First, thanks to all that have answered the myriad of questions I have had on reloading issues. I have a problem I want to discuss. I have this fine 375 H&H that is troublesome. I have sevral dies available to me and still get variations on bullet seating. I have tried to seat bullets with a Redding die, Lee Collet die, Bonsnza die and a Vickerman clone made by Fred Zegland at Z-Hat. I am using a Bonanza press and each bullet I seat Regardless of choice of bullet seater results in a different OAL. How can one get good predictable results and accuracy when you get varying bullet/Cartridge lengths??? I have this trouble out of same lot boxes of Barnes 270gr. TSX. What is the culprit in some groups that are tight for three or four shots and then throw some fliers?? Really confusing.

I like a seating stem that only touches the bullet on as close to it's diameter as possible. Then, in theory, one is seating it as it will engage the lands.

So pick the seating stem that's as close to this description or drill one out larger and polish it.

One can make quite a good "lathe" from a 1/2" electric drill held in the jaws of a bench vise.

Consider that the OAL that counts in terms of accuracy might be the ogive that touches the lands so use a Sinclair type "nut" to measure that OAL. You can make one from something if you don't have one.

Square shooter,

I notice a similar problem when I was developing a load for my 9.3x62mm with the 286grn Barnes X.

Firstly, how are you measuring the COL and what sort of variation are you getting??? I used a Stoney Point comparitor which clamped onto my caliper and I noticed that it was quite easy to read a variety of different measurements for the COL of the same cartridge, and as a result I had to be very careful to get any consistency. I think there are better system out their now than the Stoney Point such as the Sinclair.

Next, have you tried measuring some of the TSX bullets both for overall length and then length to the Ogive? Again I noticed quite a variation when I did this with the 286grn Barnes X. In the end I gave up and loaded the rounds to a compromise length based on Barnes recommendations, the distance to the lands and what would fit in the magazine.

If I do my part I get groups between ¾†and 1†which I am more than happy with…What size groups are you getting by the way?

From a more practical perspective, how about loading up say 25 rounds, and mark the measured COL to the ogive on each case with a permanent marker pen…At the range, shoot for groups and you should be able to determine if the fliers match the rounds which were showing any significant variation..

Regards,

Pete

There's no such thing as a Lee Collet seater, but that's irrelavent to the discussion here.

If, with any properly mounted and adjusted die, the cartridge overall length varies, it is due to inconsistencies in the bullet ogives. Since the seater plug engages the ogive at a given diameter, if that diameter falls further up or down the bullet nose, then the COA will vary accordingly. I had not heard of a particular problem with the Barnes bullet, but that is where the problem appears to be from your description.

To check it out, take a caliper and set the jaws to approximately the inside diameter of a seating stem from one of your sets of dies, say .330". Then, lower the calper jaws over an upright bullet to see how far down it goes before it comes to rest at the .330" diameter on the radius of the ogive (or slope of the spire). Do this with a sample of bullets, say 10, and see if there are variations approximately corresponding to the variations you are finding in your loaded ammunition.

Let us know what you find.

Stone Creek, there is a bullet seating die with each Lee collet die set, what ever you want to call it. I don't know how else to describe it.I like your suggestion on measuring where the specific mark falls on a set of these bullets. I set up the die so that my OAL is about 3.85. That is about .015 short of the moal for my magazine box. My loaded rounds measure from 3.79 to 3.92. I surmize that the bullets must vary by a similar amount. These bullets appear to be from the same lot. The Nosler Partition 260gr. loads are wonderfully accurate and consistant in this rifle.

Pete E., The technique you suggested is what I am doing. The bullets measure .028 average out 10 bullets. My 375 will shoot 3-4 shot groups into about 3/8?1/2"at 100 yards one time then the next group witl open to 1.25". We have checked case run out issues, bullet run out issues, and now are working on bullet inconsistancy issues. If one uses a vickerman die to seat bullets and the bullets are deminsionally similar then the length of the loaded round should be close, shouldn't it???? I really want to shoot the 270gr. TSX this fall in Africa but am buggabood about this load. I just might have to look for a different load that is more stable. I have just ordered 200 rounds of RWS brass to see if the consistancy can be improved with better quality brass. Who knows what to do next? By the way, how long have you been loading your 9.3x62? We have about 10 of them we have worked with over the last 20 years. I like the 250gr.X and Mike Brady's soft point. Our loads are fast and accurate. Have you tried the 300gr. Swift A frames or the 320gr. Woodleighs in your rifle yet? My rifle shoots the 320's(soft and solids) into the same hole at 100 yards. My rifle does not like either of the Nosler bullets and that is a first for me. Perbaps I need to develope a different powder for it. If the 375 doesn't settle down soon we will be taking a 9.3 instead.

lb404,

I would be interested to know what variation you get when you just measure the bullet heads straight from the box..

With regards to my 9.3, I am relatively new to it. It was bought for my recent plainsgame hunt and at the suggestion of Saeed, I worked up a load with 286grn Barnes X...

The "problem" with my CZ is that it has a very long throat, although it has a magazine to match, so its not too bad. To give you an idea, the COL for my Barnes load is 3.404" while the official max COL is 3.290".

I've also tried the 270grn Speer, but can't get that to group as yet...When I load it so its near the lands, I have only just enough bullet in the neck, in fact loaded like this even if it did group well, I would never trust it to hunt with...

Getting some of the other brands of bullets in .366 is a problem in the UK, but I would like to try them particularly the A Frame and perhaps a solid too...I would also like to try casting my own, but have not got the facilies to do that as yet..

Regards,

Pete

Pete E.We are loading 250 gr. X bullets with 63gr. IMR4895 and the velocities run 2650f/s. Very accurate in all of our guns.I also load my rounds out to 3.34 OAL with .05 lead to lands.

Looking at it simply, I thought COAL was measured to the bullet point.
The length to the point of many bullets varies quite a bit, without effecting accuracy.
The seater "cup" works on the ogiv (usually) so the distance to the lands would be fairly constant.
Also I think a lot of people regard the distance to the lands as too important in the great scheme of things.
John.

Ib404 have you checked the Ojive from the base of the bullet's? I always sort my bullets from the base and Ojive first. Then work with the bullets that are the shortest first. As long as the Ojive is the same, then the loads should group the same.

Have you tried a different lot of bullets to see if what you have is a bad lot?

By the way . . . I just remembered that when I bought my .375, the seller threw in some Barnes 235 X-bullets he had. In examining them, I found that some of them were made with spire points (secant ogive like Hornady's) and some had the more common tangent ogive. I have to assume that they were from different lots (and neither shot for crap in my gun), but they would almost certainly have loaded to a different LOA if using the same seater stem setting.

take one of your bullets and chuck it in a drill. Apply lapping compound to the bullet. Now, hold the seater stem up to the bullet while spinning it in the drill. Repeat as necessary and then spin a rolled up peice of 600grit paper in the newly lapped seated plug. That will orient the shape of the seater plug to your bullet and will greatly help to reduce runout.

secondly,..when measuring for purposes of land contact data,..the only way to do it with consistent results is to measure from case head to ogive with a comparator. Trying to use the tip of a bullet will ALWAYS give varying readings as the jacket being drawn up around the core and into a point will always be different from tip to tip,..even in match bullets. That is why the meplat trimmer tools were invented,..so the bullet tips could be uniformed in length and therefore BC as well.

Alright,
bm-3; What tool do you use to measure the base to olgive length on each bullet. If a reasonably easy task then it could be practical for making hunting loads. When I set a load for a rifle I make up about 100-200 rounds out of the same component runs in order to get the consistancy I require. Measuring the bullets would be time consuming but worth it if it will build consistantly accurate ammunition.

JustC; The idea of modifying the seater to accommodate a ssspecific bullet would require a different seater for each buller. I dont think I would want to do that. Is there anything else to do?

My current plan is to use a new batch of RWS brass. Full length size it. Uniform the primer pockets and deburr the flash hole. Trim them all to the same length. This is the way I prep all of my brass. If I get no consistancy after sorting the bullets on length then I will go back to square one and work up another load. Is there anything I am forgetting?? I really want this rifle to shoot.

I use Stoney Point tools. It takes a little time to get started, but once you get going it takes no time at all.

I use a Sinclair Bullet Comparator to measure the ogive of my bullets for length.
http://www.sinclairintl.com

As others have said you can’t measure from the tip of the bullet it is not consistent.

lb404,..the modification in my experience, makes the seater much better with most all bullets. I find that they don't like the longer nosed pills because their shape is somewhat default set for a more rounded nose profile. Todays bullets are becoming very streamlined,..and even the large bore versions will exibit this. One thing to remember,..if you modify it, you can always call and get another one shipped to you for free or very little money. I changed my runout dramaticaly after orienting the seater to grab the bullet furhter down toward the ogive. When it has been unpolished/lapped, it often will grab the pill at too high a point on the nose, which will help to cause "cant" and exagerate the runout. The further down you have the seater grab/contact the bullet, the more straight it will seat it. That is just a suggestion that has worked for me. Sometimes these ideas we have really pan out,..then sometimes we ruin a part of our equipment (grin),..this one works for me. HTH