6.5 Creed velocities with 140/142's?

[Brians356]

In shorter barrels, sometimes a case full of slow burning powder won't give a complete burn (depending on how slow of course) so you will not see the velocity advantage over faster powders.

All the powder that will burn has burned in the first 12 inches or so. There are no still-burning kernels exiting our rifle barrels.
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[Ledd Slinger]

All the powder that will burn has burned in the first 12 inches or so. There are no still-burning kernels exiting our rifle barrels.
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Depends on the powder and the barrel length. 24" barrel will burn most powders completely. You definitely can't say that every powder burns completely in the first 12" and there's no way you can measure that accurately.

I've seen plenty of kernels left behind in barrels over the years.

 

[Brians356]

Depends on the powder and the barrel length. 24" barrel will burn most powders completely. You definitely can't say that about every powder.

Which rifle powders, behind what bullet weights, will still be burning at the muzzle of a 24-in barrel?
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[Brians356]

I suggest review these threads:

http://forum.accurateshooter.com/th...-into-choosing-powders.3912308/#post-36855840

https://www.24hourcampfire.com/ubbt...topics/8796385/Muzzle_Flash_vs_Unburned_Powde

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[Ledd Slinger]

Which rifle powders, behind what bullet weights, will still be burning at the muzzle of a 24-in barrel?
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I don't know. Maybe none. You'd have to test it. Every cartridge and bullet weight will give different results. I bet if you threw some RL26 behind the 140gr in a long barreled 6.5 Creed you'd see a pretty big difference vs H4350. Do the same in a shorter barrel and the difference may not be as significant. And just because powder kernels aren't left behind in the bore doesn't mean they aren't flying out the muzzle before they've completely transformed to a gas.

 

[Ledd Slinger]

I suggest review this thread:

http://forum.accurateshooter.com/th...-into-choosing-powders.3912308/#post-36855840
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Exactly. You said it yourself. The powder may be burned but the gases are still expanding. I consider a complete burn getting the full use of the gasses the powder produces

 

[Brians356]

Exactly. You said it yourself. The powder may be burned but the gases are still expanding. I consider a complete burn getting the full use of the gasses the powder produces

In the case of the 6.5 Creedmoor, it seems case capacity and appropriate powders limit bullet acceleration to about 24 inches of barrel. After that the bullet is slowing down.
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[Ledd Slinger]

Everyone told me that H4350 was the powder to use for the 6XC for good velocity. However, the rifle I built is in a handy hunting rifle platform with a 22" barrel. Of course I couldn't quite get the 2900-2950 fps claimed velocities of the longer barrels people were using with H4350 and the 105gr Berger VLDs. Fortunately I own multiple powders in just about every burn rate you can imagine up and down the chart. I use them for testing various rifles and developing loads for wildcats that have little to no data. Knowing I needed a little faster burning powder than H4350 to get those velocities, I opted for RL17 and was able to achieve 2980 fps from a 22" barrel with the 105s. I fit the proper burn rate to the barrel length and achieved exactly what I wanted with speed

 

[Ledd Slinger]

In the case of the 6.5 Creedmoor, it seems case capacity and appropriate powders limit bullet acceleration to about 24 inches of barrel. After that the bullet is slowing down.
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I am inclined to believe you since I have not tested the 6.5 Creed myself. I am just questioning how much testing folks have done in longer barrels with various slower powders, because even in a 204 Ruger I was able to achieve much faster velocities with the 39gr BK in a 26" barrel over my last 24" barrel by going to a slower burning RL15 and BLC-2. Those 2 powders held no velocity advantage in my old 24" barrel.

 

[Rob01]

What's the advantage of a 28" or 30" barrel with 6.5 Creedmore when velocity peaks at ~24-in barrel? More weight forward for static stability?
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Velocity does not peak at 24" no matter what the artricle says. Take that with a grain of salt. The Creedmoor was based off a 28" barrel. You get more speed with a longer barrel with H4350 burn rate powders.

In my 27" I get 2850fps with the 140 ELD and 2820fps with the 147 ELD. My 28" is at 2880fps with Factory 140 ELD load. As a comparison for the above conversation the same lot 140 ELD factory load in my 27" is 2820fps so no velocity lost going longer.

That Rifleshooter article has done more to spread bad info than anything as it's posted everywhere on Facebook when Creedmoor barrel length is mentioned. Not sure how they managed what they did but seeing the slow velocity they were getting with the 142s I am guessing it was either barrel or load related.

 

[Rob01]

A couple pictures as well. When Hornady changed the packaging on the 140 AMAX load from listing the 28" velocity, as was originally on the box, to the 24" data the velocity went from 2820fps to 2710fps, respectively. That is with the same loading of H4350 they were using before they changed powder in early 2013 due to the H4350 shortage. If we were to believe the Rifleshooter article it should have gained velocity going from that 2820fps in the 28" to the 24" barrel. It didn't.

28" 2009 lot

24" 2010 lot

 

[Ledd Slinger]

That Rifleshooter article has done more to spread bad info than anything as it's posted everywhere on Facebook when Creedmoor barrel length is mentioned. Not sure how they managed what they did but seeing the slow velocity they were getting with the 142s I am guessing it was either barrel or load related.

Some of those magazine writers don't know their head from their rear end. I always get a kick out of how they are praising a rifle for how it had 'amazing' and 'pinpoint' accuracy. Then you look at their results and maybe one group hit under 3/4" at 100 yards and the rest were outside if an inch.

Im not calling anyone a liar, but I just can't believe that 24" is max velocity in a 6.5 Creed. I've messed with way too many powders and chamberings to truly believe that claim. Although I haven't dealt with the 6.5 Creed, I have had rifles with similar size cartridges like the 260 Rem, 6.5x47, and 6.5x55. Although not quite the same, I am having a barrel spun up for the 6mm Creedmoor and will soon be experimenting with it.

 

[AckleymanII]

I don't know. Maybe none. You'd have to test it. Every cartridge and bullet weight will give different results. I bet if you threw some RL26 behind the 140gr in a long barreled 6.5 Creed you'd see a pretty big difference vs H4350. Do the same in a shorter barrel and the difference may not be as significant. And just because powder kernels aren't left behind in the bore doesn't mean they aren't flying out the muzzle before they've completely transformed to a gas.

Yes, R#26 will run the 140+g bullets to 2900 at 48.5g and 3000 fps with the 50g load in my 24" barrel. 48.5 was the most accurate, PLAY WITH PRIMERS in the large rifle cases, get ready for a serious shock.

I believe that a lot of people think that if you don't shoot H4350, that you will start talking with a lisp and suddenly develop a limp wrist.

 

[Rob01]

No there are others powders that will work with the Creedmoor but H4350 was the original powder used in development and in the initial factory loadings over the first few years so it has gotten a good track record as it works very well. It's all I have used in mine since 2008. With it being in shorter supply people have ventured out and tried other powders and found them to work well but they all are either a hair slower or the same burn rate area as H4350 for the 140+ weight bullets with the longer barrels. You can use Varget with shorter barrels and the 140s and find some decent velocity but in the longer barrels you lose some velocity as you hit pressure before getting to higher velocities in the 2800fps+ range.

 

[Ledd Slinger]

Yes, R#26 will run the 140+g bullets to 2900 at 48.5g and 3000 fps with the 50g load in my 24" barrel. 48.5 was the most accurate, PLAY WITH PRIMERS in the large rifle cases, get ready for a serious shock.

I believe that a lot of people think that if you don't shoot H4350, that you will start talking with a lisp and suddenly develop a limp wrist.

Lol. Exactly. Scared to step outside the box.

 

[mikecr]

I can think of nothing about a longer barrel that would slow a bullet from shorter barrel MVs.

 

[Ledd Slinger]

I mean a longer barrel starting to slow a bullet is definitely true when talking about a 22LR. I have tested 22LR velocities myself by running the same ammo through a 24", 19", and 11" barrel. No doubt that the 19" barrel yielded the best speeds. About 70-80 fps more over the 11" and 24" barrels. The powder charge is so small in the 22LR that bullet friction will slow the bullet after a certain distance in the bore. Just not enough gas in the charge to fill the volume of a long barrel and maintain peak pressures.

Tho I've NEVER seen a bullet slow from a 24" to 26" barrel in medium sized hunting/target rounds. I've heard that once you start using barrels over 30" there may be very little to no further speeds gains achieved with the smaller cartridges, but thats different.

 

[Rob01]

Exactly. We got guys going from a 20" .223 to a 26" for more velocity but we are supposed to believe a cartridge with twice as much powder is going to slow from 24" to 28"? Lol come on.

 

[JBT47]

In the case of the 6.5 Creedmoor, it seems case capacity and appropriate powders limit bullet acceleration to about 24 inches of barrel. After that the bullet is slowing down.
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Simply not true at all. Do you see guys that shoot 6BR or Dashers in 1,000 yard benchrest using 24" barrels? No they use 30" and sometimes longer...and the BR has less capacity than a 6.5 Creed.

 

[AckleymanII]

I like longer barrels for a couple of reasons. I usually have a muzzle break on the front, and getting that concussion away from my head helps a lot.

Also, I like to get a barrel that has some "straight" on the breach end of the barrel so that it can be set back without going to a Savage type of barrel nut. When the throat dia gets opened up around .0008, you may see some loss in accuracy, so set the barrel back at that point.

Also, not everyone is a long range shooter. So, another 200 fps with a tad bit of accuracy loss may serve a guy extremely well that hunts deer/elk at ranges of 250 yards and under.