View Single Post
Old June 11, 2014, 08:27 PM   #16
highrolls
Senior Member
 
Join Date: January 20, 2009
Location: already given
Posts: 115
Magic Load Project

Last summer I began a project to look for good loads for longer barreled 9mm carbines. I selected the Hi-Point 9mm carbine, the Lage M-11 carbine, and the UZI carbine. The Lage barrel was 8", the UZI was 10" and the Hi Point was around 16 ". A good load to me meant good velocity at the Lowest SAAMI pressure level I could use to cycle the action rapidly for the Hi Point and Auto for the other two.

The key to a pleasing conclusion was adding the requirement for a single functional load for all three carbines. This made the driver to be the IMI carbine, which has a very difficult bolt cycle action. Difficult because it tends to prefer "hot" (meaning + P ) load-outs. I spent the remainder of the summer working out the safe action test loads for the IMI carbine which were well under SAAMI maximum pressure with longer (rather than short spike) pressure curves. This allows the IMI bolt to see more "average pressure" for a longer time, thus cycling the bolt at much safer pressure levels. After several hundred function-test rounds and ten or so range trips, I found four very satisfactory loads that work well in the long barrels. I believe these loads will function well in any modern, long-barreled 9mm.

Here are the magic loads.

1. 115 grain Winchester FMJ-Hollow Base (WB9MC115) bullets over 5.5 grains of Ramshot Silhouette powder.
2. 124 grain Montana Gold FMJ (MGB9124FMJ) over 5.5 grains of Ramshot Silhouette powder.

That is NOT a typo, you read it right, the SAME powder charge for both bullet weights. It gets better. Wait for it.

3. 115 grain Winchester 9mm FMJ-Hollow Base (Same part #) bullets over 6.3 grains of Alliant Power Pistol powder.
4. 124 grain Montana Gold FMJ (same part #) bullets over 6.3 grains of Alliant Power Pistol powder..

Again, the same charge weight of powder for the different bullet weights. It still gets better. Ready ?

All four magic loads have the SAME OAL. It is 1.145 inches.

The secret is in the 115 grain Winchester bullets. If you research why they were made with the hollow base, you are on to something neat. The Montana Gold bullets have almost the same side profile as the Winchesters but with a flat base.

Disclaimer : use of the above load data with bullets other than those listed must be load-worked over again.

My goal was not to review the Hi-Point carbine, just try to find good loads for it. Before this testing, when first firing the Hi Point, it wanted to jam a lot, and on all the magazines I had. The magazine springs seemed a bit stiff to me so I loaded them up about half way and stored them for a couple of weeks. Next time out, it performed flawlessly, and has ever since. In fact, I changed the scope of the project to develop a common carbine load to ADD challenge, because I cannot find ANY reasonable load that will not perform well in the Hi Point. Same for commercial ammo. I believe it will perform well on just about any standard load, and the manual states that it is designed to function with SAAMI +P loads with no limitation there.

Final project remarks. The low but longer pressure curve of these loads implies to me that for short barreled guns, these loads may not yield enough cycle force to properly function the action. Knowing they are moderate pressure loads, they should be safe to fire in any modern 9mm, but not expected to properly function in a short barrel. Only had a chance to test this once so far, and I got a pleasant surprise. A magazine full of the number 1 load above (the lowest pressure load of all four) functioned flawlessly in a 1911 style 9mm Rock Island pistol. Hmmm... Food for thought.

Special note: It has been a long time since I last tried something like this. The last time I did, I found only one low pressure load for the UZI that I liked. It was a 125 grain FMJ over 5.9 grains of Hecules Unique. So when I began this time, I started with Alliant Unique since Hercules no longer produces it, but in working up the loads, I saw pressure signs at 5.8 grains so never got to 5.9. True Blue and a couple of others I tried had similar results.

Final note: Power pistol does flash a bit so it is my day time load. Silhouette is noted for almost no visible flash so it is the indoor range load.
highrolls is offline  
 
Page generated in 0.04901 seconds with 8 queries