SyberShooter

I think the point that I was looking for (and that I took away from above) is that the peak pressure at the chamber is going to be the same no matter if there is a comp installed or not. An unsafe over pressure load will be just as unsafe no matter what is hanging on the end of the barrel. Did I interpret that correctly?

Thanks for the replies and info, I feel a lot better about it now knowing the comp isn't going to affect pressure or velocity much at all. I was afraid the load data associated with comp guns might influence normal data in some way, skewing it higher. My 38 Super and .40's all have full support and it was the loads for powders not found in most manuals that I was wondering about. I hear ya about loading to a PF, that's one reason I chrono my loads. Those are GREAT links... thanks a lot!

Once while loading some Hot 95gr 380s with AA5, I mistakenly picked up some 124gr and stuffed them into the case. With the heavier bullet seated like a 95gr, they had to be way over pressure for a 380. I found out my error when I fired them. The Mustang held together and I learned a lesson about pulling bullets from under the bench.

but you are not firing it out of a .380 you are firing it out of a 9mm I see your point, kind of like firing a 38 in a 357mag gun. It wouldn't be the same as firing a 9mm load in a 380 case in a 380 chamber but neither would it be the same as firing an OEM 380 load in a 9mm chamber Taking the extra volume of the seating difference into consideration there is still a little less volume to start the burn pressure in and my guess it would be like seating a 9mm a bit deeper than normal. A higher Pressure spike would probably occur before the bullet got going too much. The results are anybody's guess. There are a lot of variables that are only guesses without the proper test equipment to find out fer sure. It may not be as catastrophic as I originally thought, but I wouldn't want to try it. I guess if someone wanted to volunteer and report back their results... (just joking:)

Not So! There is quite a bit of danger in doing this! CAUTION: The following post includes loading data beyond currently published maximums for the cartridges discussed. Do Not Use This Data for actual loads .Only You assume any liability for any damage or injury resulting from use of this information. The 380 case is significantly smaller than the 9mm and we all know how sensitive the 9mm is to reducing it's volume by seating too deep. In this case OAL might be the same on the outside but what counts is inside. Lets look at some case measurements and volume. First, I measured some random samples of fired cases (and also consulted my spreadsheet of previously compiled averages) and a Speer #13 manual. Fired cases are typically a little shorter than the max given in the book so I'll use what I measured which won't exactly conform to max spec but will be close. Also, I am going to round to 2 or 3 decimal places for convenience. All statements are general to the samples I have taken over time and are representative of actual samples so don't nit pick me what the spec says it should be. I'm not writing a thesis although it may sound like it. We all also know the 9mm cases are tapered while the 380 isn't, and both may be tapered on the inside and also the case walls vary in thickness from different points- I'm ignoring all that for convenience and use a straight cylinder in this comparison which will increase the volume slightly but won't change the point to be made, which is about safety. The following table compares 380 case dims on the left with 9mm Case OAL: 0.674" vs .745" =.07" Delta Mouth ID: 0.353" vs .358" =.006" Delta Depth: 0.51 " vs .585" =.075" Delta Volume of a 380= .05ci (.813cc) vs 9mm= .059ci (965cc) Only a difference of .009 cubic inches... you may say it's not enough to worry about. Converting CI to CC (1 ci = 16.38706 cc) gives a difference in case capacity of .152 cc - now we can use some powder VMD charts to see how many grains of powder that translates into. I used one that gives the powder, the VMD (cc/gr) and the Density (gr/cc). I also calculated it myself to check the #'s with the Lee chart. (reassuring huh) For this test I will use data for a 9mm 115gr .55" long bullet seated .20" into the case. This leaves a case volume for uncompressed powder of .486cc in the 380 and .637cc in the 9mm. Using 3 popular powders from the manual we find that Speer #13 lists the following Min/Max loads for the 9mm: Bullseye - 4.2 / 4.7 gr W-231 - 4.5 / 5.0 gr AA-5 - 6.1 / 6.8 gr and Max for the 380 with a 95gr bullet: Bullseye - 3.3gr W-231 - 4.0gr AA-5 - 5.0gr So no matter which charge we are using for 9mm, even the minimum is over the 380 Maximum. As for the VMD case volume, even after seating the bullet .20" into the .380 case, the remaining available space would allow a charge of: Powder 380 Bullseye 4.6gr W-231 5.2gr AA-5 7.8gr If this isn't enough, now lets consider the bullet OAL and seating depth. I have found from marking and pulling OEM 9mm rounds that the typical OEM 115gr bullet is between .55 & .60 long with a typical seating depth into the case .20 ~ .25". So lets assume we will seat to about .20. This results in a nominal OAL for our 9mm of 1.1" If a 380 case does slip into the batch, and doesn't fall out of the shell holder, it may come out with an OAL of 1.1 but the bullet will only be in the case .124". Barely 1/8", if it stays in at all, it should be very noticeable next to the 9mm. Considering the powder charge data above, I doubt case volume similarities or differences will make much difference in the catastrophic end result and saying otherwise is foolish at best.

I separate my brass by caliber after tumbling, then by head stamp into baggies and then at some point during the load process they are racked in 50 round trays (from factory boxes) so they do get caught along the way. Most of the time in the 1st or 2nd sort but one time I did have one make it to the tray just before going to the press.

I haven't been able to find the answer to the following question searching, so maybe some of you can help me out. If I haven't posted this question to the right forum, go ahead and move it. Also, before I get started, I am experienced enough to know to work up my own loads from reduced starting charges, chronograph and to look for pressure clues as I go. So, to save some time we don't need to cover that again. OK here are the background conditions, When looking to work up a new load, we often search for posts using the desired powder & bullet or we ask for recommendations from others. Load data is abundant on various forums and often is accompanied with OAL and chrono data as well, so far so good. (irrelevant stuff removed for brevity...al) Recently I was doing some load research and happened to be looking at one of the "Jeff Maass IPSC Load Lists". As I was browsing I noticed that a lot of the notes indicated the number of ports in the source's compensator or that their barrel was ported. Some of these loads definitely looked high pressure to me, but I realized they needed the gas to work the comp. Then it occurred to me - what would happen if it WASN'T mentioned that there was a X-port comp attached to this gun? Would that load blow up my uncompensated gun? Even if I reduced it 10% to start? What about the loads I collect from forum posts.... they don't always mention if they are running a comp or not, just that their load works great for them. Lots of what-if's go from there... I do not have a compensator on my gun and during load development, want to be careful even with reduced starting loads ... if a load is higher than normal to work a comp, the typical 10% reduction for a starting load will also be higher than normal. Now my questions... awkwardly worded as they are... redundantly asked in different ways. I'm not asking for details of comp. design, as I do know that will make a difference in the final answer, but a rule of thumb would be a good thing to know. o- How many grains of powder should a comp load charge be reduced if no compensator is present? o- How much extra pressure does it take to work a typical comp with X number of ports? o- What affect does bullet weight have on this? o- What is a typical range (in grains of fast/slow powder) OVER published Max, does the average compensator user load? o- Do comps and ported barrels affect chamber pressure / max safe load in a similar manner? Any added info along these lines would be appreciated. I am trying to come up with my own idea of a 'red flag' rule when I think a load is not quite right and that a comp might be used with a particular load recommendation. Thanks Al

Nice job.... Thanks

I don't have any personal data for 175gr yet but one time I saw a couple loads listed over on centerfire central that were slightly faster but were from a longer bbl. They were using over 40 grains of Varget according to my notes. Best to work up your own loads for your particular gun.

on the Wolf primers... I can't say for sure but at the range one day there was a guy shooting his AR-15 with reloads. He had a bunch with Wolf SR primers and was getting several double and triple slam fires. Raised a few heads... talking with him later, he said they were the copper colored Wolf and that the CCI he used for other loads didn't do that. From this I take it they may be softer. I see they have come out with a version specifically for the AR-15 so maybe that is why.

That also surprised me since I usually like Winchester brass. You need to study the table to really appreciate the nominal differences between the brands but the SD numbers show which seem to be a little better in their manuf and QA specs. Other things that surprised me was the low standard deviations of a few of the brands, how different WCC is from commercial WIN and how many have a deeper cavity at the floor - which might actually help with pressure despite the thinner web. I also have a theory as to why nny has deeper primer pockets... anyone know why or have an idea?

That looks like a case canneleur that can be helpful to prevent bullet setback in the original load. You frequently find them on military brass and others.

Well, I only have to do it once and I have the reference for later use, kinda like weighing different brands of brass or filling cases with water to see their capacity. At some point you quit asking others for the answers and try to figure it out on your own. I already mentioned I'm retired with plenty of time to play, so I'm a little bit surprised that that is all anyone cares to comment on...

This is the attachment with table data at the end for the main post - I ran out of upload bytes and my pdf is also too big. This table will be helpful since the table data all ran together in the main post. and here are the last two sets of photos I didn't have room to attach - if a moderator would like to fix up the original post with this stuff, this post could be deleted. TZZ- Avg.Wt.=85.2 , SD=1.1, Case mouth a little on the thick side. Good Mouth2Seat & web, other dims average. nny- Avg.Wt.=79.1, SD=0.9, ppd=.128, hd=.474, A very light case with thin but uniform walls. Convex floor and thinner web type. OD of head largest of the group (.474”-also PMP) and very deep primer pockets (.128”) Probably best as recycle trash if unable to be used for plinkers. back to the original post

What’s in your bucket? This little project started off while reading a forum question that asked which brass is good to keep and which is junk to toss. Realizing everyone has their Ford or Chevy, Colt or Smith I decided to evaluate a range of available brass. Almost universally everyone said to toss AMERC as junk and quite often a few other well known brands, but few gave a reason why. I figured I might find the answer, at least to my own curiosity. One of the benefits of retirement is that you have a lot of “free time”. I used to think that was time I could use for hobbies and pursuits, now I know it really means all the time you spend doing things without pay. I had about 5 gallons of 45 acp range pickups I had just sorted by headstamp, and decided to put some to the sacrificial dremel tool. I narrowed my selection to 15 common headstamps and due to the number decided to only sample cut one of each (retirement has other prerequisites… like frequent naps). I randomly selected each sample, based on an appearance of once fired factory brass, (culling those obviously reloaded) and having no obvious defects, dents or other stress. I also picked 10 more for weighing and other external measurements. I then ran each through my RCBS sizing/decapping die. Although initially vibrator cleaned, no other case prep was done. To section, I snugged the case in a table vise and used my dremel cut-off wheel to slice each in half lengthwise, starting at the case head. I tried to cut perpendicular to the walls, through the primer pocket and leave the brand stamp readable. I then used a knife to lightly scrape the burrs off the cut edges. I numbered each half and taped them together for later analysis. Here is the pre-mission group photo, notice that some seem to use dirty powder: Initially, I looked them over with a hand held magnifier for obvious differences. Keeping in mind that this is a small sample and observations are only general indicators. 10 samples will provide a fair number for statistical analysis of things like average weight and standard deviation of external tolerances but additional samples and lab quality tools would be necessary to provide better analysis and conclusions... However I think these results give a reasonable comparison between the samples… Good enough for me. Here’s the disclaimer you all have been waiting for… I’m not a brass expert and I don’t know enough about its characteristics, limitations and internal ballistics to give valid advice or recommendations. Any attempt to analyze or explain anything herein is only my opinion. I present my review data in the interest of discussion, under the premise that there are certain characteristics of reusable brass generally accepted by most of us as desirable and this exercise may help identify those. We can discuss the data and each form their own conclusion for their purposes. Visual inspection yielded the following general observations; • The flash hole on the Winchester stood out as much larger than any other brand, at least 2x larger. This is not noticeable when looking from the back down the pocket but in section it is noticeable. It may be that the cutting wheel sliced this one just right and not the other 14. I may cut another or two to verify. • Some cases have a much thicker web area at the case-head / primer pocket area. Again, the Winchester appeared to be the thickest. • Some cases have a thicker rounded wall section at the web shoulder area while others are straighter with thinner walls joining the web. Some almost look like they were inflated by a balloon while others look made with a well formed punch. • The floor of the case is flat in some and raised in a hump (convex) in others. • All cases appear to have uniform wall thickness from the mouth to a point about midway down the case where the brass starts to progressively thicken to the web shoulder. The location of this point of departure varies slightly in most. Some cases have a noticeable change in taper from this point while others change gradually and continue the thin walls much further toward the web. I took measurements with a digital vernier caliper for each case in several places, to try and arrive at nominal values. Some cases were fairly uniform while others showed a wide range of tolerances. Even with this small sample, by comparing the tolerance range and std. deviations for each brand, we can get an idea of quality and “relative strength” for our purposes. Keeping in mind that this started out to see which brands were better cases for reloading and which should be discarded or at least not be used for “hot” loads, I didn’t want to get to complicated in my analysis. One characteristic to consider is standards. I assumed that the major OEM’s produce a cartridge with conformance to standard specs and only a cursory verification is necessary for the little known headstamps to check their tolerance to that spec. If their measurements were similar to the major names then I assume they are generally within standards. Anything anomalies should show up quickly (like the nny primer pocket depth). One of the primary signs of quality is uniformity. Manufacturing uniformity within points of a single case and between several cases of the same OEM is what I was looking for. Brass thickness and how uniform it is around the case affects our loads in many ways at various points in case design. Some points of particular interest include the case mouth, the web and shoulder walls, and the point along the side wall where brass starts to thicken. Another area to look at is the diameter of the head area just above the extractor groove and shoulder for excessive expansion. This is a critical area where cracks, bulges and case separations often occur if the brass is stressed or thin or otherwise pressure too great. When measuring thickness of the sectioned cases, the area where the case wall transforms to the web shoulder & radius was the hardest point to measure accurately and this area appears to have a wide variety of profiles . Keep that in mind when reviewing the data. Probably the best way to evaluate the shoulder area is to look at the photos. Pics show each case next to a Winchester for comparison. The sectioned case points I measured are as follows; Web Thickness- Measured on either side of the flash hole from primer pocket to inside floor. There seem to be two groups, thin webs of .40-.45” and thick ones over .55”, not much in-between. IMO thicker is better. Distance Web Floor to Mouth- Inside measurement from the case mouth to the floor of the case. Attempted to get to a flat area when side radius or center hump was in the way. Non-flat bottoms appear to account for up to .016” of difference in depth measurements. Cases with thinner webs tend to have deeper cases which may help lower pressure. Case Wall- Cases are constructed with a thin wall from the mouth down to about midway where it starts thickening. I called that point of departure the “Seat Point”. That is the point where the bullet, if seated deeper in the case, may start bulging the case outward due to the increased inside wall thickness. My method to measure the seat point started with examining the wall under a microscope and using a fine black marker to mark the point of departure. I then used the caliper with the microscope to measure from the case mouth to that seat point and also from the floor to that seat point. In the table these two measurements are called the “Mouth2Seat” and “Web2Seat”. Adding these two distances should equal the inside distance Web2Mouth but in most cases don’t, due to various errors such as angle of caliper, minute differences in visual measure points and case floor variances. External measurements were taken on 10 cases of each brand selected like the others, sized & deprimed. I averaged them for total weight in grains, thickness at mouth, head diameter at base and primer pocket depth. Averages and Standard deviations were calculated for all measurements taken in order to evaluate OEM consistency and uniformity. This is an important consideration when comparing two brands with similar average measurements. A quick check of the OD at the mouth showed most all to be .467” since they had just been resized. Most cases also had a head diameter of .471 to .473. One notable exception is the Israeli surplus with nny headstamp –Their 79.1g weight was much lighter than most (86.1g avg) and the head dia. was at the upper end at 474”. Case Mouth - Initially I measured 3 thickness points around each sectioned case half and averaged the results. This proved to be inadequate to evaluate uniformity and standard deviation of each brand so I measured all 150 cases in 4 places around each case mouth to arrive at the values indicated in the table. I took the measurement past the first .05” of the mouth up to about .125”. This amounts to 690 readings for the case mouth alone and should give a fair idea of the upper case wall & mouth thickness. Taking a too small purchase on the mouth lip would only measure brass possibly thinned due to previous crimping and stretching. Too much introduces error due to case contour and caliper alignment. I also calculated the Min to Max tolerance of all 10 cases (40 measurements)as a group. That is called Mouth-Tol in the table and gives an indication of case wall variance. Smaller is usually better. It’s not a perfect indicator as some cases may have measurements like (.01, .0095, .01, .01) or (.0095, .011, .0105, .01) while another would be (.12, .008, .0105, .011) and one brand might have 30 of its 40 measures equal .10 while another brand would be all over the map yet in the same Min-Max range. I wasn’t able to easily reflect this. Primer pockets were checked for depth only, most were in the .117”-.119” range with a few .116” & .120”. Variance of .001” could be included because I didn’t clean them. The one notable exception was Israeli nny which measured.128” depth on all cases. Case weight is probably one of the most used measurements used to estimate various perceptions of quality. At the least, close weights are thought to indicate closer tolerances and uniformity. Each case was weighed to the nearest .1 grain on a PACT BBK-II digital scale at 70F room temperature. A 20 gram check weight was referenced periodically to verify scale accuracy. OAL was not considered since cases had unknown history and were not trimmed. Case volumes were not undertaken and will be left for some other enterprising soul to report. Following are my general observations for individual brands with specific measurements in the table at the bottom; Winchester- Avg.Wt.= 85.5g, SD=3.9 Used as the standard others are compared to. Appears uniform overall. Mouth thickness seems fairly uniform with average variance. Has the thickest web @ .075” and largest flash hole of all evaluated. Mouth2seat is .405” vs .38” for the group average. Although popular and widely used, surprisingly has some of the worst spec tolerances that almost rival Amerc. Federal- Avg.Wt.= 90.9, SD=0.2 While weighing I noticed two different batches of Federal marked cases. (I’m sure there are many more) One is a darker color brass with a larger flash hole. It averaged 83.2 gr. The other is a bright shiny brass and has a dot before and after the Federal name. The cut case is of the 2 dot type. These weighed more, averaging 90.9gr and their head dia. were all .470”– one of the smallest and most consistent of the batch. Both are well made with very good consistency. R-P- Avg.Wt.=83.4, SD=1.0 , CCI- Avg.Wt.= 85.2, SD=0.8, CBC- Avg.Wt.= 87.5, SD=2.5,Magtech brand, Average looking, Fairly uniform, nothing remarkable, Closer examination of the inside wall showed a lengthwise crack clear through the upper ½ that was not initially noticed. PMC- Avg.Wt.=88.7 , SD=2.2, Aguilla- Avg.Wt.= 85.0, SD=0.7 , Very uniform throughout with low std.deviations. Blazer- Only had one case. An average looking case with marginal web and short seat. GFL- Avg.Wt.= 84.7 , SD=2.6, Thick walls at mouth also high variances. Not one of the top choices. Geco- Avg.Wt.=N/A, Convex floor, short seat and thin walls & web – another plinker or discard candidate. AMERC- Avg.Wt.=94.1, SD=3.7, The mouth is typically thicker than average. The floor at the web has a dished area tapering into the flash hole which gives it a wavy profile that is difficult to measure. The web is the thinest of the bunch but the wall at the web shoulder is the thickest. Comparing to others, there is a lot less brass thickness in many critical areas even though the case weighs the heaviest and its SD is lower than Winchester. Amerc also has the largest head and mouth thickness variance. They must think tolerance is a good thing as they give you plenty. Everybody’s favorite-What’s there not to like about this one? WCC 71- Avg.Wt.=89.9, SD=0.5, This one surprised me. I expected either the same as Winchester or a bit beefier since its MilSurp. What I found was despite similar numbers, it appears to be a slightly different design. The walls taper more gradually, appearing thinner further down toward the shoulder, Has a .054” web, a small flash hole and flat floor with smaller radius at the shoulders. There is a canneleur ring around the case at about .31” from the mouth but the walls do not start thickening until .425” and then not by very much at all-I had to really split hairs under the microscope to select a point I thought was where the transition began. The walls and shoulder area looks thinner than many but the table numbers say on average it is not. I wonder if they are made of a stronger alloy. PMP- Avg.Wt.=84.7, SD=1.4, Dims typical and average. Looks like I ran out of upload bytes for the remaining pics...TZZ and nny - will try to continue 45 acp Sectioned Cases Table of measurements pic of the Table is in this post (open it in a new window or tab and click the save button) Well there you have it, not totally scientific, but enough info hopefully for you to draw your own conclusions next time you look in your brass bucket. Use the table below to compare your range pickups for potential reuse. Although these measurements help us see the differences in various case brands, they really don’t answer some important questions… When is the case mouth too thick? What thickness is too thin at the shoulder? How thick should the web be? Does this one’s alloy mix allow it to be thinner? Will this one stretch more than that one? Unfortunately I don’t have the expertise to answer or evaluate suitability of any measurement taken. These are all engineering questions few if any of us will be able to answer. Other than standard specs, about the only guide we can use to make our guess is what the major OEM’s measurements are and what has worked in the past. Hope you find this interesting and helpful ...in case the formatting is all messed up, I will provide a pdf of everything... either by pm or in another post unless a moderator wishes to let me edit this one to include the remaining material. al