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223. 75 eldm stability

DLT

Silver $$ Contributor
I have been trying to get a 223 load worked up for banging various size steel targets at 800 yards with the 75eldm in an 8 twist barrel. When I went through cfe 223 started at 24gr my bullet holes at 200 was nice and round (uniform black ring all the way around the bullet hole). I tried varget next starting at 23.2 and noticed larger groups and also the bullet holes were round but looked like the powder/burn ring was non existent on one side. I have never noticed that before almost like they was not stabilized but definitely not keyholing. Is that possible to have it stabilized with one powder and not the other ? BOLT GUN ALSO
 
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The powder shouldn't matter, but velocity could. Are both loads running about the same velocity? If the Varget load is slower, I can it see it being less stable. Especially since that bullet is probably borderline stability with an 8 twist. I know a guy who runs an 80gr bullet with an 8 twist, so you should be good, but you may need to tweak the load a bit.
 
6Creed73 said:
The powder shouldn't matter, but velocity could. Are both loads running about the same velocity? If the Varget load is slower, I can it see it being less stable. Especially since that bullet is probably borderline stability with an 8 twist. I know a guy who runs an 80gr bullet with an 8 twist, so you should be good, but you may need to tweak the load a bit.
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I do not know the velocity, I only got 3 charges loaded up and shot before I had to get to a ball game. I noticed it when I went to get the target. All 3 groups was 1 set way out and 2 close together in no particular order
 
There have been a number of threads in the last year or two regarding twist rates for the ELD Match bullets. Below are listed two threads that might be of interest. People keep wanting to run these bullets in rifles with insufficient twist rate barrels and they keep having stability problems. The ELDMs are long for their weights and at some point Hornady even increased the recommended twist rates printed on the box form what they used to be. It's possible that even the shorter 73 ELDM requires a faster twist rate than 8.0 for optimal performance.

73gr eldm .224 no go

Well got 500 of these to make it worth the shipping. I used 98 of them. Loaded for my rem 700 tactical 1-9tw 20”. I loaded from 2.300-2.245 Aa2520, cfe223 and n540 This is the best they gave me. Looks like I’ll be selling to buy 75gr Hornady bthp. It shoots those well, even loaded for my ar.
forum.accurateshooter.com

https://forum.accurateshooter.com/threads/80gr-eldm-223.4097932/#post-38685119

According to Bryan Litz' Sg values, the 75 ELDM does not reach the desired Sg of 1.5 under any conditions out of an 8-twist barrel. Further, under Worst Case conditions of low temperature and/or low elevation, the predicted Sg drops to a point (1.05) where it is likely the bullet would be going through a target sideways. Can the 75 ELDM be stabilized to the point it doesn't keyhole out of an 8-twist barrel under moderate to optimal conditions? Of course it can. The Sgs listed in the Nominal and Best Case would not be predicted to cause keyholing. It is possible 75 ELDM bullet holes operating under the the Nominal Sg might exhibit very slight signs of instability, such as slightly oval bullet holes, or even the minor change in the appearance of the bullet holes as the OP described above. Regardless, the manufacturer recommends a 1 in 7 twist for the 75 ELDM bullet. There is a reason for that. IF you are running the 75 ELDMs in an 8-twist (or slower) barrel and you think you might be seeing signs of an insufficient twist rate, then maybe you are.

75 ELDM.jpeg
 
Ned Ludd said:
There have been a number of threads in the last year or two regarding twist rates for the ELD Match bullets. Below are listed two threads that might be of interest. People keep wanting to run these bullets in rifles with insufficient twist rate barrels and they keep having stability problems. The ELDMs are long for their weights and at some point Hornady even increased the recommended twist rates printed on the box form what they used to be. It's possible that even the shorter 73 ELDM requires a faster twist rate than 8.0 for optimal performance.

73gr eldm .224 no go

Well got 500 of these to make it worth the shipping. I used 98 of them. Loaded for my rem 700 tactical 1-9tw 20”. I loaded from 2.300-2.245 Aa2520, cfe223 and n540 This is the best they gave me. Looks like I’ll be selling to buy 75gr Hornady bthp. It shoots those well, even loaded for my ar.
forum.accurateshooter.com

https://forum.accurateshooter.com/threads/80gr-eldm-223.4097932/#post-38685119

According to Bryan Litz' Sg values, the 75 ELDM does not reach the desired Sg of 1.5 under any conditions out of an 8-twist barrel. Further, under Worst Case conditions of low temperature and/or low elevation, the predicted Sg drops to a point (1.05) where it is likely the bullet would be going through a target sideways. Can the 75 ELDM be stabilized to the point it doesn't keyhole out of an 8-twist barrel under moderate to optimal conditions? Of course it can. The Sgs listed in the Nominal and Best Case would not be predicted to cause keyholing. It is possible 75 ELDM bullet holes operating under the the Nominal Sg might exhibit very slight signs of instability, such as slightly oval bullet holes, or even the minor change in the appearance of the bullet holes as the OP described above. Regardless, the manufacturer recommends a 1 in 7 twist for the 75 ELDM bullet. There is a reason for that. IF you are running the 75 ELDMs in an 8-twist (or slower) barrel and you think you might be seeing signs of an insufficient twist rate, then maybe you are.

View attachment 1485205
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Great post full of helpful information. Thank you much
 
I've never seen an issue with the 75 ELD stabilizing of out of a 18" 1:8 barrel but the elevation here is 4400 feet. I've shot the 85 RDF, which is longer at 1.135", out of the same gun at 6700 feet elevation. It went all the way to 1100 yards with no stability issues, and velocity was around 1000 FPS out there.
 
I've tried using them in an 8 twist Tikka with mixed results. A few groups have been good, but the vast majority have been much looser than what the rifle is capable of. Out to 800m, none have keyholed but they don't group well.
They were advertised as suitable for 1 in 8 twist when I decided to get them, but sure enough, the box says 1 in 7 minimum. I won't be buying any more.
Berger does the same thing with their 80.5 and 85.5 bullets. The box says 1 in 8, but when you run the bullet in their own stability calculator, it shows marginal stability.
 
Chilly807 said:
I've tried using them in an 8 twist Tikka with mixed results. A few groups have been good, but the vast majority have been much looser than what the rifle is capable of. Out to 800m, none have keyholed but they don't group well.
They were advertised as suitable for 1 in 8 twist when I decided to get them, but sure enough, the box says 1 in 7 minimum. I won't be buying any more.
Berger does the same thing with their 80.5 and 85.5 bullets. The box says 1 in 8, but when you run the bullet in their own stability calculator, it shows marginal stability.
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That’s interesting. The first box of the 75eldm I got did say 1:8 now it’s 1:7
 
The bottom line here is that no one else's results with an 8-twist barrel matter...only yours do. Ultimately, velocity, temperature, and elevation can make a huge difference in stability when using a twist rate that according to the manufacturer and other sources is right at the margin. There may be no way of knowing whether someone else using an 8-twist barrel with success isn't operating with at least some of those factors [more] in their favor. All you can do is try to determine what is happening with your specific setup under the specific conditions in which you are shooting it. Nothing posted in this thread proves that an insufficient twist rate is the problem. However, nothing posted in this thread proves an insufficient twist rate isn't the problem, either.

Ideally, switching to a 7-twist barrel would address the question. But that may not be a realistic solution at the moment. Circumstantial evidence might be something like test results generated at higher elevation on a nice warm day. Likewise, comparing muzzle velocity between the two powders might be illuminating. Running a faster load might also switch the balance slightly more in your favor. Regardless, none of these approaches is going to prove anything one way or another, but collectively they may provide further support for the notion that insufficient twist rate could be the cause, or fail to support that conclusion. Either way, the desired outcome is a load that shoots well and without any qustions about its performance. Whatever you can do to make that happen, such as trying a shorter bullet if necessary, may be of benefit.
 
1-8tw. Benchmark barrel. 80eldm H4895, 600 yard f class. No problem shooting HM scores most of the time. I usually shoot 1 out of 6 relays just out of HM scores. Is it the bullet or is it me? I believe it's me breaking the shot on a condition change. It doesn't take much. The barrel was throated for the 80eldm.
 
karrarararararar said:
1:8 shouldn't be an issue, I've even shot them in a 1:9 pushing them real hard. You can certainly load them warmer than 23.2gr. 24.0-24.5gr of Varget is common with 75-80gr bullets.
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I don’t see any pressure signs in my gun up to 24.2 of varget running magnum primers. I have had brass troubles with either junk brass or too hot of a load of ar comp. I want my brass to last longer than a couple firings, will it running that much varget ?
 
ronemus said:
You can't get enough Varget into a .223 case to get high pressures with a 75 gr ELD-M, even with a compressed load.
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I thought I read in here in the past where some competition shooters were only getting a couple firings with heavies before primer pockets was toast, i maybe just assumed it was varget being used
 
DLT said:
I thought I read in here in the past where some competition shooters were only getting a couple firings with heavies before primer pockets was toast, i maybe just assumed it was varget being used
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You can get into pressure trouble with 80-90 gr bullets and Varget. Federal brass has relatively soft case heads and their primer pockets expand after a few firings even with SAAMI max pressures.
 
DLT said:
I thought I read in here in the past where some competition shooters were only getting a couple firings with heavies before primer pockets was toast, i maybe just assumed it was varget being used
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F-TR shooters using heavies (i.e. 85.5 to 95 gr bullets) with a powder such as H4895 are likely to experience such issues. Even with Varget, it is possible to push pressures sufficiently high in typical F-TR rifles with the longer bullets to kill the primer pockets in a single firing. Because the 75 ELDM is a shorter bullet and will typically not be loaded as long as is humanly possible using crazy long freebore chambers, it may well be true that it isn't possible to get enough Varget in the case to cause pressure issues. However, I don't think it's a very good idea to make a blanket statement like that at a shooting forum. Not everyone here knows enough to know that just because something may be true with Varget, it doesn't necessarily have to be true with a different powder. The next thing you know, someone is actually trying it because of what they read at a shooting forum.
 
8 twist at 3000 fps is about 270K rpm. As stated above the 75 eld is a long bullet that is going to require some RPM which I think you are close to but it may be on the short side? I stabilize that bullet out to 1000 with about 283k rpm.
 
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