6 ARC Gas Guns

[black5.3]

Just started testing today with Reloader TS15.5 and liked what I saw today as far as velocity, ES/SD but groups left a little to be desired. Looks like 28.0-28.2 gr of TS15.5 is where I will concentrate on because the numbers looked good and gave me similar velocity to 29.0gr of Leverevolution.

Specs are:
Alpha 6ARC brass 1x fired at this point
Cci 450 primer
Berger Elite Hunter 108gr
Coal 2.250”

Starting to get fairly compressed loads around 27.5gr of TS15.5 so you can imagine 28.0gr and above are compressed enough to where my seating die is leaving a little ring on the bullet that you can just barely feel with your fingernail.

Dropping powder with a Area419 powder funnel with the 3” powder drop extension so that part is covered. What are you guys doing to help with your fairly compressed loads…. Except backing off the powder or going to a different powder.

Despite how compressed the 28.0gr load is I don’t have any pressure signs and like I said earlier velocity looks good for a non temp sensitive powder so Im trying to test this powder more and see how well I can get it to work.

Thanks everyone!

 

[DHDeal]

Use 2 3" extensions? That's what I use, but I'm probably trying to make up for something.

I use a 24" drop tube when I load black powder and I can get 80 grains of 1.5F in a 45/70 fireformed case. With a regular funnel, 77 grains will fill it to the rim. 1.5F is bulky.

Not apples to apples comparison, but still valid. I don't know where you will run into pressure with 15.5 though, but a slower pour with a longer tube will stack it up.

 

[black5.3]

Use 2 3" extensions? That's what I use, but I'm probably trying to make up for something.

I use a 24" drop tube when I load black powder and I can get 80 grains of 1.5F in a 45/70 fireformed case. With a regular funnel, 77 grains will fill it to the rim. 1.5F is bulky.

Not apples to apples comparison, but still valid. I don't know where you will run into pressure with 15.5 though, but a slower pour with a longer tube will stack it up.

Ok i will add another extension and see what happens. I doubt the advantages I will get from switching to TS15.5 will be worth it if im effecting the bullet negatively by squishing the jacket in while seating.

 

[DHDeal]

Ok i will add another extension and see what happens. I doubt the advantages I will get from switching to TS15.5 will be worth it if im effecting the bullet negatively by squishing the jacket in while seating.

How far up the neck is your current charge? Or is it still below the neck? Obviously seating out will give you more space for powder.

Is there any reason to go with that shorter OAL? Have you tested a longer OAL? Most 6ARC or 6.5 Grendel mags will allow longer seating depths. I do not have that bullet so I have nothing there about where they like to be in relation to the leade.

 

[black5.3]

This is a gas gun so im stuck at about 2.260” as being the max coal. The powder is not up in the neck yet, it’s still just below the neck in the shoulder area, probably about half way up the shoulder. I ordered a couple more drop tube extensions from Area419 this morning so when they come in I will be testing that.

 

[bbyars]

This is a gas gun so im stuck at about 2.260” as being the max coal. The powder is not up in the neck yet, it’s still just below the neck in the shoulder area, probably about half way up the shoulder. I ordered a couple more drop tube extensions from Area419 this morning so when they come in I will be testing that.

I've seen guys use electronic toothbrush to vibrate the sides of case to "pack" down powder. That being said, why not just use a faster powder?

 

[black5.3]

I've seen guys use electronic toothbrush to vibrate the sides of case to "pack" down powder. That being said, why not just use a faster powder?

That would be easier and i have tried some faster powders but im wanting to go to a temp stable powder which narrows down the selection a lot. When I tried Varget, i had great accuracy but pretty low MV and pressure signs came on fast. TS15.5 is actually in a pretty good burn rate for heavies with the 6ARC but it is definitely bulky. Which leads me to the problem im currently trying to fix.

 

[bbyars]

Been down that road trying to figure out how these guys are getting 45-47 grs of varget into a 308 Win case..... juice probably isn't worth the squeeze. Especially if you're not willing to do it in bulk. But in the name of "science" lemme know how it works out for you. Is there a certain speed youre trying to get? Im guessing 2400-2500 with 108s and slow powder?

 

[padom]

That would be easier and i have tried some faster powders but im wanting to go to a temp stable powder which narrows down the selection a lot. When I tried Varget, i had great accuracy but pretty low MV and pressure signs came on fast. TS15.5 is actually in a pretty good burn rate for heavies with the 6ARC but it is definitely bulky. Which leads me to the problem im currently trying to fix.

You can only fit so much powder in a small case that needs to fit in an AR15 mag, and hold a long, heavy 6mm 105/108gr bullet and still want to be temp stable.

In this situation you have a few options, do what I did and drop down to shoot 80's fast with temp stable powder and not have compressed issues. Or drop your powder charge to fit your heavy bullet in the case. Accuracy over velocity has always been my philosophy. I would rather have an extremely accurate, extremely temp stable load with a little less velocity than a hot rod load with high SD's and huge velocity swings when temps change.. You build your dope with your final load and you shoot or hold whatever your dope is. That extra few FPS doesnt mean much when you have to constantly chase a speed thats always changing....

 

[black5.3]

Been down that road trying to figure out how these guys are getting 45-47 grs of varget into a 308 Win case..... juice probably isn't worth the squeeze. Especially if you're not willing to do it in bulk. But in the name of "science" lemme know how it works out for you. Is there a certain speed youre trying to get? Im guessing 2400-2500 with 108s and slow powder?

Based on what I shot yesterday, 108gr Berger Elite Hunter with 28.0gr of TS15.5 got me 2550-2560fps. Im plenty happy with at speed for a 108gr bullet. I loaded 15 more at 28.0gr and 15 more at 28.2gr to confirm velocities and shoot several more 5rnd groups. It will probably be Wednesday or Thursday before I can shoot them though.

 

[black5.3]

You can only fit so much powder in a small case that needs to fit in an AR15 mag, and hold a long, heavy 6mm 105/108gr bullet and still want to be temp stable.

In this situation you have a few options, do what I did and drop down to shoot 80's fast with temp stable powder and not have compressed issues. Or drop your powder charge to fit your heavy bullet in the case. Accuracy over velocity has always been my philosophy. I would rather have an extremely accurate, extremely temp stable load with a little less velocity than a hot rod load with high SD's and huge velocity swings when temps change.. You build your dope with your final load and you shoot or hold whatever your dope is. That extra few FPS doesnt mean much when you have to constantly chase a speed thats always changing....

I agree. If a little longer drop tube doesn’t help and/or my groups don’t match or do better than my Leverevolution loads then I have some Sierra 107’s and Hornady 108 eld-m’s to test before I drop down to a lighter bullet and start testing those. Maybe Sierra 95’s…

 

[padom]

I agree. If a little longer drop tube doesn’t help and/or my groups don’t match or do better than my Leverevolution loads then I have some Sierra 107’s and Hornady 108 eld-m’s to test before I drop down to a lighter bullet and start testing those. Maybe Sierra 95’s…

Sierra 95's have been on my list to test, I have a bunch of them and they shoot stupid accurate lights out in my 6BR's.. Thats probably the heaviest I would go in an AR15 platform 6 ARC... I find the 85 Sierra HPBT and 87 VMAX stupid accurate and fast...

My 87 VMAX load is 2885 and 0.5mil better elevation than 105 Elite Hunter @ 2550 to 800 and matches exactly at 1000yd..

 

[black5.3]

Sierra 95's have been on my list to test, I have a bunch of them and they shoot stupid accurate lights out in my 6BR's.. Thats probably the heaviest I would go in an AR15 platform 6 ARC... I find the 85 Sierra HPBT and 87 VMAX stupid accurate and fast...

My 87 VMAX load is 2885 and 0.5mil better elevation than 105 Elite Hunter @ 2550 to 800 and matches exactly at 1000yd..

Interesting info. Can you notice a discernible difference in wind calls between the 105 and the 87 vmax?