Bullet seating question

So I am reloading .40 S&W currently and there is a overall max length recommendation of 1.135. I put my calipers on my rounds and a few of them are reading 1.137, 1.138. Is there a +/- tolerance of OAL? I have since adjusted the settings and I am currently in the 1.120 range which I like but now I am getting a small ring at the nose of the bullet. You cannot feel the indentation of it but you can see it. Is this normal, and is it safe?

Being new to reloading, I am pretty much doing everything one step at a time, even pouring my charge out on the scale to make sure it is correct before seating the bullet. I am probably being overly cautious, but I would rather it be right than regret it later.

I have had some problems with my Hornady LNL not indexing fully to the next station but since have put the 3/8" lock washer on top of the other washer on my shell plate I haven't had an issue but haven't ran many rounds. I saw this on one of Highboys videos so hopefully that corrects the issue I am having.

Sorry for all the questions!
 

walterbunning

Administrator
You have several questions.. I’ll take the bullet seating one : (and keep in mind that the following is based on my own personal experience. Other’s may chime in and have additions subtractions)

First, the max length given in your book is the SAAMI spec for that round around which manufacturers design their firearms. EXCEEDING that length may result in rounds that will not properly feed, or come into battery. So the max length given should be considered the upper limit of tolerance. Keep them shorter than that, and use the OAL stated for the particular bullet you are loading. Study the data section for .40 S&W and you’ll notice that each bullet is seated to different OAL, but generally less than SAAMI max.

Secondly, YES, some variation in OAL after your seating die is “set” is to be expected, and +/- .002 or so is not uncommon, and generally will not produce any noticable difference in handgun performance. The phenomenon results from a couple of sources: first, all your bullets are not identical. The tips will have some variation from manufacture, and that will dictate how seating stem contacts them. For example, a flat-point bullet’s meplat (the top face) may actually be slightly beveled, causing the seat stem to only contact one edge of it, rather than the entire face. Second.. those variations in meplat may cause your caliper to indicate a variation in OAL, depending on where you take the measurement.

Third, your shell plate on the progressive press has two spring-loaded ball bearing detents on it’s bottom surface. Those detents will cause the shell plate to flex a bit, more so for the first 2 or 3 and last 2 or 3 when the plate is unbalanced by not having a cartridge at each station. That can easily cause a couple thousandths of difference in OAL. Not a problem for short-range handgunnery, but not good for long range/precision rifle shooting.

The rings on your bullet are caused by a seating stem that doesn’t fit your bullet. A small mark may not be an issue, but COULD be if you get a significant “cut” with plated bullets. I would look into either finding a bullet that fits your seating stem, or get a stem that better fits your bullet.

If you can, post a photo of a seated bullet that shows the mark, and tell us what dies you are using.
 
Last edited:
Bullets are Siearra 165 Gr JHP. Dies are Hornady American Series. The round on the left in the first picture is one without the ring that I made a while back, the one on the right in the first picture you can see the small ring. The lone round by itself you can see the small ring around the top of the bullet. I really can't even feel any indentation at all but you can see it.



6465
 

walterbunning

Administrator
Bullets are Siearra 165 Gr JHP. Dies are Hornady American Series. The round on the left in the first picture is one without the ring that I made a while back, the one on the right in the first picture you can see the small ring. The lone round by itself you can see the small ring around the top of the bullet. I really can't even feel any indentation at all but you can see it.



View attachment 64View attachment 65
That ring is definitely from a seater plug that doesn’t match the bullet shape, and could also be a player in your OAL variance, though neither are really serious enough to be a problem. A person CAN modify a seating stem so that it won’t contact the bullet that way, or get ahold of Hornady to see of they can make you a custom stem for that bullet, or you could look around for a die with a semi-wadcutter type stem to do your seating with if you”re married to that bullet. Or, you could switch bullets to fit the stem you have. At this point, though, I wouldn’t worry about it, the rounds will shoot just fine. Keep at it and build your skill and expertise..keep good records and try different bullets.
 
Walter, Thanks man for the help I really do appreciate it. In my Sierra reloading manual the C.O.A.L. is 1.125" for the JHP 165 Gr bullet. Overall the OAL for the .40 S&W is 1.135. This is where I am kind of confused. From what you previously posted and I agree, I am going to pull the bullets anything over 1.135 OAL just to be safe. Should I do the same if the bullet I am reloading is over the 1.125" OAL? Or since it is within the overall tolerance of the round it doesn't matter? I apologize for all the questions, just want to make sure since this is the first load I will be shooting.
 
M

Mike

Guest
Walter is on point.

Uniquetek offers custom seating stems for Dillon dies, specifically for SWC (Semi Wad Cutter) bullets. They may help with your issue. That being said, I get those rings on certain plated bullets and never had an issue. As Walter said, make sure that the plating is not cut into.

 

walterbunning

Administrator
In my Sierra reloading manual the C.O.A.L. is 1.125" for the JHP 165 Gr bullet. Overall the OAL for the .40 S&W is 1.135. This is where I am kind of confused. From what you previously posted and I agree, I am going to pull the bullets anything over 1.135 OAL just to be safe. Should I do the same if the bullet I am reloading is over the 1.125" OAL?
The “1.135” value, given in the diagram on the first page for 40 S&W is the SAAMI max for ANY .40 cartridge with ANY bullet, but should not be considered the “go-to” OAL for ALL .40 cartridges, rather the “never exceed” value for any round you make in that caliber. You just need to study the data set for your particular bullet. In your example you should be seating the 165 grain JHP at 1.125” if you expect results to be similar to those reported by Sierra in their test. In fact, Sierra lists 1.125” as the proper OAL for ALL of their .40 bullets. Other manuals will give different OAL for bullets other than Sierra.

You do not need to worry about a +/- .002 variance from your 1.125 measurement. That’s going to happen.

Get yourself an additional manual before you do any more reloading. One that has instructional chapters preceeding the data sections. The Lyman and Lee books are both good in that department, but there are others. Read those preliminary chapters.

How many of those rounds did you make at 1.135”? If it’s just a few, pull them. If you made 50, then here’s what I can suggest: make a DUMMY round at that length. NO PRIMER, NO POWDER, and properly crimped. Make sure your firearm is clear, then load that dummy round in a mag and see if it will chamber OK. If it does, then take the rounds to the range. Load ONE in the mag, chamber and fire. If that works OK, i.e. doesn’t hang up in the breech, goes bang, cycles the action, hits the paper and the case ejects, then shoot the rest. Start with a fresh target and make sure there’s a hole in it after firing. If the dummy round DOESN’t chamber, then pull them all.

Edit: I should note that shooting rounds at longer than specified OAL will result in lower than stated pressures. If pressure is TOO low, the action may not cycle or worse, the bullet may not exit the barrel. Hence the reason to only load one round to try. Your 1.135” bullets are not likely to have those issues unless your powder charges are also way too light. The above test process should not be used if you inadvertently seat rounds way too short. In that case, the error will cause internal pressure to be too high, and the rounds should be pulled down, regardless. I can’t tell you what “way too short” is with a number. Use the value given in the data for that bullet, but expect and accept a couple thousands variance as normal.
 
Last edited:
As far as modifying any seater or sizer nose punch I found years ago that after having one bullet seated and aligned in a caae, you take the punch out, clean it up with degreasing agent, put a bit of oil on the tip of the bullet wiping off access, mix up some epoxy putty enough to fill the cavity in the seater, replace the seating stem, press down firmly on the bullet and leave it for 20 minutes or so. Aftewards clean up access putty and seat/ size bullets for 20 more years. If you find semi wudcutter seating or sizer punces for a good price, buy a handfull and keep them for those custom bullets.
 
I made about 19 rounds previously that were around the 1.135 mark. Since I adjusted it last night I got the measurements just about right at 1.125. I just seated a dummy round below and it measured 1.128. That is a win for me right now (y) Only bad thing is I can't load a dummy round at the old OAL as you suggested above and cycle it though. I am going to take the safe route and pull those rounds. I do however have 6 good rounds that measured around the suggested OAL for this bullet. They do have the slight "nose ring" on them and might not be the most accurate load, but really all I am searching for this stage of the game is a click/bang/paper. Even doing this little exercise I have learned a few things and that is what it is all about for me because I am going to lean on the more experienced re loaders in this group a lot! One last question and it's probably a dumb one for many on here....after I pull the rounds, can I still use the bullet since it has the small indentation from being seated previously?


Thank you Janito, Walter and Dassd for the help and info.
 

Attachments

I ran into that with my lock and load. I spoke with a rep from hornady and we came to the conclusion that changes in oal are normal and to be expected. What i do is to set up my seating die with all the stations full and my oal is on point except the first and last 3 rounds. This is due to flex on the plate. What i do now is overlap batches that way i always start and finish with a full shell plate. So i alway’s have some shells ready for resize, some ready for case exp, some ready for powder and some ready for seating and crimping.
 

Critter9a

Moderator
Staff member
I ran into that with my lock and load. I spoke with a rep from hornady and we came to the conclusion that changes in oal are normal and to be expected. What i do is to set up my seating die with all the stations full and my oal is on point except the first and last 3 rounds. This is due to flex on the plate. What i do now is overlap batches that way i always start and finish with a full shell plate. So i alway’s have some shells ready for resize, some ready for case exp, some ready for powder and some ready for seating and crimping.
I'm not really following? what kind of changes in OAL are we talking about?
 

walterbunning

Administrator
I'm not really following? what kind of changes in OAL are we talking about?
Most presses, and in particular progressive and turret presses which have rotating platforms for the brass or the dies, will produce variation in COAl of a few thousandths, one way or the other. Such variations can be caused by differences in the shape of the bullet nose and how it fits into the seater plug, sloppiness in a shell holder, or tolerance issues in the bearings of a shell plate or turret. With the Hornady LNL, there are spring-loaded bearings on the shell plate that allow the plate to flex. The first 3 or 4 cases through the system will produce different COAL than a full shell plate due to different pressures on different spots on the plate, and the plate flexes accordingly under that seating die. When the plate is full, and an operation is being performed at each die, the pressure on the plate remains more uniform and the amount of flex is balanced around the system. The variance in COAL produced is not really a problem for short-range pistol ammo, or “blasting” rifle ammo. But it is why we use a more solid system such as a single stage press for more accurate ammo.

Edit: I should mention that some turrets, such as the Redding T-7, while having some play in the turret at the ram position, that “play” will be the same for every cartridge and isn’t as much a factor as variance in bullet shape. There are other sources of COAL variation as well. For example, powder granules or other debris on the shell holder can do it, deformation or gunk on the case head, and bullet lube building up on the seating stem.

In any case, a thousandth or two of difference in COAL from cartridge to cartridge is normal, and in fact very difficult ro improve upon. It’s when we start seeing variation of several thousandths that we need to take a look and see what might be causing it. -wb
 
Last edited:
I figured the rings that I have been getting on the top of my bullets might be user error. :unsure: So I decided to read up a little more, watch a few more videos and it seems that I did not have my seater die adjusted properly. I stripped my press down, and started the whole process over and I actually have some really good looking rounds that are running right at the OAL. Attached picture you can see the ring on the right side of the reloads, and in front and on the left after I adjusted the seater die. One day I am going to be a really good teacher for all the troubles that I have run into. :D

648
 
Top Bottom