IMR 7828SCC with 6MM Creedmoor

Starlite

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I have some Berger 90gr tgt projectiles that I’m wanting to shoot out of my 6mm CM. I usually try to load powders that have a Load Density above 95%.
I found some data in my swift manual however it’s for the 243 that show promise for 7828. (42.3-45.5gr with a 90 gr swift scirocco II)
It pays to buy powder when you find it. So..I have some IMR 7828 and 7828SCC. I think I can get ~ 43.5gr (max) am I way off with this amount.

anyone have experience with IMR7828 in their 6mmCM?
 

jasonco

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7828 any, more than not, is too slow, for a 90 grain in 6mm Creedmoor. I run H4831SC with 110SMK, in a 26" barrel @3200 AVG FPS and that's a mid-charge in this rifle, that gives a lot of reloading's with Starline LRP case and tight primer pockets.
 

Starlite

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7828 any, more than not, is too slow, for a 90 grain in 6mm Creedmoor. I run H4831SC with 110SMK, in a 26" barrel @3200 AVG FPS and that's a mid-charge in this rifle, that gives a lot of reloading's with Starline LRP case and tight primer pockets.
Velocity aside do you have any experience loading 7828? Are you saying it’s unsafe to use regardless of the charge wt?
 

Starlite

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Probably, not unsafe, it'l most likely run out of case space, with that slow of a powder.
I just went to my loading room to check on some previous shooting as I thought I loaded some pills under some VV N-160.. Turns out I didn’t; but I found a page I printed some time ago. Speer table has 7828 on it too. 100gr SP 42.4 (2883 FPS) - 47.1C (3199 FPS). It has 4831 at 39.7 (2806 FPS) -44.1 (3082 FPS)
 

jasonco

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I settled on 44 gr, a full and light compressed Starline case, 110 SMK, H4831SC, as it was a low ES/SD load @3043FPS during initial barrel break-in and load dev and have stayed with this since the beginning. After putting a few hundred down the barrel, not only did my barrel speed up, but at my elevation, Geo Ballistics Arc gives me a corrected firing solution velocity and the Kestrel confirms it, with the 110SMKof 3262FPS on average.
 

Starlite

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I settled on 44 gr, a full and light compressed Starline case, 110 SMK, H4831SC, as it was a low ES/SD load @3043FPS during initial barrel break-in and load dev and have stayed with this since the beginning. After putting a few hundred down the barrel, not only did my barrel speed up, but at my elevation, Geo Ballistics Arc gives me a corrected firing solution velocity and the Kestrel confirms it, with the 110SMKof 3262FPS on average.
I do have one can of 4831 but im keeping that for something that I can’t quite remember. I’m waiting on 200 pieces of alpha (SRP) and 200 Berger 109 HyTgt. Should be here in 1 week when the barrel will be GTG firing these 90gr tgt. I’m gonna break out my unicorn dust (H4350); it’s hard to find around these parts so I use it sparingly. Varget is even rarer to find right now. Maybe I’ll load a few with 4831.
Thankx for the information. Hopefully someone will chime in on 7828.
 

jasonco

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Make no mistake, that 6mm Creedmoor is in fact an overbore cartridge, in behavior and slow powder selection. Here's a 90TGK test.
1609111292708.png
 

BPollard

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7828 any, more than not, is too slow, for a 90 grain in 6mm Creedmoor. I run H4831SC with 110SMK, in a 26" barrel @3200 AVG FPS and that's a mid-charge in this rifle, that gives a lot of reloading's with Starline LRP case and tight primer pockets.
Try win760
 

jasonco

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Just a curious question
In the area of small rifle vs large rifle primers and “cold weather ignition “
Like with all the small rifle primer match brass available these days ?
What is the question, that SRP has an effect on ignition in "cold weather", as in Rocky Mountain States cold?
 

Starlite

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What is the question, that SRP has an effect on ignition in "cold weather", as in Rocky Mountain States cold?
I have had hang fires with standard SR primers in the 6.5 CM using slower burning powders.
However Running CCI-450 SR mag primers i've been down to -25 C with no issues.
Just my 2c here:
IF your hunting. Run the large primer version.
IF your running BR. SR primers are the ticket.
IF your stuck on the small primer version for hunting. Use magnum and Test it before you trust it.

edited as I posted wrong temperature 🤒
 
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