How heavy of a bullet can a 1 in 12" twist 26" .308 shoot?

[TonyAngel]

You've gotta remember that published velocites are only what the publishers got when testing the loads using either a particular rifle or test barrel in certain environmental conditions. These published velocities are for reference only.

My rifle, with the tight cut chamber, gets around 2750 fps with 44gr of Varget under a 168gr bullet. Really, you should run any load that you work up over a chrony. It's the only way to know what it's actually doing.

 

[chaser_2332]

also remember, most cronys arnt that reliable. Get 100 yeard zero, gather dope at differnt distances and reverse the math over a balistic program and you will have varified velocity.

 

[TonyAngel]

chaser, maybe you need to try a different brand of chrony.

 

[chaser_2332]

i have tried many, just dont trust one enough to run solid dope off of one alone. You can work a load up until it starts to show pressure and work back from there to find an accuracy node, assuring that your getting the most out of your rifle.

 

[kestak]

168 grains passed 700 meters gets too much pushed by the wind.
All the usual guys at the range who shoot the 1000 meter target use the 170+ grains.
In fact, yesterday I look at the target of one guy I saw for the first time at the range and all his hits at the 1000 meter target were keyholes. I asked him and he shot 168 grains.
Also, I saw he had to walk his shots on the target with the holes from left to center.

 

[TonyAngel]

I'm not debating that heavier bullets with higher ballistic coefficients are better for shooting out to 1000 yards, but I also wouldn't say that the key holing is a universal occurrence. I've only been out to 1000 a few times, but I've never gotten key holing. I'll guess that his loads weren't running fast enough either because the loads weren't loaded to take on the task or the rifle just isn't capable of enough velocity.

As for his having to walk his shots in, maybe that's just the way he does it, with the equipment he has. A lot happens to a bullet during a long flight and it is very rare that you don't have to account for environmental conditions.

 

[Dthunter]

I have used chronies EXTENSIVELY for more than 20 years. They "WORK".

As long as you plug "ACCURATE INFORMATION" into a ballistic program, they will get you out to distances that are amazing!

The only piece of info that is occasionally a little off, is the B.C.
If you find your physical data starts off accurate for the first 500 yards or so, then starts to deviate, it can be an inaccurate B.C. value.

Shoot your rifle at 200yard intervals (at least 4 points) and measure/record you vertical adjustments to maintain center impact point. Take the vertical values you record, and adjust the programs B.C. up/down until all the vertical adjustments in the program correspond to your physical data.

Then go out and prove your information.

If your values/scope adjustments just dont add up, try a function test on our Scope to prove your scopes adjustment values. This should be done to EVERY SCOPE used for longrange. It confirms repeatability and "individual click value". Most manufactures claim 1/4, or 1/3 MOA clicks. But quite often the ACTUAL CLICK VALUEis different by a small amount. This small discrepency adds up over long range. (Progressive and accumulated Error).

These two things should help a few shooters.
I could also type out my personal proccedure for a scope function test if some of you are interested.

Have fun guys, and straight shoot'in!

 

[kestak]

Indeed, his velocity must have went subsonic just before the 1000 meters, hence the key holing.

I agree wind is hard....darn hard...I use the function I saw in that youtube video about how to adjust the sights for a M1 Garand and it works very well. In fact, I got a hell of a lagh when the guy talks about the guys learning that math in middle school...when now most of our high school graduates can't even do that.

The function is easy BTW for those who wonder:
Distance (remove 2 zeros) x wind speed / 10

200 yards x 10 miles per hour / 10
2 x 10 / 10 = 2 clicks headwind

350 yards x 5 miles per hour / 10
3.5 x 5 / 10 = 1.75 = 2 clicks headwind

I am sure the old timers here will get a good laugh at that video. And the youngsters should pay close attention and notice how our education system got gutted with the years and now the country is filled with dumb Americans.

http://www.youtube.com/watch?v=yj5KsXDflS4

 

[TonyAngel]

I've never tried that formula, although it may work for a particular caliber, shooting a particular bullet at a particular velocity. The easiest way to cover all bases these days is to have a ballistics program on your phone.

As far as the chronies go, I've found them to be pretty darned accurate. I use them to make sure that my rounds are moving with enough speed that they won't go subsonic before reaching my target distance and I use the data to plug into a ballistics program to get a rough dope.

 

[kestak]

My point was not the formula. My point was the ineptitude of the current American.
Moreover, this formula works with M1A, m1 and m16/m4 using military rounds. It also works pretty well with most of my reloads.

 

[TonyAngel]

If it works for you, keep at it.

 

[unwise11]

Just picked up a box of 175 SMK's... Hoping to shoot out to 1000.

 

[TonyAngel]

What powders are you planning to try out?

 

[unwise11]

I am a varget burner.

 

[snake284]

I've been a member for a while, and I reload, I just got a new Remington 700 SPS Varmint in .308 Win... I broke it in today and was shooting sub MOA at 200 yards.
I'm wanting to know how heavy of a bullet will this be able to handle..
I'm shooting 168 SMK's right now with pretty good results (I handload)

Thanks guys.

Only one way to find out. Try it. Each rifle can have a mind of its own. Just try out different bullet weights and see what the heaviest bullet ends up being. And be it known, that might vary not only with bullet style, but also with brand of bullet. because some bullets of the same weight can be different. Depends on a lot of things, such as BC and length etc.