C.O.L. ...help!!
- Thread starter 6.5x55swm
- Start date
Is that with different bullets? I had set up my bullet seater just right for the C.O.L. for the 50 grain V-Max bullets in my .22 Hornet and when I tried to seat a 40 grain Sierra soft point it seated it way too far down.
604shooter
CGN frequent flyer
- Location
- Neither here nor there.
Invest in a bullet comparator. That way you're measuring from the ogive and not from the tip. Lead tips get deformed, dented, etc....resulting in variations in COL.
I was wondering if your loading on a turret press?
As stated, get a comparator to measure your rounds.
Try measuring a few bullets on their own. You will probably get .010-.015 differences in the overall length of the bullet due to the swaging of the jackets and or lead tips.
Try measuring a few bullets on their own. You will probably get .010-.015 differences in the overall length of the bullet due to the swaging of the jackets and or lead tips.
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I was like you when i started seating bullets for the first time. They are correct. Bullet manufacturing gives for a 15 thou + or -.
What I normally do is figure out what the specs call for the bullets overall length, and find one that matches in my batch. Set your bullet seater to that one and then just seat the rest.
But eventually, I think a bullet comparitor would be the best way to squeeze more accuracy out of our loads.
What I normally do is figure out what the specs call for the bullets overall length, and find one that matches in my batch. Set your bullet seater to that one and then just seat the rest.
But eventually, I think a bullet comparitor would be the best way to squeeze more accuracy out of our loads.
- Location
- Coquitlam, BC
Get some Redding comp dies, you won't be sorry 
(Wallet might be though )
(Wallet might be though )
How else are you going to determine your overall length? You measure as you are setting up your die for the seating depth you want. Start long and work down to your optimal OAL. Once your die is set you should not have to bugger around with it.
You stated you wanted a 3.25 C.O.A.L.
Since your bullets tips will vary in length, you will never get a consistent measurement off the tip.
Here is is how I determine my seating depth:
I take a bullet and hold it to the lands with a handgun cleaning rod (you can use a pencil a stick or your ##### if you want
), I then put my cleaning rod down the bore until it touches the bullet, I mark my rod at the muzzle, remove the bullet and put the bolt in. I then push the cleaning rod to the face of the bolt and mark the rod again. This gives me the distance to the lands with ONLY that bullet. I then use my seater to seat the same bullet until I have the same measurement as the marks on my rod. This is where the comparator comes into play, Let's say the bullet I just seated gives an overall length (base of case to bullet tip) of 3.75
I can then measure that dummy round with my comparator and since the comparator measures off the ogive you will get a true and proper measurement of your OAL. Let's say the Comparator measurement is 3.45
Now, if you know that your optimal OAL is .020 off the lands you can seat your bullets .020 deeper into the case than the dummy round to an OAL of 3.25 measured with the comparator. You subsequent rounds will (or should) measure within .0005 of that number if your dies are set up properly etc...
If you load 5 rounds, all checked with the comparator to within that .0005, and then measure the same 5 rounds with your normal tip to base method you will probably find that .010-.015 difference again, but you can be assured that the ogive is in the same place on all 5 rounds and only the extruded tip/lead tip is causing the difference.
Hope this explains it for you.
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If you know a gunsmith who fits custom barrels you can get a quality cmparator tool for free.
They often cut a piece off the muzle end of a new barrel. Target rifle barrels usually have an inch cut off because the last inch is bell mouthed. Take one of these pieces and ask him to run a chambering reamer into one end of it so the stub has a bit of a chamber throat.
This piece is now a "hat" that can sit on a loaded round. Since it is sitting on the bullet ogive, it will give a OAL based on bullet ogive, not the bullet tip.
If you find your rifle shoot best with a particular bullet with a OAL of 3.45 (while wearing the hat) then you can find the same effective seating depth with an entirely differently shaped bullet.
They often cut a piece off the muzle end of a new barrel. Target rifle barrels usually have an inch cut off because the last inch is bell mouthed. Take one of these pieces and ask him to run a chambering reamer into one end of it so the stub has a bit of a chamber throat.
This piece is now a "hat" that can sit on a loaded round. Since it is sitting on the bullet ogive, it will give a OAL based on bullet ogive, not the bullet tip.
If you find your rifle shoot best with a particular bullet with a OAL of 3.45 (while wearing the hat) then you can find the same effective seating depth with an entirely differently shaped bullet.
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