Reloading .308 with 175gr SMK. Using my Wilson hex comparator I get a spread of about .005" in the cartridge length from one reloaded case to another. Is this consistent enough for a weekend plinker of am I doing something wrong?
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Length to Ogive - What's consistent enough"?
- Thread starter 03psd
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Im not sure about how the hex comparator works, I dont see it on their website, but if its a comparator it should be measuring off the ogive and not the over all length. If thats true of your hex then .005 of ogive variation is a bit more than I would like to see. Might take the seating stem out and see if you match king is able to go all the way up into it or if the bullet tip bottoms out on the seating stem before the stem contacts the bullet the entire way around. If thats not true and it actually does the over all length then .005 doesnt seem to be so bad, especially for plinking.
Edit: I found a sinclair hex tool thats similar to what I think you might be describing. [IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/cdn-us-cf2.yottaa.net\/53ff2f503c881650e20004c9\/www.brownells.com\/v~13.79\/userdocs\/products\/p_749002942_1.jpg?yocs=p_&yoloc=us"}[/IMG2]
So with this you would put it on the bullet of a loaded round and then measure both with your calipers and would provide you a ogive measurement. If that measurement is .005 in variation then you might want to figure out if its the bullet thats out or if its the seating of the bullet. But it should still be just fine for plinking.
Edit: I found a sinclair hex tool thats similar to what I think you might be describing. [IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/cdn-us-cf2.yottaa.net\/53ff2f503c881650e20004c9\/www.brownells.com\/v~13.79\/userdocs\/products\/p_749002942_1.jpg?yocs=p_&yoloc=us"}[/IMG2]
So with this you would put it on the bullet of a loaded round and then measure both with your calipers and would provide you a ogive measurement. If that measurement is .005 in variation then you might want to figure out if its the bullet thats out or if its the seating of the bullet. But it should still be just fine for plinking.
yes, that's the comparator. I measured it's width (.9990), zeroed my calipers and then inserted the loaded round in the hole marked 30 and measured from the case bottom to the top of the comparitor. This gives ogive length. I'm using a forster micrometer die for the first time. I followed the direction installing it in my turret press but I still think it might be too far in.
I'm actually looking at one for a caliber in which my barrel hasn't come in for yet so I haven't used it but it appears from the instructions that you need to use the hard stop of your press so you need to have enough wiggle room for that. If you're compressing the sleeve entirely maybe that's leading to the discrepancy in depth?
Have you measured just the bullets to see if they themselves are the sorce of the discrepancy?
Have you measured just the bullets to see if they themselves are the sorce of the discrepancy?
@03,
First, .005" of difference is meaningless given your stated goal of weekend plinking. I've shot many thousands of the 175 smk from a .308 and you will never shoot the difference being +/-.0025
Second, there is a chance your measurements are not all exactly accurate. I've tried the tool pictured above and I found it awkward and slightly difficult to be consistent. Most around here use the Hornady or Sinclair bullet comparator that attach to your calipers; they're much easier to use.
But, don't go looking for problems where none exist, the Forster seating die is outstanding.
First, .005" of difference is meaningless given your stated goal of weekend plinking. I've shot many thousands of the 175 smk from a .308 and you will never shoot the difference being +/-.0025
Second, there is a chance your measurements are not all exactly accurate. I've tried the tool pictured above and I found it awkward and slightly difficult to be consistent. Most around here use the Hornady or Sinclair bullet comparator that attach to your calipers; they're much easier to use.
But, don't go looking for problems where none exist, the Forster seating die is outstanding.
Many thanks for the response. Yes it is very awkward trying to hold the round with the comparator on it with the calipers spread open very wide. I've seen the ones that attach to the calipers, it's on my list.
for shits and giggles I measured several loaded rounds using the comparator then measured them COAL to see how inexact the bullet tips were manufactured. Amazing. Surprised me. Now I see why coal is a worthless measurement as long as they will fit in the magazine.
.005" is more than I like to see. I'm happy with everything being within .003". I use the Hornady comparator to measure rather than the hex comparator. They clamp on to the jaws of your dial caliper.
Two suggestions though. First, make sure the primer is flush or below the head of the cartridge. If it is even .001" proud, that will make your CBTO measurement that much longer. Second, when seating the bullet, after lowering the press ram, rotate the cartridge 180 degrees and seat it again. If either your shell holder, case head or seating stem is not even, this second press to seat the bullet to its deepest point.
Two suggestions though. First, make sure the primer is flush or below the head of the cartridge. If it is even .001" proud, that will make your CBTO measurement that much longer. Second, when seating the bullet, after lowering the press ram, rotate the cartridge 180 degrees and seat it again. If either your shell holder, case head or seating stem is not even, this second press to seat the bullet to its deepest point.
Excellent suggestions. Thanks. And yes, I ordered a Hornady LnL comparator today with the .308 insert that has the thumbscrew lock for my caliper
I've noticed that seating the round twice seems to help with the consistency also, that's a good point rotating the round...I'll have to try that.
Usually when you have excessive differences in seating = your seating die needs a good cleaning from top to bottom.... and don't underestimate running the handle / ram consistently
i had a lot of 140 ELDs recently that the base of the bullet to the ogive varied up to 6 thou. It was throwing my seating depth all over the place and thats what i narrowed it down to. Make sure to check the consistency of your bullet itself.
This made no sense to me a few years ago but now through first hand experience I couldnt agree more. Still don't fully understand it but it's a cause and effect.
I find .002 to .003 to be the norm with SMK's and they have at least that much variance in their ogives min to max. When I first began reloading it really bothered me and I began sorting my bullets by weight and ogive. I got some very consistent OAL's that way but found that it made no discernible difference in accuracy. I also grew tired of having about 8-10 piles of sorted bullets. Too many other factors that really made a difference in accuracy became my focus. I do appreciate the very consistent bullets from Lapua and a couple others, though - one less variable to worry about. When you get lucky - as that is all I can attribute it to - you get a barrel that is not fussy. It shoots everything okay and some are just stellar. Those are the barrels that are easy to reload for without getting hung up in minutiae. That's my .002...
... and stop using stainless tumbling media.
Can you elaborate? I anneal after every firing but use stainless media and haven't experienced an issue
Not trying to pick here, but I do not understand how varying bullet base to ogive measurements will give you a different cartridge base to ogive measurement. You should be seating them using a seating die that is roughly close to ogive and measuring them with a comparitor that usually sits close to the ogive on a bullet.
nice article. im not quite chasing 1/4" groups yet but I might try the rice for removing my lube after sizing since I have 2 vibrating cleaners sitting idle. Did you use any case cleaner in the rice or just dry rice? also the article states 1 type of rice didnt clog the flash holes barely at all. What kind was that? If I have to unplug 95% of the cases, I likely wont use the rice method.
I only picked some up last week to try out so I cant offer a corrobatory report on it just yet. Its here linked in his article but heres the link https://www.amazon.com/Nishiki-Prem...&linkId=e52cda36b4680a5901276fe430b0749f&th=1
Its like the bottom right. Its thicker than the normal thin grain on the top row but not as fat as the bottom left arborio rice. It like like a nice mix between being too big to fit in flash holes but not so large that it wont get into the cases.
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Its like the bottom right. Its thicker than the normal thin grain on the top row but not as fat as the bottom left arborio rice. It like like a nice mix between being too big to fit in flash holes but not so large that it wont get into the cases.
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I only picked some up last week to try out so I cant offer a corrobatory report on it just yet. Its here linked in his article but heres the link https://www.amazon.com/Nishiki-Prem...&linkId=e52cda36b4680a5901276fe430b0749f&th=1
Its like the bottom right. Its thicker than the normal thin grain on the top row but not as fat as the bottom left arborio rice. It like like a nice mix between being too big to fit in flash holes but not so large that it wont get into the cases.
Great pictures and explanation of the rice!
I now know more about rice than I ever thought I wanted. Still, good information Spife.
I wonder if Nikishi execs are noticing an odd spike in their product sales in the despicable part of America.
I wonder if Nikishi execs are noticing an odd spike in their product sales in the despicable part of America.
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Yeah, but you didn't answer my question about dry or with added case cleaner mixed in?
if the ogive of the bullet varies, the seating die will either push the bullet into the case more, or less, depending if the ogive is higher up or lower on the bullet.
Which would change the amount of bullet "inside" the case... but what lash is saying is that you can't detect bullet bearing length variation by measuring base of the cartridge to ogive. The die is going to contact the bullet significantly above the ogive, and is going to seat it as consistently as the setup will allow from that contact point to the cartridge base contact point on the shell holder or ram of the press. Bullet variation can be measured with two comparators, on the bullet alone, as it pertains to bearing length... or from the base of the bullet to the ogive as well as OAL. However, once the bullet is seated in a case, that ability is gone.
Yes, but is your seating die not catching the bullet very closely to where the ogive is? Is you comparitor not measuring from roughly where the ogive is? I can see how this would make the COAL vary accordingly, but if you are measuring Length of cartridge base to ogive, then your measurement is not comparing how deeply seated the bullet is compared to COAL, it is comparing how deeply seated they are with respect to the ogive. The ogive itself will be relatively in the same place every time with respect to the base of the cartridge.
i dont ever measure COAL, i only measure base to ogive. My seating die seats a bit away from the ogive, i've not found a seating die that seats at the same place my comparator measures. I know that this is caused by variances in the ogive on the bullet because if i sort the bullets by base of bullet to ogive, i can seat the bullets at the same depth without touching my die and and get the same result every time. However as soon as i introduce a bullet that does not measure the same, i had to adjust my seating die to get the same seating depth.
Okay, that makes sense. If the ogives were varying by as much as 0.006", then how much did that variation affect your Base-to-ogive legnth? Was it a direct correlation?
it was always very close. Since the seating die doesn't seat in the exact place the comparator takes a measurement, there is some margin or error.
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