Bullet Lot to Lot Uniformity

[wIg SpLiTtEr]

Do you guys mix bullet lots when reloading for accuracy? I have Sierra 6mm 95gr BTHP and Hornady 9mm 115gr FMJ-RN in particular. I had quite a few boxes before the panic and just got a couple hundred more in of each. What do y'all recommend?

Thanks

 

[Wildwillalaska]

Re: Bullet Lot to Lot Uniformity

I think it depends but you really have to compare to know. I had a few hundred 178 amax that were older to some I recently added and they were very different even looking at the two seperate lots--and produced .008" difference in ogive legnth.

 

[armorpl8chikn]

Re: Bullet Lot to Lot Uniformity

I would weigh all the 9mm bullets just to make sure.

 

[timelinex]

Re: Bullet Lot to Lot Uniformity

Definitely do NOT mix lots. So far I have changed lots on both my 338 and 308. For both of them, I did not have to change my load. I did need to change the setting on my seating die to seat it to the same length.

However even though my load did not need to be changed, both lot changes did change my resulting zero. So I would not mix lots.

 

[wIg SpLiTtEr]

Re: Bullet Lot to Lot Uniformity

I guess I should mention that these lots are a little over a month apart. I was just curios due to the fact that Id think that SMK's would be held to tighter tolerances so to speak being that they are a match bullet. Hell idk, I may end up just considering my 9's as plinking ammo..

Thanks

 

[DocB]

Re: Bullet Lot to Lot Uniformity

Good day,

SMKs can vary 0.020" or more for ogive length in the same box. Sierra says that's within their tolerance spec. Always measure OGL with new lots of any bullet, even if purchased from the same place.

HTH,
DocB

 

[Aimsmall55]

Re: Bullet Lot to Lot Uniformity

Kevin Thomas from lapua helped me.


Aimsmall55,

For what it's worth, all of the SMK bullets are trimmed to within +/- .0015 of one another (total length variance of .003"), and that's a constant length for ALL runs of a given type; 175s, 168s, 155s, whatever. Each of these bullet types has a specific length that they're trimmed to for each and every production run. Not true with spitzer designs, which vary consdierably from run to run, and have no set "standard" to which they're set. In the case of the spitzers, the length is set and adjusted so that the lead and gilding metal meet up precisely when the tips are formed. whatever length is needed to accomplish that is what the trimmers are set for, and the rest of that run will be done to the same length. In the case of the SMKs, there is a set length, and the nose is simply closed up during the final forming operation. In both instances, the amount of movement that the metal undergoes is a variable that has several other factors that go into the final length. With the SMKs, the length of the finished bullet isn't something they pay any attention to; it simply is what it is, and that's fine. As a result, it's not at all uncommon to see SMK bullets varying by .010", .015", .020" or even more from one lot to the next. Many handloaders get worked up over this, but in reality, it makes virtually no difference. It's the ogive we need to pay attention to, not the OAL of the bullet itself. So long as the ogive to rifling relationship (jump) remains constant, whatever difference there is in the bullet's OAL becomes meaningless. Since almost all seating dies seat off the ogive rather than the tip or meplat, it becomes a non-issue. Don't sweat it, you're golden here.

Hope that helps.
_________________________
Kevin Thomas
Lapua USA

 

[DocB]

Re: Bullet Lot to Lot Uniformity

As,

Glad to see you still don't read (and reply correctly) to posts.

Thanks,
DocB

 

[Aimsmall55]

Re: Bullet Lot to Lot Uniformity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DocB</div><div class="ubbcode-body">As,

Glad to see you still don't read (and reply correctly) to posts.

Thanks,
DocB</div></div>

Doc B, glad to see you are still a complete fuck head

No, thank you aimsmall

 

[armorpl8chikn]

Re: Bullet Lot to Lot Uniformity

I am pulling your chain Shoot, I have never heard anyone ask about lot importance on a bullet that will be used at less than 25 yds. So I could not resist jabbing you.
Buy 9mm bullets where and when you can get them then load em and shoot them. You will never know the difference. If you are running a pistol bullet so hot that a tiny difference in length will screw you up then stop that shit.

 

[excaliber]

Re: Bullet Lot to Lot Uniformity

The last 600yd match I shot, I had two different lot# bullets loaded. One lot shot a consistant 1.5"-1.75". The other lot# shot around 2.250" with same lot# brass, powder, and primer. They both were Berger 6mm 105gr bullets. Just shows they are a difference.

 

[wIg SpLiTtEr]

Re: Bullet Lot to Lot Uniformity

Cool, I think I'm just going to weigh the 9's and mix the .243's. I mean, just weigh the .243 and mix the 9's. Fuck, I think I meant, I'll just weight them all. Lol, thanks for the mixed signals guys...

 

[Justshutupnhunt]

Re: Bullet Lot to Lot Uniformity

I've been reloading for quite a while now. Seems to me that Sierra put a date and lot number on their boxes for those that wanted to use the same components ran in the same lot. As time went on Sierra stamped a # lot on the bottom of the boxes. A little later it was back to a hand stamp that looked like it was back in the 60's as i was a kid helping and watching my dad reload. All of this typing just to tell you that everytime you change one varible whether it be a different lot of primers, different lot of brass, or a different lot of bullets your bullet impact can and will change from time to time. If you have a Stoney Point or Hornady OAL guage, check just the bullet to see if it has a different ogive. If it doesn't, reload a small batch and try them to see if the POI has changed. This information back in the late 70's and 80's meant a lot more than what it means to me now for sure. Used a different tool but was the same result. Eyes aren't what they use to be. Hope this helps,

JW

 

[milo 2.0]

Re: Bullet Lot to Lot Uniformity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: excaliber</div><div class="ubbcode-body">The last 600yd match I shot, I had two different lot# bullets loaded. One lot shot a consistant 1.5"-1.75". The other lot# shot around 2.250" with same lot# brass, powder, and primer. They both were Berger 6mm 105gr bullets. Just shows they are a difference. </div></div>
I can relate to excaliber on this. I don't really mess with Sierra, or Hornady for anything but .224 caliber.
But when it comes to Berger, and I'm not bad mouthing them, but do pay attention to lot to lot.
I shoot the 7mm 175 xld bullet, last year I had to replenish my stock, so I bought 1k of them, molyed them up and went to town. Accuracy was great, but pressure ensued, but it took about 200 rds to figure out why, my fault there, but the bullet had .020" more bearing surface than the old ones. They just changed the whole design of the bullet, without publishing it of course.

Then just last fall, a freind who shoots a 300 Norma mag, 230gr Berger hybrids, long story short, 2 diff lots of bullets had ogive diff of ..005" to .007", within limits, but with his Forster seating die, he had diff seating depths of .020". So I moly them up for him, dump them in one big box, which he adds to with his remaining stash, you can see where this is going. Anyway, one day we're shooting at 1450 yards, full size IPSC, and he's shooting a 7 foot group and getting pissed. Now this is a fully custom C Dixon built gun. So I take the gun from him and shoot a 2" at 950 yards, pretty much tell him to shape up! Well back to 1450 and the circle jerk starts agian, shoot, make an adjustment , shoot.

We got to his place afterwards and started looking things over, found the diff seating depth problem. Turns out he never measured for OAL because nobody else touches his stuff, should've been set, and it was for the one lot of bullets. Turns out the 3 I grabbed to shoot must have been the same. He seperatd the bullets and things are ok now. Measures also.

Needless to say, today I measure and inspect every berger that I buy!