What are Heavy 223/556 bullets
- Thread starter Kram
- Start date
I choose bullets weighed against the barrel twist rate I plan to shoot them in. My bolt gun is a 1:12 twist and really bullets under 55gr are best suited for it. The 1:12 twist in my rifle will not stabilize anything over 60gr. I shoot the heavier bullets in my faster twist rate rifles like 69gr and up to 80gr. in a 1:7 twist.
The 223 Remington or 5.56 NATO can be loaded with a wide range of bullet weights and powders. The main difference between the .223 Remington and 5.56 NATO is operating pressure and chamber throat. The brass is identical. I have never seen a powder referenced "for heavier bullets" but if you could reference a specific powder it would help. Some powders show up pretty much across the board for bullet weights.
What twist rate and barrel do you have? Bolt or semi-auto? What bullet weight did you want to load for?
A few examples:
Ron
The 223 Remington or 5.56 NATO can be loaded with a wide range of bullet weights and powders. The main difference between the .223 Remington and 5.56 NATO is operating pressure and chamber throat. The brass is identical. I have never seen a powder referenced "for heavier bullets" but if you could reference a specific powder it would help. Some powders show up pretty much across the board for bullet weights.
What twist rate and barrel do you have? Bolt or semi-auto? What bullet weight did you want to load for?
A few examples:
Ron
TAC will work nicely for 55-77 grain bullets and it meters very nicely.
To me, and I'm no expert, anything that must be loaded longer than 2.26" COL is too heavy for me. So 77gr is the heaviest I load and I use TAC or IMR8208XBR. I don't like long-cut stick powders.
For 223 I generally consider 68-77g to be heavy, 50-62 generally to be medium, and under 50 to be light.
Slower powders tend to do better with heavier bullets, faster with lighter. Slower powders will work with lighter bullets, but may under perform velocity wise.
What bullet weights are you loading? I woukd go with tac for 55 or 62. And 4064 or varget if your in the 68-77 range. But that's just me.
As stated above your twist rate will dictate how heavy you can go. Generally 1:8 to 1:7 for the 70g+ stuff. 1:9 for 62g and down. And some slower twists, generally for light varmint bullets
Slower powders tend to do better with heavier bullets, faster with lighter. Slower powders will work with lighter bullets, but may under perform velocity wise.
What bullet weights are you loading? I woukd go with tac for 55 or 62. And 4064 or varget if your in the 68-77 range. But that's just me.
As stated above your twist rate will dictate how heavy you can go. Generally 1:8 to 1:7 for the 70g+ stuff. 1:9 for 62g and down. And some slower twists, generally for light varmint bullets
jetinteriorguy
New member
I like H335 for 55gr, H4895 for 62gr, and Varget for 68gr and heavier bullets. But I don’t load for MV, I load purely for accuracy.
Thanks fellas....
I know about the twist rates and such, I just couldn't figure out what all these powder manufacturer's mean by Heavy...
I loaded up some 62gr FMJ bullets with 4064 and Varget a few weeks ago. I picked up some Tac on Wednesday and loaded some 55gr FMJ yesterday.
I'll see if I can order some bullets larger the 62gr. This is all for plinking ammo.
Enjoy you weekend
I know about the twist rates and such, I just couldn't figure out what all these powder manufacturer's mean by Heavy...
I loaded up some 62gr FMJ bullets with 4064 and Varget a few weeks ago. I picked up some Tac on Wednesday and loaded some 55gr FMJ yesterday.
I'll see if I can order some bullets larger the 62gr. This is all for plinking ammo.
Enjoy you weekend
4064, never tried it.
Varget, tried it with 62gr and 69gr bullets and not as satisfied as some others.
TAC, Still use it with 55gr, 62gr and 69gr bullets. Nice enough I bought 10lbs.
Also if you can find it Benchmark and Accurate 2460 work well in the 223.
Have also tried Hodgdon BL-2C but not enough to make a judgement though it did show promise.
Varget, tried it with 62gr and 69gr bullets and not as satisfied as some others.
TAC, Still use it with 55gr, 62gr and 69gr bullets. Nice enough I bought 10lbs.
Also if you can find it Benchmark and Accurate 2460 work well in the 223.
Have also tried Hodgdon BL-2C but not enough to make a judgement though it did show promise.
I agree with others 65gr and higher are heavy for cartridge .
I'd first say don't confuse optimal/best with anything lighter won't work . IMR=4064 will shoot 55 , 60 , 62gr bullets just fine it's just a tad to slow to be "optimal" for those lighter bullets .
Second I'd say long extruded powders like IMR-4064 fill the case fast and the heavier the bullet the longer the bullet . This means the deeper in the case the bullet will sit/seat . That can be an issue if you are using a powder that bridges in the case and leaves air pockets of space in the case . This results in not enough room to seat the bullet as deep as need be for ... lets say mag length for an AR .
Example :
This is how deep a 77gr smk needs to be seated in order to feed from an AR mag . If your powder fills the case to the bottom of the neck , it's going to be pretty hard to seat that long bullet in there .
There are ways to get bulky powder to settle and allow for more room in the case to seat the bullet . Powder funnel with 12" drop tube helps and some guys will use a 36" drop tube . You can tap the sides of the case or vibrate the case to force the powder to settle .
My over all point is many powders that are best for heavy bullets for the 223 will likely need compressed loads , All my 77gr 223 are compressed by at least some .
I'd first say don't confuse optimal/best with anything lighter won't work . IMR=4064 will shoot 55 , 60 , 62gr bullets just fine it's just a tad to slow to be "optimal" for those lighter bullets .
Second I'd say long extruded powders like IMR-4064 fill the case fast and the heavier the bullet the longer the bullet . This means the deeper in the case the bullet will sit/seat . That can be an issue if you are using a powder that bridges in the case and leaves air pockets of space in the case . This results in not enough room to seat the bullet as deep as need be for ... lets say mag length for an AR .
Example :
This is how deep a 77gr smk needs to be seated in order to feed from an AR mag . If your powder fills the case to the bottom of the neck , it's going to be pretty hard to seat that long bullet in there .
There are ways to get bulky powder to settle and allow for more room in the case to seat the bullet . Powder funnel with 12" drop tube helps and some guys will use a 36" drop tube . You can tap the sides of the case or vibrate the case to force the powder to settle .
My over all point is many powders that are best for heavy bullets for the 223 will likely need compressed loads , All my 77gr 223 are compressed by at least some .
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I agree that bullets of 60-62 grains are borderline heavy and can use classic powders normally used for 55gr bullets like H335 and N133 and lighter or slower powders like Varget and IMR4064.
For me, bullets heavier than 62 grains shoot more accurately with powders like IMR4064 and Varget as well as IMR 4166 Enduron and VV N140.
These heavier bullets seem to perform best with the slightly slower powders because they seem to burn more evenly in longer barrels, although the performance advantage holds even for my 18-inch 416R barrel on my Les Baer Super Varmint .223.
For shorter barrel ARs (under 18 inches), I don't have any data that I can personally attest to.
The comment by Metal God about the heavier bullets being limited by the internal length of AR mags is very true. You either have the choice of loading to fit the AR mags or loading with a longer OAL and shooting single shot with a mag follower.
Of course, loading single shot tends to make shooting an AR a contradiction.
In my .223 bolt action target 1:9 twist barrel rifles, the mag length limits do not apply.
I load the 69 and 77 grain bullets out for a 0.020 jump and get the best accuracy.
The guidance on the Sierra 77 SMK and TMK bullets says they are recommended for 1:7 twist barrels and all the Stabilization Calculators that I have ever used says that a 1:9 twist barrel will only marginally stabilize a 77-grain bullet.
Interestingly, my two 1:9 twist rifles that shoot 77 grain Sierra bullets more accurately than any other bullets, including the Sierra 69 grain bullets.
However, any of the 75 grain bullets I have tried in either don't seem to perform as well.
I concluded that the good performance may be related to ballistic coefficient and/or bullet body length. The difference in bullet body length may induce more twist in some of the bullets.
For me, bullets heavier than 62 grains shoot more accurately with powders like IMR4064 and Varget as well as IMR 4166 Enduron and VV N140.
These heavier bullets seem to perform best with the slightly slower powders because they seem to burn more evenly in longer barrels, although the performance advantage holds even for my 18-inch 416R barrel on my Les Baer Super Varmint .223.
For shorter barrel ARs (under 18 inches), I don't have any data that I can personally attest to.
The comment by Metal God about the heavier bullets being limited by the internal length of AR mags is very true. You either have the choice of loading to fit the AR mags or loading with a longer OAL and shooting single shot with a mag follower.
Of course, loading single shot tends to make shooting an AR a contradiction.
In my .223 bolt action target 1:9 twist barrel rifles, the mag length limits do not apply.
I load the 69 and 77 grain bullets out for a 0.020 jump and get the best accuracy.
The guidance on the Sierra 77 SMK and TMK bullets says they are recommended for 1:7 twist barrels and all the Stabilization Calculators that I have ever used says that a 1:9 twist barrel will only marginally stabilize a 77-grain bullet.
Interestingly, my two 1:9 twist rifles that shoot 77 grain Sierra bullets more accurately than any other bullets, including the Sierra 69 grain bullets.
However, any of the 75 grain bullets I have tried in either don't seem to perform as well.
I concluded that the good performance may be related to ballistic coefficient and/or bullet body length. The difference in bullet body length may induce more twist in some of the bullets.
reynolds357
New member
IMO anything over 65 gr.
kilotanker22
New member
I agree that 65+ would be heavy for caliber. That said, Varget would be my powder of choice for everything 69 grain and under. 70+ weight bullets will certainly be better with a powder like Power Pro Varmint, Tac, or BLC-(2).
No, it doesn't induce more twist. Twist rate is determined by the pitch of the barrel rifling, and is a constant,
What a longer bearing surface (bullet body length) does is puts more bullet in contact with the barrel. This will change the overall amount of friction and result in what for practical purposes might be considered a "tighter" fit, between bullet and barrel and that MAY result in better accuracy in one barrel and no change in a different one.
Glad to hear it. Hope you can get some more powder soon. I generally find 1lb, for 223, gives me roughly 250rnds per lb, give or take a little. In short, I buy what I need to load a batch, and don't short myself to help the next guy. Buy I don't buy extra I don't need either. I keep my powder, primers, brass, bullets, evened up so I have enough to load what I have.
Kilo,
I think you may have things a little backwards there, buddy.
Typically a slower burning powder is used for heavier bullets.
Alliant Varmint, and Ramshot TAC are faster burning than Varget.
I use Varmint with the lighter to me 52gr TMK.
Alliant PP2000MR with the 69-70gr bullets.
These out of a Savage 110 with 1:9twist 24" barrel.
No magazine to worry about, so loaded to 0.020-0.030" off the lands instead of SAAMI spec length.
I think you may have things a little backwards there, buddy.
Typically a slower burning powder is used for heavier bullets.
Alliant Varmint, and Ramshot TAC are faster burning than Varget.
I use Varmint with the lighter to me 52gr TMK.
Alliant PP2000MR with the 69-70gr bullets.
These out of a Savage 110 with 1:9twist 24" barrel.
No magazine to worry about, so loaded to 0.020-0.030" off the lands instead of SAAMI spec length.
The 77-grain SMK was designed for magazine feed. That's why its ogive is short and its BC is more than 20% lower than an 80-grain SMK's, despite the weight being less than 4% lower. The longer bearing surface increases start pressure a little by the bullet having to engrave more copper length. The difference in bore friction is not proportional to that length because compressed bullet fit in the bore is not the only source of friction. The other contributor is the g-force experienced by the bullet as it is accelerated. That force tries to squash it, creating a radial outward force pushing against the bore. That outward upsetting force is greatest at the bottom end of the bearing surface, there being more "weight" above it than at points closer to the ogive. The resulting outward increase in the normal force against the bore (what you multiply by the coefficient of friction to arrive at the friction force in pounds) is why copper fouling is heaviest in the first couple of inches in front of a rifle's throat, reflecting the bullet's position when the pressure peaked and acceleration (g-force) was greatest.
I really have no interest in the 223/556 other then my ARs. I've loaded 55gr and 62gr bullets and will probably stick to one of these if I continue to reload for em.
I'm pretty sure prices will drop and we will see 1k cases for $300.00 again. Its not worth it when that happens (Rock Chucker press)
Thanks again for all of the info
I'm pretty sure prices will drop and we will see 1k cases for $300.00 again. Its not worth it when that happens (Rock Chucker press)
Thanks again for all of the info
75s and 77s are fun. While slightly slower out of the barrel, due to being more aerodynamic they fly flatter and carry energy farther. They are also generally more match type bullets and can give better accuracy then bulk fmj. I like the hornady 75g match bullets as they are reasonably priced, and shoot nicely. They do cost a little more. Say 15 per hundred vs 26 per 100. But for me it's worth loading some up to play with. Similar to the military mk 262 mod 1 5.56 designed marksman ammo.
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Kramer,
The 77's are used in the AR. It was designed for them. If you shoot the Service Rifle matches with the AR, the 600-yard line makes you aware you need better wind bucking than the lighter bullets will get you. The 77-grain bullet is used by the military for the MK 262 ammo for the SDM program for that reason.
The 77's are used in the AR. It was designed for them. If you shoot the Service Rifle matches with the AR, the 600-yard line makes you aware you need better wind bucking than the lighter bullets will get you. The 77-grain bullet is used by the military for the MK 262 ammo for the SDM program for that reason.