Thread: 243 load research/development

Originally Posted by Zedrex

Everything I've read has suggested that for my twist rate, a flat base is far easier to produce reliably consistent results whereas the boattail is more sensitive to factors not being perfect and there's the issue of propellant gas blowby on boattail projectiles which CAN?MAY cause instability as the bullet exits the muzzle and the cloud of gas, the following is a link to one of my references https://www.gunsandammo.com/editoria.../375628#replay

The second number you dismissed is energy at POI and my understanding is that the rule of thumb is 1000ft/lb is reckoned to be the safe minimum on medium size game or am I missing something?

Don't overthink it. What that article doesn't show is any evidence of any actually significant difference in precision achieved. Boat tail bullets shoot fine. Once a bullet is stable, there is no such thing as "more stable". It is not "better". A bullet that will stabilise in a 1:10 twist - will stabilise in a 1:10 twist. The important things that will drive your precision are: what is the quality of your barrel? What is the quality of the bullet you are using?

Energy tells you nothing about how a bullet will kill. Especially so when you are comparing 2 bullets of approximately the same weight at approximately the same velocity. It is a secondary characteristic derived from velocity. There's been some very in-depth discussions about this in recent times here. Even for those that believe in "energy" being important (it is not) - the differences you are talking about are fractional.

How much bigger of a hole in the deer's important organs does an extra 28 foot pounds of energy make?

Thanks all for your input, having caught up with my "mentor" who might be around here somewhere..and having taken on you lots input, I/we are going to work some loads using the SST with 2209, once I've got that dialled in then I may well have a look at the other bullets mentioned.....

Note that the SST is an older bullet design with a canellure and lower production quality standards and you should expect slightly worse precision in general from it than something like an ELDX.

That's not to say it's inadequate by any means. However I don't recommend it because there isn't really any reason to buy it at the same price vs the ELDX, BT, etc

why not try the eldx or BT, both which have (I assume @gimp?, without checking myself) better ballistics, knowing you can most likely fall back on the SST if they don't work? Personally I'd be tempted to try the 95gn Targex if I could get a few. Would have bought some myself for my recently aquired 243, except I ended up buying the 6mm projectiles that came with it, so now have plenty of 100gn Sierras and A-max projectiles which seem to shoot well (its a 1:9 twist), though only been to the range with it to date.

Originally Posted by gimp

Don't overthink it. What that article doesn't show is any evidence of any actually significant difference in precision achieved. Boat tail bullets shoot fine. Once a bullet is stable, there is no such thing as "more stable". It is not "better". A bullet that will stabilise in a 1:10 twist - will stabilise in a 1:10 twist. The important things that will drive your precision are: what is the quality of your barrel? What is the quality of the bullet you are using?

Energy tells you nothing about how a bullet will kill. Especially so when you are comparing 2 bullets of approximately the same weight at approximately the same velocity. It is a secondary characteristic derived from velocity. There's been some very in-depth discussions about this in recent times here. Even for those that believe in "energy" being important (it is not) - the differences you are talking about are fractional.

Gotcha on the energy although I'd be interested to hear why energy is not important? Yep, many rifles shoot BT's just fine, if they were crap across the board then they'd have been consigned to the bin labelled "lessons learned during development"

whilst the article does not specifically show any demonstrable evidence of affect on accuracy, the findings do show that there is a correlation between base shape and the action of the exiting gas in relation to position of projectile and that there MAY be influences introduced in the moments of the bullet exiting the barrel that MAY have an impact on it's stability and flight path, specifically around yaw and tip...and I'm sure that this could be amplified or not dependent on caliber/grainweight/twist/barrel quality etc etc on a per rifle basis, so to my mind, removing any MIGHT's is not a bad thing.

From what I've read the collective wisdom is that BT's excel over long range but flatbase are reckoned to be more accurate (or should that be more consistently accurate) in the short/medium range

What you're missing regarding boattail vs flat base is effect size - the relative contribution to precision. It is maybe a 4th or 5th order effect, and it is absolutely dwarved by things like barrel quality, bullet quality, brass quality, "barrel preference" for [bullet and/or powder], shooter error, etc.

If a difference exists it's in the fractions of % optimization realm and you will never be able to detect it.

My understanding (from heresay mostly!) is that historically at least, more rifles would shoot flat based projectiles more accurately than boat tail. So if you weren't having any luck with boat tail projectiles, try flat base. But maybe it doesn't apply so much with modern rifles, given in general production tolerances are much tighter across industries than they used to be?

Anyone feel free to add/correct me on that.

Originally Posted by bjp

My understanding (from heresay mostly!) is that historically at least, more rifles would shoot flat based projectiles more accurately than boat tail. So if you weren't having any luck with boat tail projectiles, try flat base. But maybe it doesn't apply so much with modern rifles, given in general production tolerances are much tighter across industries than they used to be?

Anyone feel free to add/correct me on that.

"Conventional wisdom" is often largely wrong, or is information poorly understood and misapplied out of context.

Keep your hair on fellas.please. there is only one thing better about boattails for a sub 350y guy like myself.one thing and ONLY one little thing. They flyshit easier to start seating in case.thats it full stop. If it shoots straight ENOUGH and kills stuff dead ENOUGH anything else is just window dressing. And I've heard eldx described as a SST with a better BC due to tweak in profile/shape....yip pretty well sums it up.same type jacket,same type core,ones just more slippery through the air.

Originally Posted by Micky Duck

Keep your hair on fellas.please. there is only one thing better about boattails for a sub 350y guy like myself.one thing and ONLY one little thing. They flyshit easier to start seating in case.thats it full stop. If it shoots straight ENOUGH and kills stuff dead ENOUGH anything else is just window dressing. And I've heard eldx described as a SST with a better BC due to tweak in profile/shape....yip pretty well sums it up.same type jacket,same type core,ones just more slippery through the air.

no ones loosing hair Mick, from my pov we're just having a good discussion, it hasn't even reached the level of "robust discussion" which as we all know is just one level below someone throwing the toys out

Wish I could keep my hair on, that started disappearing 20 odd years ago...

Originally Posted by Micky Duck

Keep your hair on fellas.please. there is only one thing better about boattails for a sub 350y guy like myself.one thing and ONLY one little thing. They flyshit easier to start seating in case.thats it full stop. If it shoots straight ENOUGH and kills stuff dead ENOUGH anything else is just window dressing. And I've heard eldx described as a SST with a better BC due to tweak in profile/shape....yip pretty well sums it up.same type jacket,same type core,ones just more slippery through the air.

My hair is long gone - but

Why pay $1.09 for an SST which is an objectively worse bullet in every way, vs $1.09 for an ELDX?

Mate....I have 170grn Speer round nose...no longer made. Winchester 130grn silver tips... No longer made. Hundy Speer grandslam150s. All sitting waiting to load in 270 when I need them. I could use nbt but over them...been there and done that. Got some Hornady 140grn spbt...they are boringly good. Sub 200 they all kill fine,some work out further happily too. Sometimes I think we overthink it.dead is dead.

Originally Posted by Micky Duck

Mate....I have 170grn Speer round nose...no longer made. Winchester 130grn silver tips... No longer made. Hundy Speer grandslam150s. All sitting waiting to load in 270 when I need them. I could use nbt but over them...been there and done that. Got some Hornady 140grn spbt...they are boringly good. Sub 200 they all kill fine,some work out further happily too. Sometimes I think we overthink it.dead is dead.

Yes you have them in stock. Would you go and buy them new for the same price as an ELDX when you do not have them and don't have an established load?

Of course it makes no difference