this may seem stupid but loading some 303brit, first I have lots of 30cal .308 projectiles of different weights, I can size the necks by switching the swage from a 3006 die and the fit is good, my question is for a 140grain versus say a 200grain do you mostly seat it to get full contact on the neck length as a rule? this will make the OAL as much as a 5/16 inch between the two weights
seating depth for different projectiles
- Thread starter laurencen
- Start date
length will change from one bullet weight, shape to another. this is normal.
the shape of the bullet changes position of the ogive. some bullets may be longer, and some may be shorter, but both fit and shoot well in the rifle.
The trick is to find where the bullet touches the lands. There are a few tricks to find this length cheaply.
make a bullet way too long and put it into the rifle, get it to push into the lands. Take a cleaning rod and painters tape. push the rod down the barrel until it touches the bullet. mark the rod with tape. Now remove the bullet and make the rod touch the bolt face whent he bolt is completely closed. mark this length with tape.
measure the distance, subtract .020 and that's a great starting point.
you can also buy things like a precision micrometer that will measure this for you.
does this help?
the shape of the bullet changes position of the ogive. some bullets may be longer, and some may be shorter, but both fit and shoot well in the rifle.
The trick is to find where the bullet touches the lands. There are a few tricks to find this length cheaply.
make a bullet way too long and put it into the rifle, get it to push into the lands. Take a cleaning rod and painters tape. push the rod down the barrel until it touches the bullet. mark the rod with tape. Now remove the bullet and make the rod touch the bolt face whent he bolt is completely closed. mark this length with tape.
measure the distance, subtract .020 and that's a great starting point.
you can also buy things like a precision micrometer that will measure this for you.
does this help?
nowarningshot
CGN Ultra frequent flyer
Am i missing something here.....303 is usually between .310 and .314.....not .308. Best slug your barrel, and if you want accuracy, use the right projectile.
Winchester-1897
CGN Ultra frequent flyer
- Location
- Newmarket,Ontario
............
Depending on the groove/bore diameter of that 303, it may or may not shoot those .308 projectiles just fine.
I would slug it first. If groove diameter is larger than .3135, the results will likely be poor.
I have personally shot a number of 220 grain, .308" diameter projectiles out of one of my 303 Brits [P14 @ .3132"] that shot just fine.
You will not know until you try them. However, .311/.312" bullets will probably work best, overall.
Regards, Dave.
I would slug it first. If groove diameter is larger than .3135, the results will likely be poor.
I have personally shot a number of 220 grain, .308" diameter projectiles out of one of my 303 Brits [P14 @ .3132"] that shot just fine.
You will not know until you try them. However, .311/.312" bullets will probably work best, overall.
Regards, Dave.
Of the 4 .303's I've loaded for, 2 of them shot .308" bullets very well. They only had iron sights but there was no discernible difference between .308" and .312" up to 100yds. I wouldn't be using iron sights past that so anything farther is moot for me.
The other two .303's I loaded for were .315"ish and .316"ish and will tumble and keyhole all over with even .3105" bullets.
The other two .303's I loaded for were .315"ish and .316"ish and will tumble and keyhole all over with even .3105" bullets.
