Faster as she goes

[rwintuc]

Hi guys. I am new hear and appreciate the information you share so freely.

I had a question I thought you might be able to answer.

Should a load get faster as the gun gets hotter?

I was testing some new load for .223 Rem and noticed all my loads get faster as I get through the magazine.

For Example:

Nosler BalTip Spitzer 55g
Rem 7 1/2 BR
LC Brass
18" Barrel 1/9 Twist

IMR 4064 25.8g
Shot - Velocity
1- missed by chrono
2- 2854
3- 2830
4- 2930
5- 2902
6- 2863
7- 2897
8- 2925
9- 2925
10- 2861

A trend line on these shots graphed out shows a 23fps increase over the course of ten shots.

Is this Normal?

 

[AJ Peacock]

In general yes, a lot depends on how long the cartridge sits and bakes in the hot chamber. Also, the type of powder will determine how large the difference will be.

AJ

 

[Mikecr]

Every gun I have does it.

 

[rwintuc]

I was alway one who from youth tried to hold for wind and Elevation not understanding what i was doing.

Today i have learned a lot about making true adjustments and holding center and having faith all the work i did to get there will pay off. And it has paid off.

Question - at what change in valocity will i have to start changing my adjustments? or have I already seen the extreams in my testing? ex: Prarie dogs @ 500yd's