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6.5 creedmoor and RS62 temperatures


ronzi83

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Hello all. I read a lot about 6.5 , 139 lapua and rs62 here on forum. I found my load with it, but it was in summer and temperatures were quite higher 30 celsius. My load was 44.3 rs62, 139 with 2809 coal/2245 ogive. If i remember my speed was 2796 fps/852ms. When reloading this much of powder i can hear sound of powder compression when seating bullet in. But now i tested now same load and i lost a lot of speed and therefore my load is out of OBT. I reaload 44.4 grains and my speeds were 2670-2640fps /804ms at 1 celsius. Anyone here with any info on RS62 temperature sensitivity ? I added 0.1 grains but looks like still to little. But if i would go more with powder than my seating deph will not be that consistent cose of bullet hitting /compressing powder. Would i need to consider to get new powder, any sugesstions on this one? 

Forgot to add, i use Lapua case with 1.910 lenght SP and .290 bushing on my redding FL die

 

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I doubt this is just temperature driven. 1>30C is approx 34F > 86F, a 52F change. If you said your velocity was c50 FPS different I’d imagine it would be temp driven but a 140 FPS change or 3 FPS per 1F is possibly too great. Some of the most temp sensitive powders are about 1FPS per 1F. I do think RS62 is more sensitive than they claim but not perhaps this much ??

How many rounds do you have through the barrel ?

Are you using the same Lot of powder ? There have been reports of considerable variation in Lot to Lot consistency with RS powders. 

 

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4 hours ago, ronzi83 said:

Hey, i have around 2000 shoots on barrel. Lot it was same in past, but now i dont have same lot. 

Thanks. So it could be down to both round count and Lot variation in addition to 50 FPS or so of the difference coming from the change in temperature. 

2000 is a little on the low side to see velocity drop off so much especially if you’ve only been pushing a 139gr at 2800 but it depends on the barrel and how you’ve shot those 2000 (ie rapid hot strings) rounds.

Throw in a little variation in Lots and that could explain it. If you want to keep the barrel but push for more velocity then you could try N550. You shouldn’t need as much powder which will help avoid the crunch issue you described.

I’ve moved to buying components in bulk to avoid the Lot variation issues. Something to consider for the next barrel but it’s expensive upfront.

 

 

3E768F8F-A4BE-41B8-9CF7-F0F99896DD2A.jpeg

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They say 6.5 creedmoor has around 3000 shoots on barrel life. I did some of my 2000 push it to 2900-3000 with mostly n150 or n550 powders. But now i was thinking to actually try 147eld with RS60. Some people say it is really temp stable and great powder, but i have never worked with it. 

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20 minutes ago, ronzi83 said:

They say 6.5 creedmoor has around 3000 shoots on barrel life. I did some of my 2000 push it to 2900-3000 with mostly n150 or n550 powders. But now i was thinking to actually try 147eld with RS60. Some people say it is really temp stable and great powder, but i have never worked with it. 

Me neither without RS60, perhaps someone else will chime in.

Average for 6.5 CM should be 2500-3000 but if you’ve been pumping them out at 3000 FPS with N550 then that could be it, i bet you’ve got some throat erosion ?

I’ve heard good things about the 147 but you have to put them down at 2700+ to get optimal stability from a 1:8 twist, 1:7 seems to be a popular option for this particular bullet. 

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18 hours ago, ronzi83 said:

But now i was thinking to actually try 147eld with RS60. Some people say it is really temp stable and great powder, but i have never worked with it.

 

RS60 is Alliant Reloder 17 under another name. American experience says this is one of the most temperature affected powders on the market and many competitive US shooters have dropped it for this reason.

It will potentially give very velocities in this cartridge, but if loaded to maximum pressure / MV it will accelarate barrel wear significantly compared to RS62 or other non high-energy grades.

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Compared to RS52, RS60 will definitely fry your barrel. I have a 308 with a Bartlein that's only had RS52/155's at 3000fps through it, and after 1500 rounds, it still looks as good as new.

The 6.5 with a Lothar and 600 hot rounds of RS60/123 Scenars is another story................not a pretty sight, but still shoots well.

RS52 is a double base powder, but it's a bit more barrel-friendly than RS60, for sure.

Pete

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On 2/17/2019 at 6:27 PM, TJC said:

 

I’ve heard good things about the 147 but you have to put them down at 2700+ to get optimal stability from a 1:8 twist, 1:7 seems to be a popular option for this particular bullet. 

Hornady recommend a 1:8.5 twist for this bullet.

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  • 5 months later...

So i got this from swiss reload 

Temperature coefficient          m/s pro K

RS36 7.62mm x 39 0.60
RS40 .223 Rem 0.45
RS50 .308 Win 0.70
RS52 .308 Win 0.55
RS60 8 x 68 S 0.25
RS62 .270 Win 0.90
RS70 .300 Win Mag 0.45
RS76 7mm Rem Mag 0.20
RS80 .338 Lapua Mag 0.20

 

Looks like rs62 is the most sensitive per c? Any sugesstion to try another EU powder for 6.5 creedmoor ? N550 ? 

 

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3 hours ago, ronzi83 said:

So i got this from swiss reload 

Temperature coefficient          m/s pro K

RS36 7.62mm x 39 0.60
RS40 .223 Rem 0.45
RS50 .308 Win 0.70
RS52 .308 Win 0.55
RS60 8 x 68 S 0.25
RS62 .270 Win 0.90
RS70 .300 Win Mag 0.45
RS76 7mm Rem Mag 0.20
RS80 .338 Lapua Mag 0.20

 

Looks like rs62 is the most sensitive per c? Any sugesstion to try another EU powder for 6.5 creedmoor ? N550 ? 

 

Thx. N550 is 1.00 so not really a great option for temp sensitivity 

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I've got a couple of pounds of Alliant Re16, yet to try it - but on paper it looks a good option in this bracket. This is one of the new Swedish (Bofors) made Alliant grades with the company's 'TZ' temperature technology and is claimed to be as good as H4350, possibly better in this respect.

As to applications and burning speed, it's very close to H4350 but can usually produce higher MVs if loaded to maximum levels.

See:

http://bulletin.accurateshooter.com/?s=Alliant+Reloder+16&submit=Search

 

Norma (all of whose powders are made by Bofors) appears with a couple of additions such as URP to be offering an unchanged range from say 20 years ago without any updates, and this seems rather unlikely given the way all propellant manufacturers have ugraded their products in recent years. So, it may be that today's Norma N204 and Alliant Re16 are one and the same thing. (I have some N204 on the way too and will be able to compare their grain structure, density, and performance.) Right now, the reintroduced Norma grades are considerably cheaper in the UK than Alliant powders, worth considering by British forum members. (Re15 and Norma 203-B are one and the same thing for instance.)

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4 hours ago, Laurie said:

I've got a couple of pounds of Alliant Re16, yet to try it - but on paper it looks a good option in this bracket. This is one of the new Swedish (Bofors) made Alliant grades with the company's 'TZ' temperature technology and is claimed to be as good as H4350, possibly better in this respect.

As to applications and burning speed, it's very close to H4350 but can usually produce higher MVs if loaded to maximum levels.

See:

http://bulletin.accurateshooter.com/?s=Alliant+Reloder+16&submit=Search

 

Norma (all of whose powders are made by Bofors) appears with a couple of additions such as URP to be offering an unchanged range from say 20 years ago without any updates, and this seems rather unlikely given the way all propellant manufacturers have ugraded their products in recent years. So, it may be that today's Norma N204 and Alliant Re16 are one and the same thing. (I have some N204 on the way too and will be able to compare their grain structure, density, and performance.) Right now, the reintroduced Norma grades are considerably cheaper in the UK than Alliant powders, worth considering by British forum members. (Re15 and Norma 203-B are one and the same thing for instance.)

Very interesting. Is RE16 a double-based powder ? Temp sensitivity looks excellent but just wondering if it is double based / how they get such good velocity ? Thx

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Ok a bit weird. Seems Alliant use the same SDS data sheet (which lists all the specs and ingredients of each powder) for Rel 15, 16, 19, 22, 23 and 25.

Seems they all reference Alliant AR Comp powder.

If this is true and not quite a big content error on their website, then Rel 16 is a double base powder:

https://www.alliantpowder.com/products/powder/reloder16.aspx

https://www.alliantpowder.com/downloads/sds/Reloder_Series_SDS.pdf

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On 25 July 2019 at 6:40 PM, Catch-22 said:

Ok a bit weird. Seems Alliant use the same SDS data sheet (which lists all the specs and ingredients of each powder) for Rel 15, 16, 19, 22, 23 and 25.

Seems they all reference Alliant AR Comp powder.

If this is true and not quite a big content error on their website, then Rel 16 is a double base powder:

 

Yes, all Alliant 'Reloder' series rifle powders are 'double-based' Most come from the Bofors, Karlskoga, Sweden plant and a smaller number from Nitrochemie in Switzerland (ie the 'Reload Swiss' people).

This goes back to a US government pre-WW1 anti-trust ruling that split the USA's single propellant / explosives combine up. In smallarms propellants, all single-based products and manufacturing facilities went to what later became IMR and all double-based equivalents went a new outfit the Hercules Powder Co. Alliant ATK eventually bought this side of the business and rebranded its products 'Alliant'. There is no legal requirement these days (at least AFAIK) for Alliant grades to be in this form, but the company has stuck with it.

Likewise, all Norma powders come from Karlskoga and are also double-based. Norma quotes the nitroglycerin %s and they range from low single figures to barerly into double figures. (Viht N500 series are generally considerably higher.)

All of the new IMR 'Enduron' powders are also 'double-based'. There is a tendency it seems for new additions / results of recent R&D to have at least some nitroglycerin in the recipe. I imagine this is partly about performance, but also all the other things that prpopellants are expected to do nowadays from accepting temperature stability to copper fouling reducing additives.

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1 hour ago, Laurie said:

 

Yes, all Alliant 'Reloder' series rifle powders are 'double-based' Most come from the Bofors, Karlskoga, Sweden plant and a smaller number from Nitrochemie in Switzerland (ie the 'Reload Swiss' people).

This goes back to a US government pre-WW1 anti-trust ruling that split the USA's single propellant / explosives combine up. In smallarms propellants, all single-based products and manufacturing facilities went to what later became IMR and all double-based equivalents went a new outfit the Hercules Powder Co. Alliant ATK eventually bought this side of the business and rebranded its products 'Alliant'. There is no legal requirement these days (at least AFAIK) for Alliant grades to be in this form, but the company has stuck with it.

Likewise, all Norma powders come from Karlskoga and are also double-based. Norma quotes the nitroglycerin %s and they range from low single figures to barerly into double figures. (Viht N500 series are generally considerably higher.)

All of the new IMR 'Enduron' powders are also 'double-based'. There is a tendency it seems for new additions / results of recent R&D to have at least some nitroglycerin in the recipe. I imagine this is partly about performance, but also all the other things that prpopellants are expected to do nowadays from accepting temperature stability to copper fouling reducing additives.

Interesting Laurie.

The thing that got me scratching my head was the fact that Alliant seem to use the AR Comp data sheet also for Rel 15, 16, 19, 22, 23 and 25.

Either the makeup of the powders is the same (which I can’t believe is true...surely some powders will have different % of Nitroglycerin) or Alliant haven’t been bothered to make individual data sheets.

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On 7/24/2019 at 8:52 AM, ronzi83 said:

So i got this from swiss reload 

Temperature coefficient          m/s pro K

RS36 7.62mm x 39 0.60
RS40 .223 Rem 0.45
RS50 .308 Win 0.70
RS52 .308 Win 0.55
RS60 8 x 68 S 0.25
RS62 .270 Win 0.90
RS70 .300 Win Mag 0.45
RS76 7mm Rem Mag 0.20
RS80 .338 Lapua Mag 0.20

 

Can anyone comment on those numbers? I'm just starting 6.5CM load development with RS62 and it got me really worried as I shoot beetween 0-30°C...

Michał

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