This is the Pacific Tool blueprint of my chamber that I received from Northland/Criterion prior to buying my barrel from them.
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6.5 156 EOL
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This is the Pacific Tool blueprint of my chamber that I received from Northland/Criterion prior to buying my barrel from them.
SwampDog13
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I was finally able to sneak out to the range this evening and run my first pressure test with my saum. 11 rounds loaded from 54.0gn to 59.0gn Rl26 in half grain increments. I failed a little on the conservative side so I'll have to keep moving up in charge weight as no signs of pressure yet. The round count on this barrel is only 111 with this test included so I wouldn't be surprised if it speeds up a little more on its own.
As far as rl26 and hot outside ambient temps go, I've yet to test with it less than 90degF. Nothing has jumped out at me as crazy erratic like I was warned.
Funny story in my haste to get out of the house and to the range before too late I grabbed the wrong target. Turns out 1/4" ar500 does not play well with the 156 Berger with a MV of 2730fps at 300yds.
It didn't even cross my mind that I should not be using my >800yd steel at only 300yds but as soon as I heard the impact I knew I screwed up. Oh well it is only one dent, but I didn't get to track my impacts vs muzzle velocity.
As far as rl26 and hot outside ambient temps go, I've yet to test with it less than 90degF. Nothing has jumped out at me as crazy erratic like I was warned.
Funny story in my haste to get out of the house and to the range before too late I grabbed the wrong target. Turns out 1/4" ar500 does not play well with the 156 Berger with a MV of 2730fps at 300yds.
It didn't even cross my mind that I should not be using my >800yd steel at only 300yds but as soon as I heard the impact I knew I screwed up. Oh well it is only one dent, but I didn't get to track my impacts vs muzzle velocity.Wachsmann
Well-Known Member
Greyfox,
I think you have also ran the Shilen barrels as well on your 6.5. Which of the 2 the Criterion or the Shilen barrels gave you the best overall results in speed and accuracy? Those are some impressive numbers for the 156. Have your tried any other powders?
Sorry, I haven't owned a Shilen barrel. I will say that the Criterion is comparable in speed and accuracy(which is quite good). I also have 6.5x47 Criterion barrels and they are also comparable in speed and accuracy to my other top quality custom barrels. R26 is the only powder I tested so far. I would also like to try Retumbo, and N565, if I can get my hands on any when I get s chance.
Powder Valley has N565 in stock
Wedgy
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What I suspect you will find is a big drop in velocity when you go below ~84F, keep us posted.
SwampDog13
Well-Known Member
I'm thinking of throwing 10 rounds in the cooler next time I'm out to see what happens. It'll be a while before we see <85degF.
My work with R26 in my 6.5x284's is limited compared to other powders, but I'm wondering if the temperature stability of R26 at elevated temperature is over-stated. Cartridges with the capacity and over-bore dimensions common to the 6.5x284 and PRC by design heat chambers very quickly. This can also be a dynamic when attempting to generate higher then spec velocities with the smaller capacity cases like the 6.5CM with R26. The velocity come from pressure, and pressure generate heat. Perhaps, it's not so much the basic ambient temperature of 85F that causes velocity spiking with R26 as it is the greater tendency of the chamber temperatures to elevate with high pressure/high velocity cartridges common with R26 use. While I don't know the exact amount, I'd suspect chamber temperatures can easily elevate +50 degrees higher then ambient during shooting sessions in +85F temps simply due to the inability for the chamber to cool as quickly as it does in cooler weather. This over-heats the chambered round which will elevate pressure/velocity. In my experience with R26, it seems that simply chambering a cartridge loaded with R26 at 85-90F into a chamber at the same ambient temperature does not demonstrate the velocity spiking seen when shooting subsequent rounds a hot chamber. To some extent, velocity spikes with powders generally considered very temperature stable can occur under very heated chamber conditions and the chambered cartridge allowed to elevate in temperature. Myself and others have experienced this even with highly stable powders like H4350 and Varget during heavy shooting action with sports like PRS and Egg Shoots in the hot summer months....thus all the contraptions seen for cooling barrels. I have also experienced this with H1000, H4831sc, and Retumbo under similar, hot weather conditions and chambers are not sufficiently allowed to cool down. They have not been problematic under hunting conditions when chambers are not allowed to over-heat. Similarly, cartridges allowed to over-heat in direct sunlight can produce the same issue. I'm not sure if this proposition is valid concerning R26's temp stability based on just the few tests I've tried, but if it was, it would me much less of an issue for hunting applications even where warmer temps are encountered,.... given care is taken not to let your chambered ammo get over-heated....and kept out of direct sunlight. I'm not so sure it would behave much differently then any other high intensity load using the slower burners in high intensity loads.
Just some thoughts... and I wouldn't die on this hill...but I would be interested to hear of any relevant observations, or tests by other shooters.
dirtytough
Well-Known Member
My 7SS shot faster with RL 26 @18 degrees than it did @85 degrees.
Nomosendero
Well-Known Member
I have heard that from others as well.
codyadams
Well-Known Member
Im doing load developement now with 26 in 2 different guns and the 156, I'll see what I can find with velocity now (hopefully we get a hot day, it doesn't get much over 80-85 very often) then shoot the same loads later this year, september and october will likely see temps in the 30's on a couple days here or there. I already did a test, but the rifle was at one set temp, I think around 65 or 70, not ambient on a hot/cold day, and I just put the ammo in an ice chest after it was in the freezer overnight. When I did that, temp swing was .15 fps per degree, very minimal.
Nomosendero
Well-Known Member
"hopefully you will get a hot day", don't rub it in !
I do look forward to you further testing.
SwampDog13
Well-Known Member
Monday, it will most likely be in the low to mid 90s here, I plan to get out to continue my rl16 testing. I will do the majority of it my standard way of 10 or so shot strings with a minute or so in between rounds with nothing being chambered until I'm nearly ready to fire using rounds sitting in the shade beside me. I'll repeat this test with rounds fresh out of the cooler with each round not coming out of the cooler until time to chamber and fire. I may also do a heat soaked chamber test starting with a cold chamber, cold being relative here in 90degF ambient temps. Fire a round, immediately chamber the next, let it soak, fire, rinse and repeat.
It's in the name of science right?
It's in the name of science right?
Longtooth32
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You guys suck!...
I had no idea that Berger was shipping their 156 6.5 EOLs...
Ordered from Grafs...at this time they are still in stock and are still on sale...
Looking forward to shooting these out of my 28", 1-8 twist, Pac-Nor, 6.5/257 Wby. Maybe old Roy was right about his long freebore...
I had no idea that Berger was shipping their 156 6.5 EOLs...
Ordered from Grafs...at this time they are still in stock and are still on sale...
Looking forward to shooting these out of my 28", 1-8 twist, Pac-Nor, 6.5/257 Wby. Maybe old Roy was right about his long freebore...
