175 Sierra Matchking variable ogives

I am trying out the 175 SMK again after doing a load development last week, they shot well. Made a batch today, after seating a bullet and i checked ogive to check proper settings, it was spot on. Seated a 2nd bullet and checked ogive again, it was off by .008" and I did not readjust the seating die and resumed a 3rd and it was spot on again, 4th one was off .004" and so on. I measured the ogive of each bullet from the box and they measured .641", .644" and .649" out of 25 bullets. There are 3 different lengths and is it normal?

I was thinking to sort each bullet to its own respectable length or is it a waste of my time?

I just got a 500 round batch of the 168's and would it be worth it to sort them by ogive length?

I don't know what Sierra's tolerances are as I don't shoot them, but I'd expect they'd be tighter than that...

Had a box of 147 ELDMs giving me the same fit loading up a set for a match. Started measuring random ones out of the box and got up to .015" variances. Looked in my stash and I still had 6-7 boxes out of the same lot. Opened each box and randomly measured 25 and they all were within Hornadys .003" tolerance claim. Called them up and they replaced the whole lot.

May give Sierra a jingle...

It would surprise me f you see very much difference in shooting those bullets. The ogive on that bullet is friendly, more so than say a VLD bullet.

Give Sierra a call and see what they say https://www.sierrabullets.com/ask-sierra/talk-to-a-tech/

Tack,

How are you measuring the ogive, specifically? From the base of the bullet to the ogive? .008" variance seems huge for measuring a few bullets.

Yes Chad, I am measuring them as you described, even with the hex comparator tool to double check to make sure the Hornady Lock N Load tool is not the issue or the dial caliper. Several bullets came up with those exact numbers and it tickles me that I take my time to anneal my brass, walnut tumble, full size, trim with the Giraud, prep my pockets and case necks/ mouths and weigh to the kernel and at the end I find this crap.

Ok, that's how I would do it also. That's a lot of variance, honestly. But, when you seat the bullet, it's basically being seated from the ogive area of the bullet with the seating die. So, the seating depth should be close, I would think. But the bearing surface of the bullet could also vary. That seems like a lot of variance. The SMK is a good bullet, and easy to get to shoot well. It can certainly shoot tight groups, but I do prefer other bullets.

Just don't get too anal about sorting stuff. I did a test years ago when shooting my 300 WM with 190 SMK at 1000 yards. I shot 2 groups at 1K with my brass that weighed the most and the lightest. I couldn't tell a noticeable difference in the group from any vertical spreads. So I stopped weighing cases and sorting brass out. I felt like I was going crazy with all the sorting and such. I just made sure the powder was spot on, the seating depth was consistent, and my case prep was all the same from case to case. After that, I worked on me as a shooter being consistent. That, IMO, is more important than weight sorting and bullet sorting for a tactical rifle.

Chad, I did some checking, took the die apart to check bullet seat in the seating stem and it rests on the ogive, not the tip. Next thing I did was sort each bullet according to BTO measurement and loaded 20 rounds, perfect and spot on at 2.260" Using the .641" batch, all seated the same. I have another loaded batch with variances in base to ogive and will shoot them to see if it has any effect on accuracy.

Yes, I was going to recommend shooting the different one's to see what difference you see. Shoot them at distance to get a better idea.

Damn, I literally just got a Hornady bullet comparator kit in the mail so I can start measuring to the ogive on my loads instead of the tip. Sure it will be fine, but irritating nonetheless.