2-Q's: 308 powder and gas gun reloading

Got a couple probably newb questions:

1. I have some Winchester 760 and ramshot tac powder. I want to reload for 308. Which would be better for a 168 or 175 bullet? Please, no other powder suggestions. I have these already and want to use it.

2. Fireman gave me some good step by step instructions for reloading, which I religiously follow. Is there any additional considerations I should make when reloading for a gas gun? It's a "custom" build 6.5cm with 1:8 Krieger barrel.

Thanks in advance.

I'm sure Chad and JG will chime in with good info and JG is reloading 308 for his AR10. I reload for my AR15 in 6.8 and 556/223 and will offer the following:

- full length resize when using in an autoloader
- trimming the case "may" be more critical in an autolader vs bolt
- pay attention to maximum length that will fit into the magazine
- most will not bother crimping the bullet but, since it is an autoloader, you might consider a very light crimp. I like the Lee Factory Crimp die for this application...and Lee dies are JG's favorite
- I would suggest the 168 or even 150 in a gas gun since you will be loosing a bit of velocity as compared to a bolt gun. I think JG chose 155 for his for this reason.
- I lean toward non-tipped bullets for a gas gun to avoid tip deformation and it seems the ogive is a bit closer to the lands this way (I could be wrong on this)

I reload 308 for an AR10 with very tight tolerances. Full length resize and a case gauge is really helpful.

http://www.lewilson.com/casegage.html

I did drop down to 155 gr TMK to gain some velocity back in the 16" AR .308. Chad pointed me to IMR 8208 XBR because of burn rate, and it has been stellar!

KR, look up the burn rate chart. Where does each of your powders fall on the chart, compared to each other?

TAC is the powder of choice (allegedly) used by Black Hills Ammunition in their 308 match ammo.

That is good enough of a recommendation.

Small base dies can help with resizing and thus cycling in semi-autos.

Just to clarify, the 308 is in a bolt gun (a factory tikka t3). Just want to know what powder of the 2 choices I have already. Not sure how to quantify burn rate but I found a hodgdon site rating fastest to slowest with the following rankings:
87 Ramshot tac
99 reloader 15
101 varget
111 Winchester 760
Given jeff's comment I guess ramshot is the winner.

The gas gun consideration is a 6.5 creedmor, not a 308.

Now look at max powder charge for each, given the bullet weight. The powder with the highest grain weight of powder will give you the most case fill. And a full case of powder has always been a good thing for me, in bolt action. The slower the burn, the more the fill volume, typically.

So, your Winchester 760 will probably be the powder that gives you the most case fill for the .308 bolt action.

And Ramshot, being a faster burn will give you more velocity out of the gas gun. Get the powder burned before it gets to the gas port.