I am a new reloader...one of the questions that has come up, is what is the best place to start when building a new load as far as the overall length of the cartridge? So far I have just been settign them to the maximum COAL as set out by the reloading manual...but obviosly different bullet shapes means that different bullets must be seated to different depths.(Example would be 50 grn. Bergers vs. 50 grn Vmax in my .223) I have been told to try to seat the bullets closer to the lands...what is the best way to measure that length?
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Over all Length?
- Thread starter Xs24-7
- Start date
Start at the start....Determine your max length to the lands with the bullet you are going to use, in YOUR rifle.....Max COAL is a SAAMI guideline so that the cartridge loaded to that length will fit every rifle chambered to that cartridge. It has no bearing on YOUR rifle.
Determine what your rifles max COAL is, then go from there.
And to do that, seat a bullet in a sized case, close to what you think it might be, (but long), cover it with black marker down to the neck, and chamber it. (The cartrige of course being not primed, and not charged with powder). Feel for resistance as you close the bolt. You are just looking for the lightest of marks on the bullet when you close and lock the bolt. If the bullet is seated too long it might engage the lands and pull out when you extract the case. This will show up if you colored all the way to the neck by there not being marker all the way down to the neck anymore. Or the bullet will not be in the case anymore. (tap it out with a cleaning rod.) Easy Breezey.
Determine what your rifles max COAL is, then go from there.
And to do that, seat a bullet in a sized case, close to what you think it might be, (but long), cover it with black marker down to the neck, and chamber it. (The cartrige of course being not primed, and not charged with powder). Feel for resistance as you close the bolt. You are just looking for the lightest of marks on the bullet when you close and lock the bolt. If the bullet is seated too long it might engage the lands and pull out when you extract the case. This will show up if you colored all the way to the neck by there not being marker all the way down to the neck anymore. Or the bullet will not be in the case anymore. (tap it out with a cleaning rod.) Easy Breezey.
You need an OAL gauge and a bullet comparator
The one I have is made by stoney point however I believe it is now made by Hornady and called :Lock-N-LoadTM O.A.L. Gauges
. It measures the distance to the lands.
The comparator fits on to your calipers. It allows you to measure from the base of the case to the furthest point on the bullet that is still thick enough to engage the lands.
Using these two devices you can seat to an relativly exact distance from the lands and do this with bullets of different profiles.
The one I have is made by stoney point however I believe it is now made by Hornady and called :Lock-N-LoadTM O.A.L. Gauges
. It measures the distance to the lands.
The comparator fits on to your calipers. It allows you to measure from the base of the case to the furthest point on the bullet that is still thick enough to engage the lands.
Using these two devices you can seat to an relativly exact distance from the lands and do this with bullets of different profiles.
You need an OAL gauge and a bullet comparator
Actually you don't need either.
1.I use a case fired in the gun,but not sized.
2.I put a dent in the neck so that a bullet can barely be pushed into the case with my fingers.
3.I barely start a bullet into the case.
4.I carefully chamber this dummy round and slowly close the bolt.
5.I carefully remove the dummy round and measure the overall length.
6.I repeat steps 3 through 5 several times until I obtain the same results several times.
7.You now have the overall length to the lands with that particular bullet.
You are correct you do not need either. You could use that method to find the distance to the lands however minus the comparator you need to do the whole darn thing again with a different bullet. If you have the comparator with either method you just need to get the measurement once.
They are only about $20. I use the chrome looking one from Sinclair. It works great and does a whole bunch of cal's
They are only about $20. I use the chrome looking one from Sinclair. It works great and does a whole bunch of cal's
OK...so once I know what length hits my lands, how far should I back off that measurement to start with?
Depends....Moly coated bullets? Or naked? Already have a load figured out for pressure? I start less than 5 thou off, but I run moly.
And this is assuming that you don't have some other constraint completely unrelated to the chamber, such as are you using a magazine that limits your COAL? Do the loaded cartridges eject through the loading port?
My 223AI won't eject loaded cartridges through the port when I use VMax's, however they are incredibly accurate, so I can put up with that.
