Is the Hornady 6gt brass large or small rifle primers. I know alpha is small but can't find anything on the Hornady brass
- Thread starter MachoMan
- Start date
Group size has little to no bearing no effectiveness of this ignition combination. How about some data with with ES, SD, and sample size.If anyone is interested in using H4831SC in the GT, here are some of my results with 115 RDFs (I have more of the 4831 powders than anything else, so I thought I would try it).
.020" jump
26" 7.5 twist Bartlein 5R HV (~850 rounds so far)
Hornady brass
Fed 205M
Rear bag and bipod off a bench. 3 mph 7 o'clock wind. 86 degrees F.
Did a 200 yard test of 38.5-40.5 grains if H4831SC (basing the loads on Hodgdon's 41.3 max. of Superformance for 110 grain A-Tip).
38.5, 39.0, and 39.5 were slightly crunchy; 40.0 and 40.5 were crunchy, but no pressure signs on any of these.
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39.5 looked good, so I loaded more of that and tried it at 200, 300, and 510 yards.
200 still looking good, 300 was so awesome I stopped after 3 shots (knowing the Random Damn Flyers were coming, and it opened up a bit at 510. I didn't chrono it, but based on the come-ups the velocity looks to be 2875-ish.
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Group size can be optimized with tuner and/or seating depth.
Sorry, I completely forgot that I did shoot a five-shot string of the 39.5 load over a chronograph at 100 yards a few weeks later. Not the greatest sample size for sure, and yep, doing it assbackwards as usual .
Velocity
2852 Average 2848
2836 High 2855
2849 Low 2836
2850 ES 19
2855 SD 7.30
Looking at my notes, the temp for the day I shot the groups was 86F and the day I shot for velocity was 87F, so I am not sure what was causing the slowdown.
Thanks, very helpful!Sorry, I completely forgot that I did shoot a five-shot string of the 39.5 load over a chronograph at 100 yards a few weeks later. Not the greatest sample size for sure, and yep, doing it assbackwards as usual .
Velocity
2852 Average 2848
2836 High
2849 Low 2836
2850 ES 19
2855 SD 7.30
Looking at my notes, the temp for the day I shot the groups was 86F and the day I shot for velocity was 87F, so I am not sure what was causing the slowdown.
Thank you! That helpsSorry, I completely forgot that I did shoot a five-shot string of the 39.5 load over a chronograph at 100 yards a few weeks later. Not the greatest sample size for sure, and yep, doing it assbackwards as usual .
Velocity
2852 Average 2848
2836 High 2855
2849 Low 2836
2850 ES 19
2855 SD 7.30
Looking at my notes, the temp for the day I shot the groups was 86F and the day I shot for velocity was 87F, so I am not sure what was causing the slowdown.
What rifle case is that?
What is the parent case for the 6GT or is there any?
6.5x47 Lapua necked down
Never mind, just found the massive 6GT thread 
This is an old post, but I will tell others what works great for me with brand new Alpha 6GT brass (currently $130/100 at GAP as of 2/2024):
1. Use a mandrel or expander if you want something different than the factory tension…I personally use a .241 expander, which springs back to .2405ish
2. Next, the critical step: dry tumble the new brass for 90 minutes or so with a bit of brass polish added to your media…this seems to add just enough lube inside of the neck to overcome the friction of the factory new brass [this suggestion comes second hand direct from Alpha customer service]
3. Finally, I DO chamfer the new brass…try it with or without, but it makes for more consistent seating.
Let me hear your feedback…the Alpha 6GT brass is definitely a bit more stout than the Hornady brass.
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Keeping this thread going... Anyone else using Vitavourhi powder in their 6GT. My rifle shoots great with RL TS15.5 (see 200 yd target below) and Varget, but the Vit powders are SO much less expensive, I'm wondering if it's worth giving them a try. For background I'm using Fed 205M primers,, Alpha brass and Berger 105 hybrids though a 26", 1:7.5 barrel.
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N140 is a great Varget substitute. It will run fine (and cleaner IMHO).
Temp stability?
