Bullet leade

G

GTNMUDY

New member
Just finished reading a article in a gun mag discussing accuracy.

His new rifle (in this case a 300mag), with factory ammo he was grouping 1.25".

He then took some of the factory ammo and pulled the bullet out to lengthen the COL.

These adjusted ammo grouped 25% tighter.

Now I have been reloading for about 40 yrs now and I also have read that bullet leade and be a good thing and a bad thing.

I most often keep to the suggested COL, but some bullets just dont seat properly.

Playing with my AR15, I took a unloaded bullet (no powder) and pulled the bullet out as far as possible (without it falling out of the case) and chambered it. Then took and measured the COL. The COL was longer than specs called for.

I know you dont want the bullet touching the rifleing of the barrel but it was suggested that .010 bullet jump is what you want to end up with for best accuracy (according to the article).

I have read that too small a bullet jump can cause higher CUP pressures.

In the case of a AR15 the overall length can cause issues feeding from the mag.

But I wondering about a single shot bolt.

Any thoughts :confused:
 
Reseating bullets to a longer length may cause high pressure issues due to shorter bullet jump(or even jamming the bullet into the lands). Most factory loads are "at the max" as loaded so messing with them may cause problems.
 
For the AR platform, and anything loaded through a magazine, your pretty much stuck with SAAMI COL.

For the target guys, shooting bolt guns, and loading singly, well, lets just say SAAMI length gets thrown out a lot of times... :rolleyes:

For my bolt guns, I usually find that 0.015" off of the lands, gives me my best accuracy.
For the Savage 7mm Rem Mag that I have, shooting 150gr. Accubond LR, I found that 0.005" off of the lands gives me my best accuracy for that particular bullet/gun combo.

Others have found the same bullet seated 0.060" off of the lands to shoot well.

Just depends on the bullet/powder/gun combo.
 
I agree on the AR platform you are kinda stuck with COL due to the mag design and feeding.

I was just messing around one day when loading some .223.
 
Ah, bullet leade

Ah, bullet leade and my experience with same.

First a bit of history. I'm sure I have used just about every powder, bullet, primer, case, die, tool, etc. Plus reams of information concerning reloading available, in over 50 years of reloading. Some worked, some didn't. COL (cartridge overall length), not COAL ( a black rock like substance that burns), was one which didn't pan out for me.

In the time consuming search for the one hole group bullet leade reared it's ugly head. From angstrom units to millimeters I tried them all. None seemed to work as advertised for me. The one hole group escaped all my efforts. I did however acquire enough powder and bullets to last me for years.

The final COL blow came when after much time spent with other rifles I decided to try it out on my old Remington .270 deer rifle. I decided that maybe it would work with a 150 grain bullet. Loaded up a batch to COL specs. and took it out back for a test drive. Quickly I found out that these rounds couldn't be chambered. Back to the drawing board I went. After some time I finally hit on the problem. The published COL for the 150 grain bullet was 3.285in. and the chamber length on the rifle was 3.160in. from head to lands. 125 thousands too long. I had assumed that published info was correct, it wasn't……… What did I learn after all this? Don't believe everything you read………. To shoot good tight groups the first thing you adjust is the nut behind the butt plate.
 
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