257bob vs 243

MNHNTR

MNHNTR

New member
So as to not hijack another mans thread I will continue this on here. BC has a direct effect on velocity and energy. Just because the 257 is slightly bigger in diameter and a few grains heavier does not make it better. Some of you need a lesson in physics and math, or read a book once in a while. While the two calibers are so close in velocity and energy in factory loads you simply cannot make the 257 do what the 243 can when you use the very best components. You also cannot go from 58gr bullets to 115gr bullets in the 257. You do not have over 120 choices of bullets in the 257. You cannot get the same velocity out of a 257 and the list goes on and on. I know you guys love your quarter bores and I am not bashing the round it is just not what the 243 is sorry.
 
Its a hard pill to swallow for all of us 25 cal lovers. Been shooting 25'S for along time until last year I built a 243 imp should have done it years ago, Ive shot everything 55 to 100 grain bullets in it. Just cant do that with the 25s. Itcomes down to what you like I guess but the high BC bullet opitions its a no brainer if you want to shoot longer distances.
 
Originally Posted By: MNHNTRSo as to not hijack another mans thread I will continue this on here. BC has a direct effect on velocity and energy. Just because the 257 is slightly bigger in diameter and a few grains heavier does not make it better. Some of you need a lesson in physics and math, or read a book once in a while. While the two calibers are so close in velocity and energy in factory loads you simply cannot make the 257 do what the 243 can when you use the very best components. You also cannot go from 58gr bullets to 115gr bullets in the 257. You do not have over 120 choices of bullets in the 257. You cannot get the same velocity out of a 257 and the list goes on and on. I know you guys love your quarter bores and I am not bashing the round it is just not what the 243 is sorry.

I don't care about factory ammo I don't use it. I don't need 120 bullets I use five or six. If I want a 58 grain load I will use a .224 in one of my .22 bores. And, I don't know what physics class you had but if the .257 has a bigger case capacity it can push something faster than a .243, if velocity is your thing. My personal experience after having compared them for years, is that the .257 does what I want it to do better than a .243. YMMV
 
For about 95% of hunters, BC has nothing to do with their hunting. In most practical terms, I've never seen a worry for BC 500 yards and in. Just learn your trajectory and wind deflection, and let the critters fall.

Now, I am getting more and more interested in longer and longer range shooting. When I get my ideas in my head sorted out, I'll revisit these BCs and SDs and all that sort. But for killing game/predators/varmint, currently, I don't much care.
 
Originally Posted By: Greg_MeyerOriginally Posted By: MNHNTRSo as to not hijack another mans thread I will continue this on here. BC has a direct effect on velocity and energy. Just because the 257 is slightly bigger in diameter and a few grains heavier does not make it better. Some of you need a lesson in physics and math, or read a book once in a while. While the two calibers are so close in velocity and energy in factory loads you simply cannot make the 257 do what the 243 can when you use the very best components. You also cannot go from 58gr bullets to 115gr bullets in the 257. You do not have over 120 choices of bullets in the 257. You cannot get the same velocity out of a 257 and the list goes on and on. I know you guys love your quarter bores and I am not bashing the round it is just not what the 243 is sorry.

I don't care about factory ammo I don't use it. I don't need 120 bullets I use five or six. If I want a 58 grain load I will use a .224 in one of my .22 bores. And, I don't know what physics class you had but if the .257 has a bigger case capacity it can push something faster than a .243, if velocity is your thing. My personal experience after having compared them for years, is that the .257 does what I want it to do better than a .243. YMMV

The case capacity difference is roughly 2 grains. It does not make the 257 faster. If you have researched this for years you would know that. You are stating the 257 does it better but it is only perceived not factual.
 
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I have nothing against the 243...but the 257 has always been a personal favorite of mine, I usually stay in the middle as for bullet weights, usually 85-100grs.
 
Well, I can now see this is a trolling thread of which I don't think I will participate. The OP has his mind set, and that's all there is to this thread.

I wonder if he has ever verified BC, or just uses what the box says. They're not always real true....
 
Aw heck...

Yes, the 257 Roberts will push a bullet faster than the 243 Win.

100 GR. SPR BTSP Hodgdon Hybrid 100V .243" 2.650" 40.0 2868 45,400 CUP 43.7C 3100 51,700 CUP


100 GR. SPR SPBT Hodgdon Hybrid 100V .257" 2.770" 44.0 2968 38,800 CUP 48.0C 3205 45,400 CUP

100 GR. SPR BTSP IMR IMR 4007 SSC .243" 2.650" 37.2 2784 47,000 CUP 39.5 2905 50,400 CUP

100 GR. SPR SPBT IMR IMR 4007 SSC .257" 2.770" 41.4 2894 41,800 CUP 44.0 3059 47,300 CUP

100 GR. SPR BTSP Hodgdon H380 .243" 2.650" 34.0 2639 43,600 CUP 36.0 2770 50,100 CUP

100 GR. SPR SPBT Hodgdon H380 .257" 2.770" 40.5 2868 37,800 CUP 44.0 3108 46,600 CUP

There's plenty more than 2 gr difference...
 
Originally Posted By: pahntr760Aw heck...

Yes, the 257 Roberts will push a bullet faster than the 243 Win.

100 GR. SPR BTSP Hodgdon Hybrid 100V .243" 2.650" 40.0 2868 45,400 CUP 43.7C 3100 51,700 CUP


100 GR. SPR SPBT Hodgdon Hybrid 100V .257" 2.770" 44.0 2968 38,800 CUP 48.0C 3205 45,400 CUP

100 GR. SPR BTSP IMR IMR 4007 SSC .243" 2.650" 37.2 2784 47,000 CUP 39.5 2905 50,400 CUP

100 GR. SPR SPBT IMR IMR 4007 SSC .257" 2.770" 41.4 2894 41,800 CUP 44.0 3059 47,300 CUP

100 GR. SPR BTSP Hodgdon H380 .243" 2.650" 34.0 2639 43,600 CUP 36.0 2770 50,100 CUP

100 GR. SPR SPBT Hodgdon H380 .257" 2.770" 40.5 2868 37,800 CUP 44.0 3108 46,600 CUP

There's plenty more than 2 gr difference...






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There is just something about a 257 R that's hard not to love. Traditional maybe? 6mm, 257R, 7x57.......
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I use my .257 for deer, hogs, etc. My bullet of choice has been the Nosler Ballistic Tip. The .243 is a 90 gr and in .257 it is a 110 gr.... That is over 20% more of my favorite deer bullet, and it has a better (higher) BC. So, even with a 100-200 fps advantage I know at 300 yards I have better energy than a .243. Got that from reading...lol

Now, your AI may get closer on capacity anxd therefore have a bit more velocity... but a .257 AI would erase that in an aplles to apples comparison.

At lighter bullets for fox, coyote, etc. you might make an argument that for that purpose the .243 is better. I would agree since that is what I use for those critters. And, my .22-250 is way better for Prairie Dogs than my .243.

Now, for Elk, Moose and Griz...my .257 ..... j/k
 
Originally Posted By: pahntr760Well, I can now see this is a trolling thread of which I don't think I will participate. The OP has his mind set, and that's all there is to this thread.

I wonder if he has ever verified BC, or just uses what the box says. They're not always real true....

I am not trolling but this all started in another thread were it was said the OP should buy a 257 for his kid to bear hunt even though he already had a 243.
Anyways you can do this all day long it just depends on which manual you are reading. The newest Lee manual shows usable case capacity for the .243 3.42cc and the .257 at 3.45cc
.243 100gr bullet using 40.0 gr of H4350 at 2973fps
.257 100gr bullet using 45.0 gr of H4350 at 2970fps
So instead of throwing numbers you read out of manuals I suggest real data be used.
 
So the data I posted wasn't real? Where did I conjur it from, I wonder?

Your data is obviously derived from rifles with different barrel lengths.

100 GR. SPR BTSP Hodgdon H4350 .243" 2.650" 37.0 2806 45,100 CUP 40.0 2973 51,000 CUP

100 GR. SPR SPBT IMR IMR 4350 .257" 2.770" 44.8 2896 38,400 CUP 47.7 3077 47,000 CUP


See what happens when you level the playing field? There is not logic behind this argument. First you said '2 gr difference' then said I need real data, not just data from a manual...all the while quoting data from a Lee manual...you have a way with words...

And Cubic Centimeter capacity and Grain capacity are different things. Also, there is a wide variance in cases from brand to brand, and even lot to lot. So that quoted capacity is flawed in its self.
 
Mnhtr, looks like you need to check a few more manuals. Many of them limit the pressure on the 257 because of the suspect military actions that were re-barreled to the round in earlier times. Those that show +P data go well above what you've shown.
In a modern action there is no reason to hold the 257 to pressure under what the 243 operates at. At those pressures some manuals move the 100 257 up to around 3200fps. Hodgdon shows 3 powders over 3100 with one at 3200 and none over 47K CUP pressure, with the 243 they go up to 51k.
My own 22" barrel with the 100 Hornady does 3050 with 45gr. H4350 in a Win case with Win primer. There is pressure tested data out there that supports 46 gr. H4350 as not being max.
Run them both in modern strong actions to the same pressures and the comparison will change.
 
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Originally Posted By: pahntr760So the data I posted wasn't real? Where did I conjur it from, I wonder?

Your data is obviously derived from rifles with different barrel lengths.

100 GR. SPR BTSP Hodgdon H4350 .243" 2.650" 37.0 2806 45,100 CUP 40.0 2973 51,000 CUP

100 GR. SPR SPBT IMR IMR 4350 .257" 2.770" 44.8 2896 38,400 CUP 47.7 3077 47,000 CUP


See what happens when you level the playing field? There is not logic behind this argument. First you said '2 gr difference' then said I need real data, not just data from a manual...all the while quoting data from a Lee manual...you have a way with words...

And Cubic Centimeter capacity and Grain capacity are different things. Also, there is a wide variance in cases from brand to brand, and even lot to lot. So that quoted capacity is flawed in its self.
I am not saying the data you are using isn't real but unless it is marked on what barrel and twist rate and all the other rifle stats you never really know what you are comparing. My point to this whole argument was to point out that the .257 will not do anything better than the .243. Couple that with the fact that you can choose from more than twice the bullets and when loaded with bullets like the 115 VLD and 117gr Dtach the .243 far surpasses anything the 257 could muster at distances over 400yds. Is the .257 a good deer antelope and varmint round? Yes my wife's 257 has taken its fair share of deer. Will do more than a .243? No it will not do anything more. It is limited and in most cases equal at best. Put it out on the 1000yd range and the .243 will eat its lunch.
 
Originally Posted By: ole_270Mnhtr, looks like you need to check a few more manuals. Many of them limit the pressure on the 257 because of the suspect military actions that were re-barreled to the round in earlier times. Those that show +P data go well above what you've shown.
In a modern action there is no reason to hold the 257 to pressure under what the 243 operates at. At those pressures some manuals move the 100 257 up to around 3200fps. Hodgdon shows 3 powders over 3100 with one at 3200 and none over 47K CUP pressure, with the 243 they go up to 51k.
My own 22" barrel with the 100 Hornady does 3050 with 45gr. H4350 in a Win case with Win primer. There is pressure tested data out there that supports 46 gr. H4350 as not being max.
Run them both in modern strong actions to the same pressures and the comparison will change. I load the 257 for a modern Rem 700 and I understand what your saying but it does nothing better than the .243 and is limited more due to bullets.
 
I load for both 243 and 257 as well as several others. Other than just curious experiments, I tend to standardize on one varmint load and one game load for each.
With 25 caliber bullets commonly available from 75 hp and v-maxes to 120 Partitions you'd have a hard time convincing me that the 25 is all that handicapped on bullet variety.
Truth be told, my M70 Fwt. 243 mostly stays sighted in for the varmint load(coyote calling in my case) while the Ruger M77 257 spends more time sighted with the deer load. I have nothing against the 243, just like the Roberts (and 250 Savage) better.
 
Originally Posted By: Tim NeitzkeI'm all out of popcorn, so I'm haveing fresh 243 killed deer t-loins and onions....grinning

You must have used a bunch of speed and a high BC bullet, otherwise, you woulda just wounded the poor thing...
 
Originally Posted By: pahntr760Originally Posted By: Tim NeitzkeI'm all out of popcorn, so I'm haveing fresh 243 killed deer t-loins and onions....grinning

You must have used a bunch of speed and a high BC bullet, otherwise, you woulda just wounded the poor thing...

Laff'n....

My wife let it get into bow range (30yards) and gave it a 95gr Fusion. No worries on wind or BC.
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