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I have a .223 Savage model 12 BVSS heavy barrel with a 9 twist. The reload I use is Hodgdon H335 24.5gr, 55gr Hornady bullet and CCI primer. Works great no complaints out to 600yds.
Now I want to start shooting 600 - 1200yds.
Looking for load ideas or recommendations for 600 - 1200 yds.
Thanks
Not sure a 9 twist will stabilize it, but if it will, look at the 75gr Amax. I did some 223 research not long ago, looking into building a trainer. The 75gr Amax was the bees knees. Cost effective, great BC, and shoots great at distance. I got behind a buddy's 223 last weekend for 3 rounds. Full size IPSC torso at 1005 yds. First shot was just right. 2nd and 3rd were impacts. No idea on load data though, unfortunately.
Almost anything will work if you're just fooling around. If you want to just make a piece of steel ring once in a while for grins, you might try a slightly heavier bullet. Try a 69gr Sierra Match King. It's better than what you're shooting and should stabilize well in your barrel. Expect to miss frequently and if the wind is shifty, expect to miss a lot. Changing bullets and possible powder is the cheap answer, but not the best answer.
The facts are if you go to a 600/1000 yd F-Class match you will not see any serious competitors shooting .223 with a 1:9 twist barrel. If you expect to make a good wind call and then hit something pretty small, on the next round out of your barrel, you need a heavier bullet with a better B.C. and that means you need a faster twist barrel. Berger VLD 80s will shoot OK out of a 26" 1:7 twist barrel and some folks shoot the Berger VLD 90gr bullets from 30" 1:7 twist barrels; however, other competitors prefer a 30" 1:6.5 twist barrel. In any case, if you're serious about precision at 600 yards and beyond, think about getting a long, fast-twist barrel so you can shoot those Berger 90 VLDs.
The good news is that you can buy a Savage drop in and do the job yourself without the services of a gunsmith. Ask around to see if you can borrow a Savage nut wrench and barrel vice from one of the guys at the local range. Expect to spend $400 to $500 bucks and wait about 4 months.
Or, you might be able to find a used competition barrel if you search the shooting forums like http://forum.accurateshooter.com/
I had great luck shooting steel out to 750 yds with a 69 SMK and 8208 out of my BVSS in 223 with 9 twist. Then i tried the 69 TMK. Shoots much flatter. I'm getting 3120 to 3140 fps using Varget and Winchester brass, CCI400 or BR-4. Hornaday ballistics calculator says I should be at about 2000 fps at 1000 yds. so can't wait to test it at the local range.
My 9 twist would not shoot the 75's in any form. Berger stability calculator indicates it is just not stable in a 9 twist at the velocity I could muster. So it now sports an 8 twist Criterion. And yes, changed it myself.
I've had a 9-twist that would stabilize the 75gr. and 3 that wouldn't. However the 77gr SMK's or CC's are shorter and will stabilize without nuclear loads.
I don't have a 77 SMK to be able to measure the length, but was wondering what the Berger Stability Calculator gives for a typical velocity in a 9 twist, 223? Anyone have one available and can do the calculations?
To check bullet lengths go here:
http://www.jbmballistics.com/ballist.../lengths.shtml
Quote:
Originally Posted by mikgarus
+1
Yep
Here are some numbers to play with. BC numbers from Hornaday manual. Sierra does publish BC but not length in inches, got that from JBM.
75 BTHP .981" and .395 BC
75 Amax 1.105" and .435 BC
80 Amax 1.162" and .453 BC
77 SMK .994" and .362 BC
80 SMK 1.066" and .420 BC
Berger stability calculator http://www.bergerbullets.com/twist-rate-calculator/
In my 12BVSS with 26" Criterion 8 twist the 75 Amax shoots fairly well, but the Gyroscopic Stability (SG) is 1.36 were as optimum stability is 1.5 and above.
The 73 HPBT Berger Match has an SG of 1.83, rating it as very stable.
80 Amax is 1.22, not very good in an 8 twist.
These were calculated at 70F and 500 ft elevation. I tried them at 50F and sea level and it changed only a small bit. Obviously at 100F and 7000 ft it's going to change a bunch. For instance, my 9 twist would only shoot the 75 grain HPBT well at 100 F, 500 ft and humid conditions which yields a density altitude of about 6500 ft, as I recall and an SG of 1.52. Go to 50F and it drops to 1.41. Go up in altitude to 7000 ft and 100F and the SG soars to 1.94.
I'd try the 75 a-max's seated .015 of the lands and try 8208 xbr work up to around 23-24gr and see if they stabilize.
I went to Cabelas in Buda, TX (for those who care, its pronounced bee-U-da) yesterday. They must've just got a shipment as the shelves were full of powder and bullets. It's the first time I've seen Varget and 4350 on their shelf.
They also has some Sierra TMKs available, so I picked up some 77gr TMKs to try out.
OAL is 1.068 (my measurement)
BC is .420
Funny, these measure same as the 80 TMKs, except for weight.
Using the Berger stability calculator in my 8 twist, they had a SG index of 1.42 to 1.45 at 2750 to 2950 fps, standard temp, sea level, and are rated marginally stable giving up only 2% of BC due to what I presume is wobble.
At the temps we see out here in Central Texas, 95 to 100 F, SG rises to 1.55 to 1.59 at those velocities, and are rated Stable.
With the same BC as an 80 grain SMK, these should shoot pretty dang well out of a 223 Rem.
Unless you run a good calculator for tragectory, you would be better served to use the G7, for the bulk of it's flight. G1 numbers change with velocity ranges, and still don't track well when supersonic. Once you drop trans and sub sonic, then the G1 will give you closer results.