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Neck Tension

MMH

Sergeant
Full Member
Minuteman
Mar 17, 2013
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I have been reloading .308 using a Lee FL die, and sizing to push the shoulder back 0.002". Should I switch to a body die and collet necksizer to better control neck tension? For those not fans of the Lee collet die, what methods do you use to control neck tension?
 
What neck tension are you getting with your Lee FL sizing die? What gun are you reloading for? What accuracy are you getting? What kind of runout are you seeing? You haven't provided any information for us to give you any direction or suggestions.
 
I have been reloading .308 using a Lee FL die, and sizing to push the shoulder back 0.002". Should I switch to a body die and collet necksizer to better control neck tension? For those not fans of the Lee collet die, what methods do you use to control neck tension?

You can control neck tension with bushing dies, FL dies with custom size necks, various expander mandrels, or a combination thereof.

Some people don’t like Lee collet neck dies because they don’t know how to adjust them.
 
I use Redding Type S bushing dies. You can buy different bushings to get the desired neck tension. Measure a few of your loaded rounds at the neck, get an average, minus .002 depending on how much neck tension you want, and that’s the bushing you need. I remove the depriming stem also and deprime in a different step.
 
What neck tension are you getting with your Lee FL sizing die? What gun are you reloading for? What accuracy are you getting? What kind of runout are you seeing? You haven't provided any information for us to give you any direction or suggestions.
No idea on the neck tension as I have not previously paid attention to it. I am reloading for 308 and getting 5" groups at 600 yards. Allot of it I am sure is me not the ammo. I am trying to give you all the information that I can. Still improving as a shooter & a reloader, and, always trying to learn how to do it better!

 
What gun? You need to measure the neck of your sized brass and then measure the neck of a loaded round with that same piece of brass. Then subtract those numbers and that's your neck tension...tell us those measurements...

your group size at 600yds says your good to go.. what's your load? What bullets? Brass? Powder?

example of very helpful info were looking for...

Remington 700 5R 308

308 Lapua brass
175 SMK
43g Varget
2.80" COAL

neck measures .334 after sizing my brass
neck measures .336 after seating a bullet in the brass
.002 neck tension....Perfect
 
What gun? You need to measure the neck of your sized brass and then measure the neck of a loaded round with that same piece of brass. Then subtract those numbers and that's your neck tension...tell us those measurements...

your group size at 600yds says your good to go.. what's your load? What bullets? Brass? Powder?

example of very helpful info were looking for...

Remington 700 5R 308

308 Lapua brass
175 SMK
43g Varget
2.80" COAL

neck measures .334 after sizing my brass
neck measures .336 after seating a bullet in the brass
.002 neck tension....Perfect

I have been shooting 178 gr. A-Max bullets & 43.0 gr. of varget & 43.0 gr. of 4064 out of FC brass out of a Remington 700 AAC-SD. COAL is 2.818 which is as long as I can get in a magazine (AI mag) but still leaves ALLOT of bullet jump. Stock barreled action w/ about 1500 rounds in a Manners T6A stock.
 
what mags? AICS mags allow to about 2.89" COAL
Accurate Mag & AI. Just measured them and am getting 2.88" I can increase COAL by 0.050" but it still will leave me w/ allot of bullet jump (I would have to remeasure my barrel as it was deep enough that I knew that I would never be jamming my bullet into the rifling). Guess I am conservative in the COAL because I do not want to be in a situation where I have to single feed the round.
 
So your long throat is typical of factory Rem700's. Back when I had my Rem700 5R 308 my distance to the lands was something like 2.305". 175smk liked to jump in the 2.805-2.815 range. But my rifle hammered with 42.2gr IMR4064 in Lapua brass with 178 Amax seated to 2.887" COAL. They obviously were still jumping a good bit (0.582" jump) but liked being much closer to the lands than the 175smk which were very accurate below 2.82" COAL. I loaded the 178 Amax to 2.887" COAL which were the longest they would reliably feed in my XLR Carbon chassis with AICS mags.

Here's the seating depth test I did in that rifle with the 178 Amax and you can see how the groups shrunk when I got much closer to the lands.

All my brass was sized with a Forster FL sizing die bumping the shoulder back .002 and die gave exactly. 002 neck tension.



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