.308 seating depth

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speedbird

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Has anyone else run into this situation? I'm loading Nosler Accubond .308 180
gr using 42.5gr of IMR 4064.When seating the bullet i can hear it compressing
the powder,my o.a.l. is 2.832 but i didn't want to seat it any deeper,the round still fits in the mag and chambers fine.I did 1 round this way and then dropped .5gr down to 42.0... My concern is too much presure and the bullet is .580" into the case. Do i have anything to worry about with the bullets seated below the shoulder.
 
Relax. IMR4064 does give compressed loads with that bullet weight. It's no big deal. Compressed loads don't cause excessive pressures. Your OAL is too long though. Max is 2.800".
Work up the load from the starting load. Don't just pick one.
Beginning with the starting load, load 5 rounds only. Go up by half a grain of powder, loading 5 of each keeping them separate until you get to the max load in your manual. (44.5 grains with IMR4064. It's compressed, but don't worry about that.)
Then go shooting. Shoot at 100 yards, for group only, slowly and deliberately off a bench.
Change targets between strings of 5 and allow time for the barrel to cool.
Once you've found the best group, sight in 4.5" high at 100. That'll put you on target out to about 200 yards with no hold over. 180's drop rather quickly past 200. When sighted at 100, they'll drop about 10" out at 300 yards.
 
sunray said:
Your OAL is too long though. Max is 2.800"
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a remington 700 magazine will allow for up to a 2.83" OAL. if the bullet isnt contacting the rifling, 2.83" is fine. some other "short actions" like a Winchester 70, has a 3" mag box IIRC.

also, +4.5" @ 100 is too high. three inches is plenty and should give you a +/- 3" range of about 260 yards and a seven inch drop @ 300
 
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sunray said:
Change targets between strings of 5 and allow time for the barrel to cool.
Once you've found the best group, sight in 4.5" high at 100. That'll put you on target out to about 200 yards with no hold over. 180's drop rather quickly past 200. When sighted at 100, they'll drop about 10" out at 300 yards.
Click to expand...

Sighting in 4.5 " high at 100 yards is probably the most ignorant, stupid advice I have ever heard.

Don't sight in any more than 2-3" above POA at 100 yards, unless you want to miss alot...
 
Once you've found the best group, sight in 4.5" high at 100. That'll put you on target out to about 200 yards with no hold over. 180's drop rather quickly past 200. When sighted at 100, they'll drop about 10" out at 300 yards.
Click to expand...

Once again, the man who cant figure out how to work the interweb gives out some great advice :rockOn: :rolleyes:
 
My first step when loading a new bullet is to figure out the maximum overall length for my rifle. I screw a flat jag on a cleaning rod and close the bolt on an empty chamber. Then I lower the rod down from the muzzle until it rest on the bolt face. Then I carefully mark the length at the muzzle with a piece of masking tape on the rod. Then I remove the bolt and insert a bullet in the chamber and gently press it in to the rifling. I lower the rod again until it rests lightly on the bullet and mark the muzzle position on the rod again with a piece of tape. Then I measure the length between lower edges of the two pieces of tape with a vernier caliper, that give me my aboslute maximum overall cartridge length. I usually subtract .020" from that measurement and that is my starting length as long as it will work thru the magazine (sometimes the freebore is so long that it won't).
 
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get a Forster drop tube. Usually allows 2-3 grains more powder in 08 sized cases especialy when using stick powders
 
sunray said:
Your OAL is too long though. Max is 2.800".

Once you've found the best group, sight in 4.5" high at 100. That'll put you on target out to about 200 yards with no hold over.
Click to expand...

The mag in my Sako is 2.95" and I load to OAL of 2.89", which is still .015 off the lands. And my 180's sighted in 2" high at 100 are zeroed at 200.
 
You don't need to buy a drop tube, you can fashion one yourself out of copper tubing, or any other type of tubing. Black powder reloaders have been using them forever to get as much as 10 grs extra as an example, in the 45/70. The extra compression helps with accuracy using BP though.
 
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