Chasing lands for increased accuracy

[Knightrunner]

Not judging, just find it odd you didn't use the same a-max bullets and see if you could tweak the reloads to improve on what you bought/used/tested/benchmarked.

I did like the A-max...
I also like BT's, SST's, and the FTX bullets I run in my .500 S&W. Honestly, I wanted to build .308 bullets and was limited by what was on the shelf at Bass Pro at the time. There were other brands, but the powder selection was equally limited and so I looked through all, (5), of my reloading manuals and found an in-stock bullet that worked with an in-stock powder and ran with it...
And then as I said, I wasn't aware that FMJ bullets were so inaccurate. I never had accuracy problems before with them. Of course those were 5.56 and not .308 and my eyes were nearly 30 years younger...
Guess I better get used to ordering components online as there are very few local sources available.

Thanks guys...

 

[Nature Boy]

Buy some Sierra 168 Gr SMKs, load them to fit the mag, and let them jump, they don't mind. I load them to 2.800 and they shoot great.

^^agree

Another one I found easy to tune was the 155 AMAX. 42.5g of H4895 is sub MOA 5 shot groups in every .308 I own

 

[GTS Dean]

First, I think you have WAY too much bullet outside the case. The general rule is to have approximately 1 bullet diameter in the neck. Some rifles have very long throats and chasing the lands won't allow enough bullet neck bearing depth, or it won't let the cartridge fit the magazine. I recommend doing a 4-shot powder ladder with about 0.4 grain jumps over the book range to find the best node. Then, I start backing away from the lands from your physical long-limit in .004" increments and loading 3- or 4-shot groups with a mid-range powder load to find what jump your rifle likes best. I don't worry too much about where the cannelure is. This is how my last 30-06/150 FB Interlock workup went using that method:

 

[Laphroaig]

Another one I found easy to tune was the 155 AMAX. 42.5g of H4895 is sub MOA 5 shot groups in every .308 I own

I'm a big fan of 30 cal Amax's too, both 155 and 168. Unfortunately, I think that Hornady has discontinued the 155 in favor of the ELD Match. I suppose that they are close to the same, just more expensive.

 

[Knightrunner]

First, I think you have WAY too much bullet outside the case. The general rule is to have approximately 1 bullet diameter in the neck. Some rifles have very long throats and chasing the lands won't allow enough bullet neck bearing depth, or it won't let the cartridge fit the magazine. I recommend doing a 4-shot powder ladder with about 0.4 grain jumps over the book range to find the best node. Then, I start backing away from the lands from your physical long-limit in .004" increments and loading 3- or 4-shot groups with a mid-range powder load to find what jump your rifle likes best. I don't worry too much about where the cannelure is. This is how my last 30-06/150 FB Interlock workup went using that method:

View attachment 881063

Since I'm waiting for my match kings to be shipped to me and I had already cleaned and prepped 100 cases, I decided to try out your method with some 150 FB Interlocks that I have on hand. I started at 40.4gr and increased .4gr at a time up to 43.6gr. I seated to reach the COL length listed in the book which put me a couple thousandths below the top of the cannelure on most of the rounds. I had spent extra time being as precise as possible when trimming so the variances I'm seeing have to be from inconsistencies in bullet length.
The range is closed tomorrow and Wednesday and then I'm back to work until the weekend so I guess we'll see Saturday how it goes. Worse case scenario I will have learned how to pinpoint an "accuracy node" and will be ready to repeat this test when the SMK's arrive.

 

[Walkalong]

I'm a big fan of 30 cal Amax's too, both 155 and 168.

The 168 Gr A-Max shoots to the same point of aim (Vertical) as the 168 Gr SMK in my .308 with .2 Grs less powder. SHoot very well too.

 

[Demi-human]

so the variances I'm seeing have to be from inconsistencies in bullet length.

Sometimes the cannelure gets pressed in with some variance, too.

I don't crimp any rifle rounds, so whenever I get bullets I get those that have no cannelure.

It helps with my sameness-compulsion. Since there is no index mark to coincide with the case mouth, that must line up the same for every round, I won't think something is wrong when I see some differences.