223 OAL not being consistant

[Ghostmoney]

I am trying to get a good load for my rra predator pursuit rifle. I loaded up three different bullet weights to see what it liked the best. I loaded up a hornady 60gr vmax, sierra 69gr SMK, and a hornady 75 hpbt. With the 60gr vmax I was seating the bullet to 2.260 and out of 25 all of them were between 2.257 and 2.260.
When I switced to the 69gr I was getting between 2.248 and 2.264 I kept trying to adjust the seating and would get to where I was getting 2.260 and I might get two or three at that depth then they would just be all over the place. out of 25 I got only about 8 that were 2.257 and 2.262 the rest were between 2.248 and 2.255. I did notice that with the 25.5 gr of varget I was using that it was just starting to compress the powder. I was thinking that with the bullet being into the powder that this was the cause for the varying OAL?
When I loaded up the 75 gr with 23gr of varget I was getting the same thing. This time though it was not a compressed load so that could not be what was making the oal length change on me. With the 75gr I was getting between 2.378 and 2.390
Anyone have experience with this happening with them?

 

[Varmint Hunter]

I've noticed a few things tbat can cause this inconsistencey.

1. Necks with variable resistence to seating. Could be brass thickness, age, cleanliness, tension, etc

2. Powder column touching the bullet base

3. Bullet seater that is mismatched to the bullet ogive. Bullet tip should not touch seater.

4. Bullets that are poorly manufactured, but this is unlikely.

Just a few things to consider.

 

[Ghostmoney]

Thanks for the reply

1. all brass was brand new winchester. So shouldnt the thickness be pretty much close to the same to not change the OAL so much? If it was the tension or the thickness shouldn't it be as inconsistant with the 60gr vmax's?

2. any tips for this to help with OAL being more consistant

3. How do you know if the seater is mismatched to bullet ogive?

Also how much variance is acceptable before it starts to affect accuracy?

 

[acloco]

Ran into this as well with several flavors of bullets - both plastic tipped and hpbt's.

Ended up drilling the bullet seating stem to allow NO contact with the tip.

On one occasion, I also ended up lapping the bullet seating stem with a bullet....to match the ogive. Otherwise, I ended up with a ring around the ogive of the bullet.

As Varmint Hunter stated, powder column could be the issue as well. A drop tube or longer drop tube can help as well.

 

[Ghostmoney]

acloco
Did drilling out the seating stem and lapping help solve your problem?
I just checked and on a few of the bullets I have a faint ring around the ogive

 

[acloco]

acloco
Did drilling out the seating stem and lapping help solve your problem?
I just checked and on a few of the bullets I have a faint ring around the ogive

Yes, it did...cured the issue 100%.

My bullet seating stem had both issues - tip hitting the pocket, fixed that by making the hole deeper, then found the ogive did not fit the bullet....so...had to lap a bullet into the stem with some compound.

 

[Ghostmoney]

What is the process to lap the bullet into the stem?
If I were to lap the stem to the 69gr bullets would that mean I would have problems if I wanted to load other bullet weights?

 

[acloco]

What is the process to lap the bullet into the stem?
If I were to lap the stem to the 69gr bullets would that mean I would have problems if I wanted to load other bullet weights?

I used some find metal lapping compound (Flitz will work) and a variable speed cordless drill to spin the stem.

As luck would have it, the newly massaged stem works with all the bullets that I have tried...from 40 VMax to 80 gr AMax (including Nosler, Sierra, etc).

 

[Ghostmoney]

Thanks acloco for the help I will give it a try and see if it helps

 

[Tikkamike]

I had that problem with my 243 I was using Lee dies. so I bought RCBS and never had another problem.