Question regarding freebore length options when chambering a new barrel

[Gregor.Samsa]

Fellas,

I'm proactively shopping for a new prefit barrel for my Tikka in anticipation of heavy lead times etc. I'm planning on keeping the rifle chambered in 6.5CM as I am set up for reloading dies and consumables. I've seen different options for freebore length and would like to know how these variations affect my situation. Please forgive me for the noob question, just don't want to lay down the cash on an uninformed decision.

Thanks

 

[avidflyer]

Freebore will be based on bullet choice....not 100 percent but a huge factor

 

[Gregor.Samsa]

Freebore will be based on bullet choice....not 100 percent but a huge factor

Thanks, Like everyone else, I've been shooting 140 ELDMs and 140 hybrids. I still have a stash and hope the supply opens back up in the future. What is a favorable freebore for these bullets? My current barrel favors .030-.035" jump with what I'm assuming is a SAAMI chamber. I haven't measured the distance to the lands for a while and assume a new barrel may be completely different anyways.

 

[Steel head]

Once long oal AI mags came into being I started running more freebore in my 260 chambers.
That’s something you should definitely explore with the shorter 6.5CM if you want some added speed.

You can pretty easily mock up some simple tools to see how freebore works with various bullets from hunting to target.

 

[Gregor.Samsa]

Once long oal AI mags came into being I started running more freebore in my 260 chambers.
That’s something you should definitely explore with the shorter 6.5CM if you want some added speed.

You can pretty easily mock up some simple tools to see how freebore works with various bullets from hunting to target.

Got it. So assuming I max out my COAl based in my magazine, is there a sweet spot for freebies distance? Thanks

 

[Steel head]

Got it. So assuming I max out my COAl based in my magazine, is there a sweet spot for freebies distance? Thanks

It all depends on your wants as well.
A lot of people panic if they’re more than 20 thou from the lands or if the base of the bullet bearing surface is below the shoulder/neck junction on the case.

I generally run a good bit of jump and could care less about that latter.

I shot out 3 barrels before I learned what I wanted to do.

I conversation with a smith with field and competition experience can be pretty enlightening.

 

[Gregor.Samsa]

Too short a freebore and the bullet is eating up case powder capacity. Too long a freebore and you start to run out of neck after 800rds if you want to seat close to the lands. The SAAMI Creed freebore is really long. But you can always jump your bullets. I'm not fluent with 6.5 Creed freebores like I am with other cartridges. I've only loaded for a SAAMI(?)/ Tikka 6.5 C and ended up getting the best accuracy with 140ELDMs close to the lands which had a 2.910" COAL. It was already advanced up the neck. Factory Hornady 140 ELD loads were a 2.890" COAL.

Thanks. I have a tikka ctr. It loves the 140ELDMs as well. I’ve noticed that I can easily exceed the mag’s COAL when jamming into the lands.

 

[AKMarty]

My Tikka was .030” jump new using the Hornady 147 ELDM. Currently at about .107” and still at 1/2 moa. The OACL will be limited by the magazine in the Tikka. Have seen on here where someone notched the bottom of the feed ramp and used different bottom metal to stretch it a little too.