bullet setback

[claynut69]

I am reloading 300WSM and was wondering on bullet setback from OAL. Should it be .002, .005, or .010? Trying to get the most accurate load I can work up. Didn't know if I was to close to the lands if pressure spike would affect accuracy.

[Multidigits]

The rule is not excede OAL. Each rifle is different as to where the rifling starts in the chamber. You can measure it with several devices on the market or with a round with the bullet seated out long until it contacts. Read a reloading manual on how to do it.

If your crimping your bullets, and the bullet has a cannelure, just use that as a good point to seat to. Crimping is a good idea for hunting loads and especially if your hunting with a heavy recoiling rifle.

[tomtom78]

To preform what Multi is speaking of,
Take an empty, fired case. Run it partly in the sizing die. Just enough to size the mouth enough to hold a bullet snugly but not tight.
Place a bullet in the mouth of the shell leaving it sticking all the way out.
Put the shell in the chamber of your rifle, then slowly close the bolt.
Now remove the shell carefully to prevent the bullet from moving in the casing.
Measure the OAL. Repeat this process several times to get a consistant length.Keep a record of finished OAL with that bullet stock.
Now set your bullet seating die to seat the bullet .005-.010 deeper.
Every bullet has a diffrent ogive(the curve of the bullet nose). Repeat this process with each diffrent type of bullet to determine the chamber length for each application.

[mwezell]

What tomtom is saying will give you what is called your "jam" length. This is a good place to start for accuracy load development as you only have one direction to go from here in terms of OAL. That is of course shorter. Seating depth will have some impact on pressures so reduce loads and work your way up. Then do the same after adjusting the OAL about .003" shorter at a time until you find it's sweet spot. In a hunting rifle, where function is critical, I like to start at just touching the lands versus jam because it will likely create extraction problems of a loaded round if the bullet is jammed hard into the lands. But for target shooting, alot of guns like the bullet jammed hard. Magazine length is also a limiting factor in some guns. Depending on what kind of gun it is, it may be easier to find jam length by removing the extractor and closing the bolt on a "long" dummy round and then opening the bolt and pushing the round out with a good cleaning rod. Just be careful not to damage the crown this way. There are alot of things about reloading that will affect the way a gun will shoot but I think seating depth is possibly the most important, assuming that you are doing everything else right. I look for a load that will give a nice tight "clover" and then adjust seating depth and powder charges in small increments. Only change one thing at a time. Start with a known good powder for that cartridge and you will find a good load for your gun. Load development can take some time but is very much worth it. You may know all this stuff but maybe it will be of help to others as well.---Mike Ezell

[steelslinger]

As said, each rifle is an individual

Lyman manuel 48th edition is considered by most the best tool a reloader can have. But you need at least 2 manuels, 3 is better. It is good to have a manuel from the bullet mfg and the powder mfg that you are using.

Some guns like bullets in the lands, others like the "jump to the lands". Lyman suggests .005" from the lands. As you seat deeper, you take up case capacity in turn increasing pressures. When you start touching the lands you increase pressure. Powder charges must be adjusted if signs of over pressure arise (black soot around the primer or flattened primers)

When developing a load always use referenced starting powder charge weights. If you are at max charge or pressure, then you CAN NOT start messing with bullet depth settings.

Also, different bullet brands and weights will like different seating depths. Part of the fun with reloading is learning more about your gun and knowing what it likes and don't like.

In my .308, the 150gr Sierra sbt Gameking likes .002-.003 off the lands, but the 168gr Sierra hpbt Matchking likes touching the lands(not jammed into,and a different powder)

I shoot Imr 3031 with the 150gr and Varget with the 168gr (difference is only in the velocity as both group well @ 100yds) and niether charge is at Max.

Once I found the depth my rifle liked with a particular bullet, I made dummy rounds with those bullets and keep them in my die box along with a note. This makes setting up your dies that much easier the next time.

I also write on the dummy which bullet and seat depth such as.......
sgk 150 .002 but everyone has their own way of doing things.

A note on crimping, crimping is a good idea on any rounds, it provides even neck tension for more consistant bullet release. Some may argue that, but just about every top competition bench rest shooter crimps, must be something to it.

Not trying to sound demeaning, as I don't know your experience with reloading.
Some of this is repetitive of other posts, thats usually an indicator of being important.

[mwezell]

As said, each rifle is an individual

Lyman manuel 48th edition is considered by most the best tool a reloader can have. But you need at least 2 manuels, 3 is better. It is good to have a manuel from the bullet mfg and the powder mfg that you are using.

Some guns like bullets in the lands, others like the "jump to the lands". Lyman suggests .005" from the lands. As you seat deeper, you take up case capacity in turn increasing pressures. When you start touching the lands you increase pressure. Powder charges must be adjusted if signs of over pressure arise (black soot around the primer or flattened primers)

When developing a load always use referenced starting powder charge weights. If you are at max charge or pressure, then you CAN NOT start messing with bullet depth settings.

Also, different bullet brands and weights will like different seating depths. Part of the fun with reloading is learning more about your gun and knowing what it likes and don't like.

In my .308, the 150gr Sierra sbt Gameking likes .002-.003 off the lands, but the 168gr Sierra hpbt Matchking likes touching the lands(not jammed into,and a different powder)

I shoot Imr 3031 with the 150gr and Varget with the 168gr (difference is only in the velocity as both group well @ 100yds) and niether charge is at Max.

Once I found the depth my rifle liked with a particular bullet, I made dummy rounds with those bullets and keep them in my die box along with a note. This makes setting up your dies that much easier the next time.

I also write on the dummy which bullet and seat depth such as.......
sgk 150 .002 but everyone has their own way of doing things.

A note on crimping, crimping is a good idea on any rounds, it provides even neck tension for more consistant bullet release. Some may argue that, but just about every top competition bench rest shooter crimps, must be something to it.

Not trying to sound demeaning, as I don't know your experience with reloading.
Some of this is repetitive of other posts, thats usually an indicator of being important.

I agree with everything you said except the part about Benchrest Shooters. I don't know a single one that crimps on a BR cartridge.:confused:

[steelslinger]

Let me rephrase that......

Of the br shooters I know, that shoot in the sporting class (think thats right), shooting factory guns, tell me that crimping is more accurate (.005-.1") I know, that wouldn't make a hill of beans to a deer.

True br guns are built to such tight specs that even the dies they use are of higher tolerences (even machined to fit chamber casts). Those guns would not benifit from crimping.

Sorry I didn't explain myself more. I was thinking along the lines of a factory rifle.

[rick243]

I have always set the bullet to just touch the lands in my varmint rifles and then adjust only the powder charge. In larger rifles I would seat the bullet at least .010" back to avoid any bullet sticking problems.

That said, Barnes recommends to seat all their bullets .050" back from the lands. I set the 130 gr. TSX in my .264 WM .050" off the lands and getting cloverleaf groups with this load. Great bullets but a little pricey.

There are some neat hi-speed videos on Barnes site if you haven't been there lately.
http://www.barnesbullets.com/

[mwezell]

Barnes does make a good bullet. If anyone is interested, I am about to start making custom 30 caliber Benchrest bullets. They will be in the 115-118 grain range with a 7 ogive. For anyone of you that want a true handmade custom target bullet to try in your 30 caliber guns, let me know. They will be in the same price range as any good match bullet. I have used bullets of this same basic design in hunting applications and they worked well. Forgive me for the free ad but these are something that you don't go to the local sporting goods store and buy so I don't feel as though I am competing with our sponsors with this product. Many people are not aware that you can actually make your own jacketed bullets. They are a specialty bullet for the reloader who wants the best he can get. Mods, feel free to delete if you feel this is too much and I understand but I feel it is informational to many.---Mike Ezell

[Hope Carleton]

Mike,
Good luck with your bullet making endeavor. It may be of interest to know the "maker" of your dies and the jackets you use. Do you plan on any "lighter" .30's in the furure? I would assue with your working with the .30 Major (Grendel?) that you may try some in the 110-112 gr range?
TIA for any info, hope to see you at a match in the future.....
-H

[mwezell]

Mike,
Good luck with your bullet making endeavor. It may be of interest to know the "maker" of your dies and the jackets you use. Do you plan on any "lighter" .30's in the furure? I would assue with your working with the .30 Major (Grendel?) that you may try some in the 110-112 gr range?
TIA for any info, hope to see you at a match in the future.....
-H

The dies are Corbin dies and will be using 1.00" J4 jackets.
I think the way to make the very best and most consitant bullet is to first find what will work and don't remove the die until you complete everything that you can on every bullet/jacket. Consistancy! I will likely be settle on a weight between 110-117 grains with these jackets. Once I find what works best the dies wont be adjusted for any different weights or configurations. Consistancy. Isn't that what it's all about? They will be very close to the Euber,Fowlers and BIB bullets made on the same jacket.
Still waiting for the press and dies. Got jackets and earlier.

[gurn]

A good cheap OAL tool can be made by taking a sized case, then cutting two small slots with a dremel tool across from each other in the case neck. The bullet will fit snug, but not to tight to slide back when closing the bolt.

[rarebreed]

I hold a bullet against the lands with a pencil and run a steel rod down the barrell and measure the rod sticking out with the deph gauge on digital calipers, then close the action and repeat the first step without the bullet. That will give you the over all chamber length with that bullet