Can anyone tell me why they break the edge of the hole in the comparator insert. Is it to not damage the bullet jacket when taking a reading or some other reason? Can anyone tell me their technique on getting a good CONSISTENT reading. I'm feed up with making a correction on my seating die and over shooting the correction I dial in. I'm using a Redding Compitition Seating Die, and constantly over shooting or getting an inconsistent reading and I'm pretty sure its from not getting the bullet in the comparator exactly the same every time. I figure since the die moves a fixed amount determined by the thread pitch that the error point is the comparator. Can I get some education LOL!!
Bullet Comparator question
- Thread starter axarob44
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Your problem with inconsistent seating is likely not the reading from the comparator but, instead, the seating pressure required due to variation of neck tension among the brass you are working. DO you notice that some bullets require more "ass" on the press handle to get them seated? That is what I am talking about. Take a case with, say, only .001 resize and open with .003 or .004 resize. Seat a bullet in each and you will see that these two bullets will not ever be close to the same seating depth.
I'm not saying you're wrong, but I just looked at the seating die and the seating stem sits right under the the shaft from the micrometer top that screws up and down. That shaft contacts the seating stem solidly how could there be any variations with that shaft pushing the stem?
I use a lot of Redding micrometer seating dies. Every single one of them will give inconsistent seating if I don't have neck tension consistent. Also, the stem is not (no matter the die maker) a universal fit for all bullets. I've actually seen seating stems deform from having to much pressure or seating an incompatible bullet shape.
Do you see any ring around the bullet where the seating stem contacts it?
No, no rings or anything. Ok I have some new brass that should be more consistent I hope.
Also, I took the standard seating stem and swapped it for the VLD seater stem because the regular one was bottoming out and wouldn't seat the Berger
Hybrids
The other thing that was making me mad was I already sorted these bullets by ogive and I was still getting missed readings.
Like say I needed to move the bullet in another thousandth and I would dial it and take another reading and it went in two thousandths
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It the copper flexes just .001" different due to neck tension differences, and the seater contacts it at an angle, it makes a big difference in the OAL measured with a comparator. It is a similar reason that small bore diameter increases with throat erosion makes a big difference in the distance to the lands.
.001"/tan(1.5deg)=.038"
That's .038" difference for just eroding .001" off the tapered 1.5 degree face of the lands.
Breaking the edge of a seater or comparator just spreads out the material flex more and reduces that variable.
.001"/tan(1.5deg)=.038"
That's .038" difference for just eroding .001" off the tapered 1.5 degree face of the lands.
Breaking the edge of a seater or comparator just spreads out the material flex more and reduces that variable.
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New brass especially Lapua, will likely make it worse unless you run them thru an expander mandrel and chamfer first to open up the necks. I have found new Lapua brass to be way too tight for bullet seating without any prep.
Also, and this is something that made a very big difference for my measurements, I bought the anvil that Hornady makes so I can assure myself that the case base is perfectly flat and everything is square to the comparator. My readings are much more consistent now.
http://www.sinclairintl.com/reloadi...ase-prod41213.aspx?avs|Manufacturer_1=HORNADY
Yes I already use the anvil from Hornady. I'm using the Sinclair brand comp. inserts if that means anything. Ok, I just got in some new Hornady brass. I didn't want to commit to expensive brass until I have most of the bugs and my in -experience worked out. I was using brass that the necks were all different size (length, I screwed-up trimming). I should be able to get some of this worked out then.
I have been using my LEE collet neck die on fire formed brass. Will I need to full length size this new brass? I will do all the other prep also, I did get a Wilson case trimmer and I have measured my chamber for neck length with a neck guage. I have a Redding full length size die also.
Thank you for the help again!!
I have been using my LEE collet neck die on fire formed brass. Will I need to full length size this new brass? I will do all the other prep also, I did get a Wilson case trimmer and I have measured my chamber for neck length with a neck guage. I have a Redding full length size die also.
Thank you for the help again!!
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In my opinion, and I use both, the Sinclair comparators are better than the Hornady so you are GTG there. That anvil saved a headache for me. They aren't cheap but I own two of them.
On your brass, did you chamfer after trimming? That will make a he difference in bullet seating.
The Lee Collet Die is good stuff once you set it up correctly(something it took me a bit to do) but there is no substitute for using the case body comparators to measure your fired brass and then adjusting the FL die to size (bump) the shoulder back a couple thou. It takes away the dreaded "click" that makes working that bolt difficult. Only using the Collet Die, your brass will get to the point where it will no longer fit properly in your chamber. I use the Collet Die when I happen to have a Redding set that has only a body die for FL sizing. If you FL size and then use the Collet Die you are just over-working the brass and that contributes to work-hardening. That will cause other issues with inconsistency that will drive you insane.
You are very welcome. I don't usually comment on reloading issues unless I actually have working knowledge of what is described in the thread. Forty plus years of reloading and it's still hard for me to "see" in my head what some are trying to describe.
Best of luck with your adventures at the reloading bench.
On your brass, did you chamfer after trimming? That will make a he difference in bullet seating.
The Lee Collet Die is good stuff once you set it up correctly(something it took me a bit to do) but there is no substitute for using the case body comparators to measure your fired brass and then adjusting the FL die to size (bump) the shoulder back a couple thou. It takes away the dreaded "click" that makes working that bolt difficult. Only using the Collet Die, your brass will get to the point where it will no longer fit properly in your chamber. I use the Collet Die when I happen to have a Redding set that has only a body die for FL sizing. If you FL size and then use the Collet Die you are just over-working the brass and that contributes to work-hardening. That will cause other issues with inconsistency that will drive you insane.
You are very welcome. I don't usually comment on reloading issues unless I actually have working knowledge of what is described in the thread. Forty plus years of reloading and it's still hard for me to "see" in my head what some are trying to describe.
Best of luck with your adventures at the reloading bench.
Thank you sir I appreciate it. What happened is I chamfered the case mouths after trimming and I went to far and they got thin and sharp. These were my first go at case prep. I ended up having to trim the neck to get rid of the the very thin brass. They left me with necks all over the place. I am learning and this batch of brass should be better
I guess I didn't realize how small .001" really is and didn't think such a small variation would throw off the measurement. Thank god for smart people! LOL Thank you for the explanation. Even though I really don't understand the math.
D
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I don't get that anal. Measure CBTO with a sample from the same lot and get the SD. Once loaded take another sample, measure OAL off the ogive and get another SD. From that point an acceptable difference would be the results down range. Example, my CBTO SD is .001. My OAL SD off the ogive is .001. This is using a regular vanilla Lee die set. Results down range is .5 moa. I hope people aren't being sold a bill of goods on these fancy dies.
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Wouldn't it make a difference if your load that you worked up was touching the lands or if it was just backed off the lands a small amount? Would it vary the pressure of your load if it was supposed to be touching the lands? In my case thats not a concern because my load uses a considerable jump to the lands.
Would you see a difference down range? I guess I could let be and see what it does, but I get hung up on numbers.
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I have a bunch of new Lapua 308win brass. Using a Redding die, not the comp die, I just charged the cases then seated bullets. They all seated right where I wanted them too.
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First, you tend to complicate things, not that it's bad if you're gaining an understanding.
Second, never try develop a load just touching the lands, too many inconsistencies in the bullet itself to be reliable, either jam .005" or more or jump.
Third, a unless a variance ends up at the lands, a .005" variation in seat depth is not going to do much to your pressure range.
Now let's back up to when you first develop a load on a new chamber, the lead angle going into your lands is as sharp as will ever get. So when you find that magical seat depth, when seating bullets, until you have some minor erosion, going closer to the lands will result in slight inaccuracy, where going into the case .002-004" wont show up as much downrange. Now at 300rds when throat erosion is evident, your leeway expands greatly.
As for the original question, the chamfer on the comparator is most likely to get the bullet started in w/o a cant. One of the best ways to insure consistent seat depths is to run the vld seat stem in that comp seating die you have, even better to seat a bullet with a die the next size up, ( seat 6 creed with a 6.5 creed die), the seat plug or stem grips the bullet farther down the ogive and can only produce better results.
Yeah, I do to tend to complicate things. You're not the first person to tell me that. I guess I just like to know for sure when I get seemingly contradicting information. I think It was in the LEE reloading manual they stated that one of the advantages of seating on the lands was that it kept the start pressure the same between each shot. I read all this stuff I wonder what actually matters and what does not change much. I know if I ask here, someone will know the answer. I hope to not wear out my welcome! I do thank all for the help.
Can anyone recommend a good reloading book that is not a manual per say? I say a couple on Sinclair's website. I was thinking about getting a book by a guy named Glen Zediker., " Hand loading For Competition"?
Can anyone recommend a good reloading book that is not a manual per say? I say a couple on Sinclair's website. I was thinking about getting a book by a guy named Glen Zediker., " Hand loading For Competition"?
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You're fine, lol. That is good book, along with the Lee I think, don't quote me on it. Most manuals give good info, gets redundant though. Separating myths and truths is what it boils down too, but we all came to the same place via a different route. There are 2 types of reloaders, those that speak from experience, and those that repeat what they've heard or read. Spotting the 2nd group easy, because they have the answer to it all, as usual.
axarob44 it is said that some bullets just like being in the lands and shoot best that way. Berger VLDs were given this axiom for years but now, if you read Berger's take on it, Berger says they may be happy anywhere between the lands and fifty thousandths off of the lands. I firmly believe that any bullet that like touching or jam will also shoot well at some other point off the lands. I also believe that for the precision rifle match shooter that being off is far more reliable than being in.
As for what @Milo 2.0 said, I have a short freebore 6.5x47 reamer and decided to monitor the change in throat carefully. To my amazement the lands moved out 18 thousandths within the first 150 shots down the barrel. So, my thinking is that having a fresh chamber will allow for throat lengthening quickly at first and then slow down to a "normal" rate.
As for what @Milo 2.0 said, I have a short freebore 6.5x47 reamer and decided to monitor the change in throat carefully. To my amazement the lands moved out 18 thousandths within the first 150 shots down the barrel. So, my thinking is that having a fresh chamber will allow for throat lengthening quickly at first and then slow down to a "normal" rate.
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