Match grade rifle bullet seating.

C

Chainsaw.

New member
No I don’t necessarily mean seating match grade bullets, I mean seatimg bullets all to a very consistent depth. How must should I tinker with the depth of the bullet from one case to another? I have a ogive measurer (comporator?) so Im not having to measure from bullet tips but I still get varying degree of depth up to about .050. So should I be trying to adjust the die so each bullet/case combo comes out to the same measured OAL or should I just be pressing all the give out of the press and call it good?
 
- is .050 delta measuring on the ogive a typo ? Did you mean .005 ?

I'd have to ask what brand and model seating die and what brand and type bullets, how deep are you seating, fill ratio on the case, are the rpimers seated to a recess when you are measuring etc etc
 
Chainsaw,

Even the best match bullets such as Sierra MatchKings have ogive variances, since they are coming off different machines at the factory. All you can do is find the case base to ogive measurement that places your bullet where you want it to be in regards to your rifle's lands, and don't worry about the OAL variance.

Don
 
Hownddawg. Yes those numbers are correct. That .050is the MAX variance Im getting, most are tighter than that. All measured base of the case to the ogive. Dont know what you mean by delta.

Seatimg die is a lee, I have hornady dies but I REALLY do not care for them.
Seatimg to 2.220 measured base to ogive.
Case fill is maybe 85%
Primers are set properly.

Don thats what Ive been wondering.
 
Back when I first started reloading for AR's I was using a 15 year old Lee Turret with 10's of thousands worth of pistol rounds made on it, Lee dies, and Midway bulk bullets, never got more than .005 difference so I have no clue. That poor old Lee press by that time had so much slop in the linkage it rattled and I am fairly certain the seating die was seating on the meplat. if you are .050 is a lot of variance. I get .001 - .003 variance at the extreme when loading and seating at the range using a Lee hand press and a good seating die

I would start by checking to see if the die seating stem is seating on the meplat or the ogive. I just measured half a dozen Sierra 80's most difference was .002 on the meplat. Since a press will always stop at top dead center on the ram stroke the issue is either die, the bullet consistency or operator error
 
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You don't mention if the bullet tips are mis-shaped/crushed after seating but I had a problem with a LEE seating die for my 204R. Called Lee and they recommended I drill out the seater plug a bit using a common drill bit to allow for variances in bullet construction. Solved my problem. Might try that, or try cleaning the seater die, might be some crud in there. GL
 
Chainsaw,

Is there any chance this is a highly compressed load? Often, those will push a bullet back out.

If that's not the case, then the only explanations that occur to me are:
  • The seating die's little stem is not in the same place each time (remove the top plug and check for debris).
  • You aren't getting the press ram all the way up each time (you'd be surprised how common this is).
  • You've got some wrong bullets mixed into the box or are using cheap bullets for which lots have been mixed.
I once measured a sample of 15 Sierra 150-grain .308 MatchKings each from the base of the bullet to the ogive point of contact with a comparator and got an extreme spread of 0.008", or ±0.004" from the mean and a standard deviation of about 0.0025". So I would not be surprised to see as much as about 0.010".

The thing to start with is what I did there: Use your comparator to measure each bullet base-to-ogive length and make sure they don't span more than about 0.010". If they are OK, one of the other factors is involved. If they are not OK, you've got an issue with your bullet supplier or with a gremlin.
 
What bullets are you using . Max. .050 is alot for base to ogive measurement , A compressed load I also would think could be the cause but he listed 85% of the case is full, I would guess to the shoulder height . Still don't know what bullets being used .
 
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Ah! I see that now. Not sure why it didn't register. So, it's one of the others things going on unless his bullet is very long and shoving way deep in. It would help to know the cartridge, bullet, and powder and powder charge weight.
 
I agree as well that .050 is way off the charts and something else must be going on . The one thing I'd ask but don't think it should matter as much as .050 is . Where on the ogive is your comparator contacting/stopping on the bullet ? I've found the closer I get the comparator to stop at the full diameter of the bullet the less variance I tend to have .
 
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