6BRA 6 primer test at 500 yards

[Thumper]

Those are great groups for 500 yards. well done!!! Thank you for sharing your test results.

 

[270 ftw]

All sub 1/2 MOA! Thats awesome. We need more of this kind of testing from people who if they can shoot like that obviously know what they are doing. Keep it coming!

Quick question...you mentioned being 5-6 fps over you optimal speed. What was it that indicated that to you? Something in the groups? Or from previous testing?

What happens at 5-6 fps slower? The groups get even smaller or better sd/es or both? Thanks in advance

 

[JamesnTN]

All sub 1/2 MOA! Thats awesome. We need more of this kind of testing from people who if they can shoot like that obviously know what they are doing. Keep it coming!

Quick question...you mentioned being 5-6 fps over you optimal speed. What was it that indicated that to you? Something in the groups? Or from previous testing?

What happens at 5-6 fps slower? The groups get even smaller or better sd/es or both? Thanks in advance

The prior tuning best accuracy was at a slightly lower velocity so that’s where I based the node for and load from the prior tests. So with the higher humidity and slightly higher temps I noticed the velocities had also increased.

 

[KenOath]

The prior tuning best accuracy was at a slightly lower velocity so that’s where I based the node for and load from the prior tests. So with the higher humidity and slightly higher temps I noticed the velocities had also increased.

I’ve seen similar speed changes with my BRAs tuning first light in cool conditions to shooting a match in the middle of the day which increased velocity, mostly it held tune but on a couple of occasions I felt it was out of the sweet spot..

 

[Gilbert Garza]

I’ve seen similar speed changes with my BRAs tuning first light in cool conditions to shooting a match in the middle of the day which increased velocity, mostly it held tune but on a couple of occasions I felt it was out of the sweet spot..

Is this cause of powder or are BRA’s more susceptible to velocity changes with temperature changes ?

 

[KenOath]

Maybe both? I can’t really say with 100% certainly...I’m only on my second barrel but I know my last Dasher behaved in a similar way but worse..

 

[BartsBullets]

Is this cause of powder or are BRA’s more susceptible to velocity changes with temperature changes ?

Its the Powder, not the Caliber! How much change in velocity a tune can take is determined by the barrel. Some barrels will give you a large window, while others won’t .


Bart

 

[jackson1]

JamesnTN. just want to thank you for your research and for allowing me to stand on your foot (I didn't say shoulders because I am not that good yet).

 

[Northridge]

Its the Powder, not the Caliber! How much change in velocity a tune can take is determined by the barrel. Some barrels will give you a large window, while others won’t .


Bart

I agree with Bart here for the most part but I do find in my own testing that even though velocity will sag or pick up a bit the bigger failure for me and others often will be "static bag grip" from a humid morning to a mid day less humid situation where bag glide improves and static grip or bag break away is reduced creating a different shape or result on paper simply because of this situation. everything plays a role in how a platform will develop grouping or shape or how long tune will hold interesting enough, that's what makes it fun for me I spose. As Bart mentioned and it is of my opinion some powders usually quicker per burn rate will show less trouble in a slight velocity sag or increase Vs slightly slower options on a chart, at least at long range short range would defiantly be a altered discussion.

Shawn Williams