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12/6/2019 7:27:02 PM
Posted: 3/15/2011 1:04:08 PM EST
I am in the process of restarting my loads for my .308 rifle. I started out loading my 178gr amax rounds to 2.8" as suggested in my hornady manual.

However, I have been reading and see that it is best to load long and work shorter so pressure doesn't become an issue. I have not seen any pressure signs at this level.

My previous load:
178 amax
43 gr varget
lc lr brass
2.8"

I want to start at 43gr and work up to 44, but I want to move my oal out to 2.81". Will increasing my oal .01" at 43gr cause problems? Then all the rounds following will be loaded in .2gr increments at 2.81" oal.

I have read up on the ladder test and would like to do that, but I don't have access to a 300+ yd range except once or twice a month. All testing will be done at 100yds, shooting 5 round groups. I will then load more and test more in depth on the next range day.
Link Posted: 3/15/2011 1:32:35 PM EST
So if I'm reading correctly 300 yards is maximum distance ?? If so stay with 2.80. There's nothing to gain with longer COAL at distances under 600 yards and really I want to say 800 yards....
Link Posted: 3/15/2011 1:33:48 PM EST
Link Posted: 3/15/2011 2:02:33 PM EST
I am loading mag length as the max. I have tried putting a bullet seated long in a case with a loose neck tension, then inserted the round and closed the bolt. I read on another forum this is a rough way to measure to where the rifling starts.

Even after moving my bullets out to 2.81" oal, they still have to jump roughly .088" if I have done the test correctly. The reason I decided to change the oal is because most people say it is best to start long and move shorter.

As far as max distance, I can shoot to 700yds. I referenced 300 yards because the ladder test seems to do better at 300+ yds. I don't have access to that range as often as I do the 100yd range.
Link Posted: 3/15/2011 2:11:21 PM EST
Originally Posted By m1ajunkie:
I am loading mag length as the max. I have tried putting a bullet seated long in a case with a loose neck tension, then inserted the round and closed the bolt. I read on another forum this is a rough way to measure to where the rifling starts.

Even after moving my bullets out to 2.81" oal, they still have to jump roughly .088" if I have done the test correctly. The reason I decided to change the oal is because most people say it is best to start long and move shorter. As far as max distance, I can shoot to 700yds. I referenced 300 yards because the ladder test seems to do better at 300+ yds. I don't have access to that range as often as I do the 100yd range.


why would you want to start at a higher pressure and work down? by increasing the oal you increase preasure. seems to me you should work it up.
Link Posted: 3/15/2011 2:54:49 PM EST
Originally Posted By jimr:
Originally Posted By m1ajunkie:
I am loading mag length as the max. I have tried putting a bullet seated long in a case with a loose neck tension, then inserted the round and closed the bolt. I read on another forum this is a rough way to measure to where the rifling starts.

Even after moving my bullets out to 2.81" oal, they still have to jump roughly .088" if I have done the test correctly. The reason I decided to change the oal is because most people say it is best to start long and move shorter. As far as max distance, I can shoot to 700yds. I referenced 300 yards because the ladder test seems to do better at 300+ yds. I don't have access to that range as often as I do the 100yd range.


why would you want to start at a higher pressure and work down? by increasing the oal you increase preasure. seems to me you should work it up.


From what I gather, you are starting at the longer oal and a lower powder charge. Then you work up in powder charge until you find what shoots well. Next you play with oal by moving it shorter and in doing so you can safely assume you will not be increasing pressure.

I think the reasoning is so you are not maxxed out on powder with some jump and then decide to increase oal which will increase pressure. I have read that increasing oal can lead to large pressure spikes that were not occuring at the shorter oal.

The very bottom of post 1 in this thread is where I got my info:
Snipers hide
Link Posted: 3/15/2011 3:22:41 PM EST
I shoot with a my son who seats to the lands in his match chamber, 2.865. I seat 2.80. Granted we are shooting two completely different loads...

I'm just not seeing much difference out to 800 yards.

Past 800 out to 1000 yards.... I am seeing a difference but that could easilily be accounted for by his ability to read wind.
Link Posted: 3/15/2011 7:06:56 PM EST
Here is a good read on OAL vs Pressure and accuracy. Scroll down to "From the Lab".

http://www.barnesbullets.com/resources/newsletters/september-2007-barnes-bullet-n/
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