Bullet Seating Depth Info??

[Nosler06]

I was wondering if anyone would be able to give an opinion as to which OAL they would choose for a .308. I am shooting a 1970 Browning BLR with 44.0grs Varget and 165gr Nosler Partitions. Here are some results the I have from various OAL. I am kind of leaning towards going with 2.760" OAL or is it worth even trying to go try a 2.750" OAL?

Thanks for any suggestions anyone might have.

2.720" OAL



2.740" OAL on two different days





2.760" OAL on two different days





2.780" OAL

 

[HIGHRPM]

With every rifle being different with every ammo it's hard to say which OAL would be best for you. You are going to have to decide what bullet you are going to use, as every bullet will change your OAL, measure your chamber depth with that bullet and an empty case and see how long the chamber is. And then see if it will fit properly in your magazine for proper feeding. Most bullet manufactors recommend .015-.020 off the lands for hunting rounds. Good luck.

 

[Canadian_Zuk]

OAL is probably about the last consideration when working up a load, how much development have you done so far?

Start with the OAL given in the load data you are using for your particular bullet and powder combo. Start at the minimum charge and work your way towards max charge in .5 grain increments watching for pressure signs along the way. A chronograph is the most useful tool you can get your hands on for this part. Once you reach the point of diminishing returns on velocity/powder charge there is no point in going hotter. When you find a load that provides good groups, fine tune that node up/down in .1 grain increments. After you have found the best load for your bullet/powder combo you can start playing with OAL to fine tune further. Do not expect a couple of thou in seating depth to pull your fliers in.

 

[sheephunter]

Playing with OAL without knowing your chamber depth is about as fruitful as herding cats. I personally measure every chamber before working up a load. At least I know where I'm starting and it's one less variable in the process.

 

[hometownhero]

My buddies 308 you would need a 250gr bullet to have enough bullet length to get near the lands. The lands on his are at like 2.950" so I load to mag mag length and it seems to be working alright.

 

[Nosler06]

My buddies 308 you would need a 250gr bullet to have enough bullet length to get near the lands. The lands on his are at like 2.950" so I load to mag mag length and it seems to be working alright.

I would love to load to length, but the length that I need to load to is the old metal clip magazine for a 1970 Browning BLR .308. 2.800" is already backed off 0.020" from the lands and just barely clears the magazine lip. Also the rounds do not feed very well with a 2.800" OAL. It will jam up. I am looking at the 2.760" or even trying slightly shorter at 2.750". I may buy a box of factory loads and shoot them to see groups and length, clearence issues.