Bullet seating depth question

DsrtRat

DsrtRat

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OK, I have been reloading for a couple of months and have been doing it all by the books. I want to start loading my bullets closer to the rifling.

I took a bullet and seated it extra long in the case. I marked it with marker and closed the bolt on my REM 700 .223. I did it 3 times and found an average overall length of 2.412" when I extracted the dummy round.

I am using 50 grain NOS BT which have an overall length of .800". If my case is trimmed to 1.750, and my bullet is .800" long, with the bullet touching the rifling, I only have .138" inside the neck and if you consider the fact that the bullet is a BT, there is even less in contact with the brass. If I want to seat the bullet .020 away back from the rifling, that still only leaves .158 in the brass.

What do most people do in this case? Is it more important to be seated closer to the rifling or have say a .200 " contact with the brass so that proper pressure can be built up? I was thinking of seating the bullet for an overall length of 2.340, leaving .21 in the neck and .07 to the rifling. Are there any normal prctices or does one just mess around with seating depth to find the sweet spot for their gun?
 
Only your gun can tell you what it likes.I tend to start at .010" off of the lands and experiment a little.With the Barnes TSX and TTSX,I start at .050" off of the lands.
 
A more experienced shooting buddy of mine who does precision shooting and reloading told me this rule of thumb. Whatever the caliber, there should be that much actual contact between neck and bullet. So in this case you should aim for at least .223" of bullet contact with the brass.

Anyway, in some rifles you just won't be able to reach the lands. Also, 50 grs is on the light (and thus short) side for 223. It might be doable with heavier (longer) bullets.
 
DsrtRat said:
OK, I have been reloading for a couple of months and have been doing it all by the books. I want to start loading my bullets closer to the rifling.

I took a bullet and seated it extra long in the case. I marked it with marker and closed the bolt on my REM 700 .223. I did it 3 times and found an average overall length of 2.412" when I extracted the dummy round.

I am using 50 grain NOS BT which have an overall length of .800". If my case is trimmed to 1.750, and my bullet is .800" long, with the bullet touching the rifling, I only have .138" inside the neck and if you consider the fact that the bullet is a BT, there is even less in contact with the brass. If I want to seat the bullet .020 away back from the rifling, that still only leaves .158 in the brass.

What do most people do in this case? Is it more important to be seated closer to the rifling or have say a .200 " contact with the brass so that proper pressure can be built up? I was thinking of seating the bullet for an overall length of 2.340, leaving .21 in the neck and .07 to the rifling. Are there any normal prctices or does one just mess around with seating depth to find the sweet spot for their gun?
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Rule of thumb is to have at least the bullet diameter seated in your brass. I have an older Sako in 223 and the throat is so long I can't get anything out to the lands. FS
 
I reload my 7mm mag with less of a seating depth. My Tikka seems to be a bit long. So I seat my bullet so that my OAL is 3.345 as opposed to 3.29 which is standard. In fact depending on the bullet I could go longer but 3.345 seems to work well with 160grains and 140 grain bullets. The resulting increased accurarcy is unreal.
 
I'd make a dummy round at 2.411" and smoke it, chamber it and see if there are any marks from the lands on it as sometimes when using the method you did the bullet may stick in the rifling a bit and pull out indicating a different OAL. If there are no marks then go with .010" off the lands as suggested above. I have shot rifles with less than one caliber seated in the neck and they shot fine. As mentioned your rifle will let you know what it likes.
 
hunter5425 said:
I'd make a dummy round at 2.411" and smoke it, chamber it and see if there are any marks from the lands on it as sometimes when using the method you did the bullet may stick in the rifling a bit and pull out indicating a different OAL. If there are no marks then go with .010" off the lands as suggested above. I have shot rifles with less than one caliber seated in the neck and they shot fine. As mentioned your rifle will let you know what it likes.
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The smoke idea is a good as it also helped me when I was figuring it out with the Tikka. Also if you make a dummy cartiridge that is a bit longer make sure it fit in the magazine and can chamber properly. Some gun make take a longer cartridge in the chamber but will not fit or feed a longer one.
 
Thanks. All good info guys. Instead of the smoke, I put marker on the bullet once it was seated. That way if the rifling pulled back a bit, it would show up on the bullet.

With the 50's, I may just follow the above advice and put approx .224 in the neck. That way I don't have any issues with pressure or feeding problems.
 
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