Measuring bullets..... Splitting hairs?

I have read about some people that want to make the most accurate hand loads measure thier bullets.
How many of you do that? I tried it to see how it would turn out. I purchased a box of 100 Sierra .277 135 gr. SMK and I measured them using a comparitor on the ogive. This is how it turned out:

0.639 = 18
0.636 = 13
0.635 = 15
0.634 = 64
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total of 100

Do you think the difference in lenght would really make a difference in grouping out to say 400 yds?
Do you think this is a big waste of time? I have never done this before and am wanting to get the best results.

Thanks,
Mike

Different bullet lengths at ogive will give you different seating depths. If you seat bullets to give you an exact distance to lands or jam into the lands, if the bullets are not the same length you will get variances. These differences can and will show up on target. I'm not sure a difference of .001 will show at 300-400 yards. The only way to find out is load em up and shoot them. When I was using the .308 Win in my 12 FTR the lengths of 168 and 175 SMK's, and 168 Hornady BTHP would vary as much as .012. Some boxes had 3 sorts. I use the 105 Hornady Amax in my Dasher and they have been extremely consistant and I check the OAL and adjust my Forster Mic seater as I load them. I have buddies who use Bergers and say they don't have to measure them. This issue has been cussed and discussed many times on many forums. I believe in a rifle used for match shooting it is good to do. As always other opinions may vary. Luckus

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How consistent do you guys find the Amax in general

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Better than the Sierras but not quite as good as any of the Norma Golden target bullets I have loaded.

I'll echo Luckus here, and just add that whether or not it is a waste of time can really only be determined by you. Are you going to be competing with these loads? How much do you value your time vs the tiny improvement in consistency you're likely to realize from bullet sorting?



BTW, when I add up the bullet counts in the 2nd column I get a total of 112.

Typicaly in a box of 100 Sierra's you will find 2 diferent ogives, sometime you get lucky and just find one. I think your measurements might bee a slight bit off, as measuring bullets is not the easiest thing to do, you need to wiggle them in the compairator to get them to seat into the device, I am willing to bet if you did you would find that all of them bullets measure the same, it is very hard to accuratly measure .001 diference. What I typical find in a box is more than half will measure one ogive, and the rest will measure a diferent ogive. For example I will find half that will measure .635, and the rest will measure .641. With that said out of what you have measured I would lump togeather the .634, .635, and .636, and maybe segregate .639. Measuring bullet take a bit of feel and when you get it down, you can blaze through a box of 100 in a couple of minutes.

You ask does this make a diference, you better believe it, and it will show up with a distance of a 100 yards, getting the bullets at the same seating depth is crutial. Now granted most shooters would never know the diference, unless the are consistantly shooting groups under .3 area. At longer distances it shows up more, but again the average shooter would probly never notice.

I does take some time doing it, to measure consistently and accurately. Like 82boy says you have bottom it out consistently in the nut every time to get it right.

I should have asked this on the previous post. How consistent do you guys find the Amax in general. (all diameters)

I agree that it takes some time to measure consistanly. This was the first time I have done this but could tell some measured differently. I will only be shooting these for fun and to get trigger time. I do want them to be consistant as possible. I do scale every powder charge. I loaded 30 rounds, half with IMR 4895 & half with IMR 4064 as I already had them on hand. I will be using CCI BR primers and seating 10 thousandth of the lands to start. If those powder do not work well I will purchase some IMR 4350 as it seems to be one of the more popular powder for the .270. I know the .270 is not one of the popular calibers for precision shooting but I thought I would see how well I could do with it.
I also have a box of Hornady 140 SST & 150 SST to play with after I see what the 135 SMK will do....
Thanks to all for your input, keep it coming!!! Your input will help all that read it :victorious:

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Originally Posted by Luckus

Different bullet lengths at ogive will give you different seating depths. If you seat bullets to give you an exact distance to lands or jam into the lands, if the bullets are not the same length you will get variances. These differences can and will show up on target.

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Just want to point out that if the bullets are measured with a comparator and there are different measurements, those differences will more than likely not affect the "jump" or "jam". The variances will be how much of the bullet is seated into the case. Even if the bullet had a huge difference of say... 0.1" it would still be seated to the same base to ogive length (jump would stay the same).

This is of course assuming that the difference in lengths is caused by a shorter bearing surface or boat tail section. If the difference is caused by a difference in the ogive shape then yes, it could possibly affect the jump.

This is not typical of Sierra but I once had a box of 500 130gr SMKs with 3 distinct sets of lengths. The difference between each set was 0.020". From the shortest to the longest was almost 0.050" !!! That was nuts. I still have some of that box left that I need to test on paper one of these days to see the effect of sorted versus mixed. I had shot half the box before I measured them but I used them for offhand Metallic Silhouette so there would be virtually no way for me to tell how much downrange effect there was. Maybe I'll load them up and test them. Sierra assured me that those should have never left the factory, and to their defense I haven't had that occur again.

Typically people that sort bullets sort them by the bearing surface, not the base to ogive measurement. The bearing surface is going to have the greatest effect on variances in velocity and accuracy. If there is .005" difference in the boat tail length how much will that affect groups? Probably not as much as a .005" difference in the bearing surface. To check this on boat tail bullets you need two comparators.

I just did some bullet and loaded round measuring in 308 Winchester. New Lapua brass, Sierra 175gr HPBT Match #2275.
All cases 2.009 long. Bullet #1, .588 long with sinclair nut,#2, .5925 long, and 3, .564 long. Press is a Redding T7 with Forster Mic seater. All bullets seated without any changing of seater setting and full stroke of the press handle. .588 bullet seated at 3.146 oal with nut, .5925 bullet seated at 3.1435, and .564 bullet seated at 3.114. As I stated all measurements are using a Sinclair nut.
Overall length to bullet tips, #1=2.795. #2=2.7925, #3=2.790. This proves to me that different bullet lengths using the ogive to base measurement does cause different lengths of loaded rounds, and hence jump or jam.

WOW! I have not measured to the tips and I guess I don't have the tools to do it properly. I will be loading the same thing next, after I to try the 168 SMK I have ready to go.
Thanks for posting the info for all to see!

Mike

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Originally Posted by Luckus

I just did some bullet and loaded round measuring in 308 Winchester. New Lapua brass, Sierra 175gr HPBT Match #2275.
All cases 2.009 long. Bullet #1, .588 long with sinclair nut,#2, .5925 long, and 3, .564 long. Press is a Redding T7 with Forster Mic seater. All bullets seated without any changing of seater setting and full stroke of the press handle. .588 bullet seated at 3.146 oal with nut, .5925 bullet seated at 3.1435, and .564 bullet seated at 3.114. As I stated all measurements are using a Sinclair nut.
Overall length to bullet tips, #1=2.795. #2=2.7925, #3=2.790. This proves to me that different bullet lengths using the ogive to base measurement does cause different lengths of loaded rounds, and hence jump or jam.

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Call me a skeptic, but you only measured 3 bullets/loads. That isn't enough to prove anything. Do this 10, 20 or 30 times and you'll have something.

Also, you have (ordered in descending order of bullet length):
.592" - 3.143"
.588" - 3.146"
.564" - 3.114"

There isn't any correlation there as to bullet length and loaded length. If there was a correlation you would expect the loaded lengths to follow the pattern of the size of the bullet. Your .592 bullet is actually loaded shorter than your .588 bullet, but the opposite is true between your .588 and .564 bullets.

Looking at your variances in loaded lengths I would suspect that the tips of your bullets are hitting the inside of your seater stem before it contacts the ogive. I've had to drill out some seater plugs so that the seater plug would go down on the bullet far enough to FULLY engage the ogive instead of touching the tip of the bullet. It takes very little contact to throw this off. Search the net, it isn't uncommon.

I know I can understand about the seater plug. When I loaded the .308 135 SMK the tip was so long and pointed there is no way the plug hit the ogive. Can a person purchase different seater plugs? I don't have the tools needed to properly drill out a seater plug.

Good post, Thank you!
Mike

I took the die apart, jammed the bullets into the seater stem, spun them hard enough to engrave the lower bell of the stem on the bullet, they engraved nicely, stuck a wire down to the base of the seater and checked clearance, looks like about .200 clearance. The bullets are not bottoming out on the tip. Look, I know it seems illogical, and at first glance looks impossible, but its true. I suggest you try it on 500 bullet lengths and see what you come up with.

Over the past few years I have measured a few thousand bullets and loaded rounds. I think 2 that are different in coal would be enough to prove a point. I did 3 the other day just to show what can and does happen. If you are using VLD's you may or may not have a seating stem issue. I urge you to do some measuring like myself and others have done and see what your results are. It proves some bullets are inconsistant and it will affect jump or jam. Let us know what you find. Luckus

oneshot57: If you think that measuring bullets might be splitting hairs then you should go and take a look at the 6br forum. They are the biggest pack of anal reloaders that I have ever seen. They will go on and on and on about the pickest subject on loading. One person said that he has a scientific scale and weighs out his primers and seperates them to 1/100 of a grain. He dose not even target shoot but shoots praire gophers. He got upset when I asked him why he did not pull the anvils out of the primers and seperate them by weight.

To each thier own.... That's too funny !

I have watched guys at matches open a new box of bullets,throw a load in, seat the new bullets and shoot a clean target, no measuring, no weighting,no nothing.
Me I sit home and measure till I'm almost blind,double weigh all my charges and measure every round-still don't shoot clean idk.
I have done the measuring & weighting process and all I can say from my own experience is that when I go through all the extra steps my loads are +/- .001 in length when I just load with out it my loads are uasually +/- .002-3 is that realy going to make a difference at 100-200 yards IDK but I know I can't see it when I shoot.
My loading process takes me around 3 hours for 50 rounds and that is with out running cases through the cleaner.
Mabe I am chasing after an elusive goal trying to shoot a Savage against all these customs but I am having a good time trying, although it sure is getting expensive with all this load developement for 4 different rifles, not counting the hunting guns and the ones used just for range play.

oneshot, here is a similar and just as interesting thread on this subject: http://www.savageshooters.com/showth...+seating+depth

Best wishes and good luck!

John_M
Thank you for letting us know about that thread. It was very informative. I believe I will be sorting my bullets from now on. I noticed it did make a difference in the base to ogive lenght on tonights loading sesion. That should give a better jump consistency.

Thanks to all for the input, let's keep this going!