new to reloading, seating depth 6br?

marlin1895gs

marlin1895gs

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ok im gunna sound a bit like an idiot. but im seating my 105 gr match king into my lapua brass for an overall length of 2.4409 as per 6br.com diagram.. but they wont chamber without pushing on the bolt a fair bit... then i pop em out and they shortened up to about 2.316 or something like that. i realize that heavier bullets are essentially longer bullets and that they will need to be seated further in the case, and often they say seat them so they 'jam' into the rifling lands .01 or .02 or something like that. but wont it just push it back into the case due to no crimping? oh yeah its new brass measures 1.55 or so, should be seating the bullet that same, 2.316 or whatever it seems to be? the empty brass falls into the chamber with no problems, my norma brass i have doesn't, i dont know why, but my lapua brass does no problems, and these rounds, after they've been pushed in once, go again, no problems, no markings on the brass near the rim or anything. thanks guys
 
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So seat to 2.316 then. Then get yourself a bullet comparator and the Stoney Point seating depth gauge. Chamber dimensions will vary so you may not be able to seat out as far as you want. I seat my 6BR with a 20 thous jam, I have never measured the overall length as I am more concerned with where the bullet ogive is in relation to the lands and am single feeding. What make of bbl and what gun is it on? How were your groups?
 
Do you have an adjustable bullet seating depth gauge like forester ultra Mic seater or Redding Mic? If so go to home depot, Walmart, etc and buy a sharpie metallic silver marker. Start off by Seating the bullet long or @ least what you think is long. Color the bullet with the marker, wait till it dries for a few seconds, then chamber the dummy round but go easy when you extract the dummy round. Look @ the colored bullet for rifling marks, Keep seating the bullet in deeper until you don't see any marks. That will be your zero point, then you can jam or jump however many thou you wish. Its a good idea after each time you reseat the bullet; to wipe off the old silver color and apply a new coat. Use this inexpensive trick, it works. no need for any fancy gizmos or trinkets. Enjoy. :)
 
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yeah, i have the fancy redding one. i can see the rifling marks on them without the marker, but i'll definitely try that for clarity. a good place to start would be 'zero' right, basicaly touching without jamming any? no gap either. am i correct? im gunna prime a few here and give 'em a try
 
marlin1895gs said:
yeah, i have the fancy redding one. i can see the rifling marks on them without the marker, but i'll definitely try that for clarity. a good place to start would be 'zero' right, basicaly touching without jamming any? no gap either. am i correct? im gunna prime a few here and give 'em a try
Click to expand...

Yup, you got the basic idea. Be safe and Have fun. :)
 
Seating depth with the 6BR is the holy grail of accuracy!

Lacking fancy tools, your method of locating "jam" is going to work... What you want to establish is not the OAL, but at what depth does your bullet just touches the lands in the barrel and your seating die will act sort of like a bastardized "comparator" (I would highly recommend a micrometer seating die such as Redding's)

A "Comparator" does not measure the length from tip of the bullet to base of the case, it measures the length from the base to the "Ogive", or curved part of the bullet. This measurement is far more consistent from one bullet to the next. OAL will be enough to get you in the right ball park for now though...


Anyway, Radical's technique will work to help confirm when you have seated a bullet so that it is just touching the lands... Once you're there, leave your seating die alone!!!!


From there, Load of a few rounds with 30 grains of Varget and seat bullets to the lands as per your test.

Load a few more except seat the bullets 5/1000" longer, load a few that are 10/1000 longer than that, 15/1000 and 20/1000th of an inch. Remember to keep these different loads separate so you know which ones work when you group test.

I think you will find that the best accuracy will come from the bullets seated 10 - 20 thou into the lands. I have owned many and all of them like 105's jammed into the lands.
 
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The best

way I have found yet to find the point where the bullet is just engaging the lands is this. Seat a bullet into a case and then use a bullet puller to remove the bullet from the case. Reseat it and remove it again. This will open up he neck slightly so that the bullet is not held very tightly. Seat it long and then shine it up with 0000 steel wool. No fancy pen or marker required. Chamber it and see how much of a mark appears on the bullet. If it is long re adjust your die and seat it slightly deeper. Eject round to see what the mark looks like. Keep doing this until you make a decision as to what you would say is the just starting to touch the lands mark is. I should mention this works best with the extractor plunger and spring removed. This is where a Stoney Poing or now known as Hornady bullet comparator comes into play. Measure the round and record the measurement. You now only have two ways to go deeper into the lands or further away from the lands.

Hope this makes sense.

The bottom line is OAL length of a reloaded round is not reliable. A comparator of some sort is required to be more accurate. Bullets vary to much in length to get a consistent reading from the tip.

Hope this makes sense.


Calvin
 
And you can smoke the bullet with a match or lighter... leave a little soot on it and you can see the rifling "hits"... if the shine is too hard to see...
 
I'm definitely gonna go out and buy a bullet puller and some steel wool instead of using that fancy $1.25 marker. Can't wait to remove my extractor and ejector. Seems like a hot ticket. Thanks Calvin:), Respekt
 
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thanks for the help guys. i did make it out yesterday, loaded a few that, as far as i could tell just barely touched the lands. pretty accurate measurment eh :) haha. um, without a proper bag or anything i had 5 shots at about an inch. not bad for the first few rounds, and my very first reloads in my opinion. now where do those titanium nitride bushings go in this whole operation is my next question..?
 
The bushings

go inside the sizing die. Loosen the locking nut that holds the top portion of the die secure. Unscrew the black knurled knob out all the way until it is free from the other half of the die. Drop the appropriate sized bushing thru the opening in the top with number side up. Screw down the top portion of the die until it jams against the bushing. Ever so slightly back the top portion out just enough so that when the lock nut is tightened to jam and you shake the die back and forth you hear the bushing rattling around inside. You are now set. You want the bushing loose so it centers itself on the neck of the case.

Hope it makes sense.


Calvin
 
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