300 weatherby bushing size question

[TonyQ]

I am reloading my 300 weatherby with Redding S bushing dies and the bushing that I have been using is the .332. I did this with the Berger 215 hybrid that measures .333 at the neck of a loaded round. Now I changed to the Berger 230 hybrid and I measured a loaded round and it measured .330 and I I get a bushing for it it would be .298 which seems small. I looked at the Redding chart and for the 300 weatherby the range is .332-.336. Is .298 too small for the cartridge. Thanks Anthony

 

[dok7mm]

Measure a good number of bullet diameters from both lots of bullets and you should find the Bergers are very consistent. Then measure case neck thickness at 4 points on 10-20 pieces of your brass, if you have a ball micrometer. I suspect you will find it is the varying case neck thickness causing the problem ( different lots of brass ???). Then sort your brass accordingly.

 

[robert6715]

Now I changed to the Berger 230 hybrid and I measured a loaded round and it measured .330 and I I get a bushing for it it would be .298 which seems small. I looked at the Redding chart and for the 300 weatherby the range is .332-.336. Is .298 too small for the cartridge. Thanks Anthony

I think you want a .328 bushing, not .298.

Rob

 

[Pdvdh]

.328" seems too small for a neck bushing. The smallest I've used on .308 calibers is 0.330", and that's because I outside neck turned the case necks on those casings. This on a 30/375 Ruger Improved - so not a 300 Wthby. My 300 Win Mag uses a 0.332" neck bushing.

I doubt that the Berger .308 230gr Hybrids are 0.003" smaller in diameter than the 215gr Hybrids your were previously loading. Which leaves one of two remaining possibilities.
1) Your casings now have much thinner case neck wall thickness;
2) Your case neck OD measurements with 230gr Hybrids seated in the case necks are incorrect.

If you have any of the 215gr bullets left, measure their OD on the bearing surface compared to the 230gr Hybrids, to help diagnose the source for the difference in loaded case neck OD.

 

[4xforfun]

I am reloading my 300 weatherby with Redding S bushing dies and the bushing that I have been using is the .332. I did this with the Berger 215 hybrid that measures .333 at the neck of a loaded round. Now I changed to the Berger 230 hybrid and I measured a loaded round and it measured .330 and I I get a bushing for it it would be .298 which seems small. I looked at the Redding chart and for the 300 weatherby the range is .332-.336. Is .298 too small for the cartridge. Thanks Anthony

First.....you either have a measuring tool problem or a measuring problem. I shoot a pile of 215's and 230's out of a 300 wby and WSM and have NEVER seen a difference in loaded neck diameter. I use a .334 neck in all of my 30 cal's (WSM and WBY) and run tight tollerances, so I measure often. You need to re measure.

Second, in all of the tubes that I have ever (precision) loaded for....especially for 1000 yard BR...once I found the optimem neck tension it never changes. I would experement with different bullets/powders/seating depths/neck tentions. In every case, the neck tension that worked the best was the same in all load combo's. Now, when ever I decide to tweak a load or do a major change..the one remaining constant is the neck tension.

Platworth,

There are some weirdow's out there as far as bushing size. I ran 300 wbys with a .330 chamber since the late 1990's......loaded rounds at .328., and I ran bushings as small as .322!! My first 1000 yard comp gun used the same reamer (Clay Spencer). I have since gotten my own 300 Wby AND wsm reamers at .334 NECK and run from .328 - to .332.

Good luck,
Tod

 

[Pdvdh]

Yeah, I suspect some source of case neck OD measurement error also, since Tony didn't mention the use of new/different cases, and the odds of Berger's bullets being out-of-spec on bearing surface diameter is miniscule. Now if Tony has switched to using different 300 Wthby casings, that opens the possibility of thinner case neck walls on the different cases.

My 30/375 Ruger Improved has a chamber neck of 0.337". I outside neck turn pretty significantly on my 375 Ruger casings after necking them down to accept the 215gr Berger Hybrids. Because of that, I did have to order a 0.330" neck bushing. Prior to that the smallest neck bushing I'd used on .308 caliber case necks was 0.331"

 

[TonyQ]

Sorry it took so long to respond I was in a accident and my 3 week old truck was hit and now it needs a new frame and bed and bumper. Thanks again for the help. I am using the same Norma brass so that didn't change. But what did change was the dies I used. I went from the standard RCBD dies to the Redding S Bushing dies. When I measured to buy the bushing dies it was .333 with the Berger 215 hybrid so I ordered the .332 bushing and loaded the 230 hybrid with the S bushing die. I have been reading that most people say use -.002 for hunting rounds. So I measured the other day some round I had loaded with the .332 bushing and it came out to .330 and that's when I was surprised when I saw the number. I measured a fired case and it was .333 and that why I was asking about using the .328. Thanks again Anthony

 

[4xforfun]

Measuring a fired case means nothing. You need to use the loaded round measurement when selecting your bushing.

Using the proper bushing is a big deal when shooting at longer ranges. Find the correct size and you can seriously reduce the vertical on target. I run anywhere from .001 to .003 under loaded measurement. The easiest way to test is to shoot your tests at longer ranges. It is tough to decipher vertical when shooting groups at 100 yards. Test as far out as you can. I do my testing at 750.

Good luck,
Tod

 

[TonyQ]

I checked 15 rounds and they were all .330 so I will use the .328 bushing it just seemed small to me. I was just curious if anyone else has gone that small.

 

[4xforfun]

I checked 15 rounds and they were all .330 so I will use the .328 bushing it just seemed small to me. I was just curious if anyone else has gone that small.

I gotta say that you still have a measuring/tool problem. lightbulb lightbulb A .330 loaded round equates to a .011 neck thickness. The only possible way that the necks are that thin is if you neck turn. I have shot about every brand of brass out there in 300 WBY. I didn't read anything where you said that you neck turn. Try and barrow another tool from a friend. I suggest a Micrometer instead of a caliper.

 

[Pdvdh]

Try and borrow another tool from a friend. I suggest a Micrometer instead of a caliper.

I would agree. No sense going thru the hassle of purchasing a 0.328" neck bushing and then finding out it's smaller than ideal. The information provided leads one to question your digital caliper measurements. Take some of your loaded rounds to someone with a different set of calipers or a micrometer, and confirm what the loaded neck ODs are before ordering/purchasing the neck bushing. Unless you have some other way of confirming your calipers are properly calibrated and providing accurate measurements.

 

[TonyQ]

I will give it a try and see what it looks like. They are matco calipers usually there stuff is top notch.

 

[4xforfun]

Usually 300 WBY brass is in that .014- .015 range. If it is .014 thick you should be getting a .336 loaded measurement.

.308 + .014 + .014 = .336

.338 if the brass is .015 thick.

 

[dok7mm]

Measuring a fired case means nothing. You need to use the loaded round measurement when selecting your bushing.

Using the proper bushing is a big deal when shooting at longer ranges. Find the correct size and you can seriously reduce the vertical on target. I run anywhere from .001 to .003 under loaded measurement. The easiest way to test is to shoot your tests at longer ranges. It is tough to decipher vertical when shooting groups at 100 yards. Test as far out as you can. I do my testing at 750.

Good luck,
Tod

4X, if you meant measuring a fired case's outside diameter with calipers means nothing as far as bushing selection goes, I agree 100%. When I asked the OP to measure case neck at four points IF he had a ball micrometer, I was trying to determine if he had picked up some brass w/ ultra thin necks or possibly some turned brass. In fact, good measuring with a ball micrometer, of opposing sides (say the thick and thin) added to bullet diameter should be the same as measuring a loaded case neck. The rest of your post is dead on. There is a flaw somewhere in the measuring procedure if the necks are not really that thin, that's why I asked.