Okay folks: seems like I see it time and time again "I start with shooting the bullet .01 inch off the lands" and that seems to be standard starting place. But, what about us folk who have rifles with freebore so great that we can't get enough bullet base into the case neck so the bullet rests .01 inch off the lands, or even .07 inch off the lands without the bullet looking like the Italian Leaning Tower. Don't say just simply go to a heavier bullet because even with Hornady 175 grainers there still is very little bullet shank going into the case mouth. This is especially obvious with boattail bullets, but also it happens with flat-based bullets too. I know there are other sweet spots along the bullet shank for seating depths, but how does one go about finding this depth without having to buy up 500 bullets and loading five rounds in .005 increments only to find out the rifle may not like that bullet and then having to start the whole process over again with another make of bullet? Some bullets don't have canlures (Sierra and Barnes come to mind), so I can't judge from there. My rifle is a CZ550 American in 7x57mm Mauser (I love this caliber). The magazine length is such that I can load 3.6 inch cartridges, but then feeding the round into the chamber would be a heck of a problem. I contacted the Kansas City, Kansas, CZ people and they told me that all CZs in the 7mm have a lot of freebore. So, what is the magic formula for finding the proper seating depth with a rifle that has a tremendous amount of freebore. Thanks ... Tom Purdom

Tom,

Since your barrel has excessive freebore there is not much you can do other than lopping off some barrel threads and running another reamer with less free bore.

However, what I would do is load the cartridges so they feed reliably from the magazine and try to keep them as long as possible. You can play with seating depth and neck tension to help give better results.

I wouldn't get to hung up on trying to reach the lands. If this is a hunting rifle I wouldn't want to be near the lands anyway.

So go shoot this barrel out and rechamber it later with a reamer that fits the bullets you like to use.

Ciao

Mike

European rifles have larger freebore than American ones. I have such a freebore in my Sauer Drilling 6,5x57R. I load with 156 grains round nose, pretty long bullets, but I think the LOA could be a quarter of an inch more. So I have given up to load close to the lands. But I still get good accuracy with the gun: 1" at 100 yards is quite acceptable for a soldered barrel.

I don�t think you have to worry about the freebore - go on shooting with the rifle.

Best regards,

Fritz

Do a search on "Deep Throat" in this forum and you'll find a thread on this a while back about my Mark X .30-06.

Basically I adhere to the following list of priorities:

1. Make sure there's at least a bullet diameter's worth of bearing surface in the case neck;

2. If #1 is OK, make sure the round will fit in the magazine and feed correctly;

3. If #1 and #2 are a go, seat 0.030" from the lands.

So, I came up with a few options that worked OK:

* Hornady 180-gr. SP seated 0.030" from the lands, which gets about 2650 fps with a max. charge of IMR 4350;

* Hornady 190-gr. BTSP seated so it's got 0.30" of bearing surface (i.e., the boattail section doesn't count) in the case neck, which gets about 2640 fps with a max. charge of H4350;

* Sierra 220-gr. FNSP seated as long as will feed, which is about 3.360" in my rifle, just a hair over SAAMI specs, which does 2400 fps with a charge about half a grain short of max using RL-22.

All of these go about 1.25" for 3 shots at 100 yards, which is adequate for a general purpose hunting rifle IMHO.

John

I would ask the shop I buy my supplies to let me measure there factory ammo and record those seating depths as a place to start. Some rifles like the bullet seated deeper in the case. Your only other option is load three rounds at each seating depth until you find the sweet spot. Some free bore rifles will not give better than MOA groups no matter where you seat the bullet.

I would choose my die set, my brass, and my bullets very wisely. One of the main reasons for seating close to the lands is to avoid many ill effects of runout. With excessive freeboar it is very important to maintain as little runout as possible. Neck size only, and move the seating around a little until you find the sweet spot in the harmonics. When it's all said and done you should be able to shoot good groups, and maybe even see a little added velocity. Good luck, ~lokey

I've got a 6mm Rem with quite a bit of freebore...many of my loads seat over 0.1" over SAAMI specs to get within 0.01" of the rifling. I wanted to build a nice 55-58 gr varmint load soon after I got the rifle, and was very suprised to see I couldn't get close to the rifling with that small a bullet unless I just barely seated in the case.

I can't say I finished that project, but I'll go back to it soon. I have noticed that my rifle has a cyclic sweet spot...seating the bullet at 0.015" to 0.020" increments (depending on the bullet) finds a point where accuracy is noticeably better than at other seating depths. But I've found it's trial and error at first...load some up at progressively deeper depths until I find one that's true. Goes through a lot of bullets, yes, but it also makes for some excellent shooting practice as a bonus.

The idea to measure some factory loads is a good one. The various ammo makers seat their bullets to the aprox. depth that most rifles will shoot well with for their bullets. That's likely a good place to start.

I couldn't do that with my 55-58 gr load project because no one sells a 6mm Rem offering with those bullet weights.

Hope this helps.

TXLoader

You really don't need to measure factory rounds. The reloading manuals all publish the cartridge OAL. Start with that and adjust for the best barrel harmonics by varying the seating depths out.

Adjust seating depth and neck tension;full length sizing and neck sizing...

To all who replied ... thank you so very much for your time. Each reply is much appreciated. Tom Purdom

Thomas,
With that kind of freebore, all you can do is seat bullets out as far as the MAGAZINE, will except them, then shoot them and see if they shoot..they usually do in a good barrel..I have a couple of Brno 22F and 21M's that will seat a 175 gr. bullet one caliber into the case and they still have to make a jump...Both of these guns will shoot a 130 Speer into an inch and those pills must jump an inch....

Roy Weatherby had long throats, The new Rem ultra, and all the newbies on the street have damn near a 1/2" of freebore because the pressures were to high without them and they wanted the hype of velocity and that's how they got it and many of them shoot fantastic groups...

Only one way to tell what shoots in any rifle and that is shoot it and let the theory boys be damned...I figured that out 45 years ago...

------------------
Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

I don't agree with Ray, just cause they're seated long doesn't make the load accurate. In fact, many times the opposite is true. Longer means less bullet in the neck, this means less tension. I've found poor bullet pull likely leads to high deviations in velocity, which causes strung groups (even in the best rifles). High runout(>.003")is another problem with long loads, as is balloning of the bullet. I would start with about half the bullets diameter inside the neck (if it's .30 cal seat so there is .15" of bearing suface inside the neck, don't include the boat-tail, if you're shooting them). Give that a try, see if it works out, and take a look at my first post too, precission handloads are your only hope. Good luck again, ~lokey

[This message has been edited by lokey (edited 12-08-2001).]

Lokey,
You have misinterpeted my post all together.

what I said was all that theory is just bunk, you have to TRY the loads to know what does and does not work and thats the bottom line, some do and some don't...Lots of long seated loads shoot in some guns and I have several that shoot that way. They also give one more powder space and thus more velocity. Lots of Mausers will shoot better with bullets set out near the lands, and many will shoot well seated short even though they have to make that long jump to the rifling, with is according to theory is detrimental to accuracy which you in effect just denied...

------------------
Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

Hi all: Got some feedback for you on that CZ550 American in 7x57mm Mauser. I still have a load of testing to do, and these are very, very preliminary, but do show a boat-load of promise. After glass-bedding the action area and leaving the barrel free-floated and leaving the glass-bed to cure for a good week, I took two loads and some limited time with me to Bonita Canyon in the Zuni Mountains near my home in Grants. I went with the majority rule and seated to the canlures. I loaded the 139 grain Hornady SSTs and the Hornady 162 grain boattails.
The 139 grain bullets were seated just to the bottom of the canlures and were loaded with 52 grains of H4350, virgin Remington brass full-lenght sized for the first firing, Federal match primers. That 52 grain load was really compressed after the bullet was seated. The overall lenght was 3.00 inches and the overall length to the lands is 3.312 for a jump of .312 inches to the lands.
I have to admit that my shooting setup is not ideal. A good backdrop against a clear mountain and off the back of a pickup tailgait using sandbags. Wind was gusting up to 15 miles per hour and the temperature was 43 degrees.
The 162 grainers were loaded so the top of the case mouth came to .015 inch below the bottom of the canlures. Overall length was 3.075 inches and with that bullet it is 3.255 for a .18 inch jump to the lands.
I only had five rounds each left, so there is a lot more bullet seating depths to be tested going from the bottom of the canlures toward the base of the bullets.
After zeroing the rifle and, at the same time, letting the barreled action settle again into the stock I got:
1. 139 grain bullets, 1.16 inch group with 5 shots. two shots touching and three others not touching, but slightly to the left of the first two.
2. 162 grain bullets, .68 inch group with five shots, two shots touching in a figure eight, and three just to the left all touching in a small vertical line.
I need to go back out next weekend to make sure this was not a fluke. I only wish I had a more solid rest, but I waited until some plastic strips I tied to a stake were not flapping in the breeze on each shot and I let the rifle rest in the sandbags, not pushed into position in the sandbags. I think both these bullets and powder show promise, especially the 162 grainer, but again, I need to go back out with 10 rounds each of the loads and see if there is a duplication, near duplication or if what I did out there this weekend was a fluke.
If these are indeed valid groups, I will move the bullets closer to the lands in .005 inch increments until the groups close up, or open up.
Thank you all for your advice. Each bit was very much appreciated. Tom Purdom

It's for dang sure that not every gun likes the bullet seated out to the lands. I have a heavily customized Model 700 in 300 Win Mag that I spent several months trying to work up an accurate load in. Since conventional wisdom said load bullets out to the lands, I did -- .020, .040, .010 even (stupidly).000. But no matter, best groups I could get were 1 1/2 to 2 inches.

I knew the gun would shoot because the gunsmith that did the customization shot a 10-shot test group that measured right at 1 inch WITH FACTORY AMMO!

Then I started thinking -- what made the factory ammo different from my handloads? The only thing I could come up with was the length of the seated bullet from the lands. So I tried loading some Grand Slams right down to the cannelure, which is way, way off the lands. My first group was 3/4". So was my second, third and every group there after (MOA or better, that is).

Don't know the reason why, but goes to show that every gun and chamber is different.

[This message has been edited by GAHUNTER (edited 12-11-2001).]

1 Start with a clean throat! Self-explanatory
2 Choose powders which make for a compressed or near compressed load.
3 Sort your cases by neck variance. Sinclair makes the tool at www.sinclairintl.com