Ogive Jam Length

[Wayne Powell]

Over the past three months or so, I have measured the jam length of three different rifles chambered in 223 Remington. In each case a 69 grain Nosler CC bullet was used along with the same measuring devices. The results were as follows:


1) Savage 12 FV Jam length: 1.948"


2) Savage Axis Jam Length: 1.927"


3) Savage 12 FV Jam length: 1.948"


I was surprised that Rifles 1 & 3 measured identically. Then I started to be concerned that they all should measure the same. It appears that the Axis has a little less free bore than the Savage FV 12 rifles. Anyone see any concerns?

[Cmgoff]

Do all three have the same rate of twist in the rifling? I would expect 1 and 3 to have a faster twist to accommodate new heavy bullets. Gun number 2 may be an older gun with a slower twist meant for lighter bullets. Generally speaking, the heavier the bullet the longer thus requiring more freebore and faster twist.


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[Wayne Powell]

Good thought but all rifles are new within 9 months and have the same twist. Rifles 2 and 3 bought within 6 months of each other.

[schnyd112]

I would check headspace on the axis and make sure all three are close enough to each other. . If they are not, I would start collecting brass for the short one and keeping it separate from the others.

[Deadshot2]

I would check headspace on the axis and make sure all three are close enough to each other. . If they are not, I would start collecting brass for the short one and keeping it separate from the others.

Or have a gunsmith use a throating tool and match #2 to #1 and #3.

Difference may also be due to throat angle.

[tcoz]

Maybe I'm missing something here but I'm confused as to why a Savage Axis should have the same jam length as a Savage 12FV. Everything looks fine to me.