Seating Depth and Accuracy?

FOTIS

Range Officer
Staff member
Oct 30, 2004
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What increments do you guys use when looking for accuracy?
 
I always start long and push in by 0.010" at a time until I find a happy spot. Sometimes magazine length dictates my starting length and sometimes the lands do. If the rifle or bullet likes on the lands, then I jam in 0.005" at a time. Depends on the rifle. :grin: :grin:
 
I usually make my starting point @ .015 off the lands.....I try not to get closer than .010, but will work either direction of that by .005
 
Well I try to go as long as I can or up to .010" in my hunting rifles. If I'm working on a targer load I will load at the lands, .005" off, and .015" off. If the farthest load off shoots the best I'll work up more loads seated deeper in .015" chuncks. Most of my hunting rifles I can't get close to the lands. My 338 WM with 225 AB is .105" off, and it is as long as I can fit in the box.

Once I find a load that shoots good I'll load up a batch (usually 3) of the load that shot good and three .005" longer and three more .005" shorter just to see if I can fine tune it. Might be overdoing it but I love shooting so it works out pretty good :lol:
 
Like GB, my COAL is dictated by the rifle magazine length. If magazine length is not an issue, and the bullet has tangent ogive, I will start at .010. For secant ogives and VLD's, I seat the bullet touching the land as long as it group well. If not, I'll move it at .005 incrementally.
 
Most rifles I've had, I've been able to load to reach the lands and still use as a repeater. I start at the lands and move in .010" If your not able to do that, then your limited by magazine length.

I've noticed with some bullets, inparticula spitzer type and VLD/ SMK's that its very hard to get the exact measurement everytime to the .000" or even .0001" for that matter, on a caliper anyways. Plastic tip bullets just seem to be less of a problem when really trying to fine tune on seating depth.
 
remingtonman_25_06":d01hn7r9 said:
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I've noticed with some bullets, in particula spitzer type and VLD/ SMK's that its very hard to get the exact measurement everytime to the .000" or even .0001" for that matter, on a caliper anyways. Plastic tip bullets just seem to be less of a problem when really trying to fine tune on seating depth.

I just had that problem with the VLD's tonight! Drove me nuts! I was using redding dies and I felt that when lowering the ram the bullet would get stuck in the seater, almost like a suction cup.

I HATE THAT!!!!!!!!!!!!!! Any fixes?
 
this might seem really odd to you guys:

I use a dillon for all my reloading
when seating bullets in precision rifle loads, I DON NOT use a shellplate (shell holder)
I feel it helps with concentricity as the case is free to float and find it's center instead of being forced to a pre-determined center.

I dont have a guage, but I do roll them on a mirror for visual inspection.
I'd appreciate any + or - comments on this procedure, but for now back to my point........

Without the shell plate to "pull" the case out of the seating die, gravity lets the case down. Which makes evident whether or not the slug is sticking in the die...... that tells me how clean or dirty the seating die is and I can remedy with alcohol and a q-tip. Any sort of lube just equates to more frequent cleanings as well as inconsistent COAL.
 
Some die mfg make seating stems escpecially for vlds. I know hornady does as I have a couple. Re seating depth. I've always liked to hang em out near clip length...especially in wby rifles. I had a 300 wby I just couldn't get to shoot till I moved em back about .100". (takes the sexy look away from the cartridge but we're after sexy on the target I guess)
FWIW I sometimes find that when a rifle likes a certain "jump" to the lands with one bullet it often likes it with another. I have one of the sinclair "nuts" with caliber specifice holes drilled on ea flat. I record the "jump" on all loadings besides the oal so that if/when I stumble onto that magic length I can load others to that length and hopefully get "like" results.
I've read that most "accuracy depth nodes" are about .030" wide. So I move around when testing by about .025" when experiementing with seat depth. Works for me but maybe not others.
 
Typically start at touching the lands and work "away" in .020 - .025 increments out to 0.100. Then fine tune from those results. If nothing shows up, go farther. I have found the "sweet spot" to be as far out as 0.140..

I find that working in those broad increments allows me to drill down faster to the sweet spot than say 0.10.

Now the above is all based on standard bullets. I'll approach it differently with match grade or custom bullets. I will also approach it differently with the specific throating of a barrel. However, the above works as a general rule of thumb for me..

just my 0.02

Rod
 
POP":3pw37qbj said:
remingtonman_25_06":3pw37qbj said:
...............................
I've noticed with some bullets, in particula spitzer type and VLD/ SMK's that its very hard to get the exact measurement everytime to the .000" or even .0001" for that matter, on a caliper anyways. Plastic tip bullets just seem to be less of a problem when really trying to fine tune on seating depth.

I just had that problem with the VLD's tonight! Drove me nuts! I was using redding dies and I felt that when lowering the ram the bullet would get stuck in the seater, almost like a suction cup.

I HATE THAT!!!!!!!!!!!!!! Any fixes?


I had the same problem using redding dies in my 30-06ai while seating 180 AB's. It left a ring on the bullet also.
I took the seater plug out and chucked it up in my cordless drill and polished it with a piece of 600 grit until the problem went away.
 
Somewhere, sometime in the past someone suggested starting out one tenth of a caliber from the lands. I do that and play plus and minus in .003" increments. Seems to work.
 
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