What ES/S are you getting from your short mags?

[1KBR]

I have been trying my new 6.5x47 and during a recent crono session realised the ES/SD on the smaller case is much better than I am able to get from my 7RSAUM. I have tried H4831sc/H1000/RE22, as well as a few different primers and have got it down to 20 fps ES and an SD of 6 on average over 10 shots. Do other people results mirror this, or are you able to get better spreads in your Short magnums?

 

[Chuckhunter]

1KBR I have a 300RSAUM and my pet load gives me an ES of 9 and an SD of 3 but I think anything in the single digits as far as SD is concerned is more than adequate especially if we are talking hunting rifles, which mine is. I generally let the target tell me the story and if I have a few loads that are very close, then I turn to the ES and Sd. I will tell you that most of the loads I tried had a SD above 10 until I switched to Russian primers and then they all dropped considerably.

 

[1KBR]

Chuck hunter. While the Russian SRM primers work well in my 6BR, the Russians still don't help my short mag. This rifle is a pure target gun, so I need the SD lower than 10. I would like to get the ES lower than 20fps and SD lower if possible.
Then again, how low do we really need ES/SD to see a difference on target at 1000yds?

 

[Chuckhunter]

1KBR, I do have a 6Dasher that's my 600yd Target rifle. I spend a considerable amount of time fussing with my brass and being as precise as I can be with my loading techniques. The load that I settled on does have an ES in the single digits as well as a very low SD but I didn't find that out until after many good 300 yd groups. Being a 1K shooter I'm sure you pay very strict attention to detail when your working up a match load. With that being said, If you're showing very little vertical on the target and the load appears to be shooting well for you I wouldn't fret if the numbers are a few feet more than you would like them to be. Within reason of course.

 

[Steve Blair]

My .300 WSM load is consistently in the 10.5-13.5 ES range and will hold that over a span of .4 grains. Berger 230 Hybrids, Tula LR (KVB-7) primers, IMR 7828 SSC and Norma brass. The 34" barrel may be a minor factor as muzzle pressure is slightly lower than shorter barrels.

 

[1KBR]

Steve, I was able to get around the same ES, 10-13fps on average with my 300WSM, but not so with my 7mms. I have tried the same brass prep, primers ,annealing, but the 7s don't seem to get down to the same as the 30s?????

 

[Steve Blair]

Are you using Russian LR or LRM? The LRM primers just don't produce the same numbers for me as the standard. I assume you're shooting 180 Hybrids? Have you fiddled the seating depth in small (.003") increments. Seating depth has often put the gilt edge on an otherwise very good load, bringing the ES down 2-5 fps.

 

[Desert Fox]

ES and SD from my 7WSM is pretty consistent. the first shot from a clean barrel is always a bit slower. The next shot after that is consistently in single digit. Load Consist of 65 grain Reloader 25, Federal 210 Match Primer, Berger 180 grain Match VLD in a fully prepped WW brass.

 

[1KBR]

I have only tried the std Russian primers.
Yes, I,m using hybrids and have found this barrel likes .005" jump and is a bit fussy as mentioned. Desert fox, i would certainly like to get the ES down as far as you did.

 

[Steve Blair]

Note that Desert Fox's loads are at or close to full pressure. So are my .300 WSM loads at 2947 with 230 Hybrids. My loads show lowest velocity variation when pressure is at SAAMI max or just below. Velocities start to spread again when pressure is too high. I've not been able to get very low ES with loads much below max. My current .284 Shehane barrel, a fast, 32" Krieger, delivers 2965 with ~10 ES.

 

[Desert Fox]

Yep! The load is very accurate too. However, I can't use this load for competition. The velocity combined with the 8.5 twist of the Broughton ripped some of the Berger to shred. I will try the 180 SMK when I get a chance and see if I can duplicate this load.