I am using IMI surplus 5.56 brass for reloading my Kel-Tec SU16 w/16" barrel. I am trying Speer 52grHP for Coyotes and Speer 55grTBBC for Mtn Lion and maybe one day smaller Deer. The Speer load data for the 52grHP is actually written around the IMI brass. However, the load data for the 55grTBBC is for Federal (I would assume commercial) brass. It looks like Varget is a good choice per the load data (not to mention I already use it for other cartridges), so how much of a powder reduction should I expect when converting the Federal loads to the IMI for the 55grTBBC if it lists 26.0gr as MAX for the Federal?

Deke.

Weigh your brass, the Federal might be heavier!

You might hope to find someone who uses the IMI brass in this caliber and ask. My understanding is that the company primarily makes brass for military purposes so it likely will be thicker than civilian brass and thus hold less powder. Best wishes.

Cal - Montreal

Deke, Speer recommends 26.0 gr. of Varget as a mmax. compressed load with the Speer 55gr. TBBC bullet.

Their data recommends 2.200" OAL (COL). I would recommend seating out a bit longer (2.260"). Check to see that this will feed through your magazine and doesn't leave shiny marks on the bullet that indicate that you're engaging the rifling when chambering.

I'm going to order some Speer 55 gr. TBBC bullets to test. The 'old school' said that 60+ gr. bullets were they way to go when using the .223 Rem. for deer. But that was when lead core was the standard.

Please give us reports back with your results.

Varget might be just a tad slow for a 16" something barrel and fairly light bullet, but you won't know until you try it!

Good luck!

Cal,
The purpose of my question was just that, can anyone experienced w/IMI223 brass report back?

DaMan,
You know I thought the same thing and I have some IMR3031 that might be better, but I like the idea of the temp insensitive Varget since I will fire this load from -10o to 100o F. What do you think?

Deke, SOP is to fill each case with water and weigh either the water filled case or just the water to get the case capacity. Obviously if the water in one case weighs more then that case has more capacity. You are right to be cautious though, military cases are usually thicker and have less capacity hence higher pressure's for a given load. Derf

Derf,

Don't mean to sound snotty, but I am aware of the liklihood that the IMI weighs more, has less volume, but even knowing the exact differences does not tell me what I need to know. The knowledge of these things generated the question. The knowledge of these things does not answer it. I need to know actual field experiences from those that have loaded the IMI223 surplus brass and compared it to commercial brass (preferably Federal). Those not having done so need not reply .

Deke.

quote:

Originally posted by Deke:

DaMan,
You know I thought the same thing and I have some IMR3031 that might be better, but I like the idea of the temp insensitive Varget since I will fire this load from -10o to 100o F. What do you think?

I've never liked IMR3031 much for .223 Rem. applications. It's never turned out to be the BEST powder for me with any bullet weight or in any rifle that I have in that caliber.

I would try the Varget first, to see how it works....

quote:

Originally posted by Deke:
Derf,

Don't mean to sound snotty, Those not having done so need not reply .

Deke.

No sweat Deke. It has been a long time since I reloaded military .223 cases and when I did it was with 748. I'm sorry that I do not recall any details that would help you out. derf

The following are the average empty case weight, SD, Capacity in grains of water, SD for Winchester commercial, R-P, LC02, and WWC/IMI military brass.

WW 97.4 .236 31.1 .152
R-P 95.6 .854 31.1 .250
LC02 95.4 .657 31.4 .218
WWC03 96.4 .456 31.6 .187

The commercial brass has the same water capacity despite almost 2 grains difference in case weight with WW being much more consistant than R-P. The two military cases have a greater capacity than the commercial. Sorry, I don't have any Federal to compare with. These were all weighed after firing with the spent primer in them. The WW and WWC were fired in my Bushy and the others were fired in ARs belonging to other members of the gun club I belong to. After I measured the WCC I sized and trimmed them same 10 rounds. The numbers became:
WCC03 96.0 .416 30.6 .117

No suprises that the capacity was reduced and that the volumes became more consistant.

I hope this informaton is usefull.

Interesting post C.F. Plinker!

I've never reduced powder charges when using, 5.56 military cases. I always thought the difference in capacity between U.S. military 5.56 and American commercial .223 was negligable.

Your water capacity tests show that to be true.

U.S. 7.62 military and Amercan commercial .308 Win. are another story .... and I'd suggest reducing the charges a bit when using the 7.62 military brass.

Looks like useful information. What is SD?

Deke.

DaMan

I agree that 308/7.62 brass will have significant differences in capacity between military and commercial brass. Even in .223 the 0.5 grain difference that I measured in capacity between WCC03 and commercial is enough to go from an uncompressed load to a compressed load. When I worked up my .223 load the best accuracy was just before the load became compressed. The group size almost doubled with a 1 percent change in charge weight on either side of the best load.

Deke

quote:

What is SD?

SD is the standard deviation within the group of 10 samples. The smaller the standard deviation the closer all of the weights (or if you are using a chronograph, the velocities) are to the average. About 2/3 of the measurments will be with plus or minus 1 standard deviation of the average.

I used LC brass and found one grain to be my preferred drop in powder charge from commercial RP to Lake City cases. In the 7.62 cases I drop two grains of any powder charge. In other loadings I usually work up to the middle charges on the chart for my personal maximum load. Maybe a little slow but anything I shot was dead. Packy

Deke, I found this when surfing the Speer bullet site.

Speer Data .223 55gr. TBBC

NOTE: Notice that, due to the heavy jacket construction, the bullet is longer than standard 55gr. bullets. This results in a longer contact area. Speer cautions against using data for conventional 55 gr. bullets with their 55 gr. TBBC bullet!

I went through this weighing .223 cases and filling with water/weighing business seriously long ago. I came to the conclusion that a 2% difference in case capacity between some brands on a typical 25 grain charge of most anything in a .223 case was 1/2 grain and was meaningless for my purposes since I don't shoot mixed brass and was not likely to encounter that much difference in batched cases.