I am just starting load development on my 6.5 creed and 140 RDFs. I have read a rule of thumb that your bullet should be seated at least one caliber depth into the case, in order for me to do this the bullet jumps 100 thou to the lands, is there any negatives to this? my accuracy was great so thats not an issue.
To much bullet jump? and case neck seating depth.
- Thread starter Camoman1
- Start date
I guess it depends on whether or not the accuracy you are getting is the best the rifle can give.
Not only that, some rifles don't really care how far the bullet is seated off the lands. This has a lot to do with the tolerances in the chamber. I have a Tikka T3 in 6.5x55 with a factory chamber and it could care less how far the bullet needs to jump to get to the lands. It shoots everything from 85 grain to 160 grain bullets better than I can hold, even from a rest. If the groups are larger than the normal half inch, it's my fault.
That rifle is an anomaly in my safe. I have a 7x57 that behaves similarly but isn't so forgiving with heavier bullets. The twist rate is to slow. The others in the safe like to be close to the lands, some only shoot really well with the bullet touching the lands.
One caliber is a holdover from many decades back when long heavy for caliber bullets were the norm. The necks were also usually very long and the reasoning behind that was that the neck would hold the bullet straight until it entered the lands far enough so that the bullets wouldn't cant.
I don't have any issues with seating bullets further out, with less than one caliber being held. Some cartridges such as the 300 Savag, 7 Ultra Mag and 7.62x39 have necks that are shorter than one caliber.
Just make sure there is enough neck tension to hold the bullet straight while feeding it into the chamber and if your chamber tolerances are tight enough, all should be well with less than one caliber seating.
Not only that, some rifles don't really care how far the bullet is seated off the lands. This has a lot to do with the tolerances in the chamber. I have a Tikka T3 in 6.5x55 with a factory chamber and it could care less how far the bullet needs to jump to get to the lands. It shoots everything from 85 grain to 160 grain bullets better than I can hold, even from a rest. If the groups are larger than the normal half inch, it's my fault.
That rifle is an anomaly in my safe. I have a 7x57 that behaves similarly but isn't so forgiving with heavier bullets. The twist rate is to slow. The others in the safe like to be close to the lands, some only shoot really well with the bullet touching the lands.
One caliber is a holdover from many decades back when long heavy for caliber bullets were the norm. The necks were also usually very long and the reasoning behind that was that the neck would hold the bullet straight until it entered the lands far enough so that the bullets wouldn't cant.
I don't have any issues with seating bullets further out, with less than one caliber being held. Some cartridges such as the 300 Savag, 7 Ultra Mag and 7.62x39 have necks that are shorter than one caliber.
Just make sure there is enough neck tension to hold the bullet straight while feeding it into the chamber and if your chamber tolerances are tight enough, all should be well with less than one caliber seating.
Okay thanks. The accuracy was good, 41 and 42 g H4350 were about .55" and it was quite windy. After playing with powder charges I'll play with seating depths a bit. So far this gun has been good with anything I put down the barrel.
Just pretend you have a Weatherby rifle with a long throat and don't drink too much coffee. 
My .223 Savage/Stevens 200 has a longer throat than AR15 rifles and shoots small groups. (when I don't drink too much coffee)
My .223 Savage/Stevens 200 has a longer throat than AR15 rifles and shoots small groups. (when I don't drink too much coffee)
As you change seating depth, your powder charge will need to be tweaked as well. I've found adjusting powder charge 0.1gr for every .010" change in seating depth keeps you on node. So if you're shooting 42grs @ .100" jump, try 42.2grs @ .120" off, or 41.8grs @ .080" jump
- Location
- Saskatchewan
If your accuracy is OK why worry? I have a couple of 7x64 rifles that have such long throats that light for caliber bullets aren't in the case at all before they touch rifling. They shoot accurately.
Just wanted to see if there were any negative or even positive effects.
isn't it the other way around?
I remember Litz saying you need more powder when seating the bullet long
I don’t have those bullets, but that seems off.
Speaking of factory ammo; I picked up a pile of .300 WSM awhile ago because it was cheaper than the empty brass. Not that there was any brass in stock anyway.
To shorten up the story a bit, much of it was Winchester Power-point 150s and shot 3 1/2 to 4" at 100 meters. Pure crap right? I wouldn't waste the barrel shooting more of that. Anyway; I pulled one down and determined that in factory form there was a .100" jump to the lands. I bumped a box worth ahead with an inertia puller and reseated them .010" off the lands. Guess what? That box averaged 1 MOA, with no other changes. All of a sudden it wasn't junk.
Although every rifle is a law onto itself, I find that the single biggest factor in accuracy is COAL, with getting the pressure up where it belongs a close second.
With my 270 I noticed a large difference, but it was from 5/8 to about 3” in the areas I tested when working up a load. But I was increasing the jump.
Back to the OP’s question, my 6.5 jumps 0.071”, I’m at mag length, and it shoots there, but if I marked my bullet at .263 and seated it there, my round would look like I had a pencil sticking out of it.
Back to the OP’s question, my 6.5 jumps 0.071”, I’m at mag length, and it shoots there, but if I marked my bullet at .263 and seated it there, my round would look like I had a pencil sticking out of it.
you're right. I must of been multi tasking
