Armory Sponsor
Posted: 7/6/2012 8:24:18 PM EDT
|
I've been loading M-855 pills over varget in LC brass for my general AR ammo. It's great for everyday ammo. Now I'm wanting to develop a load for a 1/9 twist Rock River Coyote Rifle I've had for several years. It's a tack driver using M-855, but I think I'd like to step up to a heavier pill....but I have no idea what pill has the best BC and ballistic performance. I'd like to stay away from a plain FMJ pill and go to something like a Sierra Match King BTHP. I'm a fairly accomplished re-loader and load precision rounds for my .308's and other sticks. There is just such a plethora of pills available....I'm not sure which ones have the best performance. Suggestions? |
|
Quoted: I tried the Sierra's 69 gr MK and Hornady 68 gr. In my 1 in 9, the Sierra shot much better. The 52 gr Sierra MK shoots great also. Haven't tried Nosler's 69 gr yet, but on my list. I'm thinking I'd like to go around 72-77 grains. I don't think a guy can go wrong with SMK's...I'm just curious if there's anything availabe that has better BC and such. |
|
77 SMK is probably too long for a 1:9 twist. I'd go with the 69SMK or maybe try the 70 Berger. I'm not sure how long it is, though. The 70 Berger VLD's BC is .371. The 77SMK is .372 It'd be nice to have G7 BC's for both, but I don't. Berger say's the G7 of their 70VLD is .190 I've read (googled) the G7 of the 69SMK is .153, but since I don't have Litz in front of me, I can't be certain. Incidentally, the Berger 70 VLD is on sale at Midway this month ($3 off 100bx). I've had some back-ordered for quite a while. They advertise it requires a 1:9 twist. |
|
The SMK 77, Nosler 77, and Hornady 75 have the best BC for any mag loadable round, and all shoot around 5/8 MOA in my WOA varmint gun, with the SMK doing slightly better. Try them with Varget, RE15, or TAC type powders. They should work OK in your 1/9, but you'll have to try them to be sure. There are longer, heavier bullets (80 - 90) but they need a 1/8 or 1/7 to stabilize, and have to be single loaded.
|
75 Hornady HPBT, 24.2 H4895, or 24.7 RE15 or 24.5 Varget. in that order. Has stabilized in every 1-9 I have ever tried them in or seen them tried in. .390ish bc, Lapua 77's are verified by Litz to be .403, but are long compared to a sierra. I did have a M700 5r with a 1-9 that would stabilize the 77's by any manufacturer but you had to drive them pretty fast to do it. Which was easy in a bolt gun with 24 inches of barrel to use. Also you used the word pill more times than a pharmaceutical salesman... they are called bullets or projectiles. 
ETA, the 70 VLD will tolerate the jump from the mag length OAL usually, depending on your chamber/throat, and just use load data from the 69 sierra until it shoots good. usually arounf 2900-3000 fps from a 20 in rifle. The 73 gr bergers are pretty good as well, and 24.5 of RE15 is the accuracy load for that one. Not real fast but rediculously accurate. They will stabilize in a 1-9 and love the jump from mag length in any chamber/throat. |
|
Quoted: Quoted: I tried the Sierra's 69 gr MK and Hornady 68 gr. In my 1 in 9, the Sierra shot much better. The 52 gr Sierra MK shoots great also. Haven't tried Nosler's 69 gr yet, but on my list. I'm thinking I'd like to go around 72-77 grains. I don't think a guy can go wrong with SMK's...I'm just curious if there's anything availabe that has better BC and such. I tried Hornady 75 gr HP's in my 1 in 9. Didn't stabilize. So I stayed with the 69 gr MK. |
|
My limited experience with 1/9 twists barrels showed I should shoot 69's and lighter grain bullets. The one exception was my M70 Winchester which has a 26" barrel. It shot Hornady's 75 grain hpbt bullets very well. Velocity was around 2725 fps to get them grouping well. I suspect the increased velocity (just over 100 fps faster than a 20") was the reason they stabilized. That, and the actual twist using a tight patch and a cleaning rod measured slightly faster than 1/9. Closer to 1/8.75.
Carbines need a 1/8 in my opinion and maybe even faster. |
|
Quoted: You're right. As a general rule a 1/9 twist should have a 72 grain or lighter projectile. I'm not sure how much lee-way that gives a guy...say to go to 75 grains. My limited experience with 1/9 twists barrels showed I should shoot 69's and lighter grain bullets. The one exception was my M70 Winchester which has a 26" barrel. It shot Hornady's 75 grain hpbt bullets very well. Velocity was around 2725 fps to get them grouping well. I suspect the increased velocity (just over 100 fps faster than a 20") was the reason they stabilized. That, and the actual twist using a tight patch and a cleaning rod measured slightly faster than 1/9. Closer to 1/8.75. Carbines need a 1/8 in my opinion and maybe even faster. It looks like I'm gonna go with the SMK 69 grain and the Berger 70 VLD. Thanks to everybody for their help. |
|
Quoted:
77 SMK is probably too long for a 1:9 twist. I'd go with the 69SMK or maybe try the 70 Berger. I'm not sure how long it is, though. The 70 Berger VLD's BC is .371. The 77SMK is .372 It'd be nice to have G7 BC's for both, but I don't.
Berger say's the G7 of their 70VLD is .190 I've read (googled) the G7 of the 69SMK is .153, but since I don't have Litz in front of me, I can't be certain. Incidentally, the Berger 70 VLD is on sale at Midway this month ($3 off 100bx). I've had some back-ordered for quite a while. They advertise it requires a 1:9 twist. I bought some 75g A-Max bullets from Hornady that had "1:8 Twist barrels only" written on the box - my bolt action target rifle is 1:9 - I decided to give em a try and it turns out they are the most accurate bullet I have ever shot out of the gun. They are extremely long and look pretty cool ( can't load them to mag length) and shot great for me. Getting to my point I will say that sometimes what "shouldn't" shoot great in a gun may very well shoot fine. Only way to find out is buy a box and load em up (following proper workup techniques of coarse). P.S. I should have my range report posted later today. |
|
I know you lean toward heavier bullets. I've had the best luck with Sierra 69gr HPBT Match bullets for "heavy".
However, after shooting many hundred of various bullets and loads, I have never found a bullet that shoots more accurately than a Sierra 53gr HP Match bullet. It's flat based, but shoots better in both my AR15 and my Remington 700 HB Varmint than any others tried. I've shot 1" groups (including flyers that ruined a 3/4" 5 shot group) at 200 yards with them. My AR15 has a 1x8" twist, while the Rem700 is 1x12". The AR15 is an Armalite A4 National Match with a Leuopold Mark AR scope. |
Armory Sponsor