Bullets question

[azgutpile]

215 berger hybrid

[.270]

if you're barrel isn't twisted really fast it won't shoot a big bullet well. need to find out what the twist is. .308 diameter bullets are some of the most twist sensitive there are. big long bullets might require as much as 1 in 8". most rifles aren't twisted that fast. Lark.

[Zeke-BE]

I bought a .30 210 Berger and the twist says on the box to use a 1 in 10 twist.

[.270]

then that's what you oughta use. a lot of .30 cals are 1 in 12's. one thing berger does do is have a twist recomendation on the box. another thing these days is that the weight of the bullet isn't the final sayso on what twist to use. a lot of bullets made for long range stuff, like bergers, have most of the weight toward the back, with a basically empty jacket toward the front. making them a lot longer than a typical bullet of that weight. you end up needing an even quicker twist to stabilize them, than you would for a normal constructed bullet of the same weight. there have been so many improvements in rifles and components in the past few years a guy can't keep up with it all. used to be you had to spend days at the range to be able to do what almost novices can do with rifles they just bought, today. range finders, incredible balistic information, wind meters, scopes that are like they are made by magicians. it amazes me what a guy can do with a rifle today. shot after shot after shot. you still have to pay attention, but it is alot easier today. Lark.

[AZkiller]

If you go on Berger's website, they have a twist rate calculator. You need to know BC, caliber, length of bullet, weight, velocity, altitude, temp, barrel twist, and it will let you know how well your bullet will stabilize.

 

I have never seen the need for a .308 to have more than a 1 in 10" twist, even with the 230 Hybrids.

 

http://www.bergerbull.com/twist-rate-calculator/

Are you talking about a .308 or a 30 cal? I have a 30/416 rigby improved that deffinately needs more twist for the 230 and its a 10. Shoots the 210s great tho.

[.270]

.308 is .30 cal. Lark.

[AZkiller]

.308 is .30 cal. Lark.

Why yes it is very inciteful. Its also a 308 as in winchester. I would argue a 230gr out of a 308WINCHESTER would need at least a 10 twist for 200gr and a 230 may work. Prolly wont work well on a 10 twist flying at 3400fps

[.270]

i'm sorry, guess i mis-read your question. but again, i've seen .30 cal's twisted from 1:7" to 1:20". it's a real twist sensitive caliber. a lot of .300's are twisted 1:12". they don't shoot big bullets well. when you get poor groups and are sure your barrel is in good shape, the first 2 places to look is the barrel twist and how close your bullet shoulder is to the lands. Lark.

[maximus]

my 300 win mag is the Remington 700 xcr tactical long range, the twist is 1:10.

should have no problem shooting 200 or 210 grain bullets.

[AZkiller]

I dont know who would shoot them in a 308 win, but ppl do crazy stuff. My 30/416 shoots the 210 at 3450fps so yes I feel you would need more than 10 twist as it would be flying around 3300 not 2800.

[firstcoueswas80]

^^^ that's how I understand it as well.

[STOMP442]

Fact of the matter is velocity probably plays the smallest role when it comes to stabilization. Its all about the length and shape of the bullet. The more stable a bullet is the more optimized the B.C. and while velocity does help its only a small percentage when compared to other factors that determine the stability of a bullet. Temperature and elevation are much bigger factors than velocity. For example, using Bergers twist rate calculator and running the numbers for the 230gr Match Hybrid in standard conditions being 59 degress at sea level the stability factor is 1.51 at 2650fps and only 1.64 at 3400fps. Run these numbers again at 75 degress and at 3000 feet elevation and you get a stability factor of 1.74 at 2650fps and 1.89 at 3400fps a much bigger difference. This particular bullet is still stable down to 1000fps with a stability factor of 1.1 in standard conditions but the B.C. is reduced by 12%

[AZkiller]

Wow...I learned something today

[Upland81]

Twist is hardly ever the issue with any .30 cal rifle they're extremely forgiving but issues with seating depth are more than likely the problem. I am sure any of the bullets you listed will be good choices. Even though you have a good load at 180 with a primer I still would pick a bullet and work with different powder primer combos and seating depth. If you compare the nosler book to steves page which is pretty much the sierra book one lists federals the other lists winchester with the 200gr bullet. The fun part of loading is test loads.

[maximus]

the berger manuals ask you to try different seating dephts,

for hunting loads:

0.010 off lands

0.050 off lands

0.090 off lands

0.130 off lands

but they don't tell you if is at lowest powder load or somewhere in between, at what powder loads would you start?

at the minimum and see what groups best and work from there?

thanks for the help.