308 Load Data

[Adam_MA]

The groups were pretty good, At the top powder charge, they were within 4". The thing I wanted to avoid (please set me straight if this isn't reasonable) was having to sight my rifle in to the new loads. This is the rifle I use for hunting, and would like to avoid having to sight it back in for my hunting ammo in the fall. Not a big task though, I guess I could just keep track of how many clicks I move it.

Now here's something else... When I take this rifle to the range, I almost always use 8.5X11 targets that I print out myself. I don't need any larger targets at 100yds, because I am always on. When I was shooting these loads, I wasn't hitting the paper for the first 3 work-ups of 5 rounds. After that, I realized that it was shooting low, and I started to shoot at a blank 200yd target that was left up right next to my paper. That's how I noticed that they were very low. So for at least half of my loads, I couldn't even see how they were grouping at all. So, that being said, would it make sense to start back where I started, using large enough targets to see the hits and compare group size, or should I still start at my max load, and continue working forward?

Thanks
Adam

 

[TonyD]

Adam - 4" at 100 yards from a bolt gun shooting from a bench is not acceptable. I assume it's scoped but even if it isn't, not good. I don't know if that's because you, the gun, the ammo, or a combination. You should be shooting within an inch with 168 SMK's at 100.

I would redo the entire test on a target large enough to record groups. Otherwise it's a waste. Remember, lower power will shoot lower.

You're not going to get a load that shoots the same as you're hunting ammo. Even if you change lot #'s your POI will change some. If you saw no signs of pressure you could include some loads higher than your last.

 

[Adam_MA]

Cool thanks Tony.
Yes it is a scoped bolt gun, and when I shoot the Federal GMM I can stay within 1"

Guess I should start this series again. I think I will just do the same series over again, and I will work past the original 42.5 by a couple of tenths to see how those do as well.

No, I need to get to the gunshop, and buy some of those big targets!

Adam

 

[Nickle]

I concur that 4 MOA from a scoped bolt gun is unacceptable. Assuming it's a sporting (hunting barrel) you should get groups about 1" or so. Heavy factory barrels, .75" and custom barrels (like Hart) about .375" to .5". Thats assuming from a bench, with front and rear bags.

Adam, don't worry about the zero, until you find an accurate load. If 4895 doesn't work for you, ask me about other powder recommendations. I have a few good ones. I do prefer 4895 first in the 308, though. It usually works well.

 

[Adam_MA]

Thanks Nickle.
For the record, I was only using front bags. They were the little sand bags that I had stacked up to support the front of the barrel.

Adam

 

[Nickle]

I hope you rested the stock on them, not the barrel. If you don't want to pay for a rest, Gander Mountain (and possibly Midway) has front bags (Caldwell) that are tall enough to work with out a pedestal rest. I bought a set of bags to have a set of cheapies available.

 

[Adam_MA]

Yes I had the front stock resting on the bags, not the barrel. I do it that way, so I wouldn't have to look for 2 more bags, but what problems would it cause if you were resting the barrel on the bags?

Adam

 

[Nickle]

It will definitely screw up your zero and your groups. Opens the groups up some. So does a Bipod that's mounted to the barrel.

 

[TonyD]

You don't want anything touching the barrel. Ideally, not even the stock. That's why all rifles of any accuracy are bedded and floated.

 

[Adam_MA]

Got it!
Thanks
Adam

 

[Nickle]

If you ever find your zero significantly changed and your accuracy gone, check your "free float" of the barrel. A file card or dollar bill works fine for a gage (thickness).