ARs with 1/7 and 1/8 twist barrels. They are economical and accurate enough to use for Prairie Dog bullets. Not as explosive as the dedicated varmint bullets like BTs and VMAXs, but effective nonetheless.

 

[Tony Formicola]

Really just try it. The worst thing that can happen is you shoot a 6" group of a keyhole in which case you have verified the manufacturer's assertations. People get way to hung up on the twist recommendations for AR's in particular. I have found that in several of my 1;8 barrels the 77 gr SMK and 75 gr Hornady OTM both shoot extremely well and out performs the 69 Gr SMK which contradicts the theoretical predictions.

 

[xsn10s]

From what you guys are saying I'm not really wanting to try the 80 grain, it could shoot good but most likely I don't think it will.

That's what I would do. It's a lot of work for a bullet that isn't ideal from the mag. Is your end goal long range target, varmints, competitions? What's the primary purpose for your loads?

 

[bamban]

We shoot tons of 80 class bullets in the slow fire prone event of the CMP and NRA matches. By rule matches are single load only. Our barrels range from 6.5 to 8 twist. Some 8s will shoot the 80 class and we found just would not shoot them precisely at 600 yards no matter how much effort is undetaken.

Here ia the issue, some button barrels the twist tolerance is the culprit. You may emd up with the slow side of the tolerance 8.xT, that would not shoot the 80s. And if you are lucky you may end up with a barrel faster than 8.0T.

When we say barrel won't shoot, it means low X count at 600, or shots not on call. One of our top shooters, the President's Hundred overall winner at Camp Perry in 2018, called and told me about his barrel that will shoot 200 at 600, but low single digit X count. He rebarreled, the next match he shot 200-13, all shots on call.

Manufacturing tolerance might get you.

Another shooter, an accomplished Palma shooter who dabbles in service rifle competition had an 8T barrel that just will not shoot any 80 class bullets. He tried prone with sling on the bench, off a bipod, and finally a machine rest. Still would not shoot any 80s, any load, any powder, any primer. Off the competition AR it went. It shot the short range (200-300) ammo loaded with 77 class bullets with no issues.

 

[del2les]

I've been using Hornady 80's for many years, and in my 1/8 twist 20" NM-AR, my 24" AR-VT and 26" 1/8tw bolt guns, and they have all stabilized well.

 

[David Urasky]

OMG, I can't believe there is such confusion and misconceptions about barrel twist requirements. Oh I guess I can.

The required barrel twist for any bullet is determined by the length of the bullet, not weight. Although you would think they go hand in hand. But I can have a longer bullet for the same weight based on different ogives, if it's a hollow point and if it has a boattail or not. A tool which can be used for any bullet is the Barrel Twist Calculator found at https://bergerbullets.com/twist-rate-calculator/. Or you can calculate it with (C x D2​) ÷ L = T. Where C=150, D is the diameter and L is the length of the bullet (https://www.ssusa.org/articles/2019...e-rifling-twist-rates-for-stabilizing-bullets). Notice weight is not considered. This is actually a very good article and would suggest it.

Now, required twist is not a given. Manufacturers provide a reqired MINIMUM twist. Meaning you can run a faster twist for a given bullet. But only to a point. If you spin a bullet too fast the jacket can actually fly apart from centripital force and the bullet not reach the target. I've seen this happen with custom bullets in F class guns. And, sometimes you can get away with a somewhat slower twist such as the 1:8 instead of the 1:7.

Go load some rounds and shoot the 80's through your 1:8 twist barrel. See how they do. If it doesn't work all that will happen is you will see "key holes" in your paper where the bullet has become unstable and has begun to tumble. Depending on the distance you're shooting you may not see this. But as the velocity and spin decay at distances it happens. Again I've seen it with 223's using the 80's at 1000 yards in F class competitions. But if you're only shooting 400 yards or less it may not be an issue.

So don't over think it. Try the 80's in the 1:8 twist barrel you won't hurt anything. You may be happy with the results.

 

[Rob67gmc]

Try a few and see. I have two identical rifles, same brand, both 1/9 twist. One will shoot 77 grain good enough for NRA Highpower. The other one can't hit the ground pointing straight down with them. You may be surprised.

 

[spladi]

Bought couple boxes of Hornady 80grain bullets for AR-15, I have a faster twist 1/8, so thought they would be good, looking at box it says for 1/7, didn't realize 80gr might be to much, looking up bullets for 1/8 twist shows 77 is about Max. Now been using 69 grain Hornady hpbt, which are ok accuracy wise but don't think I would buy again, but I look at box on 68gr and it says for 1/9 twist. Is this why they are so so in my 1/8 twist, kinda makes no sense cause they seem kinda heavy for a 1/9 twist. So should I send my 2 boxes of 80gr back to Midway since I have no 1/7 twist as they were not very cheap and don't want to waste components if it's gonna shoot crappy and why would they have 1/9 twist for 68 grain on the box.

I think in your case it's fair to say that Hornady is covering themselves from ridicule by posting 7 twist is needed as is a 9 twist for the 68 grainers. The 68 's should definitely do well in the 8 twist and the 80's will probably be marginally stabilized in the 8 twist. IN my 8 twist the 80 SMK's shoot great. A great bullet is the Berger 73 grain BTHP and it should be ideal in your AR. out to 500 yds or so, even longer if conditions are good.

 

[PatriotHenry]

So the 68 grain which says 1/9 twist on box may be better in that twist than in 1/8 twist, may explain why they are so so in my 1/8 twist

If you are twisted faster than the recommendation they should shoot fine, if slower then you have a problem.

 

[Chrsm]

La la la La la. La. To many post about twist rates for weight size bullets……. You have the rifle, mag and throat, right there in front of you! If it will chamber, pull the trigger! Let us know! I've bin running 70s with a rounded ogive, the chamber determined the COAL that fit the mags with room to spare. With the ar that is seldom the case! If I had them I'd try them!

 

[asd9055]

I don't know wher the OP read the 7 twist minimum. Hornady on home page says 8 Twist for that bullet. I have simillar in Nosler, and I will load for my 8 Twist and find out the "real" way. I bet in some it shoot, in others it might not.

 

[6pakzak]

I don't know wher the OP read the 7 twist minimum. Hornady on home page says 8 Twist for that bullet. I have simillar in Nosler, and I will load for my 8 Twist and find out the "real" way. I bet in some it shoot, in others it might not.

I read it on the box that contained the bullets

 

[asd9055]

OK , hornady then is giving out conflicting information.

 

[6pakzak]

80gr went back, local guy had 60gr Hornady varmint, first group at 24.5 varget was 1.5 for 6 shots, lowered charge to 24.2 and loaded 4 rounds, 3 we're in one hole and 1 was .5 away so seems to like 60gr as long as I keep charge low, maybe I need to lower charge on 68gr also