223 V 308 ~ range

[dhv]

Gents,

A newbie with a 223 could expect reasonable performance out to X, where as the same person with the same rifle except in 308 could expect a similar level of performance out to Y.

Name X and Y for me please. And why.

[Seddo]

I am a newbie too, everything i have read suggests the only disadvantage to the 223 is wind drift. THe 80gr 223 projies run about the same BC as the 308 so trajectory is the same. There will be less recoil with the 223 as well.

So far i have been using a 308 but will try a 223 soon.

http://www.khgs.com.au/comments/223Conversions.html

[M12LRPV]

I run a 223 amongst 308's out to 800m and they each have their advantages and disadvantages but for the most part they are on par with each other.

It is my opinion only but believe that the 223 gets buffeted more in heavy inconsistent winds over long distances. Possibly because of less inertia due to the lighter mass of the 22 projectiles.

My observations are that (ignoring wind reading ability) the group opens up a little bit more as the wind increases.


The biggest disadvantage for me has always been at 800m (the longest at my range) when the other shooters who psyche out at that distance start cross firing on your target The markers always seem to take the 30 cal hole over the 22 cal hole. Electronic targets will fix that.

[GM]

The 223 will run with the 308 in still weather.
I have shot possibles using a 1:9 twist back to 700 yards with the 69 grainers.I ran a 1:7 with the 80gr for awhile but got disappointed in the batches of projectiles I got.
The 308 will shoot as far back as the shooter needs on a 1MOA target.
I honestly believe that the 223 is best inside 600 yards.
Despite all the ballistic charts it seems to struggle after that.
I believe that it has a lot to do with the actual projectiles with the 80grainers really not being that good in comparison to the 155 projectiles available to the 308.
This is what i have found with my rifles for what it's worth.The 223 seem a bit of a tease, on its day it is brilliant but then it just plain disappoints.
cheers

[IanP]

This is an interesting topic and the BS has mostly stopped now that we are better informed thru books like Bryan Litz's latest publication.

It is a ballistic fact that a 1 gram bullet (if it was possible to manufacture) with an identical BC to a 1 tonne bullet and shot at the same velocity will track identical ballistic curves.

The current best BCs for approved 223 bullets goes to Hornady's 80gr Amax. The best approved 308 bullet is BJD's HBC 155gr bullet.

HBC = G7 BC = 0.236
Amax= G7 BC = 0.231

BCs are pretty close but the HBC has an advantage therefore is superior and I guess if I were building a new FS rifle this is the calibre I would choose.

Real world shooting (I shoot the 223 with Amax bullets) tells me the slight BC difference means very little out to 600m. Beyond that range the difference means the wind will give me greater drift and a larger group.

The problem with the 223R is compounded by the fact that the velocity is generally lower than the best 308W shooters are using. I'm shooting a full case of 2208 (25.6gr, compressed) with CCI magnum primers for 2960fps. The hotshots are getting 3000fps with the 308W and it increases the ballistic margin over the little 223R.

If the Berger 90gr VLDs (G7 = 0.281) were allowed, I could launch them at 2900fps and suddenly I would be competitive all the way out to 900m.

We need the 90gr VLDs included onto the approved projectiles list now to be competitive with the 308 guys shooting the HBCs, otherwise we are limited to the shorter ranges to be competitive!

Just my thoughts!

IanP

[Barry Davies]

The 90 grainer at a G7 BC of .281 would then be superior to the HBC. The 308 users would then want a 308 with comparable BC -- where does it all finish? I'll tell you where-- with projectiles that we cannot afford.
Barry

[Barry Davies]

To qualify my statement re being able to afford certain projectiles. There is currently a 308 x 155.5 gn projectile being produced in this country, has a claimed better BC than the HBC -- it's not approve and probably never will be. Current selling price is $25 per 20 --thats $1.25 each--is this what we want?--certainly not for FS unless you want to kill it off completely.
Barry

[IanP]

The 90 grainer at a G7 BC of .281 would then be superior to the HBC. The 308 users would then want a 308 with comparable BC -- where does it all finish? I'll tell you where-- with projectiles that we cannot afford.
Barry

Very good point Barry! Thats the reason why the 308W shooting HBC bullets is the way to go. Best price and best BC means its the preferred calibre for FS.

My 223R FS rifle will become my 12 year old son's rifle and its a perfect calibre to learn how to shoot long range. Low recoil means its kid friendly and flinch fee!

IanP

[Seddo]

You can always take the best of both and run a 223 for 300-600 and a 308 for 700-1000.

[M12LRPV]

So Bryan Litz wrote a book and because of that you can shoot a 223 as good as a 308 all the way to 1000.

That is until Litz expands the scope of his calculations and includes some more realistic environmental and bullet movement models in his calculations.


Yes, it's true that equal BC means equal ballistic performance but that is in a specific formula in a restricted model.

If you think about it there are a lot of things that effect the motion of a object in flight and it's BC is just one part of it.

If mass has no effect and it's all BC then how come the old smoke poles can accurately fling really poor BC objects over long distances accurately at 900yd gongs etc.

There's more to it than that of course.

[IanP]

You can always take the best of both and run a 223 for 300-600 and a 308 for 700-1000.

That would probably be an ideal FS setup! Low recoil 223R at the short ranges and 308W at the longs. I know at least one top FS shooter in Adelaide that is doing as you suggested.

One other point worth mentioning is lack of quality control from Hornady in the 80gr AMAX bullets they ship to Australia. These bullets vary considerably in quality from batch to batch. Initially (12 months ago) these bullets grouped consistently batch to batch but not any more. Malcolm Hill gave me a number of bullets from different batches that were coated in lead spots. You can imagine how that would effect the balance of a spinning projectile.

Just today I read a post on the following link of Hornady shipping bullets to South Africa without their boat tails having been formed! Malcolm has suggested the same thing to me about Hornady obviously shipping anything off to Australia. It was just a casual remark but I think he may have been spot on!

Look here: http://www.accurateshooter.com/forum/in ... 633.0.html

IanP

[dhv]

Sounds like 223 is the best to start with and then consider a change once you can outshoot the rifle and start pushing the distances out.

Keep in mind it's just casusal fun for me at this point.

Also 223 is more useful as a rabbit, fox & roo rifle off the range.

Does anyone have a link to the list of approved projectiles? I can't find them listed anywhere.

[dhv]

Well there is at least one opinion out there that says my preferred choice (Tikka T3 Varmint) is "pretty much useless for F class" in 223.
http://www.bcrc.iinet.net.au/equipment.html

[M12LRPV]

Well there is at least one opinion out there that says my preferred choice (Tikka T3 Varmint) is "pretty much useless for F class" in 223.
http://www.bcrc.iinet.net.au/equipment.html

Yes and no. The issue is that the throat is so short that the use of 80gr amax's (and even the sierra's and nosler's) mean you're seating them so far into the case as to cause significant pressure issues.

It will work but you'll struggle. Have a friend that's just rebarreled without supplying a dummy round for setting the throat and is having the same issues with a spec chamber.

There's nothing that says you couldn't drop the tikka off to a gunsmith and have some work done on the throat.

Their 308's on the other hand are first rate as a factory option for F-STD

[M12LRPV]

ok. Forums back up so I can post the addition that I wanted to put up last night


The reason for the harsh comment is that i've geared the whole site towards the beginner and for a beginner it's just going to be too much hard work and also a bit dangerous for them to use such a rifle.

For F-Class the 223's really are a reload only option as there isn't any commercially produced ammunition that runs 80gr projectiles.

So for a beginner who's also going to be starting up reloading the last thing they need to be doing is hitting pressure issues with medium loads.

For an experienced reloader it's potentially a different prospect.