.270 Win or .308 Win

wiersy111 · Posted: Fri Oct 02, 2009 6:52 pm Post subject: Re: .270 Win or .308 Win

Great research. I have suspected the same thing but never actually did the research, just tried to keep the brass separate. I guess now I have a reason to check my loads in different brass.

Thanks for the info.

chambered221 · Posted: Fri Oct 02, 2009 7:12 pm Post subject: Re: .270 Win or .308 Win

Just keep in mind that the next time you need brass you may find what liked Remington then might like the Federal now!!!

fnuser · Posted: Sat Oct 03, 2009 6:45 am Post subject: Re: .270 Win or .308 Win

I posted that cases comment mostly as a pressure caution as different cases have different volumes, different alloys ergo different pressures. so yes this will affect accuracy. However that load is no where close to max in my chambers, also a determining factor.

fnuser · Posted: Sat Oct 03, 2009 6:50 am Post subject: Re: .270 Win or .308 Win

Alot of hunters that shoot their game under 200 yrds wouldn't neccesarily have to sort cases, as benchrest accuracy isn't required. Having said that though, I can't imagine anyone cranking out ammunition that is not the best they can do intentionally. To me that is part of the addiction.

wiersy111 · Posted: Sat Oct 03, 2009 7:00 am Post subject: Re: .270 Win or .308 Win

Part of the addition is exactly right.

slimjim · Posted: Sat Oct 03, 2009 7:53 am Post subject: Re: .270 Win or .308 Win

fnuser wrote:

... different cases have different volumes, different alloys ergo different pressures. so yes this will affect accuracy. However that load is no where close to max in my chambers, also a determining factor.

You can indirectly measure the volume of a case within the same manufacturer by weighting the case. Equal weight = equal volume. I do this when I get my cases and mark the weight on the side to a tenth of a grain. I then repackage them in zip-lock bags in groups of 15 or 20 with matching or similar weights. That way I have matched cases when I introduce a new brass into the loading cycle. For general shooting, I don't think this is necessary. I have had long range shooters say this can be important to accuracy.

I'm addicted!

PaulS · Posted: Sun Oct 04, 2009 9:11 am Post subject: Re: .270 Win or .308 Win

An 8 grain difference in case weight is approximately 1 grain of powder difference internally if the cases have been fired and sized.
If the cases have not been fired and sized you can get lower pressures than you might have after firing and sizing because the case will expand until it fills the chamber - slowing the pressure rise.

slimjim · Posted: Sun Oct 04, 2009 10:52 am Post subject: Re: .270 Win or .308 Win

I have one load that is good with fired/necked-sized brass but is consistently better with new brass. I load it up with new brass and then reuse the brass in the other loads. Keeping detailed records of how you load your rounds including brass, COAL, and weather conditions is the only way to track down why things happen. You can only change one thing at a time. If you change more than one aspect, you won't know what contributed to the improvement or regression in performance.

PaulS · Posted: Mon Oct 05, 2009 12:17 am Post subject: Re: .270 Win or .308 Win

I often run into a first fired load that gives excellent results in unfired or reformed cases that quickly goes bad when loaded in the same cases with neck sizing. I found that if I work the load up and down I can find the sweat spot for the load in the fired cases.

fnuser · Posted: Tue Oct 06, 2009 2:16 pm Post subject: Re: .270 Win or .308 Win

That's good stuff Paul, thanks that 8-1 grain conversion is cool how'd you get that, is that original or had you read it?

PaulS · Posted: Wed Oct 07, 2009 10:21 pm Post subject: Re: .270 Win or .308 Win

The "rule" is based on the specific gravity of powder and the specific gravity of the brass alloy that is used in cartridges.
The powder for rifles is very close to the same no matter what brand you use and the differences in alloys is negligeable.
Specific gravity:
powder..... 1.12 (smokeless)
Brass........ 8.45

From a quick glance you can see that the difference is roughly between 7 and 8 to one. If you use the 8:1 ratio you will never go over pressure from adding too much powder. The actual ratio is 7.5446.
Since the specific gravity of the brass is 7.5 times that of powder it takes 7.5 grains of brass to equal the same volume as 1 grain of powder.

NOTE: this information is not meant to be used to guess at a powder charge for a case that does not have data for a given powder - it may not be safe to use in this fashion. IT will help you tune a load for a cartridge that you have worked the load up with one case and you have heavier or lighter cases that you wish to get the same pressure with the same powder.

fnuser · Posted: Thu Oct 08, 2009 7:22 pm Post subject: Re: .270 Win or .308 Win

Thanks again

wiersy111 · Posted: Thu Oct 08, 2009 8:00 pm Post subject: Re: .270 Win or .308 Win

This is some good stuff.

And to think I told my high school algebra teacher I would never use that crap after school.

Now here I am trying to learn this stuff because I'm addicted to hand loading.

Makwa · Rookie Member Joined: Oct 08, 2009 Posts: 23

There are certainly worse addictions.............and the way things are going this may well prove to be a good addiction.

labmanx3 · Rookie Member Joined: Dec 11, 2009 Posts: 2

Most everyone that have posted replies, seem to think that "bigger" is better. It has been proven over the years that "bullet placement" is much more important than the size of the caliber. You could use a 338, and with poor bullet placement loose your animal.
The question was, which is better the 270 or 308. Either one of them is plenty for deer or elk out to as far as 400 yards...as long as you know how your gun shoots and place the bullet in the vitals.
I am 61 years old,and have hunted deer since I was 11...and elk since I was in my 20's. Most all of my hunting has been in the state of Washington for blacktail deer and roosevelt elk. Other than a short stint with a 7mm mag, all of the deer and elk have been taken with a 270, 308, or 30-06. My favorite is the 270 shooting 150 nosler partitions although they all have done well.