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> .25 cal 134 ELDM
.25 cal 134 ELDM
@ 01:31 pm (GMT) |
Jake CareyHi all, I'm wondering if anyone's had their paws on this. Superficially it sounds like exactly what I've been hoping for for years. Lots of other folks too. I've had itch to build a 25-06 for a long time and it seems like maybe this moves it into the truly versatile, truly long range category. Of course there's every chance it could be a dud but the ELD track record has been pretty good.My main source of puzzlement at the moment is twist rate. From what little I can find it seems like they recommend a 1:7 for absolutely certain stability but that just sounds bananas, especially if it's anywhere near as delicate as the 180 7mm. I've had good luck with that but at moderate speeds in a gentle barrel. Who knows, maybe it's a tough jacket and 7 isn't too fast for it. Maybe it's too tough. My thought is that when they say "maybe you can get just away with an 8 twist" they're speaking to the .25 creedmoor crowd and an 8 would be 100% good out of a 25-06/.25-284. Maybe there's just a wall of efficiency in that small of a pipe and 7 really is the limit for certainty. Anwyay, imagine how much fun could be had rebarreling a burned out old savage 99 and shooting these out of a classic rifle. Curious to hear anyone's thoughts, and Merry Christmas to both hemispheres. |
Replies
@ 11:18 am (GMT) |
Scott StruifRe: .25 cal 134 ELDMHi Jake. You’re right that they’re marketing it as a compromise quarter-bore projectile for the competition crowd, . . . a compromise for those who object to the recoil of a 6.5 CM, yet who want more target splash than a 6mm. A 25-06 would not fall into that category. If you wait for them to load the 4DOF data, as well as the reloading data for a 25-06, you would be able to calculate the gyroscopic stability value with the 4DOF program. If it’s 1.4 or above at 25-06 speeds with 8 twist, then you’re good. |
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@ 05:41 am (GMT) |
Jake CareyRe: .25 cal 134 ELDMHadn’t thought of that. It looks like using modest projected speed the 134 starts out at around mid 1.6s. That’s at 4500 ft elevation, the lowest I shoot. At sea level it looks a lot more marginal, but close. Startts at 1.35 and gets to 1.4 pretty quickly. I don’t know enough about the gyro numbers to know what’s good and bad, I had thought lower numbers were better but that’s clearly not the case.If 1.4 is a firm line then 1:9 won’t work even at weatherby speeds. The most aggressive velocities only get a little over 1.3 in a 9 twist. Anyway, not totally sure why I’m worried about it, I guess I wanted to think about getting a 5r barrel and thought they’d be more likely in slower twists but there are very few available in 25. Still looking forward to hearing when people get them downrange. |
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@ 10:45 am (GMT) |
Scott StruifRe: .25 cal 134 ELDMThe documentation for the 4DOF program states:“To attain acceptable aerodynamic performance, we recommend a muzzle Gyroscopic Stability (Sg) above 1.4.” If you want to know why they recommend that number, watch this video: https://youtu.be/Y6XmujLIx84 They’re probably being conservative with that number. They don’t want customers complaining. Nathan has no issues shooting heavy 30 cal projectiles in his 11 twist 308. In the video, they also discuss the adverse effect of too much twist on terminal performance. When the bullet hits game, you want it to upset, not pencil through. You can get more velocity out of a 130 grain bullet with a 270. |
@ 01:57 pm (GMT) |
David LenziRe: .25 cal 134 ELDMOne need not wait for Hornady to update their 4DOF software. Berger's tool will do the math if you define the variables.https://bergerbullets.com/twist-rate-calculator/ Of note, Berger recommends 1.5 or above for "comfortable stability" and classifies 1.0 to 1.5 as "marginal stability." They define "marginal stability" to be that range for which the bullet is stable enough to fly point forward, but not stable enough to do so without a bit of wobble... which leads to increased drag (aka: lower effective BC than the form factor would indicate). Using Berger's own 135 grain HT as an example, it's marginally stable at 1.4 with a MV of 2750 fps and a 1:8 twist @ STP. A 1:9 twist yields 1.1 for the stability factory. I'd run the 134 ELD-M, but I don't have the length handy. I used the Berger as a stand in because they are bound to be very similar. This is arguably in response to the Market created by the ACE Blackjack 131, now defunct. From an external ballistics standpoint, the 25 Creed bests both its parent and its smaller sibling and is arguably the optimal bore size for that case design when target shooting is the goal. |
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@ 08:25 pm (GMT) |
Scott StruifRe: .25 cal 134 ELDMIf target shooting is the goal, a custom 25 cal with a fast twist makes sense. |
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@ 09:46 am (GMT) |
Jake CareyRe: .25 cal 134 ELDMScott, that's true about target shooting but I'm trying to find out if it makes sense for a deer hunter in a higher powered gun. Especially with what Nathan has noted about the 25 bore, historically. It could very well be that 3k fps is too much strain on the bullet in some bores as was seen with the 180 ELDM 7mm. Giving the 25-06 truly great hunting ballistics, has been on people's minds for a long time. A g1 better than .6 at around 2900 (based on Berger's AI data) kicking around 12 pounds with okay barrel life sounds really, really fun. But it might still be too good to be true, someone is going to have to see.The background to this is that I have a chance at paying half price on a top-tier action in a top tier sporter stock. Fits me like spandex. It happens to have a 25-06 barrel of unknown quality on it. I've always wanted a 25-06, but what I invest in for dies and how fast I yank that barrel off will be influenced by whether or not I can realistically shoot high BC slugs without blowing them up. A gentler rifling is probably the place to start, but the options are really limited for an 8 twist 5r 25 cal. Essentially I might be better off planning on turning it into a 6.5-06 and just enjoying it for what it is right now. David, I'd forgotten all about Berger's tool, it is slick. The 134 is in the Hornady app already though and the results are basically in line with your findings. Generally. Anyway maybe people will get their hands the actual bullet soon and we'll hear about it. |
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@ 01:55 pm (GMT) |
David LenziRe: .25 cal 134 ELDMI'd roll the dice on that if I were able. I'd imagine the performance is very similar to the 6.5mm 140 ELD-M - they have nearly identical SD and bullet construction. That .007" and 6 grain difference is pretty negligible I'd imagine. Like I said, I'd roll those dice. |
@ 10:43 am (GMT) |
Michael SeagerRe: .25 cal 134 ELDMFrom my reading a 1:7 or 7.5 twist might be needed but could be interesting.A step up from the 120gr Speer for relatively low impact velocity performance? Mike |
@ 10:13 am (GMT) |
Nathan FosterRe: .25 cal 134 ELDMHi Jake, The ELD-M is slightly more frangible than the Speer BTSP when used at close ranges so do not expect much greater penetration. By the same token, increasing the twist rate merely increases bullet stress, resulting in decreased penetration (those who have my latest book will have seen my notes on this). the 134gr ELD-M is also still relatively light and does not boast high kinetic energy at very long ranges. In other words, the 134gr may offer an increase in performance but there are some limitations to consider.I would suggest that while target performance may be good with a stability factor of 1.5 or above, hunting performance will diminish accordingly, should a shot be taken at closer ranges. Somewhere between 1.4 and 1.5 is likely the sweet spot (as per the norm). Some rifles shoot well enough for general hunting at 1.3. Just a matter of giving it a try if you happen to have a rifle on hand (don't let a computer program make your decisions for you). But I would not build to such specs. |
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@ 01:09 pm (GMT) |
Scott StruifRe: .25 cal 134 ELDMThe 25-06 has a well-deserved reputation in the US as a flat-shooting cartridge for “Western” hunters. It earned its reputation before the advent of range finders, ballistics calculators, and exposed elevation turrets. A match bullet weighing 14 grains more is not likely to increase its effective killing range much, because projectile speed is its forte. |
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@ 01:10 pm (GMT) |
Jake CareyRe: .25 cal 134 ELDMNathan, sorry I missed this reply all the way back in January. I was checking, I just did not see it. Thank you. It's a good point about the shallow wounding potential up close and at distance, especially since MV would be so much higher than what we typically want for close range hits in the match bullets. I wound up dual loading for my hunting season after testing the 180 7mm and seeing just how explosive it was even at mv 2650. I'm glad I did as I shot a large deer, my first, at 55 yards. The ELD would absolutely have ruined the mount, never mind potential maiming. (I wasn't hunting antlers but I walked right into the path of an extremely old and pretty buck like we were in a grocery aisle.) The limitations of the lighter delivery would be kept strictly in mind. Having seen elk up close now and even large mule deer I have no temptation to push the limits of low energy delivery. The cartridge does have many limits even if modernized but I think it's worth monkeying with while keeping those in mind.As of now I still haven't loaded or fired the stiller 25-06 I found for a song, so the entire question is moot if the current barrel shoots well since it's a 10 twist. Having the option either raw speed or .264 level payloads would be great fun, but oh well. There are just not options for alternate twists in .25 with gentler rifling. If I'm understanding you correctly Nathan the 134 is every bit as delicate as the 180, which is both what I wanted but poses its own problems for bullet stress as you say. I've been easy on the 180 in my saum but the things it does on impact at distnace are just gobsmacking. It is just raging to come apart. I've read almost everything you have twice or more but I have to admit it's still hard to lean into that type of wounding, even though I know exactly why it's a good thing and why we want it. I just have to keep reminding myself that I don't need it to be an all-range solution. At any rate it's a good topic to think about, new stuff is new stuff. Scott, a 12 percent increase in mass and a 1/3 increase in BC is equivalent to an entire caliber jump, close to 2 with how dated most 25 cal offerings are. I live and hunt in one of those " "western" " states and the principles that you're talking about have a pretty strict functional wall that is far short of what I am capable of. It's a difference of 300 ft lbs and 6 inches of drift at the edge of my range compared to the speer, which already ahs a huge leg over most 25 cal bullets. That ain't nothing, especially in open country. Flat is great, but so is adding an entire second lethal range on to where MPBR ends. |
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@ 07:45 am (GMT) |
Nathan FosterRe: .25 cal 134 ELDMThat's the way Jake, you have a good handle on it. |
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