75gr .224 vs168gr .308 out to 700 yards

[Jason280]

I have a couple of Savage 10FP's, one in .308 and the other in .223. I load Hornady bullets in both guns, and both rifles shoot .75 MOA. My .308 load uses a 168gr BTHP's out to roughly 2650, while my .223 load uses 75gr BTHP's at 2925. Now, according to the Hornady site, the BC of the 168gr is .450, while the 75gr is .435.

Of these two loads, which would you recommend for shooting out to 700 yards? A local club holds matches monthly, with ranges from 100 to 675 yards. I haven't decided which gun to use, but I am leaning towards the .223 simply for cheaper components and less recoil. Would there be any reason to use the .308 over the .223 in this scenario? Thanks!

 

[7mmRM]

Re: 75gr .224 vs168gr .308 out to 700 yards

Do the math. .435 @ 2950 Vs .450 @ 2650.

http://www.eskimo.com/~jbm/calculations/traj/traj.html

 

[Jason280]

Re: 75gr .224 vs168gr .308 out to 700 yards

Looks like the 75gr bullet will better serve my purpose, and will actually be cheaper to shoot. Now, I just need to figure out which scope to use on the rifle. I know this is a rather generic question, but do *most* scopes have enough adjustment to get to 700 yards without a canted base? The scopes I have available are a Nikon Monarch 5.5-16.5x44, a Falcon Menace 4-14 FFP, and a B&L Elite 4200 6-24x40.

 

[pj68]

Re: 75gr .224 vs168gr .308 out to 700 yards

Jay,
I don't reload so i use BH 223 75 grainers. First trip 2 range sighted in at 100. Looked up adjustments on my cheat sheet. First round hit at 650 yards. Granted, that was on steel butt i didn't miss often with it. Wind was blowing down that canyon pretty well. I just got some 77 grainers i gotta try those out now. Hope the twist will handle them.

SOTA

P.S.: for the rifles nickname check with texgal.

 

[shooter65]

Re: 75gr .224 vs168gr .308 out to 700 yards

My 223 has no problem at all going that distance.

 

[TNT]

Re: 75gr .224 vs168gr .308 out to 700 yards

Does the math count for effects of wind? I don't do numbers too much, but I'm thinking a heavier projectile is affected by the wind less, which means a lower horizontal spread?

 

[Sig685]

Re: 75gr .224 vs168gr .308 out to 700 yards

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jason280</div><div class="ubbcode-body">I have a couple of Savage 10FP's, one in .308 and the other in .223. I load Hornady bullets in both guns, and both rifles shoot .75 MOA. My .308 load uses a 168gr BTHP's out to roughly 2650, while my .223 load uses 75gr BTHP's at 2925. Now, according to the Hornady site, the BC of the 168gr is .450, while the 75gr is .435.

Of these two loads, which would you recommend for shooting out to 700 yards? A local club holds matches monthly, with ranges from 100 to 675 yards. I haven't decided which gun to use, but I am leaning towards the .223 simply for cheaper components and less recoil. Would there be any reason to use the .308 over the .223 in this scenario? Thanks! </div></div>

First off, you are confusing the Hornady 75gr BHTP and the 75gr A-Max. The former has a claimed BC of .395 and the latter has one at .435. After sending many hundreds of 75gr A-Maxex on 600 and 1000 yard flights I am here to tell you that claimed BC is inflated; the true value is closer to .400 or .410. The 75gr BTHP's BC is probably closer to .360 or .370. Doesn't make much difference inside of 400-500 yards, beyond that it does.

Second, I think your MV on the 75gr is a little high, but if you have a longer barrel, it makes sense. On the other hand you 168 MV is a little low and could be increased especially if you have a longer barrel, but if accuracy is good, then leave it as is.

You have not told us what type matches the local club is holding; that may have some bearing on the decision and the choice of optics.

Your barrel twist is probably 1:9 for the .223 and that precludes you from using the better 80gr SMK, JLK, A-Max or Berger VLD. 75 BTHP is about all you can shoot, check out the Berger VLDs for the 1:9 and the 75gr JLKs, also for the 1:9 twist.

 

[mp45acp]

Re: 75gr .224 vs168gr .308 out to 700 yards

All things being equal the heavier projectile will always buck wind better.

On paper the .223 might have the edge, i doubt it on the range.

Report back and let us know, I am curious myself.

 

[pj68]

Re: 75gr .224 vs168gr .308 out to 700 yards

Guys,
I don't think its really a matter of higher weight meaning better performance. I think its more like a better ballistic coefficient means better performance. That is if a given published BC is correct.

SOTA

 

[Jason280]

Re: 75gr .224 vs168gr .308 out to 700 yards

Yes, I realize now that I mixed up the BC on the 75gr bullet. When I pulled them up on the Hornady site, I must have clicked on the Amax instead of the regular BTHP bullet. The velocity is correct, as I have shot this load quite a bit through my chronograph. The load is a max load of H4895 in Win brass, and I haven't seen any signs of overpressure. The barrel length is 24", and here are a few of my velocity numbers: 2911 2917 2902 2930 2911

The match is point based, and includes steel and paper targets (including pop up targets and some moving targets). Each target score is based on MOA for that range, so a hit in that range gives the max points. Basically, there are 20 targets that are engaged in 12 minutes, with a maximum of 400 points.

 

[dmg308]

Re: 75gr .224 vs168gr .308 out to 700 yards

Check out service rifle comps .308 is a dead animal there.Some has to do with the platforms but if the cartridge would'nt get it done you would'nt see it.

 

[michael_aos]

Re: 75gr .224 vs168gr .308 out to 700 yards

What about the 155gr Scenar with its .508 BC? You should be able to push it faster than the 168gr.

My 22BR shoots 75gr AMAX (.435 BC) @ ~3000fps. Fun to shoot, but in the wind it loses to 260 Remington. 139gr Scenar (.615 BC) @ ~2800fps.

I keep eying the 80gr AMAX (.453 BC), thinking I could get the same ~3000fps if my 22" 1:8" twist barrel likes it, but I haven't tried it yet.

Mike

 

[Sig685]

Re: 75gr .224 vs168gr .308 out to 700 yards

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jason280</div><div class="ubbcode-body">Yes, I realize now that I mixed up the BC on the 75gr bullet. When I pulled them up on the Hornady site, I must have clicked on the Amax instead of the regular BTHP bullet. The velocity is correct, as I have shot this load quite a bit through my chronograph. The load is a max load of H4895 in Win brass, and I haven't seen any signs of overpressure. The barrel length is 24", and here are a few of my velocity numbers: 2911 2917 2902 2930 2911

The match is point based, and includes steel and paper targets (including pop up targets and some moving targets). Each target score is based on MOA for that range, so a hit in that range gives the max points. Basically, there are 20 targets that are engaged in 12 minutes, with a maximum of 400 points. </div></div>

Closer to 2900 than 3000; those numbers are exactly in line with the ones I was getting with a max load of Varget in my(then) 24 inch barrel. I was looking for that extra 100FPS because I had issues keeping the 75 A-Max supersonic at 1000 yards in cooler temps. I used Lapua and Winchester brass and just did not want to push any higher.

Interesting course of fire, I think a variable scope may be more appropriate than a fixed powed, the reticle will need to have mil-dots or come other offset marking, I would think, unless you are a fast knob turner. Any of the scopes you listed will work just fine.

You may want to go with the .308 if you have to drop some steel. The 168 A-Max is a fine bullet for the distance you are talking about.

 

[308sako]

Re: 75gr .224 vs168gr .308 out to 700 yards

.

 

[sobrbiker883]

Re: 75gr .224 vs168gr .308 out to 700 yards

I plan on shooting my AR at our local precision matches with its measley 75gr BTHP's at 2700ish. I've done it once and placed right around where I do with my 308 running 168's at 2725ish.

Depends what you want out of the match. If its to have a good time with what you have and challenge yourself for a little cheaper, then go for it. If you're a gamer, build a top o' the line custom in a different caliber than either of your choices.

I like the challenge for cheap every now and then, and once I get a few things squared away on my SPR I'll be doing more of it (if I can ever find more damned SR primers and powder that is!).

 

[bigmac125]

Re: 75gr .224 vs168gr .308 out to 700 yards

By the time you get a bullet in the 30 cal that has the same BC as the 75-90 grain 22calibers the 308 falls on its face. If the 308 had the velocity to push the heavier bullet at the same speed then and only then would it keep up with the ballistics of the 22. On the other hand if you want to use the two to hunt with at that distance then the 308 has alot more energy do to the bullet weight. Yes my friends speed still kills, but BC is what makes the killing possible.
GOD bless,
Mac's

 

[Nocalphoenix]

Re: 75gr .224 vs168gr .308 out to 700 yards

The 155s at 2900fps will do alot to close any perceived gap on paper. The lighter recoil of the .223 might allow you to stay on target better but with the .308 you will get much better feedback on misses and will be able to call your hits on the steel. Big difference between seeing you caught an edge on the steel and seeing it was center punched with the proper correction.

 

[Sig685]

Re: 75gr .224 vs168gr .308 out to 700 yards

Sobrbiker883: I sort of equate the 77GR SMK (and the 75BHTP) to the 168gr SMK. The BC of the .224 is lower but the MV is higher so the effective range is about the same.

I equate the 80gr JLK to the 175SMK with perhaps a slight edge to the JLK for its higher MV with similar BC.

The good thing about LR shooting with a .224 bullet is that you get to learn to read the wind.


Norcal Phoenix: As for the 155, its SD is similar to the 80gr .224 bullets and so I think the gain there is perhaps less than you think.