RL 17 query

[Hillhunter]

Went out yesterday and found that with 43.2 of RL 17 ( av speed 2540)I had a good node , shot one hole groups @ 300 yards. Only problem is I want to go to 1000 yards , I tried this node, it was getting there but not accurate , I have been told that I need a speed of approx 2850. My question is can I safely do this , with RL 17 , going by my node and speed I need to increase powder to 49.2 , I have a 32 inch barrel 1 in 12 .

 

[Lapua40X]

What caliber ........? What bullet ........?

 

[Hillhunter]

What caliber ........? What bullet ........?

Sorry, 308 , 185 berger

 

[Lapua40X]

Sorry, 308 , 185 berger

No need to be sorry. Everyone does that at one time or another.
OK, let's look at your predicament. First, IMO, if the bullet you are using is the 185 Berger Target your 1:12 isn't going to adequately stabilize that bullet. You need a faster twist. If you want to shoot 185s at 1K I believe you're going to need something on the order of a 1:9 twist. Or you could try a !85 Berger hunting bullet that they claim will stabilize at 1:12.
Next, RL17 data is, IMO, somewhat conservative so I feel pretty comfortable staying within published loads. Where did the 49.2 grain load data come from and is there any room left on that chart to increase the load safely?

Don't be too concerned at MV. While I suspect a MV around 2800 fps may be a reasonable goal, if your ballistic data validates a maintained velocity of about 1500 fps at 1K you should be satisfied with the results.

 

[Sling]

11 twist will work well. Alot of F-TR 308 shooters run 10 & 11 twist with 185gr Bergers.

 

[Hillhunter]

Sorry, 308 , 185 berger

No need to be sorry. Everyone does that at one time or another.
OK, let's look at your predicament. First, IMO, if the bullet you are using is the 185 Berger Target your 1:12 isn't going to adequately stabilize that bullet. You need a faster twist. If you want to shoot 185s at 1K I believe you're going to need something on the order of a 1:9 twist. Or you could try a !85 Berger hunting bullet that they claim will stabilize at 1:12.
Next, RL17 data is, IMO, somewhat conservative so I feel pretty comfortable staying within published loads. Where did the 49.2 grain load data come from and is there any room left on that chart to increase the load safely?

Don't be too concerned at MV. While I suspect a MV around 2800 fps may be a reasonable goal, if your ballistic data validates a maintained velocity of about 1500 fps at 1K you should be satisfied with the results.

I'm fairly new to this but I was told the 1 in 12 would be ok with the 185 target bullets , are you saying that I should stick to the 155s ? And be satisfied with that,

 

[Lapua40X]

I'm fairly new to this but I was told the 1 in 12 would be ok with the 185 target bullets , are you saying that I should stick to the 155s ? And be satisfied with that,

No, I'm not suggesting you try a lighter weight bullet. But you will have to choose a bullet other than the 185 target if you want to make it work with the 1:12 pitch. It isn't the weight of the bullet that's problematic, it's the shape/design of the bullet. The 185 grain hunting Bergers are designed for 1:12 twist or faster. The target 185 Bergers are designed for 1:11 twist or faster. As I see it, you have two choices. Use 185 hunting bullets or a lighter weight bullet that will stabilize in you 1:12 twist.
The 168 grain Berger target bullet should work fine with your 1:12 - you'll need to work out the ballistics for that bullet to find the MV that provides the results you want at 1K and then find a safe load that will give you that MV. With the barrel length you describe you should have very little trouble making that happen.

 

[watercam]

Berger 175s will work. I have run Berger 185 Juggernauts with Reloader 17 and managed about 2750 fps from a 32" 11" twist barrel. I believe the charge was around 47 grains. I DID see the beginnings of firecracking though after about 100 rounds and have heard that that is a problem with the high intensity powders (Hybrid 100V, Reloader 17, 500 series Viht.). With Varget the same bullet made 2730 fps with a 43.5 grain charge. To be frank in the end I ended up going back to 155s as I want to shoot Fullbore and need to be able to read the wind for them in any event. Perhaps the 155 Hybrid would be a choice as well as it needs a 12" twist barrel.

 

[effendude]

You don't need a 1-9" barrel to get the 185 Jug to stabilize. 1-11" will do fine, a 1-10" would be ideal. Run your velocity and bullet through a good ballistic program and see if you are still supersonic at 1000 yards. Buy Bryan Litz's book and you will gain a great understanding of what is necessary to reach 1000 yard accurately.

Scott

 

[Hillhunter]

You don't need a 1-9" barrel to get the 185 Jug to stabilize. 1-11" will do fine, a 1-10" would be ideal. Run your velocity and bullet through a good ballistic program and see if you are still supersonic at 1000 yards. Buy Bryan Litz's book and you will gain a great understanding of what is necessary to reach 1000 yard accurately.

Scott

I was told that Brian says the 1:12 would be fine for the 185 juggernauts , I'm using the otm tactical, they are holding one hole groups @ 300 yards, obviously my speeds are too low @ 1000 ,(2540) I'm going to try with n 140 to see what speed I can get with approx 46.3 gr

Ger

 

[Jeffvn]

A few more details about your loaded round would be helpful. What is the COAL of your loaded round with the 185s? If you are loading to Mag length (roughly 2.80-2.90"), you have a ton of bullet pushed back into the case and are likely not going to see the necessary velocity to keep it supersonic @ 1,000 yards.

If you are loading with a Mag Length chamber then the Berger 155s, berger 175s or Newer Sierra 155 (the one with the BC equivalent to the Sierra 175 smk) would be where I would look until you burn out that barrel. Next barrel should potentially be an 1:11 or 1:10 if you want to shoot the 185s in all conditions.

Jeffvn

 

[jsthntn247]

A 1:12 is fine for the juggs. Stick with N150 or Varget. You should have a node around 2630 and another one around 2750. Even at 2630 I am still above Mach 1.2 at 1000 yards, you don't need 2850.

 

[Steve Blair]

No, I'm not suggesting you try a lighter weight bullet. But you will have to choose a bullet other than the 185 target if you want to make it work with the 1:12 pitch. It isn't the weight of the bullet that's problematic, it's the shape/design of the bullet. The 185 grain hunting Bergers are designed for 1:12 twist or faster. The target 185 Bergers are designed for 1:11 twist or faster.

[br]
Is Berger wrong? [br]
http://buybergerbullets.3dcartstores.com/30-Cal-185-Grain-Match-Juggernaut-Target_p_69.html

 

[Lapua40X]

Hillhunter, perhaps I can best explain my suggestions this way:

Berger makes a wide range of 185 grain bullets. And most, if not all of them, have very similar technical features. Typically, you'll find that they are uncoated, .30 Caliber , 185 grain, 1.353 in length with a diameter of .308. For example, the Berger Hybrid Target bullet and the Berger Tactical have identical technical descriptions. But when you check a little deeper into their "design" features you will find that one may not stabilize with less than a 1:11 twist. That's why I suggested you either look for a faster twist or another bullet.
The Berger Hybrid Target Bullets 30 Caliber (308 Diameter) 185 Grain Hollow Point Boat Tail will have problems stabilizing at 1:12; the Berger Tactical (Juggernaut) Bullets 30 Caliber (308 Diameter) 185 Grain Open Tip Match Boat Tail can handle that slower twist without stability issues.
Your post described a problem that appeared to be stability rather than powder charge/muzzle velocity. That's why I asked which bullet you were using and your response indicated to me that you may have chosen the wrong "185" Berger. Making an unstable bullet more accurate by increasing its velocity is a fool's errand.
I suggested you try a lighter bullet and work toward the velocities you wish to achieve because, except for its ability to resist wind influence, I see no advantage to the 185 grain bullet with RL17. You're going to have the learn to read the wind, regardless of the bullet you select.
Best of luck with your shooting ..........

 

[Hillhunter]

Hillhunter, perhaps I can best explain my suggestions this way:

Berger makes a wide range of 185 grain bullets. And most, if not all of them, have very similar technical features. Typically, you'll find that they are uncoated, .30 Caliber , 185 grain, 1.353 in length with a diameter of .308. For example, the Berger Hybrid Target bullet and the Berger Tactical have identical technical descriptions. But when you check a little deeper into their "design" features you will find that one may not stabilize with less than a 1:11 twist. That's why I suggested you either look for a faster twist or another bullet.
The Berger Hybrid Target Bullets 30 Caliber (308 Diameter) 185 Grain Hollow Point Boat Tail will have problems stabilizing at 1:12; the Berger Tactical (Juggernaut) Bullets 30 Caliber (308 Diameter) 185 Grain Open Tip Match Boat Tail can handle that slower twist without stability issues.
Your post described a problem that appeared to be stability rather than powder charge/muzzle velocity. That's why I asked which bullet you were using and your response indicated to me that you may have chosen the wrong "185" Berger. Making an unstable bullet more accurate by increasing its velocity is a fool's errand.
I suggested you try a lighter bullet and work toward the velocities you wish to achieve because, except for its ability to resist wind influence, I see no advantage to the 185 grain bullet with RL17. You're going to have the learn to read the wind, regardless of the bullet you select.
Best of luck with your shooting ..........

Thanks for the all the replies ,I have decided to develop a load with the berger 155 hybrids for now, I have n140 at my disposal , so I will try this first and then as lapua has said I will try to obtain the correct 185 , am I reading this correct I have chosen the wrong 185 ? Which one will stabilise? Which 185 will suit my 1:12 ? Thanks again.
Ger

 

[Steve Blair]

Berger's 185 Juggernaut (former BTHPLR) will stabilize fine in 1:12". You should try to reach a higher muzzle velocity and I would dump RL17. It is undependable firing long strings. Any of the single base, medium rate powders should be fine.

 

[Hillhunter]

Berger's 185 Juggernaut (former BTHPLR) will stabilize fine in 1:12". You should try to reach a higher muzzle velocity and I would dump RL17. It is undependable firing long strings. Any of the single base, medium rate powders should be fine.

Thanks , I will try the n140

 

[Lapua40X]

Which 185 will suit my 1:12 ?

http://www.midwayusa.com/product/249578/berger-target-bullets-30-caliber-308-diameter-185-grain-hollow-point-boat-tail-box-of-100?cm_vc=ProductFinding

http://www.midwayusa.com/product/370669/berger-tactical-bullets-30-caliber-308-diameter-185-grain-open-tip-match-boat-tail-box-of-100?cm_vc=ProductFinding

Read the Technical Information and the Ballistics Information at the center left of the pages.

 

[6BRinNZ]

HillHunter - + 1 to Steve's advice. Also have a read of this blog, it should help you to figure out how to go about developing a load for .308 and 1000 yards.

http://riflemansjournal.blogspot.co.nz/2011/01/cartridges-1000-yard-308-load.html

If you combine the blog above with the approach below you should be a long way down the track to having an accurate load that is pressure safe and still above transonic at 1000.

http://forum.accurateshooter.com/index.php?topic=3814361.0

Good luck.

 

[Medic505]

+2 on Steve's info. I've shot 185 Juggs out of a 1-12 and they did fine. 175 BT's are also a good choice for your twist. N-140 should work great. I make it a point to stay away from anything that starts with RL.