Total Newbie Question on Where to Start

[jab00]

I’m hoping that you guys can help me figure out a starting point for my first hand loads. I’ve got all the equipment, powder, primers and two types of bullets that have worked in my gun as factory loads (those being FGMM 168 and 175 SMKs).

Here’s the specs on my gun:

• Rem 700
• 16.5” 1:10 twist Bartlein
• .308 Win (haven’t measured my fired brass yet)
• Muzzle velocity with factory FGMM 168s has been averaging 2535/fps
• Muzzle velocity with factory FGMM 176s has been averaging 2444/fps

My original plan is/was to use my saved factory brass and then try all four loads (low to high) that are listed in the Sierra manual for Varget and IMR4895 for both bullet weights and see which works best.

So, I guess my question is whether or not there’s a more “scientific” method of figuring out where I should start or do I just need to do the OCW exercise and see which one works best?

 

[Kadams1563]

Isn’t like 44 grains of Varget behind a 175 THE .308 load? Can’t recall as I’ve never loaded for it but I think that’s pretty close.

 

[jab00]

Isn’t like 44 grains of Varget behind a 175 THE .308 load? Can’t recall as I’ve never loaded for it but I think that’s pretty close.

I’ve seen that mentioned before but I’ve also heard that Federal is using a proprietary blend. However; I guess I could always use 44 grains as the target for 168s and 42 grains as the target for 175s (just need to check the max load for each in the manual)

 

[RegionRat]

You could start with 43 of Varget or 43 of 4064 for both the 168 and 175, just to get things rolling.
(ETA: 4895 will be slightly less than Varget or 4064 in some rigs, so back down a little for the 4895, say to about 40.0)
If you do a spread for velocity to match the factory speed, it won't take many rounds spread around these starting points to determine what your rig wants.

The design of experiment called OCW, is intended to help reduce the number of rounds it takes to find an optimum. When you are shooting a standardized design, you have the advantage of narrowing your search down based on lots of background data. You won't have to work very hard to find a good load with your starting point.

Don't worry about prioritizing speed if your rig shows a liking for a different one than the factory ammo. If there is an obvious accuracy node that is close, go with that instead. What group size were you getting and what kind of shooting are you planning for this rig?

 

[jab00]

You could start with 43 of Varget or 43 of 4064 for both the 168 and 175, just to get things rolling.
(ETA: 4895 will be slightly less than Varget or 4064 in some rigs, so back down a little for the 4895, say to about 40.0)
If you do a spread for velocity to match the factory speed, it won't take many rounds spread around these starting points to determine what your rig wants.

The design of experiment called OCW, is intended to help reduce the number of rounds it takes to find an optimum. When you are shooting a standardized design, you have the advantage of narrowing your search down based on lots of background data. You won't have to work very hard to find a good load with your starting point.

Don't worry about prioritizing speed if your rig shows a liking for a different one than the factory ammo. If there is an obvious accuracy node that is close, go with that instead. What group size were you getting and what kind of shooting are you planning for this rig?

Thanks for info....

I’m getting very good groups with both grains of FGMM as long as I don’t screw up. This picture is an average group at 100 including a round that I screwed up on.

As far as shooting type goes, I do mostly paper and steel from 100-300 yards which where my range maxes out at.

 

[RegionRat]

For now, you are doing great. Don’t worry too much till you go out past 300, or even 400.

By the time you start shooting at 600 and beyond, your technique and loading discipline will be more developed and will need to be for the groups to stay tight as the yardage increases. To go out past 600, the SD and ES numbers will also have to stay tight.

 

[jab00]

For now, you are doing great. Don’t worry too much till you go out past 300, or even 400.

By the time you start shooting at 600 and beyond, your technique and loading discipline will be more developed and will need to be for the groups to stay tight as the yardage increases. To go out past 600, the SD and ES numbers will also have to stay tight.

Thanks - this actually brings up another question...

...is there a way to calculate/predict what my ES/SD would be at distances beyond 300? Or, put a different way, is the data that I gather good enough to have an idea as to what will happen at 600 and beyond?

The reason I ask is that I plan on taking a 1000 yard class once a year and I’d hate to get there and find out that my hand loads suck beyond 300 yards. I used factory loads for the class this year but I’d love to be able to get out to 1k yards with something that I put together.

 

[supercorndogs]

Your SD and ES is the same for the most part all the way for your chronograph to impact. If you are looking for vertical spread in groups as an indication, you are going to need to shoot it farther than 300.

Be careful and work up your loads, FGMM brass is heavy and has less capacity than some others. 43 grains of varget under a 175 may lead to an overpressure situation.

 

[jab00]

Your SD and ES is the same for the most part all the way for your chronograph to impact. If you are looking for vertical spread in groups as an indication, you are going to need to shoot it farther than 300.

Be careful and work up your loads, FGMM brass is heavy and has less capacity than some others. 43 grains of varget under a 175 may lead to an overpressure situation.

Thanks - I just loaded two rounds of 175 SMKs with 42.3 grains of Varget in a FGMM case (which will be the max load for the 175s) and then down from there. For the 168's in FGMM cases. I'm going to use 42.5 grains of Varget as the max and go down from there.