The Firing Line Forums - View Single Post - Looking for a powder recommendation: 9mm subgun

highrolls · June 13, 2014, 08:25 PM

jclayto: "Highrolls - Thanks for the detailed write up. Berry's now makes a 115grain hollow base bullet. They claim it to be "thick plated" so that it loads using FMJ data. I am curious if they might perform similar to the Winchester hollow base? I will also look for the Winchester hollow base. "

Here was my thinking when I tried them. As I remember the article I read (can't locate it again without retracing my original research) the idea of the hollow base was to allow the same seating depth for the lighter bullet provided the heavier bullet had the same profile when placed side to side with the hollow base. In the case of the winchesters, it was also found to perform very close to the heavier bullet with the same powder charge, but using the winchester 125 grain flat base as the heavier bullet.

So, I walked around the gun shops comparing the winchester hollow base to various style heavier bullets until I found a side profile match on the Montana Golds. I noticed rather quickly that anything much heavier than the 125 grain weight will NOT give a side profile match, if that makes sense to you ? If it does make sense, I believe you could do the same thing with the Berry's hollow base bullet. Now, what I mean by side profile is the shape into the seater die. When the die is set for the test depth on the heavier bullet, the lighter bullet, using the same seater setting will give the same OAL seat for the lighter bullet.

The load development work was mainly on the heavier bullet. Once I found a functional load, meaning no jams, stovepipes, or even dinged cases, then I used the same charge and seat depth for the lighter hollow base and got exactly the same result as to function. I had no problem trying this because the safe charge found on the heavier bullet should be slightly safer on the lighter bullet plus the hollow base adds a bit more safety margin. But by that logic, you would NOT want to work up the loads in the reverse order, on the lighter bullet first.

Also the reply by jmorris just above yours caught my interest. When he says a faster powder is better, I noticed he is referring to the cans. For example, a really fast powder like Bullseye simply will not cycle the IMI (UZI) bolt on any non + P load I have tried. Period. Put a can on it and the loads in the 4.5 grain range for Bullseye and 125 grain bullets start to cycle. Obviously, something is changing. (Pressure curve)

Something else to watch for with the UZI is the bolt rubbing on the top cover plate. If it is doing that, it is stealing a lot of cycle force and load testing is wasted. The one I tested is the model B with the better cover plate clearance and the racheted bolt cocking device which is lacking on the model A's. Most auto UZI's I have seen are the model A's.

June 13, 2014, 08:25 PM	#21
highrolls Senior Member Join Date: January 20, 2009 Location: already given Posts: 115	jclayto: "Highrolls - Thanks for the detailed write up. Berry's now makes a 115grain hollow base bullet. They claim it to be "thick plated" so that it loads using FMJ data. I am curious if they might perform similar to the Winchester hollow base? I will also look for the Winchester hollow base. " Here was my thinking when I tried them. As I remember the article I read (can't locate it again without retracing my original research) the idea of the hollow base was to allow the same seating depth for the lighter bullet provided the heavier bullet had the same profile when placed side to side with the hollow base. In the case of the winchesters, it was also found to perform very close to the heavier bullet with the same powder charge, but using the winchester 125 grain flat base as the heavier bullet. So, I walked around the gun shops comparing the winchester hollow base to various style heavier bullets until I found a side profile match on the Montana Golds. I noticed rather quickly that anything much heavier than the 125 grain weight will NOT give a side profile match, if that makes sense to you ? If it does make sense, I believe you could do the same thing with the Berry's hollow base bullet. Now, what I mean by side profile is the shape into the seater die. When the die is set for the test depth on the heavier bullet, the lighter bullet, using the same seater setting will give the same OAL seat for the lighter bullet. The load development work was mainly on the heavier bullet. Once I found a functional load, meaning no jams, stovepipes, or even dinged cases, then I used the same charge and seat depth for the lighter hollow base and got exactly the same result as to function. I had no problem trying this because the safe charge found on the heavier bullet should be slightly safer on the lighter bullet plus the hollow base adds a bit more safety margin. But by that logic, you would NOT want to work up the loads in the reverse order, on the lighter bullet first. Also the reply by jmorris just above yours caught my interest. When he says a faster powder is better, I noticed he is referring to the cans. For example, a really fast powder like Bullseye simply will not cycle the IMI (UZI) bolt on any non + P load I have tried. Period. Put a can on it and the loads in the 4.5 grain range for Bullseye and 125 grain bullets start to cycle. Obviously, something is changing. (Pressure curve) Something else to watch for with the UZI is the bolt rubbing on the top cover plate. If it is doing that, it is stealing a lot of cycle force and load testing is wasted. The one I tested is the model B with the better cover plate clearance and the racheted bolt cocking device which is lacking on the model A's. Most auto UZI's I have seen are the model A's.