Ok I am loading these at 2.236 to ogive. 2.825 oal. This NEW lot has me at 2.813 oal to get 2.236" to ogive. Should I load based on previous loads to ogive. Got a match saturday and need your input
- Thread starter Aimsmall55
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Re: Different shape 175 smk what to do ??
tips will vary, this why we load to the ogive
tips will vary, this why we load to the ogive
Re: Different shape 175 smk what to do ??
Load to the same base to ogive length as the previous load, and you'll be good to go.
There's been no change to the profile or shape here. You're just looking at the differences that occur from lot to lot, and that's perfectly routine. Different batches of gilding metal, varying amounts of lube during the forming stroke will show these types of variations, even if the two lots come off the very same die. Bullet lengths routinely vary by far more than this, based soley on the variables I've mentioned here. It's not a big deal, and loading off the ogive length will resolve all of these issues, no problem.
Load to the same base to ogive length as the previous load, and you'll be good to go.
There's been no change to the profile or shape here. You're just looking at the differences that occur from lot to lot, and that's perfectly routine. Different batches of gilding metal, varying amounts of lube during the forming stroke will show these types of variations, even if the two lots come off the very same die. Bullet lengths routinely vary by far more than this, based soley on the variables I've mentioned here. It's not a big deal, and loading off the ogive length will resolve all of these issues, no problem.
Re: Different shape 175 smk what to do ??
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kevin Thomas</div><div class="ubbcode-body">Load to the same base to ogive length as the previous load, and you'll be good to go.
There's been no change to the profile or shape here. You're just looking at the differences that occur from lot to lot, and that's perfectly routine. Different batches of gilding metal, varying amounts of lube during the forming stroke will show these types of variations, even if the two lots come off the very same die. Bullet lengths routinely vary by far more than this, based soley on the variables I've mentioned here. It's not a big deal, and loading off the ogive length will resolve all of these issues, no problem.</div></div>
You were exactly correct. Proven today at 520 yards. Thanks for your advice.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kevin Thomas</div><div class="ubbcode-body">Load to the same base to ogive length as the previous load, and you'll be good to go.
There's been no change to the profile or shape here. You're just looking at the differences that occur from lot to lot, and that's perfectly routine. Different batches of gilding metal, varying amounts of lube during the forming stroke will show these types of variations, even if the two lots come off the very same die. Bullet lengths routinely vary by far more than this, based soley on the variables I've mentioned here. It's not a big deal, and loading off the ogive length will resolve all of these issues, no problem.</div></div>
You were exactly correct. Proven today at 520 yards. Thanks for your advice.
Re: Different shape 175 smk what to do ??
I've fired about 7500 of the 175s out of my 308 over the last 3 or 4 years, and obviously, those bullets came from many, many different lot numbers. I never once adjusted my seating die, nor cared to.
I agree that "best practice" is to adjust as necessary to keep the cartridge length from casehead to ogive the same, but I think the .308" 175smk simply doesn't care, because I've never had any issue whatsoever not bothering to adjust.
I've fired about 7500 of the 175s out of my 308 over the last 3 or 4 years, and obviously, those bullets came from many, many different lot numbers. I never once adjusted my seating die, nor cared to.
I agree that "best practice" is to adjust as necessary to keep the cartridge length from casehead to ogive the same, but I think the .308" 175smk simply doesn't care, because I've never had any issue whatsoever not bothering to adjust.
Re: Different shape 175 smk what to do ??
Let's think, rather than just play with numbers from a measuring device.
One lot has OAL 2.825
Another has 2.813 with the same load-to-ogive seating.
2.825 - 2.813 = .012. of an INCH.
Now LOOK at a .012 gap on your calipers or micrometer, and consider whether that magnitude of difference on the least-critical axis of a loaded round will really make much of a difference.
Let's think, rather than just play with numbers from a measuring device.
One lot has OAL 2.825
Another has 2.813 with the same load-to-ogive seating.
2.825 - 2.813 = .012. of an INCH.
Now LOOK at a .012 gap on your calipers or micrometer, and consider whether that magnitude of difference on the least-critical axis of a loaded round will really make much of a difference.
Re: Different shape 175 smk what to do ??
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Grump</div><div class="ubbcode-body">Let's think, rather than just play with numbers from a measuring device.
One lot has OAL 2.825
Another has 2.813 with the same load-to-ogive seating.
2.825 - 2.813 = .012. of an INCH.
Now LOOK at a .012 gap on your calipers or micrometer, and consider wheth
er that magnitude of difference on the least-critical axis of a loaded round will
really make much of a difference.</div></div>
If you will look 2 posts above I posted that it did not make any difference. Was just asking bc I am shooting in a 600 yard br match Saturday and I wanted to make sure. I went and shot at 520 yesterday and the dope was the same.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Grump</div><div class="ubbcode-body">Let's think, rather than just play with numbers from a measuring device.
One lot has OAL 2.825
Another has 2.813 with the same load-to-ogive seating.
2.825 - 2.813 = .012. of an INCH.
Now LOOK at a .012 gap on your calipers or micrometer, and consider wheth
er that magnitude of difference on the least-critical axis of a loaded round will
really make much of a difference.</div></div>
If you will look 2 posts above I posted that it did not make any difference. Was just asking bc I am shooting in a 600 yard br match Saturday and I wanted to make sure. I went and shot at 520 yesterday and the dope was the same.
M
milo 2.0
Guest
Re: Different shape 175 smk what to do ??
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Aimsmall55</div><div class="ubbcode-body">
If you will look 2 posts above I posted that it did not make any difference. Was just asking bc I am shooting in a 600 yard br match Saturday and I wanted to make sure. I went and shot at 520 yesterday and the dope was the same. </div></div>
I'd consider myself lucky if I were you.
I'd bought 1k Berger 175XLD's for 7mm Saum in 2010, then this spring bought 1k more. When I got into them, my load pressured up, after multiple cleanings and bore scoping tube, finally measured the bullet. It had ".020" more bearing surface than the old ones.
So I lost over 200fps with it, it is still deadly accurate, and I have 300 more of them to shoot. But I would entertain the notion of going to church on Sundays if I could get my velocity back.
I'll switch to the 180gr Hybrid when their gone.
I had almost the same experience with Hornady's .224 68gr HPBT. I bought 5 boxes to try, liked them, so I bought a 4600 count box. They came with a cannelure, total different bullet shape ,they shoot ok, but I had to drop 1 full grain of powder to get them in the safe range.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Aimsmall55</div><div class="ubbcode-body">
If you will look 2 posts above I posted that it did not make any difference. Was just asking bc I am shooting in a 600 yard br match Saturday and I wanted to make sure. I went and shot at 520 yesterday and the dope was the same. </div></div>
I'd consider myself lucky if I were you.
I'd bought 1k Berger 175XLD's for 7mm Saum in 2010, then this spring bought 1k more. When I got into them, my load pressured up, after multiple cleanings and bore scoping tube, finally measured the bullet. It had ".020" more bearing surface than the old ones.
So I lost over 200fps with it, it is still deadly accurate, and I have 300 more of them to shoot. But I would entertain the notion of going to church on Sundays if I could get my velocity back.
I'll switch to the 180gr Hybrid when their gone.
I had almost the same experience with Hornady's .224 68gr HPBT. I bought 5 boxes to try, liked them, so I bought a 4600 count box. They came with a cannelure, total different bullet shape ,they shoot ok, but I had to drop 1 full grain of powder to get them in the safe range.
Re: Different shape 175 smk what to do ??
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.
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.
Re: Different shape 175 smk what to do ??
Thanks Kevin. Your advice is greatly appreciated. Nice to have a few folks on the hide give their knowledge in a way that doesn't make the op feel like an idiot. For the most part everybody is nice but their are a few.........
Thanks Kevin. Your advice is greatly appreciated. Nice to have a few folks on the hide give their knowledge in a way that doesn't make the op feel like an idiot. For the most part everybody is nice but their are a few.........
Re: Different shape 175 smk what to do ??
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kevin Thomas</div><div class="ubbcode-body"> Bullet lengths routinely vary by far more than this, based soley on the variables I've mentioned here. It's not a big deal, and loading off the ogive length will resolve all of these issues, no problem. </div></div>
If you are using a seater die that seats by contacting the bullet close to the ogive it pretty much eliminates the error in bullet lengths.
Measure finished rounds using a comparator on the caliper. If case head to ogive measurements are consistent, shoot em
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kevin Thomas</div><div class="ubbcode-body"> Bullet lengths routinely vary by far more than this, based soley on the variables I've mentioned here. It's not a big deal, and loading off the ogive length will resolve all of these issues, no problem. </div></div>
If you are using a seater die that seats by contacting the bullet close to the ogive it pretty much eliminates the error in bullet lengths.
Measure finished rounds using a comparator on the caliper. If case head to ogive measurements are consistent, shoot em
Re: Different shape 175 smk what to do ??
No problem at all, and glad to share. Spent more than a few years there, and know those bullets inside and out. Lots of interesting stuff to be told, since most shooters never get to see the operations that go into these things.
Glad to help.
No problem at all, and glad to share. Spent more than a few years there, and know those bullets inside and out. Lots of interesting stuff to be told, since most shooters never get to see the operations that go into these things.
Glad to help.
Re: Different shape 175 smk what to do ??
AimSmall and Milo-2:
Bearing length is indeed a different animal than just the OAL of the bullet. Bearing surface is quite critical and I'm not surprised at Milo-2's experience.
It would be quite interesting to gather some data points from others and compare them with how QuickLOAD predicts changes in bearing length. I know that with the mathematical modeling used, there is a ridiculous level of almost-meaningless "measurement" of very small changes in parameters like seating depth at .005.
I might be able to get some by comparing Hornady 55-gr FMJBTs with those from Sierra. The Sierras have a longer boat-tail = more intrusion into powder space at cannelure seating, but also shorter OAL at that seating, AND a shorter bearing surface than the Hornadys. That could count as two or three variables, depending on how one analyzes it...
But I'm interested more in SHOOTING right now, than writing down more chrono data. With a new .223/5.56 in the house, THAT has led to more load development...
AimSmall and Milo-2:
Bearing length is indeed a different animal than just the OAL of the bullet. Bearing surface is quite critical and I'm not surprised at Milo-2's experience.
It would be quite interesting to gather some data points from others and compare them with how QuickLOAD predicts changes in bearing length. I know that with the mathematical modeling used, there is a ridiculous level of almost-meaningless "measurement" of very small changes in parameters like seating depth at .005.
I might be able to get some by comparing Hornady 55-gr FMJBTs with those from Sierra. The Sierras have a longer boat-tail = more intrusion into powder space at cannelure seating, but also shorter OAL at that seating, AND a shorter bearing surface than the Hornadys. That could count as two or three variables, depending on how one analyzes it...
But I'm interested more in SHOOTING right now, than writing down more chrono data. With a new .223/5.56 in the house, THAT has led to more load development...
Re: Different shape 175 smk what to do ??
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Deadshot2</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kevin Thomas</div><div class="ubbcode-body"> Bullet lengths routinely vary by far more than this, based soley on the variables I've mentioned here. It's not a big deal, and loading off the ogive length will resolve all of these issues, no problem. </div></div>
If you are using a seater die that seats by contacting the bullet close to the ogive it pretty much eliminates the error in bullet lengths.
Measure finished rounds using a comparator on the caliper. If case head to ogive measurements are consistent, shoot em </div></div>
That's exactly what I'm doing. Using a hornady comparator locked on to my caliper that is giving me my readings to ogive. Thanks for the advice though.
I shot yesterday at 520 yards with this new lot and #'s are the same on dope. 4" 17 shot group on a 5" circle painted on ar500 plate with 15 to 20 mph wind. It was TOUGH but I made my notes and feel really good about the match on saturday
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Deadshot2</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kevin Thomas</div><div class="ubbcode-body"> Bullet lengths routinely vary by far more than this, based soley on the variables I've mentioned here. It's not a big deal, and loading off the ogive length will resolve all of these issues, no problem. </div></div>
If you are using a seater die that seats by contacting the bullet close to the ogive it pretty much eliminates the error in bullet lengths.
Measure finished rounds using a comparator on the caliper. If case head to ogive measurements are consistent, shoot em
That's exactly what I'm doing. Using a hornady comparator locked on to my caliper that is giving me my readings to ogive. Thanks for the advice though.
I shot yesterday at 520 yards with this new lot and #'s are the same on dope. 4" 17 shot group on a 5" circle painted on ar500 plate with 15 to 20 mph wind. It was TOUGH but I made my notes and feel really good about the match on saturday
Re: Different shape 175 smk what to do ??
I should mention that I found an awesome new powder. 2000 mr by alliant. 48.0 with lapua brass and fgm210m is giving me 2755 fps out of a 22" bartlein. Gap crusader. No op what so ever. Guys with 28" are shooting the 185 juggernauts at over 2800. Hauling ass if you ask me.
I should mention that I found an awesome new powder. 2000 mr by alliant. 48.0 with lapua brass and fgm210m is giving me 2755 fps out of a 22" bartlein. Gap crusader. No op what so ever. Guys with 28" are shooting the 185 juggernauts at over 2800. Hauling ass if you ask me.
