[Smokin45]

Just picked up some TAP 75 gr. and was wondering how it would shoot through a 1:9 twist barrel? I will be using it with a Armalite AR with a 16" heavy barrel if that makes a difference..

[larson1122]

The only way to know for sure is to shoot it and find out. Some barrels will shoot it just fine and others wont.

[Armchair Commando]

My 1-8 loves 77gr Sierra Matchkings. Only way to know is to shoot it.

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[faawrenchbndr]

Originally Posted by Armchair Commando

.....Only way to know is to shoot it.

[cowboy1964]

I'm only shot 75gr TAP through 1:9 at 25 yards. Works ok but that distance really doesn't prove anything.

I've since decided to standardize on 1:7 twist so I can shoot 77gr Mk 262 and such.

[Travclem]

My 1:7 ARs love it, my best friend's 1:9 loves it, and my 700P 1:10 loves it. My 75gr Hornady OTM handloads are good out of all of our guns out to 200yds. I haven't shot them further than that on paper. I have killed a couple hogs at further distances than that so I assume they are still stable enough.

My 700p shoots cloverleaf groups at 100 and 1-1.25" at 200 with this load and according to the interwebz it's impossible due to the 1:10 twist.

I have yet to find a gun that wouldn't shoot it, but go shoot some out of yours to be sure. That's the only way to know for sure.

[Matthew Courtney]

More than being a rifle to rifle thing, its an environment to environment thing. Gyroscopic stability requires more rpm's in environments with more friction from the bullet passing through the air as well as higher rpm's when the center of pressure is farther forward. In less dense air, friction is less. Temperature, humidity, and low barometric pressure lessen the density of the air and allow bullets to stabilize at lower rpms.

[Foxtrotx1]

Originally Posted by Matthew Courtney

More than being a rifle to rifle thing, its an environment to environment thing. Gyroscopic stability requires more rpm's in environments with more friction from the bullet passing through the air as well as higher rpm's when the center of pressure is farther forward. In less dense air, friction is less. Temperature, humidity, and low barometric pressure lessen the density of the air and allow bullets to stabilize at lower rpms.

So good at 7,000 feet. Not so good at 2000?

[Travclem]

Originally Posted by Foxtrotx1

So good at 7,000 feet. Not so good at 2000?

That's the idea but I can tell you that mine work at 3,256 ft. (Lubbock, TX), 2,605 ft. (Post, TX) and 3605 ft. (Amarillo, TX).

[Gunnut 45/454]

The 75gr Horn match bullets shoot fair out of my 1:9" and Sav 1:9" good enough to use for close work. But the 75gr Amax shoots real good in my PSA 1:7" and yes you can load them to fit the Mag.

[Steve in PA]

Both my Savage 12FV and Bushmaster rifles shoot the 75gr bullets just fine. Both are 1:9 barrels.

[smokin762]

My Bushmaster AR has a 20” 1/9 barrel. It shoots Hornady 75gr Superformance at 100 yards very nicely with iron sights. I tried it with the scope and kept tight groups.

As said, you just need to try it out.

[WoodenPlank]

As others have said, try it and see.

Longer barrels are more likely to see good results than shorter, however. Since you asked about TAP, you might want to check out some of the lighter 62-64 grain bonded soft points, Gold Dot JHP, or the various loads out there using Barnes TSX bullets.

[WinterWizard]

Originally Posted by Smokin45

Just picked up some TAP 75 gr. and was wondering how it would shoot through a 1:9 twist barrel? I will be using it with a Armalite AR with a 16" heavy barrel if that makes a difference..

I have wondered about this, as well. The packaging even states "1-9" twist or faster," so 1-9" should be good to go. However, there is the occasional report from shooters that their 1-9" barrel didn't stabilize this round. It does seem to be a very, very small minority, though. I bet 19 in 20 barrels with a 1-9" twist will stabilize this round just fine. But, like others have said, no way to be sure until you shoot it at about 200 yards and check for keyholes, etc...

I wonder what Hornady would say if someone with a 1-9" twist barrel contacted them to say their barrel couldn't stabilize this round? Since it's even on their package, couldn't that be false advertising or misleading? I bet they would send out some replacement rounds, maybe 60gr Tap or something similar if you made a big enough stink.

[brisk21]

I know a dude who just got a DPMS with a 1-9 twist. He said that the 100yd groups opened up to about 6-7 inches with 75gr. bullets. He was holding 1-2 inch groups with 55gr. ammo.

[cowboy1964]

Originally Posted by WinterWizard

I wonder what Hornady would say if someone with a 1-9" twist barrel contacted them to say their barrel couldn't stabilize this round? Since it's even on their package, couldn't that be false advertising or misleading? I bet they would send out some replacement rounds, maybe 60gr Tap or something similar if you made a big enough stink.

Possibly. OTOH, they make no claims about accuracy at distance, so...

[WinterWizard]

Originally Posted by cowboy1964

Possibly. OTOH, they make no claims about accuracy at distance, so...

Yeah, but if it's keyholing, it's obviously not stabilized, and there is physical proof by way of the paper target. If they say a 1-9" twist will stabilize this bullet and the bullet is tumbling sideways through the air from a 1-9" barrel, I believe that's a problem. Of course, there are small discrepancies from barrel to barrel. Your 1-9" may actually be a 1-8.8" or a 1-9.2", etc. That is where the problem lies likely.

[jrs93accord]

Typically, a 1:9 barrel is good for 55gr. to 72gr. ammo. When you get into the 75gr. and higher, 1:8 or 1:7 is the best route to take. They can stabilize the heavier round better. This is not a hard fast rule, but more of a guideline. Sometimes, it can depend on the load of the heavy round as to what kind of performance you will get in a 1:9 barrel. Personally, I have a dedicated 1:8 (18") AR (Mk12 Mod0) for shooting heavy ammo (in my case, 77gr.). Everything else is for the .55gr. - 63gr. ammo. My advice, if you want to shoot a heavy round, build an AR that is more suited for it.

[Warp]

Good reason to buy a proper 1:7 barrel if you ask me

[smokin762]

Originally Posted by Warp

Good reason to buy a proper 1:7 barrel if you ask me

[Warp]

Originally Posted by smokin762

Many, if not most, of the more desirable bullets are 75gr or heavier. These bullet weights (well, lengths) work best with a 1:7 twist. This is a great reason to get a rifle with a 1:7 twist.

[smokin762]

Originally Posted by WinterWizard

I have wondered about this, as well. The packaging even states "1-9" twist or faster," so 1-9" should be good to go. However, there is the occasional report from shooters that their 1-9" barrel didn't stabilize this round. It does seem to be a very, very small minority, though. I bet 19 in 20 barrels with a 1-9" twist will stabilize this round just fine. But, like others have said, no way to be sure until you shoot it at about 200 yards and check for keyholes, etc...

I wonder what Hornady would say if someone with a 1-9" twist barrel contacted them to say their barrel couldn't stabilize this round? Since it's even on their package, couldn't that be false advertising or misleading? I bet they would send out some replacement rounds, maybe 60gr Tap or something similar if you made a big enough stink.

I have several boxes of Hornady Superformance Match 5.56 NATO 75 gr. BTHP. There is nothing on the box that I can see that say’s anything about what rifling to use. It just states not to use it in .223 Chambers. I checked their website and it didn’t come up with anything either.

I would post a pic of one of my targets from last weekend but, I left it at work Friday. We were having this same discussion between AR owners.

[smokin762]

Originally Posted by Warp

Many, if not most, of the more desirable bullets are 75gr or heavier. These bullet weights (well, lengths) work best with a 1:7 twist. This is a great reason to get a rifle with a 1:7 twist.

Some 1:9 barrels can shoot 75 gr bullets without any problems. Some can’t. Some 1:7 barrels can shoot 55 gr bullets without any problems. Some can’t.

I know it’s true, that certain rifling was designed for certain weight or length of ammunition. It’s just not always the case. Nothing is in stone.

A person doesn’t know what their firearm can and cannot do, if they don’t put it through its paces. Then those tests may only be good for that particular firearm.

[Warp]

Originally Posted by smokin762

I know it’s true, that certain rifling was designed for certain weight or length of ammunition.

For 55-77gr ammo, your best bet is still 1:7

[smokin762]

Originally Posted by Warp

For 55-77gr ammo, your best bet is still 1:7

I think 55-77gr is more common with 1:7 barrels, but not exclusive.

My 20” Bushmaster has no problem with any of these. I have not tried anything over 62gr in my 16” RRA yet. I just haven’t gotten around to it yet.