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6.5cm powder.

Jscb1b

Dumbass.
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Minuteman
Dec 22, 2018
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Arizona
What is the best powder for 6.5cm? I'm in AZ so I need good temperature stability. I'm running a Remington 700 with 22" barrel. 140gn BTHP bullets and Hornady brass. I've got 500 once fired cases. Thank you for your time and help!
 
H4350 and RL16 are the two best, when using a 140 gr. Their are a few others, but start with either
one of these first. Very close in measuring weight. The RL16 seems to produce a little more fps
before you hit max.
 
From what I've read rl16 is temp sensitive. I'm shooting from 55 to 120F.
 
I think you meant RL16 is INSENSITIVE to temp swings. I tested RL16 when it was first released and I found it to be far less sensitive to temp changes than H4350. From my testing, I found an 11 fps change TOTAL from below freezing to about 75°
 
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I think you meant RL16 is INSENSITIVE to temp swings. I tested RL16 when it was first released and I found it to be far less sensitive to temp changes than H4350. From my testing, I found an 11 fps change TOTAL from below freezing to about 105°
Where you getting good velocity from rl16?
 
Where you getting good velocity from rl16?

With Alpha brass and a 140 ELDM, my load is 39.36 grains and it gives me 2800-something (don't hold me to it, but I wanna say 2816) out of my 26" Desert Tech barrel. In Prime brass and 140 ELDM, I get 2830 with 41.0 grains out of a 24" Bartlein
 
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There's nothing wrong with RL17, aside from it being really sensitive to temp changes and having to adjust your loads for the seasons. If you have a hot load in winter, it'll almost certainly be way over-pressure in summer. It's been a few years since I used RL17 in my 6.5 Creedmoor, but I remember having a summer and winter load. My loads were very accurate and really fast, though.
 
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Depends on bullet weight. I’m running rl16 with 140’s and 147’s with good velocity, but I’ve heard (yet to test) that some rifles like varget with the lighter bullets (130 and under). If you want to push things with heavies, there is some promising info and testing with rl26 with 147’s out there. Have those test loads ready too, just waiting on time and weather to line up!
 
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All iterations of 4350 (I know of 3) worked in my 18” 6.5CM. Don’t remember the load as it’s been years since that rifle has seen daylight.
 
I'm using rl17 right now. I don't want to dick with winter and summer loads. I'll get a pound of rl16 and start over.
 
I’ve only used H4350 since it work in my 260 rem as well and the load data is on the box, I believe it is not temp sensitive but not 100% sure as I only shoot from 42- 95 degrees lol
Cheers
 
I'm using rl17 right now. I don't want to dick with winter and summer loads. I'll get a pound of rl16 and start over.
why one pound? by the time you have a load and shoot a match you need more, and it'll be a different lot

RL16 will be less sensitive than RL17, and will be fast. but it doesnt seem to shoot as accurately for everyone as H4350 does
 
but it doesnt seem to shoot as accurately for everyone as H4350 does

I'm curious, where did you hear or read this? I was one of the first to test RL16 when it was first introduced, and I pretty much gave up on H4350 because I found RL16 to be a superior powder, including accuracy. I've never heard of anyone who has had an issue with accuracy when using RL16, so I'm genuinely curious.
 
I'm curious, where did you hear or read this? I was one of the first to test RL16 when it was first introduced, and I pretty much gave up on H4350 because I found RL16 to be a superior powder, including accuracy. I've never heard of anyone who has had an issue with accuracy when using RL16, so I'm genuinely curious.
several highpower guys who shoot 6XC and others shooting 6.5 creed
 
I haven't strayed from H4350 [ have a shit-ton of this powder for '06 use too ] but am going to try RL16. I too have seen the RL26 loads posted here and thought that's a large jump in burn rate. IF it's working then more power to those guys. I'm curious to know if anyone has tried RL23.
 
H4350 hands down SD'd under 10 are standard in 10 shot strings. RL17 was very temp sensitive and did not excel on the chronology SD's over 20 regularly for me.
 
There's nothing wrong with RL17, aside from it being really sensitive to temp changes and having to adjust your loads for the seasons. If you have a hot load in winter, it'll almost certainly be way over-pressure in summer. It's been a few years since I used RL17 in my 6.5 Creedmoor, but I remember having a summer and winter load. My loads were very accurate and really fast, though.

Same for me: RL-17 shot groups in the 0.25” to 0.5” range from a 26” factory Savage barrel at 2850 fps, and could go even faster before pressure signs showed up. At least a 150 fps faster than H4350 before half moon and full moon ejector marks appeared. Have been told that is wears our your barrel faster, but not sure about that. Also: Very temperature sensitive.

Most accurate results came from H4350: Best 3 shot group ever was 0.08”, 0.15” to 0.25” was typical at 100 yards.

Replaced the 26” factory barrel with a 30” Shilen Select Match barrel (intent was to experiment with a longer barrel and see what speeds could be achieved). H4350 did not gain any speed! Big surprise. I bet a 28” barrel would have shown a speed increase and that it is losing speed after that. Would be interesting to hear what others have found with 27 or 28” barrels. Accuracy was best with Berger 140 Hybrids and 140 ELD-M.

RL-17 could achieve incredible speeds from the long 30” barrel: At 60 degrees F ambient temp the 140 gn ELD-M achieved 2920 fps. Around 180 to 200 fps faster than the max load for the old 26” barrel. The load was not safe for peak summer temps (105 deg F). Peak summer speed was around 2880 fps. Needed a winter and summer load.

The addition of the 30” barrel combined with RL-17 effectively changed a 6.5CM into a 6.5x284, but with far better barrel life. I got 2,800 from the fist barrel. Of course, the gun is now heavy, hard to transport (2.5” long Vais brake has to come off before it can fit into the bag), also very front heavy and not at all practical for a walk and stalk hunt. But it has shot 2”-3” groups at 600 on calm days using RL-17 (and Superformance, which is also very temperature sensitive).

Would not recommend Superformance, gave up on it after a case was badly mangled shooting on a hot day.

Moral of the story is: RL-17 works very well in short and especially long barrels, as long as you develop a winter and summer load. Pros and cons.

But H4350 gave the smallest groups. Most people who own a 6.5CM and reload use H4350 and so it is in short supply and often overpriced.
 
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Ok I need help here. RL powders have always been hit or miss with consistently in my group (30 cal persons). So much so that the few M1A competition shooters out there will pay a pretty penny for the old IMR charged FGMM over the new RL 15 charged stuff. Has something changed? Or is the 30 cal issue not found in the RL powders for the 6.5? Not trying to derail the conversation. I’m interested reguardless as posted above I’ve got a CM resting in the safe.
 
With Alpha brass and a 140 ELDM, my load is 39.36 grains and it gives me 2800-something (don't hold me to it, but I wanna say 2816) out of my 26" Desert Tech barrel. In Prime brass and 140 ELDM, I get 2830 with 41.0 grains out of a 24" Bartlein
I got pressure isses with 140 ELD, Ppeterson brass using 41 gn of H4350. it was a 24 Bartlein.
 
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41 grains of H4350 on a 140 is pushing it I hit pressure signs at 39.5 and 40 grains but it shot good so I didn’t go above pretty sure 41 would be pretty close to blowing primers out of my gun anyways.
I’ve tried reloader 16,17 and 19 in my creedmoor all shot good but very temp sensitive and terrible SD that’s why I have stuck with H4350 and N160 I personally like N160 the best in my 6.5
 
My initial load runnung 41 of rl16 under a 147 in a 24” barrel (didn’t have time to develop at the time between getting the rifle and first match) has given me 2709 FPS and an SD of 11 over 13 rounds grouping about .4-.6 (I’m a rookie and my fundamentals are still rough). Tests at 41.5 have the SD’s into the single digits, but still working on finalizing. I don’t get to shoot a lot, so there is a lot of downtime between range sets!
 
41 grains of H4350 on a 140 is pushing it I hit pressure signs at 39.5 and 40 grains but it shot good so I didn’t go above pretty sure 41 would be pretty close to blowing primers out of my gun anyways.
I’ve tried reloader 16,17 and 19 in my creedmoor all shot good but very temp sensitive and terrible SD that’s why I have stuck with H4350 and N160 I personally like N160 the best in my 6.5


What rifle did you use? Tight chamber?
 
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I know this is an old thread, but LOL at telling guys in AZ to run RL17. That is crazy talk. RL17 is one of the most temp sensitive powders on the market today.

The powders for the 6.5CM with a 140 class are: H4350, RL16, and H4831SC.

4831SC will suffer a slight velocity penalty compared to H4350 or RL16, but it's stupid accurate in a lot of guns.
 
When you say it's "crazy talk" to say RL17 is a viable powder, did you ignore all the warnings of "it's VERY temp sensitive" and that any load developed in cooler temps would almost certainly be over pressure in higher temps?
 
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When you say it's "crazy talk" to say RL17 is a viable powder, did you ignore all the warnings of "it's VERY temp sensitive" and that any load developed in cooler temps would almost certainly be over pressure in higher temps?

If you want to keep things simple (not a bad goal), and use the same load all year round, then use one of the so-called “Extreme” powders, like H4350, that are properly temperature stabilized.

I have tested how temp sensitive H4350 is: Put two loaded rounds in a cooler packed with ice for two hours, kept two on the bench, and most likely they reaches 105 F ambient temp. Labradar showed virtually the same speed. But a small sample test. So this limited scope experiment showed that the claim that H4350 is temperature stabilized is indeed valid.

Not trying to push RL-17, as it takes much more work (developing a winter and a summer load, wearing out your barrel), but just wanted to note that if you want or need more speed, then RL-17 is one of the few options available to you. The speed gain can be quite significant, equivalent to a caliber ‘upgrade’. Like moving from 6.5 CM to 6.5x284.

You will have to make an informed decision on your own if you want to work with such a finicky powder. Major pros (speed, energy on target, less drop, slightly less wind drift, ability to drive heavy high BC bullets fairly fast), and major cons (severe temperature sensitivity, less barrel life from all that load development work, potential pressure problems, and yes safety).

Also wanted to report a useful experimental result applicable to 6.5 Creedmoor: VERY long barrels (beyond 28”) do not increase MV if you use standard / typical powders like H4350. You have to use the so-called ‘progressive’ powders, which have a lower pressure peak and a wider pressure curve to exploit such a long barrel. Superformance and RL-17 gave me a significant speed benefit in a 30” barrel, but they are both very temperature sensitive. During load development (winter time), i managed to get a RL-17 load that delivered 140 gn projectiles at over 3000 fps, but the load was not accurate, and i did not continue with it. Found a nice wide node around 2920 fps. Also managed to get the 150 SMK to fly at a max of just over 2950 fps (barrel has a special order 1:7 twist rate). All loaded long, with small jump, to gain more case capacity, but none were jammed. Best node was lower around 2880 fps, which is not bad for such a small cartridge. I gave up on Superformance after a while, and would not recommend it.

So the experiment (to get long heavy high BC bullets beyond 2900) by using a long barrel and ‘special’ powders technically worked, but the rifle became an unwieldy heavy monster of a bench gun, and good for one thing only. Also very front heavy, and does not ride the bags well anymore. That affected accuracy negatively. More than what the ballistic calculator will predict you gain in wind drift. So not worth it.

I will not buy such a long barrel again, 26” or 27” would do just fine.

Also, the fast 1:7 twist rate worked well to stabilize the heavy 150 SMKs, but group size was 1.5x bigger than the previous 26” factory barrel with a standard 1:8 twist.

Reading Bryan Litz’s latest book, it is clear that any imperfections in the bullet jacket will cause bullet imbalance, which is then amplified by the faster twist rate, causing bigger deviations from target. BR folks will often select the slowest twist rate that their short stubby flat base bullets can tolerate, for this very reason. A more robust setup, less sensitive to bullet imperfections.

If you shoot super consistent perfectly made bullets, a faster twist rate would be good if you want to intentionally over stabilize a copper bullet and shoot it out to ELR distances, where the bullet becomes subsonic, as the fast spin rate helps the bullet transition into the subsonic range. [Solid copper bullets do not suffer from bullet disintegration because of excessive spin rate.] But no lead core bullet with a soft copper jacket is ever truly perfect.

IMHO: Stay away from overly fast twist rates unless you are in the ELR game and shooting solid copper bullets. The loss in accuracy due to jacket imperfection being amplified by a fast twist rate is not made up for by the calculated wind drift benefit gained by shooting heavy high BC bullets in this long specialized barrel.

My latest 6.5 CM is a 26” MPA with a 1:8 twist. Shoots 140’s very well using H4350. Rides the rear bag very well.

Summary: For middle distances (500-600 yards), the inherent accuracy of a well balanced rifle (ability to shoot smaller groups) with an appropriate twist rate barrel appears to beats the moderate wind drift benefits of the 150 SMK (which required a 7.5:1 twist rate). Failed experiment, sadly.
 
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just getting into reloading 6.5CM as well. I had planned on H4350 to start with but have been hearing a lot about RL16. I know RL17 is out because of the temp swings but hadn't heard much about RL16 temp sensativity.

Found this nice thread here about H4350 and RL16 with some temp/velocity readings.


would be nice to have some larger sample sizes but at least from this it does look like RL16 is a lot more stable than RL17. Plus a bit more velocity.

Worth doing some loads in both and see what my rifle likes.
 
My test showed a 1fps per 3 degress of temp change on avg. With h4350 and 140 gr. Projo's. Rl 16 showed no discernable changes, but was very dirty and prone to a carbon ring in a creedmoor case. Easier to get better accuracy for me with h4350. If developing a hunting load I would look at rl16.
2cents
 
As I said earlier, I tested RL16 when it was first released. I found RL16 offered higher velocities at lower pressures than H4350 and RL16's temperature behavior was actually better than H4350. I had an 11 fps change over a 50° temp change. As with anything else, do your own testing and see what works best for you

Edit: Just an aside, but I probably have around 20 pounds of RL16 left, 13 of Varget, and 16 of H4350 for the short action calibers I load (6 Dasher, 6 XC, 6 Creedmoor, 25 Creedmoor, 6.5 Creedmoor). I use them all as I see fit, so I have lots of experience with them all and I use what works for me.
 
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I explored my slower velocity node tonight, with 147gr ELD-M in 4 times fired Alpha brass with CCI BR-2 primer over 40.8gr of RL-16.
My high node had me at 2820 in my 24” PVA barrel which was pretty impressive, but this low node. WOW! Not only am I seeing low single digit ES, it’s shooting sub half minute 5 shot groups consistently, and I’m a new shooter who’s just beginning to learn the fundamentals.
That 8lb keg of H4350 will need to wait for something else I think.
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It seems i will have to try RL-16 next summer.... will shoot the remainder of RL-17 in the winter months starting end October.

Thanks for the insight.
 
I have been using h4350 with 140's and found a really nice node with lapua 136gr scenar L's. I was getting 2820 from a 22" factory bergara barrel. Recently switched to 120gr coppers for hunting and was kicking around trying RL16 to get more speed out o them since copper solids likes speed for terminal performance. Ended up getting the 120gr barnes ttsx to come out at 2960 with h4350 and as good of groups as I can ask for with a factory rifle. I feel like even if I was able to push things a little faster on another powder there wouldn't be a lot of benefits to it and wear would go up a lot.
 
With Alpha brass and a 140 ELDM, my load is 39.36 grains and it gives me 2800-something (don't hold me to it, but I wanna say 2816) out of my 26" Desert Tech barrel. In Prime brass and 140 ELDM, I get 2830 with 41.0 grains out of a 24" Bartlein
Dang! I wish I would have found a load with r16 now lol. I’m using starline small primer brass, cci 450, 42.8gr of 4350 and it gets me 2800-2805 out of both of my 26” rifles
 
I have used RL16 for 2 years now. It’s accurate, very temp stable and speed is awesome.

That said... I’m going back to H4350. RL16 is just too dirty for me. The carbon ring creeps up fast with this powder vs what I have seen with H4350.

41.6 of H4350 w/140eld gets me 2820
41.8 of RL16 w/140eld gets me 2845

I can live with the loss of 25 fps.
 
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Couple twists witch a chamber brush when I get home each time keeps that carbon ring at bay.
 
RL-17, for any bullet weight. RL-19 for heavy bullets, loaded long to get more powder in. IMR or H4895 for 120 class bullets. Varget works for the lighter 120 - 130 grain bullets as well. The 6.5 is so accurate, it really isn't hard to find a good shooting load with any powder really.
 
Ew. Yikes. Pretty sure no one has used RL-17 since we learned the temp sensitivity of RL-16 is so vastly superior, and if you want something slower for heavier bullets, RL-26 would be the way to go. Not RL-19.
 
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Powder selection is always about selecting the trade-offs that work best for your situation. In a 6.5CM, H4350 is accurate, gives adequate / moderate speed, good temp sensitivity (but not perfectly insensitive either), and is not too dirty, and not known for causing a carbon ring in the neck of the chamber. Low frequency cleaning (every 150-250 shots) worked ok in my factory Savage barrel. A middle-of-the-road powder without vices. [But at times folks start hoarding it, and then it becomes almost impossible to find. Too popular for its own good?]

From my research, it seems RL16 has very good speed, low temp sensitivity but is rather dirty and tends to cause a carbon ring, according to fellow shooters who used it extensively. And a carbon ring can really mess with your accuracy. It seems RL16 has at least one vice to worry about. Frequent and more thorough cleaning is recommended. [Buy a low cost bore scope and check up on it.]

RL-17 has good speed, good accuracy, is very easy to find in large quantities, but it is very temp sensitive, and a winter load is not suitable for hot summer conditions. Might lock up your bolt, or worse. If you don’t want to develop a winter and a summer load, you should stay away from it. Yes, double the load development eats into barrel life. Have seen some loads that deliver close to 180 fps more in a 30” barrel compared to H4350 for heavy 147 and 150 gn projectiles. But speed is not everything. Also read reports that it might be worse for barrel life, as it runs hotter, but not sure about that.

Not familiar with RL26, but many people recommend it. Any vices you guys know about?

My point is this: There is no perfectly ideal powder out there. Pick your powder with full knowledge of its pros and cons. Every one represents some or other compromise. Figure out what is important to you, make your selection, try to stick with it, and learn to manage the downside.

Constant load development from trying out five different powders will wear out your barrel and reduce your practice time with a fixed load that you know works well in your particular rifle.
 
+1 for RL 16, I shoot between 100+ in AZ to 20’s in CO

That is truly superb temperature stability.

Curious how often you have to clean the barrel, any issues with carbon ring, any special cleaning regimen, what solvents you use, any loss of accuracy after x shots, etc.

If the carbon fouling could be easily controller, it would make for a superb 6.5CM powder.
 
That is truly superb temperature stability.

Curious how often you have to clean the barrel, any issues with carbon ring, any special cleaning regimen, what solvents you use, any loss of accuracy after x shots, etc.

If the carbon fouling could be easily controller, it would make for a superb 6.5CM powder.

I haven't noticed the dreaded carbon ring in any of my rifles, or should I say I haven't noticed any symptoms of a possible carbon ring. I typically shoot two matches a month, plus however many range trips, so I clean fairly regularly and I use KG1 which cuts through carbon very well
 
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That is truly superb temperature stability.

Curious how often you have to clean the barrel, any issues with carbon ring, any special cleaning regimen, what solvents you use, any loss of accuracy after x shots, etc.

If the carbon fouling could be easily controller, it would make for a superb 6.5CM powder.
I clean every 100-200 rounds. I do get a carbon ring, but it cleans out with Bore Tech Carbon Remover, a nylon brush and short cleaning rod without much trouble. YMMV. For the rest of the barrel I just run 3 wet patches, followed by dry patches and repeat once. The Teslong borescope is great for checking for that carbon ring and seeing when it is cleaned up. The temp sensitivity shown in 4DOF for RL16 is .11 fps per degree. I haven’t based my cleaning frequency on any accuracy changes, just on convenience. I think if you stay ahead of the carbon buildup it is easier to deal with.... just my theory.