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> 243 load research/development
243 load research/development
@ 08:42 pm (GMT) |
Pete LangfordBackground: I am a "new" hunter having been bitten hard by the bug 2 years ago. I hunt mostly open tops and sub alpine bush with a Franchi Horizon in 243 and from trial and error have found that Win Deer Season 95g produces reliably consistent results (barring the nut behind the trigger) all the fallow I've taken have been out around the 300m mark with bang flop results. With my preferred ammo being hard to come by locally and with prices continuing to head north I have dived into the rabbit hole of reloading.My research thus far has revealed the following, Winchester Silvertip delivers more bang than Deer Season but I'm pretty sure it has a boattail whereas the Deer Season has a flat base, more suited to my 1:10 barrel. Hornady's SST seemed to be the semi obvious choice BUT the ballistics say it does not seem to deliver as much punch as the Silvertip running out of velocity and punch at around 300 metres (2211/1035) compared to the silvertip (2185/1007 at 374m) So my question, finally is this, is there a flat base projectile that will give me similar performance to the silvertip with appropriate load development. (I'm aware of the Nosler BT Silvertip, which is also BT base and used by Winchester in their silvertip factory ammo) My aim is to recreate similar to the Win Silvertip so that on the rare occasion where I may need the 243 to reach out a little further and/or to deliver more knockdown on larger game (Red hinds/stags) closer in. Side note: I am a rank beginner so some of the above may be incorrect or drawn from incorrect assumptions. I'm not interested in shooting out beyond the distances mentioned, IMO thats not hunting, just target shooting on live targets, getting in "close" is part of the challenge. Also at some point I MAY go up in caliber but for now I want to maximise the 243 whilst honing my shooting/hunting skills especially around consistent accurate shot placement. Cheers Pete |
Replies
@ 07:33 am (GMT) |
Nathan FosterRe: 243 load research/developmentHi Pete, the 100gr boat tail has been standard for the 1:10 .243 twist rate for decades, as was the 105 grain Speer. The current emphasis on twist rates is a new thing.There is much information published on websites and in podcasts etc., describing a particular bullet as being sub optimal in a certain twist rate, but this does not necessarily mean that the rifle will be inaccurate. The trouble is, the target shooting sport has been dominating the shooting scene for some time now. Target shooters do need to consider optimal twist rates to maximize their BC's out at long ranges (i.e. 1000 yards) and especially through the transonic barrier. At 300 yards using a .243, such concerns are irrelevant. Really, it comes down to what the rifle likes or dislikes. There is of course a limit as to how much bullet length the 10 twist will handle, but the 95 / 100 grain factory hunting loads are adequately suited to the 10 twist. If your rifle does not like a certain load, it will more likely be related to harmonics. Regarding construction, you must understand that many 6mm projectiles are in fact designed around varmint jacket specifications. Years ago, folk used to say "its just a rabbit gun". I used to dismiss this when I was young but following intensive studies, there is some truth to this. The .243 does not produce much energy and so a soft bullet must be used as a means to ensure that this low level of energy is transferred on target. I have performed a comprehensive study of deconstructed 6mm projectiles and it is obvious that these have been the general industry accepted design parameters, regardless of how the projectile is advertised. One must also factor in the difficulty of making a projectile this small (actually getting enough lead into it). Evidence is the key. So as you say, one needs to guard against assumptions. My advice would be to try a different load and see how it shoots. The advertised velocities don't really count for much these days unless we are talking about Hornady Superformance ammo. Regarding your comments on long range, I started long range shooting while I was guiding many years ago. I used my long range rifle to clean up mucked up shots, taken by clients at close ranges. I wrote about this in the first chapter of my book, The Practical Guide To Long Range shooting and provided photographic evidence. I also eventually banned my clients from using the .243 on boar due to multiple failures. But in any case, yes, one should ideally learn how to stalk before learning how to shoot at longer distances. I understand where you are coming from regarding the modern gear oriented generation. I hope that helps provide a bit more background to the .243 in general. With a better understanding of its design, you can make appropriate choices while also being aware of its limitations. In saying this, don't assume that the original bullet makers got it wrong and that you should be using a tough bullet. If you do use a modern tough bullet, that 1000ft-lb figure you aptly quoted, will no longer apply as more energy is be required to do the same work (wounding). All the best. |
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@ 08:28 pm (GMT) |
Pete LangfordRe: 243 load research/developmentHi Nathan,Thanks for your detailed response and yep, I get that for my range of shooting, some of the parameters are irrelevant as you said. What I ommited to mention was that the two BT projectile factory ammo I've tried Fiocchi 100gr and Win SuperX 100g did not shoot well out of the Franchi, poor consistency on POI and the Deer Season IS consistent and the one factor that differentiates between all 3 other than weight is that DS is a flat base projectile and thus my conclusion that this particular rifle favours FB projectiles over BT's...since posting I've relooked at the Hornady SST and I'm going to try that first, it's unfortunate that whilst Deer Season projectiles are available to purchase...that's only the case if you're a US resident! Still, the process of developing a load will be an interesting journey for sure |
@ 03:27 pm (GMT) |
Scott StruifRe: 243 load research/developmentHi Pete. You need to trust Nathan on the twist rate issue, even though some of his comments might seem inconsistent with other “authorities” on the Internet.All bullets, flat base or boat tail, exit the muzzle with some wobble. There’s no such thing as a perfectly concentric bore. The bullet’s spin can help counteract that wobble’s effect on accuracy, depending on the aerodynamics of the bullet after it has been engraved by the rifling. That’s dependent on the individual gun. A twist rate calculator doesn’t take that into account. The only thing you need to know is whether you can shoot an accurate enough group at your maximum hunting distance. Don’t stress over whether your bullets are keyholing slightly through paper. All bullets tumble when they hit game. With small calibers, tumbling on impact with a deer is a good thing. You’re not going to punch through a red deer’s shoulder with a 243, so quit worrying about it. Shoot in the chest. It will drop. |
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@ 09:47 pm (GMT) |
Pete LangfordRe: 243 load research/developmentHi Scott,I do trust Nathans observations, which is why I posted in here, from reading his articles I see someone who has a great deal of knowledge and I'm keen to soak up as much as I can and whilst I'm no slave to "authorities" I'm open to all perspectives, some of which makes sense and other...not so much and that's objective to the individual. There IS a documented train of thought that offers that BT projectiles MAY be unduly influenced by the vortex of gas as the bullet exits the muzzle, specifically as in the tests the BT projectile is completely enveloped by the propulsion gas whereas the FB projectile is always slightly ahead and that there is a slight leak of gas past the BT as it travels up the barrel and that the base of the boattail does not deform to seal the bore in the same way as a FB, which shows up as a slighly lower muzzle velocity on the BT (same load, same weight projectile, same gun) Here's the link for your interest. https://www.gunsandammo.com/editorial/boattail-vs-flat-base-projectiles/375628#replay I'm not saying that this is the holy bible of the discussion but it's food for thought imo and yes, I take your point that what I need is a bullet that groups well and will knock animals over, I have zero interest in placing one round in exactly the same hole as the previous round, I shoot paper only for zero's and scope adjustment...and I guess in the near future for load development, thanks for taking the time to share your thoughts, it's appreciated. |
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@ 12:10 pm (GMT) |
Scott StruifRe: 243 load research/developmentHi Pete. Thanks for the article. Always fun to read an interesting article, especially from such an authority. But you should follow Nathan’s advice for hunting, and not get too wrapped up in ballistics theory:1. Aim small, miss small. (Especially with a 243. Accuracy should dictate your choice of bullet base shape.) 2. Speed is your friend. (Especially with a 243. Assuming accuracy and weight are equal, choose the boat tail for more downrange velocity.) 3. Choose bullet construction for task. (At 300 meters, aim for shoulder. A miss in either direction will result in a chest or lung shot. A stouter bullet, like a Partition, or even an Interlock, will give you an advantage if you hit the shoulder socket.) |
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