Custom Barrel jump to lands

[tim tarras]

I am getting ready to purchase a 257 Roberts AI barrel on a tikka action from Preferred Barrels. I have everything determined except for the jump from dummy round, 117gr LRX, to the lands. I was thinking of having it set at 0.050".

This going to be the first custom barrel I have ordered and want to get it right. I want to leave myself options if I want to shoot heavier or lighter bullets and not be too close or too far from the lands.

Any help in this is greatly appreciated.

TIA

Dummy round

 

[D@l@N]

My preferred barrel shoots excellent, but it is finicky on load and seating depth. Took a lot of work to get it dial but now it’s a tack driver!

 

[Sadie]

I always want to be able to seat bullets with bearing surface above the neck shoulder juncture to eliminate possible donut problems. I don't own any tikkas but assume you have plenty of magazine length. It looks to me like you are throating for pretty much the longest 117gr bullet out there which might take away seating options with lighter cup and core bullets if the rifle wants closer to the lands seating. I don't know your use intentions but if it was my personal rifle I would question if I really need a 117gr all copper bullet. Don't know your accuracy requirements, lighter bullets hopefully will shoot well with the long throat. My match grade stainless barrels end up at about $800 fitted I always hope they will handle at least a few bullets well. Just my thoughts and experiences. Good luck with it.

 

[tim tarras]

I always want to be able to seat bullets with bearing surface above the neck shoulder juncture to eliminate possible donut problems. I don't own any tikkas but assume you have plenty of magazine length. It looks to me like you are throating for pretty much the longest 117gr bullet out there which might take away seating options with lighter cup and core bullets if the rifle wants closer to the lands seating. I don't know your use intentions but if it was my personal rifle I would question if I really need a 117gr all copper bullet. Don't know your accuracy requirements, lighter bullets hopefully will shoot well with the long throat. My match grade stainless barrels end up at about $800 fitted I always hope they will handle at least a few bullets well. Just my thoughts and experiences. Good luck with it.

The rifle is going to be used for hunting 200-300 yards and practicing out to 500-600 yards. I have purchased a long action magazine and a Long action bolt stop. I have moved away from the cup and core as I have not liked how much meat loss I have had.

 

[tim tarras]

I called Preferred and left a message and emailed them but haven't heard back about if using a 257 Roberts case for the dummy round instead of an AI case would make a difference in the chambering. I am sure it won't but want to confirm.

 

[Harvey_NW]

Pretty much exactly what I do. If you have a couple different bullets you want to shoot, keep bearing surface lengths in mind. Otherwise, I just load the bullet I want to start with and eyeball it with calipers so the bottom edge of bearing surface/boat tail is about .050-.060" above the neck shoulder junction of the brass, and tell the gunsmith to make that "touch". I'd definitely rather have more jump than have the bullet stuffed deep in the case, but I also don't believe seating depth makes a difference in precision so I don't fiddle with that.