Hypothetical Question

[Swampman]

If you launch a .30-06 bullet & a .270 bullet of equal weight and at the same speed............

How much difference will there be in recoil & trajectory?

[PartsMan]

I suppose the recoil would be the same and the 270 would shoot ever so slightly flater because the bullet has a better B.C.

[grvj]

...if the Chuck Hawks trajectory table is used, a 150g bullet in either does not have much of a change-maybe an 1/8".

I suppose a .270 could have better game digging power sue to better sectional density. My reason for a .270 use would be to shoot new 130g bullets like a TSX.

[Graybeard]

If rifle weight is same recoil would be same. The .270 would hold an edge in all ballistics performance factors due to the higher BC of the smaller diameter bullet of same weight.

Would it make a real world noticeable difference on game? Nope.

[IOWA DON]

To get a .277 bullet to shoot as fast as a .308 bullet of the same weight with the same case will take more pressure as the smaller caliber will be less efficient. Given the same weight rifle, the recoil from the bullet will be the same. However, the increased pressure will probably have more of a jet effect in the .270 adding a little more recoil. Given the same point shape the smaller caliber bullet would have a better ballistic coeficient an fly flatter.

[Rangr44]

[If you launch a .30-06 bullet & a .270 bullet of equal weight and at the same speed............How much difference will there be in recoil & trajectory?]

If both are fired from rifles of equal weight & barrel length & sight height above the boreline, the recoil difference would be undetectable by a shooter, with the only easily detectable difference in trajectory at extremely long range. (My $0.02)
.

[IOWA DON]

Ranger44 - I agree. The advantage of a .270 would be to use a lighter bullet for a flatter trajectory and less recoil. The advantage of the .30-06 would be to use a heavier bullet for more thump on heavier game. - DON

[Swampman]

The current trend seems to be toward heavier bullets in the .270.  That would seem to negate the theoretical advantages of that cartridge.

I'm sorta new to the .270, so it was just something I had been thinking about.

I like the 165 in the .30-06 but I used the 150 for a long time.

[PartsMan]

Winchester loads the 270 and the 308 with 150g power points.
2850 in the 270 and 2820 in the 308. Not enough difference to matter.
Anyway they show the 308 1.2" lower at 300yd if both are sited in at 200yd.

I shoot both 150g and 130g winchester power point in my 270.
The 130g is 2" high at 100yd and the 150g is 1" high.
So it's like turning my 270 into a 308 in an instant.

[Coyote Hunter]

Assuming all other factors are the same, the recoil would be the same.

[charles p]

I believe the weight of the powder is also a function in a recoil computation.  I assume one cartridge might require more powder than the other.  Since the 30 cal bullet has the greater circumferance, maybe the friction from the increase contact with the barrel would require a slightly greater charge.

Getting over my head here.  Could have it backward.

[PartsMan]

I believe the weight of the powder is also a function in a recoil computation.  I assume one cartridge might require more powder than the other.  Since the 30 cal bullet has the greater circumferance, maybe the friction from the increase contact with the barrel would require a slightly greater charge.

Getting over my head here.  Could have it backward.

The .270 takes more powder because of the smaller area the pressure is acting on.

[mcwoodduck]

I hate to disagree with Graybeard but I think if everything were equal, the 270 would have more recoil.
Only because, let's say a 180 grain bullet in .277 will be slightly longer than the same wieght bullet in .308.  With the longer bullet more of it will be touching the lands and grooves and cause more friction meaning you may have to use more of the same powder to achieve the same speed.  I only say this as we were shooting 170 grain 30-30 rounds and 180 grain rounds out of a 35 rem both in Marlin lever guns and both about the same speed.  If anything the 35 Rem gun should be a little lighter as it has a bigger hole through the barrel.  Everything was Rem. factory loads and as I remember close to each other in speed.  the 30-30 was a sharper recoil than the 35 Rem.  Granted there is more difference between 358 and 308 than 308 and 277 but it still makes the same point.
Other than that 180 grain is 180 grains and will have the same drop be it 277, 308, or 311 and with the same speed they should fly exactly the same.  gravity will have the same effect on the two bullets.  If one drops 4.5" at 200 yards the other will too as long as they are of the same design.  If one is a full metal jacket boat tail and the other is a soft point round nose then no you will have different impacts.  Effects on game will be very close.   The whole idea of necking  up or down is to use bullets the same lenght only lighter or and with similar construction with out loosing case capasity and keeping a long for caliber bullet in the case.  As you all have pointed out the BC of the 277 will be better than that of the 308. 

[trotterlg]

You also have to count the weight of the air in the barrel, so that would favor the 270 for less recoil.  Larry

[victorcharlie]

How many spirits can dance on the head of a pin?

Really, I shoot both calibers a fair bit and can't tell a difference in recoil between the two.

[PartsMan]

Taken from chuck hawks rifle recoil table.
                                      rifle weight  recoil energy recoil velocity                                   
.270 Win.     (150 at 2900)   8.0                 17.0            11.7
.30-06 Spfd. (150 at 2910)   8.0                 17.6            11.9

Like I said before. I suppose the recoil would be the same.

[R.W.Dale]

vuritually none

for easy computing comparing remington 150grn loads for both rounds the difference in trajectory with a 200yd ZERO is about 4" at 400yds

up the 30-06 to a 165grn bullet which i feel is a better comparison and the difference in trajectory is less than 3"........at 400yds

[wareagleguy]

Swamp,
I am glad you are tryin' new stuff!!!

[no guns here]

Who cares?  As long as they are shot from a Remington M700 they will be shot into the smallest groups attainable in the history of the world.

ngh

[Swampman]

This is true!

[diesel instructor]

I handload my Stevens 200 '06 with 130 gr Hornady SP's to 3200-3300 fps,(I know, thats max, but with no catered primers and NO tight extrations) that is 270 Wbh MV. It takes the 130 270 Win at a MV of 3100 fps about 275 yds to catch up. My MPBR being 300 yds, and YES, A 270 Win rifle of the same weight will recoil noticeable less. never could measure it, but on the bench, there IS a difference. of course,due to the superior BC, beyond 300 yds, the 270 excells. even hunting pole lines and long fields in PA., over 300 yd. shots are rare, and at my 76 year old skill level, I just won't take those shots.

[jro45]

Witch ever one weights more will have less recoil and the highest BC bullet will go more FPS.

[Coyote Hunter]

I handload my Stevens 200 '06 with 130 gr Hornady SP's to 3200-3300 fps,(I know, thats max, but with no catered primers and NO tight extrations) that is 270 Wbh MV. It takes the 130 270 Win at a MV of 3100 fps about 275 yds to catch up. My MPBR being 300 yds, and YES, A 270 Win rifle of the same weight will recoil noticeable less. never could measure it, but on the bench, there IS a difference. of course,due to the superior BC, beyond 300 yds, the 270 excells. even hunting pole lines and long fields in PA., over 300 yd. shots are rare, and at my 76 year old skill level, I just won't take those shots.

All other factors being equal (rifle weight, muzzle velocity, bullet weight, powder charge), two rifles of different calibers should have equal recoil.  You might notice a difference in felt recoil due to differences in stock design, recoil pads, etc.

If you are using different powder charges to achieve the same MV, the rifle with the smaller powder charge will recoil less.

[mcwoodduck]

Yes and no.  If everything being equal the rifle with the largest bearing surface on the rifling will have greater recoil.  But on the same note the rifle with the smaller hole will weigh slightly more and added weight of steel will make it equal.
Again we are talking the wieght of smoke in difference.  It really will not matter 150 grain bullet @ 3000 fps with an 8 pound rifle with 70 grains of powder is going to be the same.
Again if you talk mechanics of it the smaller diameter bullet of the same design will have more recoil due to the larger surface area.  But again is .00001 more in recoil really a number?

[Casull]

Other than that 180 grain is 180 grains and will have the same drop be it 277, 308, or 311 and with the same speed they should fly exactly the same.

Mcwoodduck, that is absolutely NOT correct (unless you were firing the bullets in a vacuum).  You must look at the ballistic coeficient (the abilility of the bullet to overcome air resistance) to determine which bullet will fly flatter, and if of similar shape and design, the smaller caliber bullet will have a higher ballistic coeficient than the larger caliber bullet (of the same weight). 

[mcwoodduck]

OK but I understand bullet drop to be more about speed and weight than BC if the bullets all have similar bullet designs.
Again in practice yes the smaller bullet with a greater BC will not slow as quickly and will give gravity less time to act.  Just for arguement sake lets say that gravity will pull a bullet 1 inch per second in flight.  If you have the same bullet designs one slightly larger than the other all weighing the same and leaving the rifle at the same speed the BC will not matter out to 400 yards and all will hit minute of deer.
Yes carring bullet trajectory out past that.  Yes flight times will change and bullets will start to drop differently. Again not too much to make a difference in real world hunting.

[SHOOTALL]

would a deer care ?

[mcwoodduck]

NO.

[FW Conch]

   Lets see if I can remember my Isack Newton correctly. I think Swampmans original question has
been properly answered, but I think this relates to other statements made. If the 30-06 barrel & the 270
barrel are parallel & equal height from the level earth, & a third bullet is dropped from the barrels centerline
@ the instant the 2 rifles are fired, ALL THREE BULLETS WILL HIT THE GROUND @ THE SAME TIME ? But,
because of the better Ballistic Coefficient the 270 will travel farther before it hits.    There are those that
will argue that Ballistic Excellence has been achieved in the 6.5-284. The 6.5 bullet is thought to be near
perfect in diameter & @ 140gr extremely effective on big game. The 284 case holds the same amount of
powder as the 30-06 but in an apparently more efficient shape, short & chubby. With their success @
1000yd competition it is difficult to doubt their claim. Because of "Isack's" discoveries, the 270 shoots flatter than the 30-06 & the 6.5-284 shoots flatter than both of them.?

I didn't learn this one until a couple of weeks ago, while watching the Universe series on the History channel, but there is no "PULL OF GRAVITY" ?  Objects are "Pushed" toward the center of the earth ?
Don't ask me to try & explain it, you'll just have to watch the re-run !     Good Shooting    Jim