Home Forums Hunting & Shooting Ask The Gunwriters Heavy bullets for .243?

Why do there not appear to be any really heavy-for-calibre bullets available for the .243?

For example, 7mm hunting bullets are generally available up to 175gn (SD .310),
6.5mm hunting bullets are easily available up to 160gn (SD .328)
but drop down just 0.5mm dia. to .243 (6mm) and the heaviest hunting bullet generally available is only 105gn (SD .254)

Is it a technical issue, or just lack of demand?

Suspect it's because the majority of factory barrels are 1 in 10" and getting a heaver and hence longer bullet to stabilize would require a slower twist. David Tubbs makes a 115 gr bullet but you're likely looking at 1 in 7.5" to get good accuracy. http://www.davidtubb.com/ammo_bullets.html

When you look at common bullets for the .243 run between 55 gr and 105 gr a 50 grain range and the 7mm commonly available run from 100 to 170 grs.

If you switch that to % of weight it means the .243 is bullets available over a 52% range and the 7mm over 58% range. Really not that far apart.

Thanks Pugs,

Although the weight ranges cover a similar percentage range, sectional densities over those ranges are where the .243 falls short compared to the 6.5 and 7mm calibres.
For example, a 130gn .243 bullet would equal the SD of a 175gn 7mm bullet, and a 135gn .243 bullet would equal the SD of a 160gn 6.5mm bullet, so why don't manufacturers offer these weights?

I am guessing it must be lack of demand. Technically I imagine there would be no problems using a faster barrel twist rate to cater for heavier bullets.

I guess that also there becomes a point of diminishing returns in killing power where an increase in SD cannot make up for a lack of frontal area / overall weight.

Maybe I should look at a .260 instead of trying to turn the .243 into a .260 .

Limited by available twist rates in factory rifles. The 6mm Lee Navy had a 112 grain bullet and a 1-8" twist. The usual 1-10 to 1-9 twist max's out at about 105-107 grains. Much faster and you may have problems with some light weight light jacketed bullets.

The 24s are about velocity and once the bullet gets too heavy and you lose velocity you are loosing ground.

That's where the 6.5s come into play with the longer bullets possible.

Always good advice! I'm not a big bore kind of guy but neither am I one to try and stretch the envelope too much of rifle.

I wonder if sectional density (SD) is as critical a factor in this day of premium bullets as it was in the days when cup & core were at their peak?

I shoot a number of difference 6.5mm/.264" bore cartridges and can't see any reason to go heavier than the 140 grain Partition for all of my hunting needs. While I have used the longer/heavier 156/160 grain bullets in the past with good results, as a reloader I strive for a hamonious balance of components that will give me an optimal combination of accuracy, velocity, and bullet penetration for the intended target. I the medium case capacity 6.5mm cartridges, like the 260, 6.5x55, and 256 Newton, I would quite happy if limited to the 95 grain VMax for things on the lighter side, 129 grain SpirePoints at all medium game, and the 140 grain Partition for anything bigger/tougher. If I was only shooting medium game, I might opt for the 100 grain Partition as a means by which to gain a little velocity and flatter trajectory.

In the .243" bore cartridges, the 95 grain BT and Partitions are my bullets of choice for medium game and either the 75 grain VMax or Sierra HP for varmints.

Jeff

i have yet to recover any of the federal fussions from the deer we have taken with them but the coming in holes and the going out holes all dictate that expansion occured with no fragmentation and obviously plenty of penetration, even when gone through both shoulders. don't know if a heavier slug would have done any better.

The only thing you need in the 243 is an 85 tsx. It'll do all the 243 is capable of.

i'm curious as to what you'd do with a heavier 6mm bullet, that you wouldn't do with a 100 gr. choice???
and that is without consideration of the premium bullets available...

the rifles that i used for years were chambered for the .243... my favorite do-all bullet was the 85 gameking...
for coyotes, deer and a few pronghorn, it was more than sufficient...

for no particular reason of need, i now use a 25-06... great fun... awesome cartridge...
same deal with bullets, though... i see no problem...

Pete..I've shot many deer and lopes over the years with my 243 and went down the same road you're trying now....always thought the heavier the better..but in most of my hunting scenarios I noticed not much difference between 85 - 105 at similar ranges.As someone else said the 24's are about speed and if you look closely at most manuals not much difference between 100 and 105 except you seat the bullet deeper.Think if I were you I would ditch the 100/105's and try the Barnes 85gr TSX or Nosler Partition 85 or 95 grainers.These bullets overall have performed better for me than the heavy ones and what the lighter ones lack in sectional density or BC they make up for in killing power...Good luck hope you have success with all the good info that's been posted!....FLEM

The heaviest commercial 6 mm bullet I've read about was 127 gn (SD .307). This was from early in the development of smokeless hunting cartridges.

In principle, such a conventional bullet should penetrate deeply, but deep penetration is probably desired for big animals, and for these a proportionally larger hole is often desired. Also, such a long slender bullet may be more prone to taking odd shapes on impact, causing it to veer unpredictably, defeating the goal of deep penetration. If a suitably heavy jacket in 6 mm were made, perhaps there wouldn't be enough lead in the center to make it worth the effort?

I think once you reach 100 grs in the 243 that's about top end and if you go beyond it you're pushing the envelope.Big long bullets would have to be seated way much deeper reducing case capacity and increasing pressures because of their long bearing surfaces.So if you did load a bullet in say 110-117 grs it would be a truck!!! I doubt if you could get more than 2300 FPS out of it.With todays premium bullets of 85 to 95 grs is all one needs..these make the 243 what it was supposed to be..a high speed/flat shooting killer!!!

So even if one of those was available I wouldn't use it..and if you felt the need for a bigger bullet then the practical thing to do would be step up to a 257 ROB or my choice the 260 Rem......FLEM

115gr bergers from my 243AI at 3100fps are deadly on whitetails. From 50 yards to 550 yards they have been very effective at putting down whitetails.
The 243AI with 115s is great choice for midrange shooting. I actually prefer the 243 to the 260 so long as the 243 has a fast twist.

You must use a pretty heavy load to get 3100 fps from a 243AI!

Jeff

If you can't get it done with an 85 gr. TSX, go to a 7mm, and under elk, I can't fathom what an 85 TSX won't handle.

Been shootin one along time and don't really know how that kind of velocity is possible with that big bullet..expand alittle and tell me what load gives you these numbers... guess I've been in the dark for 45 yrs !!!!

I've seen some master class silhouette shooters use the .243 with 105's. They still have to hit the rams at 500 meters in the top half to topple them.

I use a .308 and generally consider myself happy if my bullets hit the impact area and a minor miracle if I topple the target.

I think the main "benefit" gained with heavy 243 bullets is the Ballistic Coefficient. That equates to flatter trajectory at quite long ranges (something like the 115 DTAC).

I cannot see the advantage though for big game hunting over something lighter and faster in monometal.

I am shooting a compressed load of vv560 with a COAL 2.9ish using 115 bergers and lapua brass. When it was first chambered I used 3 pieces of lapua brass to work up the load. I have no idea where the pressure actually is but there are no pressure signs and I got 10 plus firing using those 3 cases without primers loosening.

Quick Load predicts I am a hair over 60KPSI according to the latest update. The pressure was 60K according to an older version, no idea what is differnt unless I modified the start pressure. Oh yea this is from a 25inch 7.5 twist pac-nor. The barrel may be fast since it is a redo chamber. This barrel was originally a 6x284 in a med palma contour (I think). The entire 6x284 chamber was cut off and it was rechambered to 243AI. Cutting about 3 inches off the back end of a palma contour matches a sendero contour pretty closely.

you can get 31oo fps out of a 6-6.5x47 lapua with a 28 inch barrel using 41 grains or there abouts of vv560 and using moly DTacs. I have no idea as to the pressurebut we are running 28 inch barrels to get this velocity

Thanks for the info..not so hard for me to believe now..only problems I have with your post is that the opening thread said 243 not the AI version or with a 27" tube.I realize we're talking about heavy bullets but your components in a standard 243 with say a 23" tube changes everything.Your data sounds great to me but I don't think it applies to the run of the mill 243 owner.....TNX.....FLEM