Share Your Knowledge and/or Opinion

[CoyoteVision]

Want to know what you think. Not sure the detail matter, but this is 6PPC 68 gr bullet.
Ok- I used the same powder, same load, same bullet and when seated the OAL is identical. The only difference is the brass length. Loaded two sets of five. One of the sets of 5 loaded, the brass was .010" longer than the other. This means that the bullet is seated in the neck .010" deeper.
Shot the first set and all hit dead dot center of the target, shot the second set with the brass was .010" longer and the group moved approx 3/4" higher and to the right approx 1/4".,still aiming center target)

I need to do a real test of which is more accurate but what does this tell me. Is the velocity higher on the second set. I'm trying to understand what is going on. I don't have a chronograph,yet) and don't know anyone who does.

 

[billmo]

Sounds like the cases "Could" be touching in the chamber and increasing pressure. If the cases are too long for the chamber, when you close the bolt, it may be partially crimping the neck. Probably are other opinions but that is the first thing that comes to mind. Bill

 

[outlawsix]

Could it be that the chamber is short enough in the neck area. That when you close the bolt it forces the overlength neck to dig into the bullet more?

What kind of dies are you using to reload? Could that also be happening with the dies? The die tappers to give a firmer bullet hold. The longer the neck, the more taper is being imparted. Thereby creating more neck tension?

Just guessing.

 

[CoyoteVision]

Using Redding Type S Bushing full length sizing die with .258 bushing. Rifle has .262 neck size. Then use Redding Competition Seating Die to seat bullet.

Thanks for the responses and help.
The bullet is seated touching lands and I have very little resistance closing the bolt.

Again thanks....