300 Blk Out woes.

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RussellC

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Just started attempting some 300 Black Out rounds and am having a little difficulty. Brass is LC once fired, cut off with a little 2Inch cutoff saw, and sized on a set of Lee 300 Black Out dies. Trimming done with a WFT in a drill clamped in a vise.

All seemed well until I noticed that while the newly sized and trimmed cases measured spot on in a LE Wilson gauge. At least before the bullet is seated. Once seated, the round no longer properly fits in the gauge, apparently the seating of the bullet is pushing the shoulder?

The bullets are some 180 grain soft points I bought at a gun show, they sort of look like giant 55 grain Hornady .223 bullet with can. just blown up to 180 grain size. They measure.307 in diameter, I forget mouth opening, .296 IIRC, will double check when I get home tonight.

Do I need different bullets, different dies, or different techiques?

Russellc
 
did they feel hard to seat? also bust out your calipers and measure the neck thickness of the case and compare to specs.
 
I will do that when I get home, and post results. The necks seemed stuffed tight with bullet in there.

Russellc
 
.296 IIRC
Click to expand...
That's tight alright. What diameter expander ball?

Did you deburr and chamfer the case mouths? It doesn't take much, just knock the 90 degree edge off.
 
I will measure the expander tonight. Basic Lee set, first time I have used it. Yes, I deburred them, although the WFT didnt leave much to deburr.

Russellc
 
They may still chamber and shoot fine. Fwiw I much prefer the Sheridan gauges for checking these. Also, when forming new brass from 223 cases, I always "double tap" the brass, rotating 180° between running through sizer twice. Seems to help get the initial forming done right.
 
Paddy said:
They may still chamber and shoot fine. Fwiw I much prefer the Sheridan gauges for checking these. Also, when forming new brass from 223 cases, I always "double tap" the brass, rotating 180° between running through sizer twice. Seems to help get the initial forming done right.
Click to expand...
For .223, I only have the LE Wilson, have both for .223. The brass formed perfectly, measured great. It was after the bullet seating it stands proud of the edges on the gauge. I wondered how it would chamber, so made a couple without primer or powder, was afraid of getting it stuck!

Russellc
 
While we are at it, any suggestions on bullets and dies would also be appreciated, if you know of any that work well in 300 Black Out.

Thanks,

Russellc
 
I have a Forster and a Hornady sizer. One is a hair tighter than the other but they both work well and neither seems better than the other. I have a standard Redding seater with the add on micro top and an RCBS "taper crimp" seater I use to lightly crimp into crimp grooves when present. If I was doing it again I would likely just buy a complete RCBS set up front. The micro top is convenient for changing bullets back and forth though.

The 110 Gr V-Max, the 125 Gr SST, the 125 Gr Hornady HP and the 130 gr Speer "varmint" bullets shoot well in my barrel. The Hornady 147 Gr FMJ shoots decent for general plinking. I bought some Sierra 130 Gr tipped Match Kings on sale but have not tired them. They'll have to shoot very well to consider more at their cost point, and even then I doubt I would buy more. I was really thinking they might give me the accuracy potential of the barrel, just out of curiosity. The first four bullets mentioned usually shoot under MOA, and sometimes post very impressive groups. I haven't played with anything subsonic yet. The Speer 130 Gr varmint bullet on sale at 19 cents apiece are going to be hard to beat for accuracy/cost. Oh, I forgot, the 125 Gr TNT shoots well too, and is usually less costly than some.
 
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I'm using the RCBS dies. I have shot Sierra 150 Game Kings, sub 1" groups with IMR 4227. I also have a box of Nosler 125 gr. boat tails that I have loaded but haven't shot. My plan isn't for a plinker, but hunting whitetail.

Have you been to the 300 forum? www.300blktalk.com/forum A lot of good info there.
 
LC brass and .307 bullet should be fine. Do you crimp? Maybe too much crimp and bulge the neck. .296 is tighter than usual, again I wonder if the brass bulged when seating.
 
Walkalong said:
That's tight alright. What diameter expander ball?

Did you deburr and chamfer the case mouths? It doesn't take much, just knock the 90 degree edge off.
Click to expand...

I made some measurements, with a HF digital caliper. Expander at its widest point is .307", inside of case diameter is .305", or that's as close as I can measure anyway. I was also asked about neck thickness, I measure the same on prepped 300 BO cases neck thickness as non prepped .223, .012".

The Bullets measure .308" at the base. I take cleaned LC brass, swage it, cut it, lube and size it, and chamfer edges. They measure fine in the gauge, seating the bullet ruins it. The necks look tight and there is some distortion of the brass just above the shoulder area, where the bullet meets the shoulder. (Once bullet is seated )

Is this the normal diameter of .30 cal bullets? Maybe Boat tail bullets would help? I have to be doing something wrong! Is my expander doing a sufficient job opening the case mouth to .305"?

Russellc
 
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HankC said:
LC brass and .307 bullet should be fine. Do you crimp? Maybe too much crimp and bulge the neck. .296 is tighter than usual, again I wonder if the brass bulged when seating.
Click to expand...

No crimp, damage is done as bullet is seated. Yes, it appears to be slightly distorted below the bullet, just above the shoulder. Cases measure perfect before seating.

Russellc
 
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I just checked and my Forster sizer expander is .304, and the Hornady one is .305. I sized a converted LC 12 case with neck thickness from .0116 to .0122. A .302 pin gauge would slip in easily while the .303 could be forced. It is tight, and one can see the slight bulge when seating a bullet that does not go all the way down the neck. All the bullets linked to above seated with no problems.
 
Maybe these bullets are just large. They are flat base, not boat tail. Appears my expander is fine, as is the opening of the case. All that's left is the bullet...is .308 large? at least with respect to a .305" hole?

Sounds like I need to try a different bullet, I will acquire a few that you mention and try them. Something boatailed...

Well, looking at these you recommended:

https://www.midwayusa.com/product/8...08-diameter-125-grain-hollow-point-box-of-100

They list the diameter to .308", so it isnt the bullet and I am not sure what the problem is.

Stumped...

Russellc
 
.308 is not "large". And .305 is tight but OK for an loader. How did you measure the .305, although that sounds about right for your .307 expander.
 
Walkalong said:
I have a Forster and a Hornady sizer. One is a hair tighter than the other but they both work well and neither seems better than the other. I have a standard Redding seater with the add on micro top and an RCBS "taper crimp" seater I use to lightly crimp into crimp grooves when present. If I was doing it again I would likely just buy a complete RCBS set up front. The micro top is convenient for changing bullets back and forth though.

The 110 Gr V-Max, the 125 Gr SST, the 125 Gr Hornady HP and the 130 gr Speer "varmint" bullets shoot well in my barrel. The Hornady 147 Gr FMJ shoots decent for general plinking. I bought some Sierra 130 Gr tipped Match Kings on sale but have not tired them. They'll have to shoot very well to consider more at their cost point, and even then I doubt I would buy more. I was really thinking they might give me the accuracy potential of the barrel, just out of curiosity. The first four bullets mentioned usually shoot under MOA, and sometimes post very impressive groups. I haven't played with anything subsonic yet. The Speer 130 Gr varmint bullet on sale at 19 cents apiece are going to be hard to beat for accuracy/cost. Oh, I forgot, the 125 Gr TNT shoots well too, and is usually less costly than some.
Click to expand...
How long do you seat these bullets? I also noted I had the seater screwed out awfully far to accomodate these bullets. Also, cannalure line is way above the mouth of the case, is this correct when loading misc. .30 cal bullets in 300 BO? My bullets look very similar to yours, other than 180 grain and soft point version. Looks like a giant .223 55 grain Hornady soft point.

Russellc
 
RussellC said:
Also, cannalure line is way above the mouth of the case, is this correct when loading misc. .30 cal bullets in 300 BO?
Russellc
Click to expand...

Yep, pay no mind to that cannelure (even though it looks odd exposed). Very few 30-cals built with a cannelure are ideal when utilized as your seating depth in the 300blk.
 
I like surplus 150 gr m80 pulls, 150 gr lee mold lead, and I robbed my 32/20 expander to open the mouth for seating. I don't think I use an expander in the sizer at all.
 
I loaded the Speer 130 (No cannelure) to 2.032 OAL. The ones with cannelures I just seated to it and lightly crimped into it. They all fed like that. The general consensus on the web is to load them longer, so where the bullet ogive is .25 is lined up with the front rib on the mags.

A pic I stole from the net and added the text and arrow.
index.php
 

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Walkalong said:
I loaded the Speer 130 (No cannelure) to 2.032 OAL. The ones with cannelures I just seated to it and lightly crimped into it. They all fed like that. The general consensus on the web is to load them longer, so where the bullet ogive is .25 is lined up with the front rib on the mags.

A pic I stole from the net and added the text and arrow.
index.php
Click to expand...
Thanks, that helps, I figured the cannlure would have to ride high on some of these bullets.

Russellc
 
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