Bullets seating tolerances?

[dfraser]

Hi all

I am doing my first bullet seating tonight for 308. The lyman book calls for over all length of 2.81" in the general section of the 308 section. But under the Hornady amax that I am using, it shows an oal of 2.78". Which one should I use? Is there a tolerance that I can have it between?


Regards

 

[Mystic Precision]

Are you single feeding or mag feeding?

Have you confirmed the location of the start of the rifling vs the OAL of the ammo?

These are far more important to answer and a number in a book.

Jerry

 

[dfraser]

It is for a bolt action

I cannot see anything in the book about the start of the rifling. I read through that chapter a couple of times. I will go back and see again.

Regards

 

[RL-300mag]

dfraser :: listen to what Mystic is telling you..........measure to the lands in your barrel with the bullet that you intend to use.......then adjust from there.
If you can't find a explanation in the book your using ...try google...

I would suggest that you measure to your rifling, and then back off .0150" . Do a OCW test starting at a min load and working up carefully. Once you find your rifle's node. Then play with your seating depth,,,to fine tune your load.. And when you do this OCW test , try it at 200 yards if you can rather than 100 yard.
It will tell you more.....There is plenty of info on the internet....to guide you through....

Be safe & watch for pressure sign's .
Just my advice and to each his own.......

A very good option is the Berger Hybrid's.....

Cheer's

 

[9x19p]

First batch you get a free pass, seat to 2.800

Read up on;
throat deapth / chamber length.
How to measure to the lands.
Bullet ogive.

*you've started with min loads, ya?

Happy shooting

 

[dfraser]

dfraser :: listen to what Mystic is telling you..........measure to the lands in your barrel with the bullet that you intend to use.......then adjust from there.
If you can't find a explanation in the book your using ...try google...

I would suggest that you measure to your rifling, and then back off .0150" . Do a OCW test starting at a min load and working up carefully. Once you find your rifle's node. Then play with your seating depth,,,to fine tune your load.. And when you do this OCW test , try it at 200 yards if you can rather than 100 yard.
It will tell you more.....There is plenty of info on the internet....to guide you through....

Be safe & watch for pressure sign's .

A very good option is the Berger Hybrid's.....

Cheer's

I don't find it in the book about the rifling, it does say to make a dummy round and chamber it to see if it fits properly, which I did

I am loading with the minimum, which is 39.5

 

[Chas59]

Invest in a gauge to determine bullet seating to the lands and then back off various amounts .015, .020, etc. Every rifle is a bit different. I use the Hornady gauges for measuring length and the comparator for measuring to the ogive, easy once you've used them and they aren't super expensive. I load .308 and end up never using the exact OAL in the books, powder on the other hand is far more important to follow the books very carefully.

 

[RL-300mag]

I don't find it in the book about the rifling, it does say to make a dummy round and chamber it to see if it fits properly, which I did

I am loading with the minimum, which is 39.5

I'm gonna private message you...I might have a couple of option's or ideas that might help......

 

[Potashminer]

As suggested, you can buy a gauge to establish the distance from your bolt face to your rifling, or you could use the "Jiffy Marker" technique. Start with a sample bullet of the type you want to load, and a case fired in your rifle. The bullet should be an easy or loose slip fit into the neck of the fired case. Use a Jiffy marker and "paint up" the exterior of the bullet. Use your thumb and press a small dent into the case neck wall. By hand you should now be able to start seating the marked bullet into the case neck - the dent provides tension and is scraping off the "paint". Leave it obviously too long - just nicely started into the neck. Carefully chamber that round - if using a mauser make certain you have the case rim on the bolt face, not the extractor. As you carefully close and lock the bolt, the bullet will run into the rifling, causing the bullet to be pressed deeper into the neck. Open the bolt. The bullet might be stuck on the rifling. Use a cleaning rod to push it out. The scrap mark on the side of the bullet from the dent on the case neck shows you how far to set it back into the case. Take your overall length measurement. This is your "tight to the lands" distance. For working up loads, you will find recommendations to set your actual loads anywhere from .030" to .015" shorter. Of course, as mentioned above, in some cases, it will be your magazine length that will be your OAL limiting factor.

 

[cosmic]

Gents - Telling a rookie to go 15 thou off the rifling is likely to cause problems, and a host of other inane posts. OP - Learn the ropes (working up a load, etc) use the factory OAL or the cannelure. In the long run, OAL is a minor variable comared to bullet weght, powder selection and charge weight.
There was a post on here recently about bogus results using a headspace tool, again by a rookie. The moral of the story? Learn to get good before you get fancy...

 

[hillbillywilly85]

Gents - Telling a rookie to go 15 thou off the rifling is likely to cause problems, and a host of other inane posts. OP - Learn the ropes (working up a load, etc) use the factory OAL or the cannelure. In the long run, OAL is a minor variable comared to bullet weght, powder selection and charge weight.
There was a post on here recently about bogus results using a headspace tool, again by a rookie. The moral of the story? Learn to get good before you get fancy...

I agree totally with cosmic. Seat to your cannelure or load Data overall length in the beginning of reloading.
Then once Dfraser you are getting into reloading and once you understand the concept of off .15 thou or jamming into lands .5 thou. Provided you are looking for this type of reloading and acurracy potential you can.

https://www.google.ca/imgres?imgurl...d=0CBsQMygAMABqFQoTCPqbt_2w_scCFYE4iAodaSAPzg

Dfraser I have left you a link that will take you to a picture of throat jump showing cartridge overall length from Berger bullets if you then click on the visit page it takes you to Berger bullets page explaining COAL and bullet "jump" but if you still aren't certain about bullet jump and if you want to reload this way? stick to loading bullet depth to load data COAL till you are comfortable with the "bullet jump concept"
Since you can very EASILY RAISE CASE PRESSURES! If you jam the bullet into the lands. Which may cause unsafe conditions if your not fully aware of what your doing. Most people load .15 thou of the lands. But it takes trial and error to see what your firearm likes. Very few load .5 thou into the rifling since the bullet really needs a running start.

Hopes this helps? Any more questions please ask: Will.

 

[dfraser]

Thanks all,

One thing that I am learning about all this reloading process, is that I am not following the manuals that I bought for this venture. Like this Lyman guide, Every question about a spec in this manual that I question here, gives me answers to work totally outside the manual. And this is the manual everyone told me to get first.

So why isn't any of this printed in any of my manuals, In the bullet seating section, basically tells me to create a dummy cartridge using the data in the data block (without the powder or primer) and test it by chambering it, thats all!

Regards

 

[Mystic Precision]

Why does a Grade 6 math text book not discuss quantum physics or String Theory?

ALL reloading manuals are designed to suit the entry level shooter and reloader. There has to be zero room for mistakes or misunderstanding leading to injury. These are US supplied documents... they have lawyers.

When you get on this and other accuracy orientated forums, you will be receiving info from shooters with a vast range of experience and knowledge. Some of the stuff considered "normal" in some sports is science fiction in others.

It would be like talking to a F1 engineer after getting your learner license.

So start with the basics, gain some experience and some positive results. As you SHOOT, questions will come up and alot of what we are saying will make sense.

I have been competing and tuning the good ole 308 for the last 4 yrs. I have shot thousands of rds in testing, development and competition, and still tweaking the finer points to reach the level of performance I want/need. Should be a no brainer right? No way... the stuff we are playing with doesn't exist in books, or forums cause we are the ones trying to figure it out.

There is little point trying to explain our tech to a new shooter. They wouldn't understand, wouldn't have the right tools and set up and likely just hurt themselves.

Start with the basics, be safe and LEARN THROUGH DOING....

Jerry

 

[Ganderite]

2.800" is a OAL that will allow the round to fit any magazine.

In the case of a Remington rifle, 2.820" will still fit.

If you plan on using the magazine, measure it and note that MAX length. Your ammo should always be at least 25 thou shorter than that.

BUT, that length might be too long for the chamber throat. You might need a shorter length.

What I do with a new rifle, is load the first round at 2.900 and try to chamber it. if I feel resistance, or if it chambers and I then see rifling marks on the bullet, I put that round aside and and turn the seater in a quarter turn (or more) and seat the next bullet.

I keep doing this until I see just a faint start of rifling marks on the bullet. I note that OAL and call it the "bullet hard into the rifling" distance. I then turn the seater down a half turn and verify that that distance leaves no marks on the bullet. I note that OAL as the "Bullet off the Rifling" distance.

Then I take the collection of longer rounds used in steps above, and seat them all to the last setting, and then carry on loading all the ammo.

if you plan on using a magazine, load a round short enough to fit the mag, and then chamber it to see if that length clears the rifling. If it does not, seat successive rounds deeper, as above, unto there are no rifling marks on the bullets.

The 2.800" in the book is a short OAL that will fit most rifles. It would be like selling only size 13 boots, because all feet will fit. You want a longer length round, but it still ah to fit YOUR mag and YOUR chamber. The procedure above will find that OAL for you. And write the results in your logbook.

I have a rifle in which 2.800" leaves rifling marks. And I have another that needs an OAL of 2.925"

 

[hillbillywilly85]

What mystic said is right on! The load manuals give you the basic knowledge and give you conservative load info to keep you and themselves out of trouble and lawsuits!
Plus I will admit learning basics is great then if you desire to go farther then you can!

 

[bigedp51]

Gents - Telling a rookie to go 15 thou off the rifling is likely to cause problems, and a host of other inane posts. OP - Learn the ropes (working up a load, etc) use the factory OAL or the cannelure. In the long run, OAL is a minor variable comared to bullet weght, powder selection and charge weight.
There was a post on here recently about bogus results using a headspace tool, again by a rookie. The moral of the story? Learn to get good before you get fancy...

I love it when people who are almost as smart, good looking and modest as I am make very good common sense postings that are short and to the point.

dfraser

I want to show you something, below are two Hornady bullets a red tipped V-Max and a green tipped Z-Max. The Z-max takes all the worry out of loading my AR15 ammunition, you just seat the bullet to the cannelure and the Zombies never know the difference when you shoot them in the head.

Below the SAAMI .223 throat below is .0250 in length, the longer 5.56 throat is .0500 in length and my off the shelf factory Savage bolt action .223 has a throat length of .0566. So simplify your life and buy Hornady bullets with a cannelure and learn basic reloading. And later when you start reloading to shoot bug hole groups you can play with seating depth. I'm 65 and have been reloading for over 47 years and still love Hornady for making life simple.

Even if I'm shooting Elephants or a Tyrantisaurus Rex with a 500 grain .458 Hornady bullet life is simple. And seating depth isn't as important when shooting these bad boys as remembering to keep your nose away from your thumb when you pull the trigger.

 

[mmahdi]

Being absolutely new to reloading, this made sense to me. The advice from Mystic Precision seems right on as well.

Thanks guys!

2.800" is a OAL that will allow the round to fit any magazine.

In the case of a Remington rifle, 2.820" will still fit.

If you plan on using the magazine, measure it and note that MAX length. Your ammo should always be at least 25 thou shorter than that.

BUT, that length might be too long for the chamber throat. You might need a shorter length.

What I do with a new rifle, is load the first round at 2.900 and try to chamber it. if I feel resistance, or if it chambers and I then see rifling marks on the bullet, I put that round aside and and turn the seater in a quarter turn (or more) and seat the next bullet.

I keep doing this until I see just a faint start of rifling marks on the bullet. I note that OAL and call it the "bullet hard into the rifling" distance. I then turn the seater down a half turn and verify that that distance leaves no marks on the bullet. I note that OAL as the "Bullet off the Rifling" distance.

Then I take the collection of longer rounds used in steps above, and seat them all to the last setting, and then carry on loading all the ammo.

if you plan on using a magazine, load a round short enough to fit the mag, and then chamber it to see if that length clears the rifling. If it does not, seat successive rounds deeper, as above, unto there are no rifling marks on the bullets.

The 2.800" in the book is a short OAL that will fit most rifles. It would be like selling only size 13 boots, because all feet will fit. You want a longer length round, but it still ah to fit YOUR mag and YOUR chamber. The procedure above will find that OAL for you. And write the results in your logbook.

I have a rifle in which 2.800" leaves rifling marks. And I have another that needs an OAL of 2.925"