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How deep to seat a bullet?
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Still pretty much a newbie when it comes to reloading (30-06 and 7x57 only right now). The question is how deep should I seat bullets?

The only advice I have given is to seat them only as deep as needed to close the bolt. (Of course, there are times that the overall length of the cartridge limits how many rounds I can get in the magazine)

Not sure the best way to phrase my question: Are there advantages to seating a bullet shallow? Or deep?
 
Posts: 862 | Location: Michigan | Registered: 17 March 2003Reply With Quote
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If the bullet has a cannelure, I've always seated to the center (or thereabouts) of the cannelure. If the bullet doesn't have one, I go by the OAL listed in the load manual.
 
Posts: 4214 | Location: Southern Colorado | Registered: 09 October 2011Reply With Quote
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Sorry but what is a "cannelure"?
 
Posts: 862 | Location: Michigan | Registered: 17 March 2003Reply With Quote
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Picture of jeffeosso
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that is the crimp groove --

you are asking how to set overall length, OAL -- if you are a newbie, i would suggest no longer than spec length in the reloading book - and NO HOTTER than the medium load listed -- a consistent length and charge will make nicely accurate ammo

when you have that perfect, than -0.0275 off the lands is, well, perfect


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Posts: 38379 | Location: Conroe, TX | Registered: 01 June 2002Reply With Quote
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Picture of ramrod340
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Groove in the bullet that allows you to crimp the case mouth into.

As to handgun I use the suggested OAL

Rifle I try to maintain at least one caliber of bearing surface in the case. So a BT goes deeper. You can for sure get by with less. I seat my bullets out so I'm just off the lands. Along the lines of Jeff's -.0275. The majority of rifles will shoot best with shorter jumps. If that won't work in the mag then the mag determines oal. Saying enough to close the bolt doesn't say much. Depending of neck tension you might not even feel land contact.

To me your advice is all wet.


As usual just my $.02
Paul K
 
Posts: 12881 | Location: Mexico, MO | Registered: 02 April 2001Reply With Quote
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The best answer would be to read your manual and work up your load. I know the internet is about instant gratification and shortcuts but if you learn the terms used and the steps of loading a round then you can learn how to make precision ammo.

The advice you were given is partially right and partially hazardous. You can jam a bullet into the lands but that is not always the most accurate round and may cause over pressure. For starting I'd recommend seating to the overall length in your manual for the bullet you are using. Light weight bullets may not be loaded as long as heavier bullets and heavier bullets get seated deeper and take up powder space.


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Posts: 1254 | Location: Norfolk, Va | Registered: 27 December 2003Reply With Quote
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quote:
Originally posted by Sam:
The best answer would be to read your manual and work up your load. I know the internet is about instant gratification and shortcuts but if you learn the terms used and the steps of loading a round then you can learn how to make precision ammo.

The advice you were given is partially right and partially hazardous. You can jam a bullet into the lands but that is not always the most accurate round and may cause over pressure. For starting I'd recommend seating to the overall length in your manual for the bullet you are using. Light weight bullets may not be loaded as long as heavier bullets and heavier bullets get seated deeper and take up powder space.


+1


Aim for the exit hole
 
Posts: 4348 | Location: middle tenn | Registered: 09 December 2009Reply With Quote
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Couple of follow-up comments: I follow the guidelines in my manuals to the letter and I am extremely careful. The only variable I have had a question I have been struggling with is the depth. I have noticed the the length listed in the manuals works well for some bullets but not necessarily all. I have found that I need to seat round nose bullets deeper than others (eg. Nosler Partitions).
 
Posts: 862 | Location: Michigan | Registered: 17 March 2003Reply With Quote
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Rule of thumb, one caliber deep. Then fine tune +/-.
 
Posts: 8169 | Location: humboldt | Registered: 10 April 2002Reply With Quote
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So for a 3006, .308" deep? 7x57 = .284"deep?
 
Posts: 862 | Location: Michigan | Registered: 17 March 2003Reply With Quote
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quote:
So for a 3006, .308" deep? 7x57 = .284"deep?

Yep "Rule of Thumb" not a requirement. If you check first crack out of the box the 300wmag is only .264.

As I stated earlier you can get by with less. but 1 caliber will normally give you firm control over the bullet. Less likely to move while chambering, loading the mag etc.

I had a single shot once that was probably less than 1/2 caliber but treated with kid gloves.

Standards are just standards. If your chamber is not cut to std dimensions then posted oal can't be counted on.

Just me I would set up my oal to give me a short jump. Adjust if needed. If that oal is too long for the mag then seat the bullet deeper until it functions in the mag. If that oal doesn't give me a 1 caliber in the case then I would consider making the oal shorter. All depends on the rifle, use etc.

Trying to cast reloading rules in stone doesn't work.


As usual just my $.02
Paul K
 
Posts: 12881 | Location: Mexico, MO | Registered: 02 April 2001Reply With Quote
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Picture of ted thorn
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This is easy and/or can be complex

1st the easy ones......pistols, autoloading pistols and autoloading rifles

Pistol....load to book length.....check for function in auto loaders.....done

Autoloading rifle....Use mag box length as maximum or book length for these.....check for function...done

Single shot rifle.....these can have any length depending on the freebore of the chamber and often have very long OAL

Google....chamber freebore

Bolt action rifle.....mag box as maximum checking to see if the round will chamber

Decrease OAL length by small amounts of your choice to find the best accuracy

There is no rule for how deep....just opinions

Your chamber and magbox determine OAL then you determine the final OAL with trips to the bench/range


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Posts: 7360 | Location: South East Missouri | Registered: 23 November 2005Reply With Quote
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We've all had to start somehwere. I always suggest starting .010 off the lands (rifling) or the max length your mag box will allow. You're next question then, would likely be...."how do I know my bullet is .010 off the lands'? The easiest way is to use a comparator to measure this.

Since you are so green, and make no mistake that is absolutely fine, I'd just seat them to measure to the SAAMI spec shown in the manual and go from there.
 
Posts: 2276 | Location: West Texas | Registered: 07 December 2011Reply With Quote
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For my bolt actions...I follow the advice on this article: seating depth accuracy Although this was written for their bullets I have found it to be pretty reliable with others as well. The one thing they don't mention is you should start with the .130 off the lands as this will have the least pressure. Just a safe thing to do even though your working with a starting load.
 
Posts: 5 | Location: SW Florida | Registered: 01 August 2015Reply With Quote
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Seat as far out as you can.Measure the distance it takes the bullet ogive to make contact with the rifling and then reduce.Make sure they fit in the mag and feed.
 
Posts: 11651 | Location: Montreal | Registered: 07 November 2002Reply With Quote
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Picture of Austin Hunter
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Minimum of one caliber depth as folks stated.

For the actual optimal length, several things are at play:

1. I usually start with the recommended length from the load data I'm using. It's specific by cartridge, bullet manufacturer, and bullet weight/type most times.

2. For large caliber (say 9.3 mm above) or smaller heavy recoil rounds (say 300 Weatherby) I crimp in the cannelure. For other rounds, say a 308 win, I go with the length that gives me the best accuracy which is usually max length or great in most of my rifles/loads.

3. I usually crimp rounds with a Lee factory crimp die when I'm outside the cannelure and also to crimp into the cannelure. Some folks say crimping increases accuracy whether in or outside of the cannelure; other folks say never crimp the bullet unless you are doing it in the cannelure. I've always had better accuracy doing this as well.

4. Loads - I believe starting with 10% less is a waste of time. I don't start with max, but usually in the middle and work up. In addition, sometimes a max load in the book will be over 100% case capacity and I always try to stay <100% - so experiment with a spent case to see what it while hold and how far you can seat a bullet.


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Posts: 3022 | Location: Austin, Texas | Registered: 05 April 2006Reply With Quote
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Famous last words: "Starting at 10% less loads is a waste of time". "Hey, give me a match, I need to check on the level of my gas tank". "See that hubcap across the freeway? I will cross all the lanes on foot to grab it". "Who says you can't mix bases and acids"? "I always smoke when I refill my propane tank". You get the picture. In reloading, better safe than sorry, period.
 
Posts: 366 | Registered: 30 November 2006Reply With Quote
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On the 10% and waste of time:

It depends on how much you already know about the rifle in question and the lot of powder to be used. If the lot of powder is already known to be a little faster, about medium, or a little slower than "book", then that can be used when estimating some starting loads within 5% of max.

Likewise, if you know that the rifle has a tight chamber then farther away below a max load is prudent, while if the rifle has a large chamber showing expansion at case head (.002"-.004") with factory loads then you may expect to end up over the max book load with safe pressures (60-65k).


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Posts: 4253 | Registered: 10 June 2009Reply With Quote
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It also depends on how close the bullet ogive is to the lands. When you start off at .010 off, 10% charge reduction is not only not a waste of time, it's imperative.
 
Posts: 2276 | Location: West Texas | Registered: 07 December 2011Reply With Quote
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I usually seat just shy off the rifling lead if magazine length permits. I've always been convinced that it was an important step for accuracy (note that many German calibers, 7x64 for ex., have some free bore imposing a certain bullet jump). In fact, their rifling lead is longer and progressive, much less abrupt than U.S. calibers. Still they won't allow a bullet to kiss the rifling but are just as accurate nonetheless.

But then, I recently bought a nice 1903A3 and I loaded some different 150 g bullets to try it out. Not wanting to disturb my dies adjustments as they are custom fit to my Sauer 202 stalking rifle, I loaded 150 SMK, Hornady A-MAX, Rem P-P and WW Silver Tips on top of the same starting load and without changing dies settings : FL, set for partial sizing in the Sauer and seating, set for 165 SGK at .01" from the lands. Results : the Springfield accepted and fed everything, then shot all between 1-1.5 MOA (over iron sights) and at the same POI. Go figure...


André
DRSS
---------

3 shots do not make a group, they show a point of aim or impact.
5 shots are a group.
 
Posts: 2420 | Location: Belgium | Registered: 25 August 2001Reply With Quote
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quote:
Originally posted by Andre Mertens:
I usually seat just shy off the rifling lead if magazine length permits. I've always been convinced that it was an important step for accuracy (note that many German calibers, 7x64 for ex., have some free bore imposing a certain bullet jump). In fact, their rifling lead is longer and progressive, much less abrupt than U.S. calibers. Still they won't allow a bullet to kiss the rifling but are just as accurate nonetheless.

But then, I recently bought a nice 1903A3 and I loaded some different 150 g bullets to try it out. Not wanting to disturb my dies adjustments as they are custom fit to my Sauer 202 stalking rifle, I loaded 150 SMK, Hornady A-MAX, Rem P-P and WW Silver Tips on top of the same starting load and without changing dies settings : FL, set for partial sizing in the Sauer and seating, set for 165 SGK at .01" from the lands. Results : the Springfield accepted and fed everything, then shot all between 1-1.5 MOA (over iron sights) and at the same POI. Go figure...

Sine when do you shoot with iron sights?
 
Posts: 11651 | Location: Montreal | Registered: 07 November 2002Reply With Quote
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André
DRSS
---------

3 shots do not make a group, they show a point of aim or impact.
5 shots are a group.
 
Posts: 2420 | Location: Belgium | Registered: 25 August 2001Reply With Quote
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I set up my chamber throat and magazine to agree with each other and strive for one caliber depth with one of the heavier bullets..Examp: 160 gr. Nosler in the 7x57 seated .284 deep in the case or the 200 gr. 30-06 seated .308 deep..I get 100 to 150 FPS more with proper powders, and at the same pressure level as the std set up. I pretty much ignore crimp grooves in bolt action rifles, never have seen the need unless you get up into the real kickers and even then I tend to use a bulk powder, and a tight neck purchase by turning down the expander ball a thousands to three thousands, and then use a very light crimp to hold the bullet where I want it.

That's just one way of doing it, and I have been very successful with that method so I use it on most all of my rifles...


Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120

rayatkinsonhunting@gmail.com
 
Posts: 41763 | Location: Twin Falls, Idaho | Registered: 04 June 2000Reply With Quote
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Depends on the bullet and rifle. I find that Barnes TTSX and TSX like a bit of jump so I seat them a bit deeper. The few longer range bullet I load, Speer Boat Tails and Nosler AB's, I like to get them a bit closer to the lands. But, even this depends on the rifle.


Start young, hunt hard, and enjoy God's bounty.
 
Posts: 383 | Location: Oklahoma | Registered: 24 December 2011Reply With Quote
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I have shot very few Barnes so I cannot speak much about them, but I have always just taken the projectile I wanted to load for, and pushed it tightly into the leade with an unloaded, unprimed case. Then I carefully remove the dummy round, measure the overall length, and back off to a nice round number, typically no more than .010" shorter than the dummy. I then load to that COL and work up the load.

I can't tell you the last time I had a round that wouldn't fit in the magazine box doing it that way... but maybe I have just been incredibly lucky.
 
Posts: 4748 | Location: TX | Registered: 01 April 2005Reply With Quote
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A good idea is to lightly put a bullet in the lead, just a bullet not a round..tap in very lightly. then using a wood dowl down the barrel to touch the bullet point..mark the dowl with a knife edge at the crown..

Then remove the bullet, close the bolt and reinsert the dowl and mark the dowl at the barrel crown once more with the knife edge.
'
Measure the distance between the two marks and you have your max length..I usually back say .010 to .050 or whatever, and that depends on your chamber and magazine.

This is the most accurate way I know of, and you can modify it anyway you wish. but you must do this with each individual make and/or weight of bullet to allow for the differences in the ojive..


Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120

rayatkinsonhunting@gmail.com
 
Posts: 41763 | Location: Twin Falls, Idaho | Registered: 04 June 2000Reply With Quote
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