just joined this site.my center fire questions are growing????i would say im really a .17hmr guy but here we go. i just bought a 270 my bud a 308- standing the shells next to each other the 270 looks like it holds alot more powder.the ballistic chart in 150 grain each doesnt make sense to me.the270 should be blazzing away from the 308.what am i missing.sorry for the long ???
150 grains in the .270 is HEAVY for caliber. It is a long bullet best suited for larger animals. The 150 is a light bullet for the .308 and it can really send them zingin'. The 150 .30 caliber bullet is mostly suited for deer and antelope whereas the 150 in the .270 is an Elk/ Moose round.
Just make sure that you keep the .308 & .270 rounds well apart!!! Not the first time somebody has inadvertantly loaded a .308 into a .270 with disasterous consequences.
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I believe the design of the casings has alot to do with it also. The shorter .308 casing burns the powder faster and more efficiently than the .270. And as for getting the two shells mixed up when you grab some and load a gun.....seriously..?? I mean, i don't doubt that it has happened in the past, but you really have to be quite the moron to confuse the two! In which case, you really don't belong behind the trigger of anything.
If you look into reloading books on the two you will see your answer. Like it was said earlier 150g is heavy for the 270 but if you still use this so you have the same weight as to eliminate one of the factors and you also use the same powder (Imr 4895) you will see that the max for the 270 is 44.5g putting the speed at 2704. On the other hand looking at the load for 308 powder at 47.3g speed at 2920. the 308 has more powder and only goes another 200 feet per second- not alot. Why is this you ask?.? Well look at the cases again and you have that answer, the inside volume of the cases is different, the 270 has more room with less powder. This will make the pressure less(basic compression rules like on a motor in a car) so there for the bullet has less pressure pushing it down the barrel and making it slower.
I hope this helps answer your question. I've been studying reloading books for quite a while and have a very good detailed gunsmith that has been loading sence 1971 who has taught me.
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Gun control is putting 2 bullets in the same hole.
I believe the design of the casings has alot to do with it also. The shorter .308 casing burns the powder faster and more efficiently than the .270. And as for getting the two shells mixed up when you grab some and load a gun.....seriously..?? I mean, i don't doubt that it has happened in the past, but you really have to be quite the moron to confuse the two! In which case, you really don't belong behind the trigger of anything.
This has happened so often you would never believe it and done by the most experienced of shooters. Some mixes you will get away with, some you won't. Just a warning to heed, especially if you're favorite ammo storage is a jacket pocket.
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I just tried a .308 in a .270.You couldn't do it without forcing it.The demensions sketches show that it could be possible.It is very easy to chamber a .308 in a .30-06,but I have read about it and the only thing you get is a blown casing.I don't know and certanly would'nt do it on purpose,but I have heard of people that have.It must not have hurt them or they wouldn't have written an article on it.I have no idea of how much pressure it would take to chamber a .308 in a .270.It might be easy,but on mine it would take a deliberate effort on my part.I was trying factory spec cases. ,,,sam.
I just tried a .308 in a .270.You couldn't do it without forcing it.The demensions sketches show that it could be possible.It is very easy to chamber a .308 in a .30-06,but I have read about it and the only thing you get is a blown casing.I don't know and certanly would'nt do it on purpose,but I have heard of people that have.It must not have hurt them or they wouldn't have written an article on it.I have no idea of how much pressure it would take to chamber a .308 in a .270.It might be easy,but on mine it would take a deliberate effort on my part.I was trying factory spec cases. ,,,sam.
That's strange Sam cos the shoulder diameter of both the .3006 & 270 are the same dimension. I have fired a number of .308 in a .30-06 chamber just for test purposes, no problems that way. (btw, I wasn't holding it!!)
I'm off to borrow a .270 for further trials.
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DNR your 270 shares the same case as a 30-06 though the case is necked down for 7mm bullets.
The 308 has a smaller case but it is what is called a higher pressure cartridge, much more than the 30-06.
Thus you have very similer calibers. The 308 is pretty close in conparison to a 30-06 for it's case size.
Now what does that tell you in regards to the 270 ? In conparison to the 30-06 ?
Which is the most potant cartridge of these two ? The 30-06 is and so then the 308 is also. The 308 is a very acurate cartridge and shoots bigger bullets than a 270 which can be an advantage.
Never the less the 270 and 308 both get the job done and done well...A.H
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Last edited by ArkansasHunter; 11-24-2009 at 05:47 PM.
alot of it has to do with the case and the powder that you use like you use faster burning powder for the 308 because the case compasity is limited and the 308 is a very efficent cartridge the 270 has more compasity and a slower burning powder is required to get full potential out of it if you look on a powder burn rate chart you will see that most of the powder that you use for the 308 is faster burning than the 270.
That's strange Sam cos the shoulder diameter of both the .3006 & 270 are the same dimension. I have fired a number of .308 in a .30-06 chamber just for test purposes, no problems that way. (btw, I wasn't holding it!!)
I'm off to borrow a .270 for further trials.
SAAMI specs,the .270/.30-06 shoulder is .441" while the shoulder on the .308 is .454",.013" difference.As I said,I don't know how much effort it would take to chamber a .308rnd in a .270/.30-06 chamber.I think what stopped me was the larger cal hitting the lands.I saw marks on the bullet about half way forward on the ogive.I do know a .308" can be chambered in a .30-06 chamber and has often been fired in them.I never did it but others say there was no damage.I am not going to do it to find out.It would be very easy to get bullet setback chambering a .308" in a .270" which if fired,would lead to not only a too large bullet (.031"larger) being pushed into a too small bore,but higher pressure from bullet setback.I believe your warning is well worth heeding.Unlike the .308"/.30-06 scenario,I believe the .308"/.270" scenario would lead to extreme structural failure,and possible great harm to the shooter if it were achieved. ,,,sam..
SAAMI specs,the .270/.30-06 shoulder is .441" while the shoulder on the .308 is .454",.013" difference.As I said,I don't know how much effort it would take to chamber a .308rnd in a .270/.30-06 chamber.I think what stopped me was the larger cal hitting the lands.I saw marks on the bullet about half way forward on the ogive.I do know a .308" can be chambered in a .30-06 chamber and has often been fired in them.I never did it but others say there was no damage.I am not going to do it to find out.It would be very easy to get bullet setback chambering a .308" in a .270" which if fired,would lead to not only a too large bullet (.031"larger) being pushed into a too small bore,but higher pressure from bullet setback.I believe your warning is well worth heeding.Unlike the .308"/.30-06 scenario,I believe the .308"/.270" scenario would lead to extreme structural failure,and possible great harm to the shooter if it were achieved. ,,,sam..
Correct about the shoulders Sam but remember the .308 shoulder is almost 10 mm before the .3006 chamber shoulder. Check the .3006 case diameter at 39.6mm from the base. With a pointed spitzer type bullet it will enter the throat no problems, or may be easily set back if it's not crimped tight.
Hey, it's great to be back at work!
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How can I 'Soar with the Eagles' when I'm working with such 'Turkeys'!
All right!!! We've both said the same thing in differen't ways! Now lets find something to argue about that we don't agree on! By the way,welcome back! We've missed you. ,,,sam.
Your ruler is off a tad. 
