Would a barrel issue cause this?

SmartDonkey

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I thought about putting this in reloading- but more wondering if it could be a barrel issue.

I have a 260 ackley that is very slow- my 260 rem is shooting faster. But I hit a point where my velocity just stops- more powder doesn't do a thing. I found a node at 2700 fps with a 143 eldx but wanted to get a higher node. So far I have went from 45.3 grain to 47 with no noticeable velocity increase (a few were 40fps faster but then the next one would be back at 2700).

I have heard that the barrel maker had some get out with inconsistent bores and such, but not sure if that would cause something like this? The barrel is extremely accurate, about 1/2 moa while fire forming and a little better with the formed brass.

This is from a 26" barrel....
Possible barrel problem? or Reloading problem?
 

Gas

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Non scientific opinion but your barrel length might be the cause. Unless you have tried on other same length barrels and got a different result, the issue may be that the powder simply doesn’t manage to completely ignite while the bullet’s still in the bore, unless you have pressure escaping the chamber which would be pretty visible on your bolt. Hope helped, good luck.
 
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SmartDonkey

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Under 100 rounds, just forming brass and starting load development. Powder is RL 19, I think it would burn all of it in 26" of barrel... But maybe not. Doesn't make sense, more powder = more pressure = more speed...
 

smoooth1

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Have you tried different powders, primers, or magnum primers to see if that changes anything?

As @Gas alluded to above, just because you can stuff more powder into the case doesn't mean it's all burning in the barrel.
 
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Steel head

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Plenty of others get some excellent speeds from 26” 260AI’s.
Something is amiss!
I think something is wonky With the barrel.

R19
H4831
R26
All three should be GTG as well as the common 260 powders.

in the end maybe You shouldn’t mess with perfection????

Lol
35739621-610C-4743-818B-EA3F33D35397.jpeg
 

MtnCreek

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I'd want someone to check the bore dia. If it's not right I'd be asking the manufacturer to make it right.
 
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SmartDonkey

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Thanks guys.... just trying to think this all through so I don't miss something. I think my next step is to have the barrel slugged and see if something shows up,- unless he can see something in the bore scope.

On the last load I wasn't seeing any pressure signs, so I could still go higher- but was hesitant to because I wasn't seeing any difference. I'm not out anything to try a different powder/primer combination- but not optimistic it will make a difference.

If I find a problem then I will try to get the maker to replace it- and if not I will switch to a 140 match bullet and shoot the barrel out. I'm not sure what kind of a problem it could have that would cause this... but not kill the accuracy?
 

Ledzep

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Slug the bore with a greased up lead fishing weight and measure groove diameters. If it's on the loose end (.2643+) it will both drop pressure and velocity.

As far as adding more powder and not getting more velocity-- assuming you're not getting pressure issues, it's usually a sign of the powder burn rate being too slow. That said, RL-19 doesn't sound like it'd be too slow for a .260 AI. You might try RL16 or H4350 on the faster side, and RL-26 on the slower side. I'd expect you could probably get 2900 in a normal situation pretty easy with that chambering with RL-26.

YMMV.
 

FALex

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Slug the bore with a greased up lead fishing weight and measure groove diameters. If it's on the loose end (.2643+) it will both drop pressure and velocity.

As far as adding more powder and not getting more velocity-- assuming you're not getting pressure issues, it's usually a sign of the powder burn rate being too slow. That said, RL-19 doesn't sound like it'd be too slow for a .260 AI. You might try RL16 or H4350 on the faster side, and RL-26 on the slower side. I'd expect you could probably get 2900 in a normal situation pretty easy with that chambering with RL-26.

YMMV.
I'm a 100% unqualified .260 flunky, but I'd like to think a 26" length would be sufficient to burn off most any of those listed powders.
 

Ledzep

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Define "burn off".

I would expect velocity to keep increasing with barrel length up to at least 35-40" in a .260, albeit by increasingly less per inch the longer you go. I think that adding more RL-19 should continue to increase pressure and velocity so that it's not happening is strange to me, but if it's a small sample size reading from a personal-use chronograph it could just be instrumental error, too. In fact, that a .260 AI is getting these low velocities maybe an instrumental error in and of itself.

Maybe something to test at range to see if elevation corrections match intuition or chronograph better.
 
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Seymour Fish

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Thanks guys.... just trying to think this all through so I don't miss something. I think my next step is to have the barrel slugged and see if something shows up,- unless he can see something in the bore scope.

On the last load I wasn't seeing any pressure signs, so I could still go higher- but was hesitant to because I wasn't seeing any difference. I'm not out anything to try a different powder/primer combination- but not optimistic it will make a difference.

If I find a problem then I will try to get the maker to replace it- and if not I will switch to a 140 match bullet and shoot the barrel out. I'm not sure what kind of a problem it could have that would cause this... but not kill the accuracy?
Doubtful, yet you could have run out of primer,, rework with a Mag for grins
 

FisherT&C

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I have a good barrel that is .243 Win it started out at 2750 node and at around 150-200 rounds through it sped up to 2950 and I didn't change a thing. The barrel always shot well. I think it's common to have barrels speed up, if it was bad it probably would not shoot good at all.
 

SmartDonkey

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I sent the barrel back to be inspected and they replaced it. They said it was just a very slow barrel... but did not list the cause of that. I wanted to change some things (like chambering) but they said they had already started the barrel so I will be getting the same spec'd barrel back. Glad to be getting a new barrel that hopefully will be faster.
 
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iceng

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Sounds like a good barrel maker who stands by their work. It happens. I had a 260ai which threw the 139 lapua scenar @ 3309fps from a 26". Rocket ship. Absolute laser. Lasted under 1000 rounds before it started turning off. My fault for chasing speed. Was a shilen match select.