A question about .223 bullet weight.

HAWKEYE10 · #1 05-05-2013, 10:26 AM

I have a Savage model 12 BVSS in .223 with a 1 in 9 twist. I have been shooting Hornady 60 grain V-Max bullets with pretty good results at 100 yards. I have been loading it with 23.1 grains of Ramshot TAC. I am almost out of Ramshot powder and can't find any more so I am switching to IMR 8208 XBR powder. What I would like your opinion on is how far can I go up on bullet wieght with a 1 in 9 twist barrel. I want to it out to 300 yards and I only shoot it off the bench. Thanks Don

jdlii · #2 05-05-2013, 11:02 AM

I have had very good results with Sierra 69 & 77 grain BTHP match bullets with my 1 in 9" twist rate barrels at 200 & 300 yards. I have no experience with IMR 8280. My loads have been with VV-N140, AA 2520 and IMR 4895. I have found that CCI BR4 primers seem to maximize performance. Good luck and good shooting.

Rule3 · #3 05-05-2013, 11:17 AM

Bullet weight up to around 73 grains for "regular" type bullets and not extreme distances. YMMV

Infidel_319 · #4 05-05-2013, 12:05 PM

I've Had Good Results With 1:9 Clear Up To 77 Grain Smk, I Hear Others Have Had Problems, Just Depends On The Gun I Guess. I Use Varget For All My 5.56 Loads 50 Grain To 77.

tlay · #5 05-05-2013, 01:42 PM

I am not familiar with your Savage. Does it have a magazine? It might make a difference on the longer bullets because they might be too long for your mag. This usually only happens on 77gr. and longer depending on your mag. You will still be able to load them one at a time if they are too long.

HAWKEYE10 · #6 05-05-2013, 03:05 PM

Quote:

Originally Posted by tlay

I am not familiar with your Savage. Does it have a magazine? It might make a difference on the longer bullets because they might be too long for your mag. This usually only happens on 77gr. and longer depending on your mag. You will still be able to load them one at a time if they are too long.

It has an internal magazine but I installed a single shot adapter. Don

Cdog · #7 05-05-2013, 03:24 PM

It's the length that dictates the required rate of twist.

Many lightweight Barnes and other similar monocomponent bullets are long for their weight requiring a much faster rate than say a round nose flat base Speer bullet of the same or greater weight.

tappedandtagged · #8 05-05-2013, 04:33 PM

Quote:

Originally Posted by Cdog

It's the length that dictates the required rate of twist.

Many lightweight Barnes and other similar monocomponent bullets are long for their weight requiring a much faster rate than say a round nose flat base Speer bullet of the same or greater weight.

This is very correct. Speer has a 70 grain soft point that is very "stubby" that works very well in a 1:9 twist and even 1:12. But, a Barnes 70 grain would likely keyhole in a 1:9 since it has to be much longer to achieve the same weight.

Using the modified (180 constant instead of 150) greenhill formula, the optimal bullet for your twist would be 1.0035" long. This is a rule of thumb only. Anything under will be fine, anything a bit longer will be fine as well, but you start going over too much and accuracy and stability will suffer.

For lead core bullets, up to 75 grains should be OK, but thats pushing it. Try some 63 and 69 grain Sierra Match Kings and see which one your rifle likes better. I wouldn't personally want to go heavier/longer.

HAWKEYE10 · #9 05-05-2013, 04:55 PM

Quote:

Originally Posted by tappedandtagged

This is very correct. Speer has a 70 grain soft point that is very "stubby" that works very well in a 1:9 twist and even 1:12. But, a Barnes 70 grain would likely keyhole in a 1:9 since it has to be much longer to achieve the same weight.

Using the modified (180 constant instead of 150) greenhill formula, the optimal bullet for your twist would be 1.0035" long. This is a rule of thumb only. Anything under will be fine, anything a bit longer will be fine as well, but you start going over too much and accuracy and stability will suffer.

For lead core bullets, up to 75 grains should be OK, but thats pushing it. Try some 63 and 69 grain Sierra Match Kings and see which one your rifle likes better. I wouldn't personally want to go heavier/longer.

I have not heard of the greenhill formula. Can you explain? Don

Ivan the Butcher · #10 05-06-2013, 12:51 PM

I bought a 8 pound keg of 8208 for 308 Win when it came out. I found it to be highly temp. sensitive and no where as consistent as Varget. It might work better in 223 but keep an eye on it on cold or hot days. If you are only shooting to 300 yards, Why use a good 600 yard bullet, I'm running my Savage 12 (left port, right hand bolt) in 223 (1:7 twist) out to a 1000 with 79-80 grain A-max and VLD's, using a Varget load. I have some TAC loads that are very consistent. Other good powders are H-322, H-335, and WW-748, they are all true ball powders a meter very well. For years I've used H-322 and a 50gr Sierra Blitzking for my 223 load out to 450-500 yards (my Cooper 21 likes the bullet touching the lands, so my load is pretty long), this gun is a 10 or 12 twist I think. Combined Technologies makes 50 and 55 grain poly tipped 22 cal. bullets that are quite accurate but cost more than Hornady, Nosler, or Sierra, I use the 50's in my 22 BR with a 14 twist out to 500 with great results.

tappedandtagged · #11 05-07-2013, 07:35 AM

Quote:

Originally Posted by HAWKEYE10

I have not heard of the greenhill formula. Can you explain? Don

Basically here it is:

Optimal Twist = 150 X Diameter squared / bullet length.

150 is a constant, not sure how it came about (I'm nowhere near a ballistician). The formula was modified years after it was invented to subsitute 180 for the constant if the muzzle velocity was over 1800 fps.

It is explained in more detail here. Topic of the Month