I am reloading for a Rem 700 in .308. Based on the measurements I've taken, the chamber OAL is 2.94. My question is, how long is too long of an OAL when seating the bullets? Is there a point of diminishing returns when seating the bullets closer to or into the lands? I'm using 175 SMK's.
.308 Overall Length - How long is too long?
- Thread starter JCB
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Re: .308 Overall Length - How long is too long?
as long as you have enough bullet in the case to hold and align it your ok, if yo go to long it wont feed through your mag so you would have to single load.
as long as you have enough bullet in the case to hold and align it your ok, if yo go to long it wont feed through your mag so you would have to single load.
Re: .308 Overall Length - How long is too long?
There is a diminishing return but you will have to test it to find out where that is. I have found that 2.85 COAL works pretty well in the 308. It is an inherently accurate round. I don't worry about chasing the lands anymore with it.
There is a diminishing return but you will have to test it to find out where that is. I have found that 2.85 COAL works pretty well in the 308. It is an inherently accurate round. I don't worry about chasing the lands anymore with it.
Re: .308 Overall Length - How long is too long?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: treebasher</div><div class="ubbcode-body">I'd say when the bullet falls out of the case... </div></div>
Or you go to pick up the round out of your cartridge box and you lift the bullet out of the case, DOH!
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: treebasher</div><div class="ubbcode-body">I'd say when the bullet falls out of the case... </div></div>
Or you go to pick up the round out of your cartridge box and you lift the bullet out of the case, DOH!
Re: .308 Overall Length - How long is too long?
I get my replacement barrels chambered a bit short in the leade because I shoot Amax so 2.82" works well.
A factory barrel has a longer leade and if you want to get closer to the lands the bullet will stick out there a ways.
Overall I dont think there is any real advantage to chasing the lands with SMKs or the Amax in the 308.
I get my replacement barrels chambered a bit short in the leade because I shoot Amax so 2.82" works well.
A factory barrel has a longer leade and if you want to get closer to the lands the bullet will stick out there a ways.
Overall I dont think there is any real advantage to chasing the lands with SMKs or the Amax in the 308.
Re: .308 Overall Length - How long is too long?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JCB</div><div class="ubbcode-body">My question is, how long is too long of an OAL when seating the bullets? </div></div>
The answer depends on the intended use. If you need the ammo to fit in the magazine or in the clip, then it obviously has to fit in the magazine or clip. If you do not need this property, and find single loading the rifle acceptable, then your are only limited in COAL by what fits in the chamber adn allows the bolt to close.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> Is there a point of diminishing returns when seating the bullets closer to or into the lands? </div></div>
As the bullet is seated out farther and farther (or identically, closer and closer to the lands or into them) there is more case volume behind the bullet. You can add more powder to this volume and increase the energy that is available to push the bullet down the tube. Done correctly, one can get a few more fps by seating the bullets out (long) and adding powder without increasing the pressure neede to 'get' that added MV.
The (T.H.E.) IMPORTANT property that is mandatory is to avoid having so much powder that the gun blows up or wears out at a rapid rate (overpressure that does not result in an immediate Kaboom). This is where the 'lands' part of the issue shows up.
If load development begins with low powder charge weight with the bullet seated at or slightly into the lands, and then load development proceeds in a normal flow until the charge weight has been determined, and the bullet can be seated farther from the lands with no increase in operating pressure to fine tune the load. Done the other way around (i.e. approaching the lands with charge weight determined) pressure can increase significantly as jump is reduced below 0.015 (or so). So, if you are going to develop a load, the proper course is to start at/into the lands and then seat deaper at the end of load development.
{All subject to whether you accept single loading discussed above.}
Most high end custom tactical guns (TacOps and the like) will have the chambers and lands 'cut' where the 175 SMK has minimal jump AND the cartrige fits in the magazine at the same time. Not so much with lawyer regimented factory stuff.
I happen to load my long range loading to 2.943 which for my bullet and my gun is 0.015 from the lands for a factory Remmy.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JCB</div><div class="ubbcode-body">My question is, how long is too long of an OAL when seating the bullets? </div></div>
The answer depends on the intended use. If you need the ammo to fit in the magazine or in the clip, then it obviously has to fit in the magazine or clip. If you do not need this property, and find single loading the rifle acceptable, then your are only limited in COAL by what fits in the chamber adn allows the bolt to close.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> Is there a point of diminishing returns when seating the bullets closer to or into the lands? </div></div>
As the bullet is seated out farther and farther (or identically, closer and closer to the lands or into them) there is more case volume behind the bullet. You can add more powder to this volume and increase the energy that is available to push the bullet down the tube. Done correctly, one can get a few more fps by seating the bullets out (long) and adding powder without increasing the pressure neede to 'get' that added MV.
The (T.H.E.) IMPORTANT property that is mandatory is to avoid having so much powder that the gun blows up or wears out at a rapid rate (overpressure that does not result in an immediate Kaboom). This is where the 'lands' part of the issue shows up.
If load development begins with low powder charge weight with the bullet seated at or slightly into the lands, and then load development proceeds in a normal flow until the charge weight has been determined, and the bullet can be seated farther from the lands with no increase in operating pressure to fine tune the load. Done the other way around (i.e. approaching the lands with charge weight determined) pressure can increase significantly as jump is reduced below 0.015 (or so). So, if you are going to develop a load, the proper course is to start at/into the lands and then seat deaper at the end of load development.
{All subject to whether you accept single loading discussed above.}
Most high end custom tactical guns (TacOps and the like) will have the chambers and lands 'cut' where the 175 SMK has minimal jump AND the cartrige fits in the magazine at the same time. Not so much with lawyer regimented factory stuff.
I happen to load my long range loading to 2.943 which for my bullet and my gun is 0.015 from the lands for a factory Remmy.
Re: .308 Overall Length - How long is too long?
First, does it fit in the magazine. Second, what does your gun like. My gun likes a little jam.
I have a theory on jam. I am running about .002" of neck tension. At that tension, if I jam more than .005", then the bullet is going to engrave a bit and the rest is going to push back into the case. So jamming .005" and jamming .015" is basically the same thing.
In factory chambers such as yours, you are going to want to seat the bullet out a little more because the lands are going to be farther out. Different guns like different amounts of jump or jam, but few are going to like to jump more than .02" The advantage of seating a bullet out that far is there is more room for powder. The problem is, eventually you run into magazine length. You want to be .01" short of magazine length for practical purposes. That will insure no feeding issues.
First, does it fit in the magazine. Second, what does your gun like. My gun likes a little jam.
I have a theory on jam. I am running about .002" of neck tension. At that tension, if I jam more than .005", then the bullet is going to engrave a bit and the rest is going to push back into the case. So jamming .005" and jamming .015" is basically the same thing.
In factory chambers such as yours, you are going to want to seat the bullet out a little more because the lands are going to be farther out. Different guns like different amounts of jump or jam, but few are going to like to jump more than .02" The advantage of seating a bullet out that far is there is more room for powder. The problem is, eventually you run into magazine length. You want to be .01" short of magazine length for practical purposes. That will insure no feeding issues.
Re: .308 Overall Length - How long is too long?
Great information guys. Thank you for all of your input.
I am limited by the magazine length being less than what would be needed to ever approach the lands. The magazine will only allow about 2.89 OAL, at least it works with dummy rounds. Will have to see if live ammo will work after recoil and any possible shifting of the rounds in the mag.
I'm fairly new to reloading so I didn't know at what OAL there might not be enough or consistent neck tension. Given my knowledge at this point that may not even be an issue.
Thanks again for helping me out.
Great information guys. Thank you for all of your input.
I am limited by the magazine length being less than what would be needed to ever approach the lands. The magazine will only allow about 2.89 OAL, at least it works with dummy rounds. Will have to see if live ammo will work after recoil and any possible shifting of the rounds in the mag.
I'm fairly new to reloading so I didn't know at what OAL there might not be enough or consistent neck tension. Given my knowledge at this point that may not even be an issue.
Thanks again for helping me out.
Re: .308 Overall Length - How long is too long?
My savage requires a cartridge with a 180SMK to be 2.840" long to be ON the lands. It requires I jump the bullet at least .030", or it will spray bullets instead of shooting them. No idea why. Word on the street is that matchkings don't mind jumping at all. What can I say? Your mileage may vary.
My savage requires a cartridge with a 180SMK to be 2.840" long to be ON the lands. It requires I jump the bullet at least .030", or it will spray bullets instead of shooting them. No idea why. Word on the street is that matchkings don't mind jumping at all. What can I say? Your mileage may vary.
Re: .308 Overall Length - How long is too long?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: treebasher</div><div class="ubbcode-body">I'd say when the bullet falls out of the case... </div></div>
LOL you beat me to it... I had this conjured up in my head as I was about to click on this topic
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: treebasher</div><div class="ubbcode-body">I'd say when the bullet falls out of the case... </div></div>
LOL you beat me to it... I had this conjured up in my head as I was about to click on this topic
Re: .308 Overall Length - How long is too long?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JCB</div><div class="ubbcode-body">I am reloading for a Rem 700 in .308. Based on the measurements I've taken, the chamber OAL is 2.94. My question is, how long is too long of an OAL when seating the bullets? Is there a point of diminishing returns when seating the bullets closer to or into the lands? I'm using 175 SMK's. </div></div>
I loaded some Scenars up last week on a 3100+ round-count Savage and was able to go 2.873" and still make the McMillan A3's internal mag box. Unless you're planning on single feeding, this is the controling factor.
I'm sure that I can go out past 2.9xx, with the 155s.
Try and leave a bullet's caliber inside the neck, but I've done 1/2 to 2/3s in the past, dicking around with things.
Chris
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JCB</div><div class="ubbcode-body">I am reloading for a Rem 700 in .308. Based on the measurements I've taken, the chamber OAL is 2.94. My question is, how long is too long of an OAL when seating the bullets? Is there a point of diminishing returns when seating the bullets closer to or into the lands? I'm using 175 SMK's. </div></div>
I loaded some Scenars up last week on a 3100+ round-count Savage and was able to go 2.873" and still make the McMillan A3's internal mag box. Unless you're planning on single feeding, this is the controling factor.
I'm sure that I can go out past 2.9xx, with the 155s.
Try and leave a bullet's caliber inside the neck, but I've done 1/2 to 2/3s in the past, dicking around with things.
Chris
Re: .308 Overall Length - How long is too long?
Thanks again for all of your input. Sounds like I'm within a range that will work. I will just have to see what the gun likes once I get some rounds through it.
Funny, when I was typing my question I figured someone would chime in that when the bullet fell out it was too long. Pretty funny stuff
I guess I could overcome that issue with a little scotch tape unless run out gets to be a problem!
Thanks again for all of your input. Sounds like I'm within a range that will work. I will just have to see what the gun likes once I get some rounds through it.
Funny, when I was typing my question I figured someone would chime in that when the bullet fell out it was too long. Pretty funny stuff
I guess I could overcome that issue with a little scotch tape unless run out gets to be a problem!
I need to revive this old thread. I bought some .338 bullets and on the case it says single feed only. I have no problem with that. The bullets are much longer than the standard size bullets I have been reloading, 2.120 vs. 1.802 inches. If I seat the new bullet to the same depth as the standard bullet that means the overall length of the bullet will be .3 longer. Is this a problem if I am single feeding the bullet?
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