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Which Caliber is better for 140 grain bullets? 270, 308


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#1 OFFLINE   Crime_Dog_McGruff

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Posted Jun. 25 2012 - 06:36 PM

Which rifle shoots a light grain bullet better? initially, I would think that the longer bullet of the 270 would be advantageous in flight. Specifically in a 22" barrel in the same model rifle. By better, I mean with better ballistics, stability, accuracy at range.

Also, with an equal grain bullet, will there be any difference in power due to the difference in diameter? Which bullet has a better sectional density? Does anyone think a 30-06 would handle a lighter load the best of the three?

Why would a 308 be better out of a 22" barrel in general(various bullet weights)?

What is the max bullet weight for a 270? Or the max that is going to perform well?


#2 OFFLINE   SSGN_Doc

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Posted Jun. 25 2012 - 07:28 PM

Which rifle shoots a light grain bullet better? initially, I would think that the longer bullet of the 270 would be advantageous in flight. Specifically in a 22" barrel in the same model rifle. By better, I mean with better ballistics, stability, accuracy at range.

Sectional density and ballistic coefficient should be better on a narrower and longer bullet of the same weight being launched at the same speed.

Also, with an equal grain bullet, will there be any difference in power due to the difference in diameter? Which bullet has a better sectional density? Does anyone think a 30-06 would handle a lighter load the best of the three?

Since the .270 is basically a necked down .30-06 and the .308 is a short .30-06 I'm thinking you could wring more out of a .270 with it's larger powder capacity if using same weight bullets. Again the drag and density characteristics would aid in less drag, and better penetration.

Why would a 308 be better out of a 22" barrel in general(various bullet weights)?

Where a .308 shines is in using faster burning powders and the fact that it can be housed in short actions that give more rigidity and faster bolt manipulation along with the handier package is size and weight.

What is the max bullet weight for a 270? Or the max that is going to perform well?

About 150 is what is listed for it. Of the cartridges you mention the .30-06 is the round you want if you want to get good performance with rounds heavier than 165gr.




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#3 OFFLINE   knot28

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Posted Jun. 25 2012 - 08:11 PM

I thought I would get better groups with the 150s through my 270 but found just the opposite, 130s were better for me.


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#4 OFFLINE   Crime_Dog_McGruff

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Posted Jun. 25 2012 - 08:28 PM

Thanks, that clarifies quite a bit!

How significant of a range advantage does a 30-06 and 270 have over the 308?

So... with a 22" barrel, how much of an velocity advantage will 270 and 30-06 have over 308?

I'll be hunting whitetail with this, but what does a person need a 165 or above grain bullet for?

Which bullets are best for extreme long range?

Edited by Crime_Dog_McGruff, Jun. 25 2012 - 08:43 PM.



#5 OFFLINE   SSGN_Doc

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Posted Jun. 26 2012 - 08:12 PM

Thanks, that clarifies quite a bit!

How significant of a range advantage does a 30-06 and 270 have over the 308?

So... with a 22" barrel, how much of an velocity advantage will 270 and 30-06 have over 308?

I'll be hunting whitetail with this, but what does a person need a 165 or above grain bullet for?

Which bullets are best for extreme long range?


With bullets under 165 gr the velocity of a .30-06, a .270 and, .308 will be very close. When you get into heavier bullets the velocity edge goes to the larger cases because the seated bullet doesn't rob as large a percentage of the case capacity for powder. So you can add more fuel behind the heavy bullets in the larger cases.

you would need a longer barrel to take advantage of the increased case capacity using the lighter bullets to get more burn time from a slower powder.

Still the .270 could have a bit of an edge on long range velocity with a bullet of the same weight at the same muzzle velocity, because of better aerodynamics of the projectile.

The .308 could have a bit of an accuracy edge because the smaller case capacity can make foe more even burn rates from shot to shot with lower volume powder charges. Also the .308 is a bit more economical withthe lighter bullets, because it acheives the same velocities with less powder. If you get into reloading this means more loads per pound of powder.

So, there you have even more to think about.


#6 OFFLINE   Crime_Dog_McGruff

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Posted Jun. 26 2012 - 10:29 PM

With bullets under 165 gr the velocity of a .30-06, a .270 and, .308 will be very close. When you get into heavier bullets the velocity edge goes to the larger cases because the seated bullet doesn't rob as large a percentage of the case capacity for powder. So you can add more fuel behind the heavy bullets in the larger cases.

you would need a longer barrel to take advantage of the increased case capacity using the lighter bullets to get more burn time from a slower powder.

Still the .270 could have a bit of an edge on long range velocity with a bullet of the same weight at the same muzzle velocity, because of better aerodynamics of the projectile.

The .308 could have a bit of an accuracy edge because the smaller case capacity can make foe more even burn rates from shot to shot with lower volume powder charges. Also the .308 is a bit more economical withthe lighter bullets, because it acheives the same velocities with less powder. If you get into reloading this means more loads per pound of powder.

So, there you have even more to think about.


So far I'm leaning towards the 270 mainly because it seems like it the 270 equals or outperforms 308 and 30-06 in every bullet weight because of better SD/BC. Is this right?

The appeal of 308 is extreme accuracy, how much better "ballpark" we talking? Also attractive, bullet availability, and the fact it has a shorter action, and utilizes a 22" barrel better due to faster burning powder.

Appeal of the 30-06 is simply it can shoot 180+ grain loads better.


#7 OFFLINE   Crime_Dog_McGruff

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Posted Jun. 27 2012 - 12:54 PM

What is surplus 7.62x51 currrently going for? Where can I find it? I assumer these type bullets are normally range only?


#8 OFFLINE   SSGN_Doc

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Posted Jun. 27 2012 - 03:23 PM

Well you say you primarily want it for shooting Whitetail deer. What kind of terrain do you shoot in? What kind of range are you looking to shoot? How big are the deer in your area?

For me in SE Georgia, the hunting areas are all tight woods. I have to fight my way in, and often evenb wade into some areas. The deer are about 100-140 lbs on average. A .30-30 made more sense for my type of hunting but, if going with a bolt gun I'd go for a .308 with an 18-20 inch barrel for the lighter weight and compact size, along with bullet selection. But most of my shots would be inside of 100 yds.

I'm getting ready to move back out West soon. I'll be putting my .30-06 back in action, because out there shooting across a draw or a clear-cut could take my shots out to 300 yds. The deer are also bigger, and black bear are a possibility, or if I've got the money and scouting shows that Elk heards have been moving in the area I might buy an Elk tag. They need a bigger bullet. I wouldn't feel under gunned with a .308, I'd just have to work a bit harder in scouting or stalking to get myself closer for a shot.

Sticking with .30 cal is easier for me because I can share certain reloading components between rifles.

I don't think you would be under gunned with any of the rifle calibers you are asking about. You could be a bit overgunned though and packing some weight you don't have to.


#9 OFFLINE   SSGN_Doc

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Posted Jun. 27 2012 - 03:25 PM

Surplus 7.62x51 will run about $15 per 20 round box, but yes it is for range use. Most states won't let you hunt with FMJ rounds.


#10 OFFLINE   Crime_Dog_McGruff

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Posted Jun. 27 2012 - 08:49 PM

Well you say you primarily want it for shooting Whitetail deer. What kind of terrain do you shoot in? What kind of range are you looking to shoot? How big are the deer in your area?

For me in SE Georgia, the hunting areas are all tight woods. I have to fight my way in, and often evenb wade into some areas. The deer are about 100-140 lbs on average. A .30-30 made more sense for my type of hunting but, if going with a bolt gun I'd go for a .308 with an 18-20 inch barrel for the lighter weight and compact size, along with bullet selection. But most of my shots would be inside of 100 yds.

I'm getting ready to move back out West soon. I'll be putting my .30-06 back in action, because out there shooting across a draw or a clear-cut could take my shots out to 300 yds. The deer are also bigger, and black bear are a possibility, or if I've got the money and scouting shows that Elk heards have been moving in the area I might buy an Elk tag. They need a bigger bullet. I wouldn't feel under gunned with a .308, I'd just have to work a bit harder in scouting or stalking to get myself closer for a shot.

Sticking with .30 cal is easier for me because I can share certain reloading components between rifles.

I don't think you would be under gunned with any of the rifle calibers you are asking about. You could be a bit overgunned though and packing some weight you don't have to.


Deer aren't that big here, I think the 270 better serves all of my hunting needs from varmints to deer. Chances are I'll be making very few long shots past 100-150 with the woods and line of sight as it is. I'm planning on playing with my toy a bit and doing some range shooting, and you've told me as I've heard elsewhere that 308 surplus can be found cheapest of any cartridge of similar caliber.

What keeps me from buying a 270, is the edge 308 may have in availability, esp in shortages I would assume.
I've heard that 308 has a wider selection of bullets, but I've yet to see anyone outline exactly what grain weights are commonly available for both calibers. I realize that 130,150 are the most popular in 270, but don't know what other grain loadings can be easily found? I'm curious as to what it maximum feasible grain weight in a 270 1:10 twist? In 308, I know that 165s are very popular and some of the surplus stuff is 175g. What else is common in 308?


#11 OFFLINE   knot28

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Posted Jun. 27 2012 - 09:32 PM

All 3 are more than adequate for North American big game. My Brother loved the black gun so much he had to take it whitetail hunting, one shot one kill his first time out, so no probs there.

The .308 and 30-06 def offer more varieties of bullets with the 30-06 seeming to offer the most.


#12 OFFLINE   Crime_Dog_McGruff

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Posted Jun. 27 2012 - 09:48 PM

Does anyone know anything about 7.62x51 147 grain Portugal 83-2 surplus ammo?

What should I pay for it? It's $.50 per round now





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