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Seating depth question

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17 April 2002, 03:11
<Kentucky Fisherman>
Seating depth question
I was seating some .243 bullets last night and ran into an anomaly that has me a little baffled. Hopefully someone here can help.

I was loading 75gr Hornady V-maxes, using a Forster micrometer seating die that I've had for 2-3 months. I haven't verified it for certain sure, but I believe the seating stem is bearing on the ogive and not seating the bullet from the plastic tip. After seating a bullet, I'm checking the depth with a Stoney Point comparator.

I love the Forster seating die and most of my bullets last night were seating right on the money, give or take maybe 2 thou. That amount of slop is acceptable to me at this point, especially given that I'm using a Lee Turret Press that has some flex (slop) in it.

Anyway, I had this one bullet/brass combo that seated about 5-6 thou shorter than the rest. I pulled the bullet and tried again, with the same result. I guess at that point I should have measured just the naked bullet to see if it differed from the rest, but I didn't think to do that. I just tossed the short round in with the rest, since I'm only shooting them at 100 yards from a factory gun. I've shot some other rounds at this seating depth and noticed no measurable difference.

But now I'm curious why that one load kept coming up short. Even if that particular bullet was short, shouldn't the overall length of the loaded round come out right anyway? If the ogive were shaped a bit funky on the bullet, could that the answer? Inquiring minds want to know what you think.


17 April 2002, 03:32
Bigdaddytacp
quote:
Originally posted by Kentucky Fisherman:
I was seating some .243 bullets last night and ran into an anomaly that has me a little baffled. Hopefully someone here can help.

I was loading 75gr Hornady V-maxes, using a Forster micrometer seating die that I've had for 2-3 months. I haven't verified it for certain sure, but I believe the seating stem is bearing on the ogive and not seating the bullet from the plastic tip. After seating a bullet, I'm checking the depth with a Stoney Point comparator.

I love the Forster seating die and most of my bullets last night were seating right on the money, give or take maybe 2 thou. That amount of slop is acceptable to me at this point, especially given that I'm using a Lee Turret Press that has some flex (slop) in it.

Anyway, I had this one bullet/brass combo that seated about 5-6 thou shorter than the rest. I pulled the bullet and tried again, with the same result. I guess at that point I should have measured just the naked bullet to see if it differed from the rest, but I didn't think to do that. I just tossed the short round in with the rest, since I'm only shooting them at 100 yards from a factory gun. I've shot some other rounds at this seating depth and noticed no measurable difference.

But now I'm curious why that one load kept coming up short. Even if that particular bullet was short, shouldn't the overall length of the loaded round come out right anyway? If the ogive were shaped a bit funky on the bullet, could that the answer? Inquiring minds want to know what you think.


The Forster is a good seater and you are right about checking the stem of the seater to make sure the tipof the bullet isn't touching and there isn't debris in the stem.....clean it with solvent and OOOsteel wool if necessary.....a LONGER bullet makes for a shorter round with a comparator and even the best bullet makers make a booboo...technical term....good luck and good shooting!!


17 April 2002, 07:15
DB Bill
It should be bearing on the ogive and not the tip when it is working correctly.
17 April 2002, 10:17
<green 788>
You mention that it was a bullet brass combo that caused short seating. I take this to mean that you were using a different type of brass with this load. It could be that the case head has some difference which is causing the case to reach further into the seating die.

Try seating one of these bullets into a case of another type and see what happens.

green 788

17 April 2002, 13:31
<KentuckyFisherman>
All I meant, Green, was that this particular bullet and this particular case kept seating shorter than the rest. But you're right that one test would have been to try the bullet with a different hull. My assumption was that something -- ogive shape, length, etc. -- was wrong with the bullet. It never occurred to me that the difference might somehow be in the brass.

So, what you're saying is that if the case head wasn't flat, had a high spot, it might cause the brass to sit higher in the shellholder, thus seating the bullet a few thou deeper in the case. Sounds like something that could happen. I may have to go back and measure 30 or so loaded rounds to find that short one and do some more analysis of it.

Thanks.