MilkMyDuds

My typical 25 yard Bill Drill is 5 second par-time at least 5 hits inside 6-inch circle. Everything was well until recently I started pushing that par-time. With a 4.5 second par-time, a clear pattern emerged - usually shots would land 3 inches below, still horizontally centered but lower. With a 4 second par-time, often 4 or more shots go vertically lower. At closer distance such as 15/10 yard Blake drill/El Prez, I do see similar pattern but not as obvious. When the splits are 0.2 or lower, the pattern is more noticeable. Going back to shoot groups at 25 yards without time limit, POI = POA. It is pretty clear an operator issue. The question is how to isolate the issue. Poor trigger control at speed? Over compensated recoil control (pushing the gun down too much)? Or not pressing trigger fast enough, e.g. a tiny bit late after the sight picture becomes acceptable before it dips down further? It may be a combination of all three... Any tips how to isolate the problem, train and overcome with specific drills? Thanks.

I obviously spoke too soon... Just loaded 200 rounds and 2 of them came out of the FCD into the finished ammo bin with bullets separated from the case, spilling powder all over in the bin. This happened before about 3 or 4 times but I never thought much. But I know better now. I measured the base of the bullets on those 2 rounds, 0.352 and 0.353. I pulled some other finished rounds and measured. 0.356 all of them. What's unique about the 2 that got pulled by FCD is that they are both CBC headstamp. I pulled more finished rounds, and found these patterns: 1. CBC - 0.352/3/4 2. JAG - 0.354 3. RP/PMC/Win/etc - 0.356 So I could either keep the current setting and not run any CBC or JAG headstamps, or switch in taper crimp die and try. My guess is that the thickness on CBC and JAG is causing the bullets to be squeezed undersized.

I am curious about the groove too. Bayou does offer 135 and 160 without groove. I am guessing the 147 mold was working so well for the customers and they don't want to change something that works flawlessly.

I got a Redding taper crimp die here, but yesterday I tried some rounds loaded with backed off FCD, no tumbling. I am not exactly sure how FCD's resizing work on the loaded case, but it appears to me the trick is to back the FCD die all the way up, then turn the crimp knob all the way down till it touches an empty case mouth. That seems to do the trick. I will run this setup until I see tumbling again, then swap the taper crimp die on.

I have seen Soloshot that is a GPS based robotic camera. It can pan/tilt/zoom by itself when you carry a tag with you. The only downside is that it requires new setup (about 8-10 minutes) every time you move the camera location. This probably works well if you are videoing all shooters going through 1 particular stage. Just have them carry the tag in their pockets before the stage start. It does not work well for my purpose - being able to shoot my stages without the hassle of asking other shooters to video me. My question is - are there any similar technology, maybe not GPS based so it does not require 8-1 min setup time? I have seen people using drone-based video systems to record USPSA stages. I don't know what difference is there between drone vs. just a GoPro set up far (which is what I am doing now). The drone has to be remotely controlled by someone to get close/followup videos. Else it would be just a GoPro in air.

Less powder usually means less felt recoil. I have tried MG, PD (both FMJ/CMJ), Xtreme, Berrys (both plated) and Bayou (coated). Now I only shoot Bayou 147gr FP.

The KKM and BarSto barrel wont chamber if the rounds don't pass gauge. BarSto sometimes wont even chamber the rounds that pass gauge. It looks like taper crimp is still needed, because with just seating no crimping, a lot of headstamps won't pass case gauge.

The FCD came in the 4-die set. I don't understand why did Lee include a seater that could crimp with the FCD in one set? Maybe they imply the FCD is not truly a crimp die because essentially what it does is to resize the finished round? Anyway, I did measure pulled bullets before they go to FCD. It looks like the bullets are already slightly sized down just by going through the Lee seating die, 0.355'' on the base. Then once they run through FCD, they are further sized down to 0.354'' on the base. I find myself learning all these even though I have loaded probably 20k 9mm. I tried different headstamps, trying to determine their brass wall thickness. It appears with Blazer, FC brass the rounds pass case gauge 100% right after seating without ever going to FCD. Others such as RP, PMC won't gauge after seating and require crimping. In short, it appears to me: 1. The seating die in the Lee deluxe 4-die set actually crimps a little bit in addition to seating the bullets 2. Both the Lee seating die and FCD will squeeze the coated bullets into a new dimension, e.g. smaller base diameter. This is with a crimp setting that does not show any crimp line. My next step is going to try Dillon and Redding seating die, and some taper crimp die. Will grab some from Cabelas and try them today. Does it matter what brand taper crimp die I buy? RCBS, Hornady or Dillon?

Steve, do all 9mm seating dies size + crimp at the same time? When I was still using SDB, I don't remember Dillon ones did that. Maybe I should switch to a dedicated seating die.

This is a very interesting aspect that I have not thought of. I did took measurements, see attached pic. It could well be that the base of the bullets getting undersized by the FCD, causing the rifling unable to engage fully when the bullets go through the bore. Why would FCD crimp more than just the mouth of the case? I already have the FCD die adjusted to as high as possible, e.g. it should only touch the mouth of the case. Maybe the seating die, on the upstroke, is pressing and undersizing the bullets? My next experiments: 1. Check the same pulled bullet base right after seating but before FCD - I always suspect the Lee seating die actually does some amount of crimping 2. Reduce OAL to 1.125'' but keep the same crimping setting - theoretically this helps to restrict the crimping only to the mouth of the case

I thought the bare minimal to stabilize 147gr is 1:16? Some google results say the MP stock barrel with 1 dimple is 1:18 twist rate.

I have the stock barrel (with 1 dimple) and a BarSto barrel. I will be trying them soon. The other interesting discovery today - I was pulling 30 bullets to investigate the cause of tumbling, and realized that some specific headstamp would give out the bullets really really easily (I was using a kinetic puller), at most 2 swings, while most others would hold until 5 swings. Because I run mixed headstamps, I suspect some got just enough crimp while others got none, due to the differences in brass wall thickness. After pulling all of the 30 rounds, I did not see any crimp line on any of them, but some do have coating shaved off a bit, exposing lead. Would too little neck tension cause tumbling? I wound not think so, but I will do some experiments focusing on specific headstamps. The other interesting thing with the Lee 4-die set, the stand-alone seating die appears to be removing the bell too. I know this because some of my loaded ammo could pass chamber gauge without going through the FCD. I thought only the seat+crimp die would seat and crimp? I do get enough belling because I run Mr. Bullet Feeder bullet seater, and I adjust the expander die to provide enough belling (about 5mm or so down the mouth) such that the bullet seater works flawless. Any ideas?

I recently started noticing a small number of my shoots are keyholeing on hard cardboard targets. Usually 10 yards or more, 2 out of 10-20 rounds. This did not happen before, and I have not changed anything... Barrel - KKM 5'' (about 10,000 rounds through it) on MP9 Pro Bullets - Bayou 147gr FP Powder - Titegroup PF - 130 OAL - 1.140'' Dillon 650 - Lee 4 die set (size, seat and crimp) with MBF (doing the belling) Some possible causes I have found on the web: 1. Barrel twist rate - KKM has 1:20 twist rate thus should be more than enough to stablize the 147gr 2. Lead fouling in bore - I cannot visually see any leading in the bore. The rifling looks in a very good shape 3. Bullets undersized - I have been using Bayou 147 FP for a long time. I measured the latest batch I got and they are in 0.357/8'' range 4. Too much crimping - I pulled some of my loads, and do not see any visible crimp line What could be causing this? Could it be the barrel already worn out at 10,000 rounds, maybe oversized by the usage somehow? I have some minor coat shaving issue but very minor. Some of the pulled bullets show the coating gone in a very small areas with lead exposed, but no lead loss. Could this be causing the occasional tumbling? Do the thickness of the brass matter? Different headstamps feel differently when they load, harder vs. easier, etc. I always suspect some headstamps make bad quality ammo, but I have not done any tests to prove it. I mainly load RP, FC, PMC, Blazer, Speer and Win headstamps.

I have Dawson front and rear on my MPs. Still if I shoot facing direct sun light (even with baseball cap blocking most of the light), I would shoot 1-2'' high, vs. regular lightening condition. Yes my Dawson front sight has the recess where the FO was melted into the hole. Just to add - this is at 20 yards distance.

Thanks everyone for the inputs. Definitely saved me a ton of time from trying things on hugely diminished returns

Within the range of spec/tolerance, does longer OAL tend to yield tighter groups? In another word, jamming the lands produces better accuracy? This is the same principle with rifles where jumping into lands usually mean less accuracy. However, I recall some precision rifles shoot best 0.01''-0.02'' off lands though. I was looking for that sweet spot for 9mm. Thanks.

When I was shooting long range precision rifles, I understood that OAL has pretty big impact on accuracy considering the profile of the bullets and the ogive off/jam lands etc. However, based on my little experiment, I have found no noticeable differences between 1.110'' and 1.135'' OAL with the same headstamp/powder weight/crimp setting in both KKM and BarSto aftermarket barrels. I tested at 25 yards off hands. 5 shot groups for 5 groups. For both OALs, KKM was about 3.5 inches, while BarSto about 2.5 inches. Is this normal with handguns, 9mm in particular? What's your experience?

No, I just looked up the USPSA rule book, and here is the specific clause for production slide mod: Because the PC models are not listed in the production gun list, the slide for PC won't be for that model of gun (MP9 pro 5'' I was thinking). Won't work for USPSA production.

Looks like +0.2gr is the consensus. Will start from there. Thanks everyone.

Have been loading exclusively with Titegroup (147gr Bayou FP) for minor PF. Just got some N320 to try. Any ideas how much N320 is equivalent to 3.0gr Titegroup to achieve the same PF? Thanks.

I have got PE for not picking up all mags (2) on the table for table start stages. I think it makes sense - if you put 2 mags on the table before stage start, but you left the table picking up just 1 mag, it should be a procedural. However, if you look at the 2011 IDPA World Shoot, at 4'18'', the shooter did just that. I don't think he got a PE because I do not see any finger from either of the two SOs. The next guy at 4'46'' did that again.

Assuming the video and photos can be used to broadly promote USPSA you should be added to the match staff. I thought he was one of the USPSA PR staff all along

Glad you are having fun IDPA tends to punish sloppy trigger control (inaccuracy in general) more than USPSA. Vogel talked about his training differences between USPSA and IDPA on youtube, and that makes a lot of senses. Should be beneficial to people who shoot both.

Has anyone tried using a non-ported barrel in a PC slide? I was wondering if the lightening effect due to the cuts on the slide is worth it. Theoretically it should make the slide return faster, and if you use a 11# recoil spring it may be even better? On the other hand, I wonder if the muzzle flip would be more noticeable due to less slide weight. This would be similar to what G34 or XDM competition slide with the lightening cuts. If someone has the stock PC slide (for 5''), can you please measure the weight and post here? I assume this setup should be legal for both USPSA production and IDPA SSP.

That's the kind of arguments I heard at 3AM in a freshman dorm! The most fun thing about IDPA is you never hear anything about USPSA. Go over on Doodie and see what USPSA shooters are saying about...USPSA! Not true... I do hear IDPA crowds mentioning USPSA Every match I went, people ask me if I shoot USPSA a lot... The fact is I have never "officially shot" an USPSA match Maybe I have that kind of college kid's aurora screaming I am an USPSA snob