impact

Hi Steve, thanks for the reply. Seems like sound advice. I'm soon gonna upgrade my tube capacity, are there any recommendation for spring manufacturers in europe? (I'll make the extension myself, so all I need is goining to be a spring in the 10 to 12 round range)

Hi folks. I'm fairly new to the shotgun game, but I got a little interested and will give it a try. I'm aiming towards IPSC Standard Semi. Currently I'm working dry on quad load mechanics, and wondered how the pros spring their 3gun/IPSC/.. shotguns? Do they generally use custom springs in their magtubes and lifters to be able to quadload better? I found some tuning springs, that are longer but thinner, which should give a little more preload on an empty tube still not too much tension on a full one, with a flatter force courve from full to empty. Are those a good idea? How do Mag springs influence other important factors like reliability? (and maybe even rate of fire? I could imagine that harder mag springs will decrease cycle time, and some are maybe after that?) What about the lifter spring? Do you prefer lighter ones than stock? (besides maybe competition ready models that already got softer springs. maybe...) I'll try my best to develop solid reloading techniques, I'm just wondering how much of an advantage a different than stock ("milspec"/combat/duty/...) spring setup could possibly give me, and what (reliability) issues I might risk running into. Or if weak springs are just for concealing weak technique? Thanks.

@Miranda That's a good tip for sure. I know what you're talking about. I got some test ammo laying around from about a year ago which I failed labing because "I know what's in there, I just loaded it, how would I forget?".... I'll likely match the expander depth to the load I'm using once I confirmed the seating depth is good to go. Currently, it also looks kinda longer than it actually is since it's still got the .352" expander section on it. On the picture above (with the two powder funnels) you can (barely) see the line between the .352" and .358" section, on the same level as where the cone starts on the unmodified one. Current status is, I actually loaded up some ammo (100rds) with the new .357" size expander and also pulled bullets on dummies and tried to push the bullets into the case further by hand and by cycling them through my glock. Bullet downsizing was on the edge of occouring. 7 in 10 still measured .356 and 3 read .3555. Probably effected by the hardness (use history) of the case and hard to measure exaclty because a caliper isn't exaclty the right tool for such fine measurements. Setback from pushing and feeding also was even closer to non existent. Impossible by hand, and on rough feeding/cycling I had some change by about .01mm, which is about .0004". So that's probably only dinging the bullet tip. Accuracy was also pretty good. I mean, I wasn't doing any ransom rest testing (which is probably pointless with a Glock anyway) but grouping looked pretty good: Again, 20 rounds at ~14yards/12.5m, all magazine fed. "flyers" for sure caused by me and I was experimenting with grip pressure/technique a bit, that's probably why there is a pronounced vertical pattern. But overall it looks like I probably found a sweetspot. The only thing that's bothering me now, is the increase in force required on the ram's downward stroke, to retract the expander/powder funnel from the case after expading. But probably a sizing die that won't constrict the case as much to begin with helps to tame down that a little bit. It might also be gentler on the brass, increasing lifespan a bit.

@4n2t0Yes, I'm aware how headspacing on a 9x19 works, I just wanted to crimp just a little more, since originally I was at the point where, as said, there was still a hair of beveling left on the very end of the casemouth. I've never been in the range where beveling was so pronounced that there was no flat ring-surface left on the face of the case mouth to prevent over insertion into the camber. And I agree, It seems FMJ bullets are a lot more forgiving because of their sturdy jacket. @Miranda .358 was just the baseline for me. What I was trying to achieve is get to the point where no bullet restriction was present anymore, and work down from there. I'm aware that I likely wouldn't have found a practical load method there, but I was able to prove that bullet restriction was the major component to my accuracy issues. I loaded up 20 bullets with a very light crimp using the modified .358 powder funnel expander, and handloaded them into the camber to prevent corruption of the test by bullet setback. Here's the result: 20 shots at 14yards/12.5m unsupported offhand. Honestly I also payed more attention to fundamentals and focused on follow through and trigger control, however the overall result is a lot better than any previous attempts with more neck tension. The 9 ring hits were all called, so I'm pretty confident in this load. I also made 20 shots of the same load but with a considerable (excessive) amount of crimp, just to see the results. It opended up a bit. Although a lot less than any previous tests with no to little crimp and the original .352" expander. So I'm headed the right way I guess. The excessive crimp was not enought to keep the bullets in place (under feeding and rough handling), that was the second reason I tried this out. I've already ground down the .358 diameter expander section to .357 and had no measurable bullet constrition (on pulled bullets) there too, but (comparatively) a lot more neck tensio to work with. I'm about to load a bunch of them up (with just a very slight crimp) and see how they perform shooting and feeing wise. Seems I'm on the edge of having no setback under normal feeding/handling circumsances, but we'll see. Regarding expansion depth, I see the benefit of having as little as possible and using the transition for the base of the bullet to rest against. However I'm limited in experimenting with seating depth then. I'm not sure how much of an contributor to accuracy seating depth is in pistol cartridges, as long as combustion (low V0 SD/ES) and feeding works fine, but I'll have an eye on that. I recon it's almost negligible in pistol lenght barrels, but it might play a role in my PCC's accuracy. On the other hand I'm not likely to go shorter then ~1.100" so raising the expander/powder funnel should work for experimentation. For proper high volume loading I'd have to machine/shorten the expander section accordingly, so I still get deep enough for the cone to bevel up the case mouth for bullet seating.

Sooo... According crimp, I adjusted the Crimp die just a hair out and now get around .380 to .3805 on the very mouth. On some you can even see and feel a slight bevel left. So that's basicvally not crimping just laying down the case mouth. I'll try that, but my guts tell me that's not how corretly loaded ammo should be like. But whatever, let the results decide... I also got a std. dillon powder funnel, and remachined it to (currently) .358 and a expander lenght of about how deep the 124s are seated (right on picture). Yes, they are surface hardened, yes the material beneath machines more easily and will probably wear faster, but the very edge on the .358 diameter expander section that leads into the brass is still somewhat of hardened material, so it probably will hold up for a long time. I could possibly evern harden it myself? Torch it until it glows red and than submerge it into oil? My metallurgy is not as strong anymore... At least considering hardening steels. Anyways. I loaded up a few dummies to try that out... well... Expanding works fine, extracting the expander from the case upon the downward stroke now becomes even more annoying and now I can literally seat the bullets by hand! There is resistance, it's on the edge of doable, but I can now seat bullets by hand (and finish them with a caliper to seat them to a very constant OAL lol ). Bullet constriction is zero. At least not measurable. Inertia unloading is very easy, comes out at first on a gentle strike every time. I'll load some up and probably single feed them into the pistol just to see what happens, and then I'll have to sand down that expander section and see if I can find a working line between very little bullet downsizing and enough neck tension to resist feeding and handling. I'll also load some up with a more pronounced crimp, to see if that helps with "neck tension" a little bit, but I don't hope that's the only way I get them to shoot... No barrel slugging yet. But it's on my list. That's it for now, I'll keep you updated. Thanks for all inputs so far!

Alright, first range update. shot 3 14yard groups today 1/L) 25rds 124RN hard crimp (the way I used to do it, OD ~.375-.376 at case mouth) 2 shots keyholed again, missing the target completely by ~2 and 4 inches. Also quite a few significant flyers within the target area 2/M) 25rds 124RN gentle crimp (pulled bullets only show a minor scratch at best, OD ~.377-.378, bullets still downsized by excessive neck tension/restriction) no keyholing in 25rds, group tightened up, still flyers (7ring borderline), the 9ring "flyers" were mostly called 3/R) 15 rds Control group, 115FMJ factory load everything outside the 10ring was 100% my fault. I'm kinda trying to re-learn good pistol form since for the last 2 years I shot mostly carbine and rifle. And I for sure jerked the trigger a few times since I shot with reddot and the dancing dot tempts me to be too aggressive with trigger pull as it meets the x-ring... So overall I felt we made progress, thaks for the crimping tips! Now I'll have to tackle bullet OD constriction by excessive neck tension, and hope I'll find a tool/setting that still properly holds the bullet in place for violent feeding. I'll also redo this test with my PCC load and see if it's helping accuracy there too.

I could possibly even remachine the powder transfer unit (fancy name) on my lathe that came with the dillon, but it's possibly surface hardened and when I get to the material beneath it possibly won't last as long...

Thanks for the input. I know that this exists, but the main difference is that it seems to have a shorter expander section before the bevel starts, so I'm afraid this section probably won't go deep enough into the case to help combat constriction as well as the HTC PTU.

thanks again everybody! So my Dillon funnel/expander measures around .352 in OD, which (without considering springback of the brass) would result in at least 4" neck tension. With rifles you'd typically want around .002", and thats with jacketed bullets. What came to my mind is using a universal expander mandrel die to finetune expansion. I've got one from Sinclair. What about that? - Yeah, I'm using no bullet feeder right now... I'd kinda always wanted to but then instead invested the money in bullets, powder and primers... So I've got a station left to work with. edit: I just realized the mandrel die I'm using is good for .17 to .338 caliber, there's a seperate for .35 to .50. But maybe worth the investment. .356 and .357 mandrels seem readily available. The linked PTU's are also interesting, especially should I ever acutally upgrade to a bullet feeder. To those who have tried, how fine is the line between having too much restriction, swaging down bullets, and having to little, giving erratic combustion and bullet setback from the lack of neck tension? What are you willing to accept in swaging down? .001"? less? I'm afraid I can't shoot milk jugs at my range. One Is more the bullseye type shooting range and the oder is a indoor IPSC/USPSA type shooting range. But I probably can make a mold, and I for sure got some air rifle pellets laying around somewhere... what OD should I strive for? .358?

Yeah, I would not have used jacketed bullets for sure. But I'll try to find someone who's shooting lead bullets and have him maybe give or send me a couple. I would have machined an aluminium barrel sleeve with a bore and one inside flange where the barrel goes into and the muzzle face rasts against, and one outside flange that rests on the face of the chucks (if that discription makes sense), so I don't have to crank them down like crazy. I'll try it and stop the experiment depending on how hard the bullet moves. I've used the tailstock before to assemble some smaller press fit parts, but nothing crazy that made me fear to damage or bend anything. So we'll see.

Thanks! Does it work with Copper pated bullets too? I don't have anything else at hand right now. For driving out bullets I got 8mm (~.315") brass rods. What about using a lathe's tailstock feed to push the rod through the bore? This way I might be able to better feel what's going on and don't run into the risk of damaging or misalingning anything. Does the procedure/measurement also work for polygonal profiled barrels?

Alright, thanks guys! I'll modify the setup and load some test ammo I can compare to the old setting. And yes, usually when I'm setting up dies or taking measurements I'll have all stations full. I just wanted to isolate the crimping die that one time so I could feel what's actually going on. Fair suggestion though, thanks.

Thanks for tuning in everybody! I haven't been able to tackle the problem as systematic as I'd like to, thats why there a still some pieces of the puzzle missing, but I'll try to answer the most important questions and keep working from there. Next range trip will probably be wednesday, that's when I'll be able to collect more "hard data". The new barrel is a OEM Glock barrel, for a Glock 17 Gen 4. I've got a new "upper" (slide and barrel) so I can switch between Production and Production/Carry Optics. I have not slugged it, and I'm not exaclty sure what is meant by that and what eqipment I'd use for that. I've heard the term before regarding (mostly) rimfire rifle barrels to make sure the tightest spot is at the muzzle, not the widest, to get the most accuracy out of non elastic lead and copper plated lead bullets. I'm using all dillon dies right now. I got my PCC (and Glocks, which is not a hard thing to do) set up dead reliable and well managable and focused on my shooting skills the most in the last couple of years, not so much on equipment and ammo. Now I started to reconsiderate my loading techniques. I've done precision rifle stuff sucessfully but have not tinkered around much with pistol ammo. I've considered upgrading to a redding pro carbide set but I'm not sure how much of an improvement that might cause. Or maybe one can tell me whats that best die for each step to get that will run on a progressive press and I'll try that out. The crimping die is also Dillon, and set to where it will leave marks on the bullet from a crimped case mouth, still not as pronounced as on the pictures shown above. But with all other stations left empty, I can feel some slight resistance of the cartridge going into the die the last ~.060" on upward travel. Here's a picture of what that would look like: Is that considered too much? Then I'll try a lighter crimp. Case mouth OD with seated bullet (just barely below the slight chamfer the crimping die setup causes) is mostly between .375 to .376. I checked bullet OD constriction, with and without crimp. I measured with (german made) calipers about .070" above the base of the bullet. Restriction was averaging (10 rounds) .00145" with and .00115" without crimping. So while there is a measurable difference, I'm not sure if thats statistically or practically relevant to be the culprit of accuracy loss. But who knows. --The load I'm using for PCC right now is 3.7gn N320 with a 123gn RN copper plated bullet set at 1.142" OAL. Groups at about 4" at 50m, typically tight center and 30% flyers. Mixed brass. Which likely contributes to precision, I just haven't tested how much. --In the new Glock I shot 124gn FMJs with 5.2gn N340 and 1.142 OAL before, that grouped well. I mainly made that load to mimic the ballistics of a factory 124FMJ load. While the Glock is not exaclty a benchrest rifle accuracy was fine to the point where I knew flyers were caused by my shooting skills and weren't unexplainable. Still mixed brass. --What I shot in the new glock, that gave accuracy issues was 123 RN copper plated with 4.1 N320 at OAL 1.102". Mixed brass too. --I used to shoot 145 RN and 147 RN with 3.9gn N340 at OAL 1.142" a lot though my older glock (~30k rounds) that hadn't got bullseye accuracy but seemed to work fine. Mixed brass, you guessed it. I never really tried to tweak any load to max precision, since overall accuracy seemed fine to the point where I could tell flyers were caused by me and not the ammo. With the glock I can confidently hold 4" at ~14 yards with 80% of the shots beeing inside 2" and probably 30% to 40% inside 1". With PCC its the same at ~55 yards. Upon using a inertia/hammer type bullet puller, I noticed differenced in neck tension... regardless of crimping or not. Some would come loose after a fist solid impact, with some it took 3. So I guess mixed brass with unknown times of reloading is causing that. While I understand that's for sure not aiding accuracy, I'd find it hard to believe it's causing issues to the degree I experienced them. But who knows, maybe it's a combination of all things that could be improved...

Hi Folks. I'm currently trying to improve both the accuracy of my pistol and PCC loads (123gn copper plated bullets with N320). Lately, I had some weird flyers when testing new pistol ammo, that first made me question my form, but then one of them even keyholed, so there's something going on there. Since the barrel is brandnew (~300 shots) it's likely the ammo. (I used 145gn Copper plated and 124gn FMJs before) I use the same ammo (just with ~.040" longer OAL and a smaller charge) in my 13" PCC too, and while it's not the most accurate load ever it's at least somewhere around 4" at 50 yards, mostly ruined by flyers, 80% of the shots cluster pretty tight, this could be me too though). Now, since keyholing is pretty serious, I tried to identify the cause and came across a thought that I tested out: I'm using Dillon's standard 9mm carbide resizing die on a 750, the die that is known for restricting the cases quite a bit giving the loaded rounds the known coke bottle type shape. I wondered if that would potentially resize the bullets bearing surface upon seating, and cause issues. The bullets OD were averaging pretty close at .356, and 5 that I pulled after seating were .0016" smaller on average, lowest measured around .354-.3535 . I'm not sure if that's normal with (copper plated) lead bullets but I feel It's not. Have you experienced something similar? I'm about trying another sizing die and compare results, but there might be issues with lead hardness too? Or is it perfectly normal and the solution likely to be found somehwere else...? What do you think?

Up to date, I teste 145 and 123gn bullet loads with n340 n320 and n310 and even tho I settled with 123 and n320 I got the smallest SD numbers with N310. N310 however meters really well, so probably thats the cause of low SDs rather than it's burning characteristics.

It works. But its magnitude fore sure depends on the load, rifle setup and comp. Get to an indoor range and use a laser, and capture the difference in movememt there, if you're unable to tell during shooting. Or shoot the carbin one handed from the hip without any other part of the body touching the gun. Without any muzzle device it should raise straigt up. With muzzle device attached it will dampen that movement. And if you index the comp to 1 to 3 o'clock, you will sure get the muzzle thrown up to the left. Of course it likely won't be a gamechanger. But it's a piece of the puzzle. And many small things done right will add up. Of course training with the carbine and getting it to know will improve your ability to control it the most. And yes, comps on open pistols will work better because theres twice or three times more powder in the case and probably ten times the pressure level at the muzzle... but you also got less mechanical leverage working for you on these comparably shorter barrels.

It's probably due to faxons design? ..most other 9mm bolts I've seen have tighter and less deep channels for the rear of the firing pin (the part with the disc), so maybe on this particular model the firing pin gets bent more due to less guidance near the striking face. I will machine a bushing and see if that improves firing pin life...

I use the holosun too. Indoor is where it can help quite a bit, but outdoors you lose the dot very quickly. It's however very well built, easy to zero and holds zero pretty well too! It can also be used as a tool for demonstrations, video analysis and for training/drypractice to build certain indexing skills. Like point shooting or shouldering the gun while keeping the barrel pointed at a target and things of that nature. It's not a must have. Just a tool. Also be very aware of using magnifying optics when lasers are around, since they basically also magnify the intensity of the laser for your eye. Kinda like looking at the sun through binoculars, which is very stupid thing to do, obviously.

I also switched to a triggertech adaptable recently and really love it so far. Run it at its almost lowest setting and due to the very light first stage (even if its not a true 2stage trigger, it kinda feels like one) the braking point still feels very solid and I haven't had any ND or bumpfire so far. What I really love about the trigger, is that it seems to keep a very consistent level of pressure necessary to set it off, which even on other high end triggers seems to vary quite a bit depending on lubrication, dirt and use and the break is very predictable. So I'm very comfortable to put pressure on the trigger early and break the shot just the moment the sight picture dictates it. What I also found interesting (especially for PCC) is that it seems to require less bolt travel to cock it (with a pulled trigger) than any other trigger I tested so far. So thats definatly interesting for the short stroke guys I guess.

My approach is, just get a comp that ports gas only in one direction (like the MBX or Armanov) to push the barrel radially and index that to whichever direction the dot is escaping on you to counteract that to the highest possible degree. Or index it so that all of the horizontal part of the movement gets dialed out. Might be possible depending on the setup and shooting technique. There's enough gas left, to actually make use of it, if you "focus" it to help with dot movement, but in conventional brake designs gas and effect just seems to get lost because it gets bled out in all directions and I'm not aware of any 9mm brake design that actually really helps with axial recoil reduction other than by adding weight.

Thanks, I'll try that. Maybe the firin pin channel is a little out of spec too. I also think that because of using a return spring in the blowback design, guidance in a critical area gets lost and firing pin has to deal with a lot of radial forces... I use mainly colt firing pins, but also turned 2 from 223 pins. I use a strike flat wire spring in a H5 buffer short stroke setup. But the first 2 breaks happend during the initial "full stroke" setup.

In ~11k rounds 4 firing pins 1 firing pin retaining pin 1 firing pin spring Whoever designed the 9mm Colt AR really f***ed up the firing pin design...

I zeroed them at the same distance so I get used to only using one set of holdovers. I also used the laser on longer shots indoors before, with uncomfortable left leans or uncomfortable shooting positions. Outdoors useful range drops pretty drastically, but indoors I used it up to 25m without problems.

Just dial the laser dot to the dot of the optic until they both coincide. If your lost which dot is which, just use the pressure pad and turn the laser on and off to be able to distinct between them. It doesn't even take a minute.

I run a Holosun 510C green and a green holosun LS117G, however I only use the Laser with the momentary switch. I got the Laser mounted like a 45° offset reddot and the pressurepad at 12 o'clock in the front of the handguard. Works for me. I don't like the laser beeing constanly on. I just turn it on the instant I need it, and I don't use it all that much, especially outdoors. However they can be beneficial at times, and also help in training with certain things. (diagnosis with camera, mouting the gun, developing a feel for indexing the gun without sights, etc). https://www.instagram.com/martin_impact/?hl=en