The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Reloading Seating depth of cup and core bulletsGo | New | Find | Notify | Tools | Reply | |
| Seating depth of cup and core bullets | Login/Join |
One of Us |
For a cup and core bullet, specifically a Nosler Partition, what is the most reliable seating depth to start with — 0.020 off the lands? Other??? Then, if tweaking for enhanced accuracy, do you always start with trying less jump? Do you ever find more jump is the ticket (I know monoliths sometimes do)? If so…commonly or uncommonly? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | ||
|
One of Us |
Only your rifle knows the answers to your questions; you will have to load and experiment. I find that some of my rifles like more jump. I do find that solid copper bullets like more jump; .050 or so. I never understood why.... And some don't. But I have 125,000 permutations of calibers and bullets alone; add in an infinite number of seating depths; it can get tedious. Do this; load some just off the lands; shoot; see how you like the accuracy. Also load some .050 off; do the same. Fire and adjust. (A tank gunnery term) I, at this point, would just go hunting because that potential .25MOA difference is not worth the time. | |||
|
| One of Us |
As a rule of thumb when shooting cup and core bullets I like to load .010" off of lands, but sometimes this isn't possible. Sometimes magazine length will limit over all cartridge length, and other times when seated this far out there is not enough bullet neck grip to safely do so. Dennis Life member NRA | |||
|
| one of us |
What dpcd said, and btw a NOsler partition is not a cup and core bullet, its a super premium bullet, and one of the first..the word partition is the first clue.. Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
|
| One of Us |
The magazine limits me to 0.070. Is there really any use to try further off. It is about a 1.5” rifle for me at 0.070 off. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
|
| one of us |
I shot Partition Bullets for years, lately went to copper due to new regulations. They shot well enough in two of my rifles, just barely off the lands. TomP Our country, right or wrong. When right, to be kept right, when wrong to be put right. Carl Schurz (1829 - 1906) | |||
|
| One of Us |
Just a double ended cup with an unbonded core of lead in each. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
|
| One of Us |
yep. it's called the partition because of the H shaped jacket. anyway some rifles just don't like the partition so much and it groups about what your getting. probably shoot something else just fine [@1" at 100] but they may or may not perform as well. or your rifle is like my rem 700 and it just groups everything into 1-1/2"s ain't gonna get no better, and it's consistent. one rifle of mention I had though. an old mossburg 270. it liked it's bullets just about falling in the case short and pushed as hard as you could go. I've never seen a rifle like that, till I got an old 243 that would only shoot 58gr. bullets. that one needs a new barrel, and I figured it did when I bought it. | |||
|
| One of Us |
Yep…this particular rifle shoots Accubonds, BTs, and Partitions all the same - about 1.5 with multiple powders. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
|
| Administrator |
This is something I never really got into. I always seated bullets to the maximum over all cartridge length. Whatever it is specified. Some bullets are too short for this, so I seat them one caliber in. For some hunting rifles, and the bullets I use, this does not work in the magazine. So I seat the bullets so the loaded round fits in the magazine. End of story. I actually went as far as to test seating depth. I think it was a 222 or 223, cannot remember. Same load. Same bullet. I seated the bullets so far out, they actually got seated as I chambered the round. I reduced the seating depth by a few thousand and carried on. Last ones were seated so far down, if one pushes the bullet it would fall in. Not much difference in either velocity or accuracy!!?? | |||
|
| One of Us |
Saeed, Then to tune a load to a rifle you just change powders and then charge weights only? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
|
| one of us |
I've never had much luck with seating bullets out to the lands. To me, it is only a way to make up for poor neck tension. I switched to Lee Factory Crimp Dies years ago and don't really worry much about seating depth. I either seat to the crimping groove or to rec'd OAL if none. I have several old Mauser military sporters with the long leades and can get MOA groups consistently with plain old flat based cup and core bullets that don't come anywhere close to the rifling. Boat tails not so much. The uniformly tight crimps give consistent powder burn so that most loads don't differ more than 15 fps shot to shot. | |||
|
| Administrator |
Yes. | |||
|
| One of Us |
After watching a lot of target shooters on Youtube, I did a seating depth test on one of my rifles the other day. Starting from 0.010" off the lands I increased the seating depth by 0.004". 3 shots per group, 10 groups in all. Groups were shot in a "round robin" fashion so that bore condition would not affect the results. I know the groups should have more shots in them but I currently only have a few cases, and I just wanted an indication of the combination's accuracy potential. Group sizes varied from just over 2MOA (55mm @100M) to just over 0.5MOA (16mm @100m). However, the largest group was the first, and it was the very first shot (thus both clean bore and cold bore, and a different powder than I had used previously) that opened it up, the other two shots were exactly 1/2" apart. On the other hand, the second largest group was 1.5" It seems from this that seating depth can potentially make quite a large difference to group size, even in relatively small increments. I will certainly be doing more tests in this regard in the future. Bullets in question were Sierra 168gr .308 match. | |||
|
| Administrator |
There is no way in HELL you can change the seating depth by 0.004" and notice any difference! NO WAY! Just opened a box of Sierra 168 MK bullets, and measured the length of ten random bullets. I use a laboratory grade micrometer which I use here in my workshop. 1.2115" 1.206" 1.1905" 1.211" 1.204" 1.1895" 1.210" 1.199" 1.1985" 1.209" Even the above sample shown here there is a difference of 0.022" in length. Youtube has an incredible amount of utterly stupid videos on shooting. There are some channels by professionals which are very good. But the majority of "look at me" idiots are totally pointless. | |||
|
| One of Us |
Saeed, What is your procedure for dialing into a most accurate charge weight with a particular powder? Do you do ladder tests? How do pick powders to start with? One other question…do ever test different brands of primers? I believe you did a test where changing primers made little difference. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
|
| Administrator |
Changing primers made very little difference. But, do not use standard large rifle primers with large cases. You will get hang fire. My normal way is to use standard primers with 30-06 size cases or smaller. Anything bigger I use Magnum primers. Basically, you can actually use any powder in any case. But you will only get good results with relevant powders for that case size. I have had some rifles that refuse to shoot well, regardless of powder or bullet. Others seem to take everything in their stride, shooting very good with a variety of powders. We really have it very good today. There is an enormous variety of both bullets and powders. Also, modern made rifles do shoot very well. Small cases, and very large ones, do require specific powders for optimum performance. Something like the 308 Winchester size we have a very large variety of powders one can pick. | |||
|
| One of Us |
I do fiddle with seating depths to tune a load but whether you tune with powder (type and amounts) or with seating depth, only do ONE THING AT A TIME. I also only go by CBTO NOT OACL because of the difference in overall length of each bullet. Zeke | |||
|
| One of Us |
and to answer your question: If your magazine is long enough, I like to start around 20 thousandths off and go in or out in 10 thousandths increments. It take lots of shooting and a steady rest to see a ton of difference so I simply quit experimenting when I find something that works. Zeke | |||
|
| One of Us |
In this particular rifle…the magazine limits me to 0.070 off the lands. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
|
| One of Us |
Saeed, When you have picked a powder…what is your method of finding the optimal charge. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
|
| One of Us |
In this particular rifle…I have tried multiple different powders and multiple different bullets. It is a HS Precision .308 Win. The good news is that shoots almost anything into 1.5” to almost the exact same POI. The bad news is that I have not been able find a load that I can consistently get to shoot MOA or better. I get the occasional sub 1” group but no matter how hard I try…can’t repeat it. HS tested it with Factory Federal Gold Medal Match ammo 168 grain Sierra match kings. They say it shoots sub MOA for them with that ammo. It is a hunting rifle for me…so those don’t work. I can’t find any of that stuff to try it for myself. Yes, I know 1.5” is good enough for hunting. I just “want” to make it shoot sub MOA for me…proving difficult. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
|
| one of us |
Most of todays bolt actions are limited by the magazine length, so load to barely clear that and feed at that length to start with usually works best, Tweek them back if you have to, but I notice your gun shoots a number of bullet makes in at the same 1.5" size which indicates to me thats about all you can expect from that rifle and for a hunting rifle that's more than enough..even borderline for small varmints, not for target,but a true target rifle usually requires a custom barrel.. After about 100 to 200 rounds, most guns settle down and improve and I expect yours if your lucky and shoot a clean bore will eventually be a one inch gun, try some more powders and bullets can sometimes speed the process up.. You can open up the magazine to seat bullets out to match the chamber, and not a bad idea in many cases..It may or may not improve anything.. Brother its just a crap shoot..win some, lose some.. Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
|
| one of us |
Being a native born son of the Lone Star State,going back to the 1700s, I live by that seremon, and its a truism, God Bless Texas and you my good man.. They took this boy out of Texas, but will never take Texas out of this boy!   (Lone Star)Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
|
One of Us |
I load most of mine to have about 1.5mm (1/16th inch) clearance, just in case my measuring it is dodgy. Though some might claim that the bullet seater should ignore the bullet-length variations Saeed mentions, I find the COL at the same die setting varies, too. This may be explained by working the press handle differently, but it is enough to deter me from flirting with having bullets kiss the lands. | |||
|
| Administrator |
Lane, In the past I have tried 0.2 of a grain change in small cases, and 0.3 in medium cases, and 0.5 in large cases. No change at this at all. Now I try 0.5 grain for small and medium cases, and 1 grain in larger cases. | |||
|
| One of Us |
dang Lane I don't blame you. if I bought something with the name precision in it I'd expect some ,,, well, precision. the fact it's a one trick pony [which I generally have no problem with] that's only good for one at a time target shooting would have me bustin their chops on a daily basis up the chain as high as I could get transferred on the phone. I had an issue with a Stag upper once and was transferred to the main guy in the big office in two hang on's. after a 5 minute conversation I had a return tag appear in my e-mail and got to hear. I don't care what your working on,, go out there and start building a new upper the way he asked for it the first time... NOW!. I felt kind of bad about it seein as how I picked it up on a clearance sale from their website. | |||
|
one of us |
Had accuracy problems a while back with my 7/08. Done some research and came up with this from Berger. Came up with a great OAL and was very surprised it was at .120 off lands. I was using the 171 Barnes and best I could do was 1.5 moa, after trying the Berger method ( .120 off) got me to .4 MOA. https://bergerbullets.com/vld-making-shoot/ "300 Win mag loaded with a 250 gr Barnes made a good deer load". Elmer Keith | |||
|
| One of Us |
I sent it back to them once. They said it shot fine for them. They got 1/2 MOA according to them using Federal Gold Medal Match ammo with 168gr Matchkings. I can’t duplicate that with my loads or Black Hills match ammo with same bullet. I can’t find any of the Federal stuff to try. They say it is me and/or my ammo. However, I seem to get other rifles to shoot.  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
|
| One of Us |
Thank you sir…this is what I have always done. I usually start 2 gr under max and work up 0.5 gr at a time shooting 3 shot groups until I find one that looks good…then try to repeat. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
|
| One of Us |
I start .015" off the lands and work up to max pressure, regardless of accuracy. I then shoot 3-shot groups in .015" increments, so .015", .030", .045", .060" off the lands for a total of 12 shots. I then take the most accurate seating depth and load 3 more of each at .5 gr. increments, so .5 gr., 1 gr., 1.5 gr., and 2 grains under max to see which is most accurate. At that point I usually have a load that is within 100 fps of max and is under 1 minute of angle, and that's good enough for me. And I've only used 24 rounds. If I need more power or velocity, I choose a different rifle. | |||
|
| one of us |
The reality is a gun will shoot or it won't, If youu have to trick one out with experimentation, its probably a so so or a lemon, even if your hard work is successful and you find a load, you are mostly limited to that one load..A good barrel will or should shoot about every load you try and shoot most to the same POI, makes life a lot more fun... Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
|
| Administrator |
At the end of the day, do what YOU think will work. It might. I have tried every imaginable way ever reported to improve accuracy. Some work. Some don't. One of the most important part is consistency. If you have quality products, and keep your variables as small as possible, you will get good accuracy provided your rifle is accurate. Playing around with seating depth never worked for me. | |||
|
One of Us |
I agree totally with Saeed on his statement. An accurate rifle to begin with and consistency in everything you do is key. Some rifles just plain shoot better than others and knowing when you have a rifle that isn't going to shoot no matter what you try is best found out early. If it cant be Grown it has to be Mined! Devoted member of Newmont mining company Underground Mine rescue team. Carlin East,Deep Star ,Leeville,Deep Post ,Chukar and now Exodus Where next? Pete Bajo to train newbies on long hole stoping and proper blasting techniques. Back to Exodus mine again learning teaching and operating autonomous loaders in the underground. Bringing everyday life to most individuals 8' at a time! | |||
|
Moderator |
my going in is -.025, -.0275, -.030 with middle of the road loads in my favorite powder for cup and core... -0.065 for monos opinions vary band of bubbas and STC hunting Club Information on Ammoguide about the416AR, 458AR, 470AR, 500AR What is an AR round? Case Drawings 416-458-470AR and 500AR. 476AR, http://www.weaponsmith.com | |||
|
| One of Us |
Go measure the same bullets from base to ogive, and you will notice they are a lot more consistent. | |||
|
| Administrator |
As I mentioned above, due to my own experience, and trials, there was no difference in performance due to seating depths. How long a finished round depends on other factors for me, such as magazine fit etc, but never to accuracy, because I found that it makes no difference. If it works for you, that is great. | |||
|
| One of Us |
I always start ten thousandths into the lands with cup and core bullets..... And then back out ten at a time. 5 shot groups. Or once I've found my powder charge shoot a ladder at 300 or 400 yards backing out 3 ten thousandths at a time looking for nodes. I think that HS action is A Remington clone..... If it is it won't be hard to open it up for a Wyatt's extended mag box..you've had a lot of trouble with that rifle. Have you ever tried jammed bullets? 10 thousandths jam is not gonna pull a bullet with any kind of neck tension..... | |||
|
| One of Us |
This rifle has detaching magazines (clips for those who use that term). I like the rifle except that it is a 1.5 MOA rifle for me. THIS has been a disappointment for me. But, it is a lightweight, 20” barreled sporter. Maybe that is as good as I should expect??? It will shoot about everything to 1.5. I have not tried beyond magazine length loadings as it is strictly a hunting rifle for me and I have just steadily been on the quest for that sub-MOA hunting load. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
|
| One of Us |
JTEX, If I get time that works for you…I am going to drive down, bring components, and let you load for and shoot that thing and see if it is better for you. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ J. Lane Easter, DVM A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991. | |||
|
| Powered by Social Strata | Page 1 2 |
 | Please Wait. Your request is being processed... |
|
The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Reloading Seating depth of cup and core bullets
Visit our on-line store for AR Memorabilia