Level of trust improving in Glock

[adam_mac84]

Previously, I have shot J-word or plated 124grain bullets for any 'important' shooting (matches).

Recently, started plinking with some of my Smoke's PC cast loads. Been running them at the end of range sessions after cleaning the barrel in field (from whatever i was shooting before).

Started with 25, then 50, 100, and yesterday 150 rounds.

I did have some of what I thought was leading in the grooves for the first ~1" of the barrel.

Little bit of time with brass brush and it is clean as a whistle.

Our local round count is usually 150 for pistol at 3 gun matches. I am working forward to 250 rounds with 'acceptable' fouling. I have recovered a few bullets, and bases are good, but lands are cutting the coat, I am going to increase 'shake' time. Also, possibly increasing range lead % to 1:2 WW/RL (I like to water drop so I can coat more quickly). Based on location of contamination and information here --> (http://www.lasc.us/Fryxell_Book_Chapter_7_Leading.htm)

Glock 34 stock barrel
1.050 OAL
HP 38 3.4 grains
952 FPS (measured out of my SW MP9)
Unsized, dropping at 130 grains
Bullet size is ~.359, but is being swaged in case to ~.357
I have shot some sized .356, Glock barrel slugs at .3555. Leading was worse in these.
Need to get a .357 sizing die
Alloy is 50/50 WW to range scrap (water dropped)

Just a data point for others I guess

[igolfat8]

Use softer lead, DON'T water drop and size to .357" and you won't get any leading. Plain ole range scrap works great. I've shot tens of thousands of PC and HT coated bullets in my Glocks in competition with zero leading.

[Lloyd Smale]

all summer ive been shooting my 29 and 20 with full power loads with a variety of pcd bullets. Mostly the lee 180tn. I cast them out ww. Pc coat them twice and after the second baking water drop them and size to 401. Id make a conservative guess and say Ive put at least 2k through each gun and never touched the barrel. Had to hose out the action with brake cleaner a couple times but that's it. Barrels look as good now as they did with 20 rounds through them. These loads run 1200 fps out of my 20 and about 1100 out of the 29. Ive probably shot half that much out of my 9mm M&P and glock 19 too. Same procedure and size to 357. I haven't got leading with any of them.

[adam_mac84]

If you feel inclined for some feedback. Pics are following 100 rounds. Did 2 sets. Similar leading both times. Cleaned with few passes of brass brush. Pic is after running a mop through for loose junk.



Rounds were sized .357. 1.120 1000fps for one group 100. Are PC with smokes and pass smash test. 50/50 WW and range scrap.

Other were 985 fps 1.060 unsized (~.359), but they seem to squeeze down to .358 in the case. Using Lyman m die.

Making few more tries before I ditch glock barrel


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[Smoke4320]

I would second not water dropping to achieve softer lead
200 rds will tell the tale

[adam_mac84]

Thanks again folks. I had these boolits already cast and had slightly opened up my sizer. So wanted to test. Also was so I could chrony them for minor PF.

Will throw a few boolits tonight and see if I can't get something working. Comp is 1 week away, so will likely shoot plated again. But the quest continues.


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[igolfat8]

Water dropping increases cast hardness from 10-12 to 22+ which is too hard to allow the bullets to obturate. This allow gas cutting and gas blow by the bullets which cuts through the PC and exposes and vaporizes lead in barrel causing leading.

When you say the bullets squeezed down from .359" to .357 can cause issues too. You could be causing PC failure inside the case walls or as the bullets exits the case it could be getting swaged on exit and scraping off PC.

You can verify this by pulling a few bullets to see if there is any PC failure and bare lead exposed.

Have you tried to shoot just range scrap? That's all I've shot in my pistols for many years and I've pushed some 9's well over 1500 FPS with zero leading in Glock barrels.

[adam_mac84]

Water dropping increases cast hardness from 10-12 to 22+ which is too hard to allow the bullets to obturate. This allow gas cutting and gas blow by the bullets which cuts through the PC and exposes and vaporizes lead in barrel causing leading.

When you say the bullets squeezed down from .359" to .357 can cause issues too. You could be causing PC failure inside the case walls or as the bullets exits the case it could be getting swaged on exit and scraping off PC.

You can verify this by pulling a few bullets to see if there is any PC failure and bare lead exposed.

Have you tried to shoot just range scrap? That's all I've shot in my pistols for many years and I've pushed some 9's well over 1500 FPS with zero leading in Glock barrels.

I have pulled some. They look good on exit, but that is how I know that they are being sized down. The leading shown above is nearly identical with my sized and unsized, so that seems to make sense to start looking at a hardness component.

I have not shot pure range scrap. I started with WW. Then obtained some RS, so went to 'sweeten' my WW added 1/2 to my 4-20 pot. Currently the pot is cooking with 50/50 mix so I can throw some bullets. I will test these, and then run it down and see where I get. It wouldn't be all bad if i could shoot RS. I can seem to come by that a bit easier

[fredj338]

I size all my 9mm stuff to 0.357", lubed, HT or PC. IT seems to work in every gun I shoot. I shoot mostly range scrap, water drop after last coating from the oven.
BTW, your load doesn't make minor PF, if that matters. Bumping the charge 1/10 & getting closer to 1000fps may help with obturation?

[adam_mac84]

PF is based on a 129 grain bullet (10 bullet average on last batch was 130.1). 129*985 = 127,065. Does this compute to 127 PF?

The 952 was out of my MP 9, the 985 is from G34. First post didn't specify this well.

Second set of info was new chrono data from the G34. (the 985 is unsized, 1000fps was from the sized .357 boolits). The sized boolits do have a touch more powder (~0.2), becuase I have more case volume to work with. (1.120 vs 1.060)

I was starting conservatively, and I knew that these did cycle and were safe, so started there. I had not considered increasing velocity as a method of increasing obturation. I just PC some, and did think about water dropping out of the oven, but allowed to air cool after PC. Looks like i'll have to load them and shoot them anyhow

[igolfat8]

Did you measure bullet OD after pulling them? Case or crimp could be squishing them undersize.

[Lloyd Smale]

yup many make the mistake of over crimping. Its a natural tendency for a revolver guy that's use to heavy roll crimp. You want your crimp to iron out the flare and not much more. Even so if your bullets are 358 they shouldn't be giving your problem because there to small. Ive got 3 glock 9s and all of them do just fine with 358 bullets. As to to hard. Ive ran water dropped bullets by the thousand though my glocks with no leading. If anything glocks lead more with softer bullets because of there shallower rifling. It tends to allow bullets to strip through especially in higher pressure loads. Try shooting some into water jugs so you can recover them and see if they have good rifling imprints on them. I know I'm not the ultimate expert by a long shot but I bet ive put enough cast bullets through glocks over the years to make a pickup squat. Its a very rare occurance when in a GOOD handgun ive EVER gotten better accuracy with softer bullets. Think about it. Most handguns shoot real well with jacketed bullets that are much harder then ANY alloy of lead. This goes doubly for guns like glocks, m&ps and most 1911s that all have shallow rifling.

[Smoke4320]

Looking at the pictures again.. It might also just be PC residue .. if the coating was not cured all the way you have a wiping effect

Easy to check .. just run one dry patch down the barrel to remove loose junk then if you see that pattern again run a couple of patches with acetone or finger nail polish remover (same thing)
let it soak for a couple minutes then run a tight fitting patch or a single stroke of a brass brush

if it is gone its PC residue .. if not then its lead

easy peasy to check

if it is PC residue .. check your oven temp at the indicated 400 degrees with a good thermometer if that checks good increase baking time about 5 minutes then try again

[adam_mac84]

I had not checked back since my last post and a range session today. Today I shot 125.

Air cooled vs water drop (50/50 WW/RS) this time. Only factor changed. Similar result.

Sprayed hopps in it at the range. Couple passes with patches/mop for photo.

About 10-15 passes through w brass brush and clean.

Will do acetone test next time.


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[adam_mac84]

This week test will be changing my PC technique (bumping the time at 400* to 20 minutes). I am also going to air cool boolits again, but water drop after PC. I don't think bumping my size is going to help much, as it has happened similarly with unsized boolits. Next step may be bumping charge or trying a faster powder to get better obturation early. Right now I am at a floor-level minor load, which I love how it shoots out of the G34, but am willing to give some recoil back for performance (competing with cast sure looks better than the $0.08/round plated pills).

I like testing all of this stuff for just the cost of powder/primers... makes my wife happier too. I am still shooting, and making less trips to buy bullets at Cabelas.

If all else fails, I may give up and re-barrel, but dangit if i am not stubborn enough to keep trying (safely)

[igolfat8]

What is your bullet weight and load specs? Check your PM inbox

[adam_mac84]

129 grains. 3.7grains hp38 1.120". 1000fps. (Most recent pic posted).


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[Beef15]

I shoot a G17 in competition minor PF, factory barrel, slugged same as yours .3555.

HT .355, .356, .357 all shot fine, no leading, routinely went 1500-2000 rounds between cleaning. TG or Bullseye.

PC .355 now, started with .356, COWW, initially got some minor leading I attribute to less than consistent PC results. TG, Bullseye, Clay Dot.

Lubed COWW, water dropped .358 have run up to a thousand between cleanings with only trace leading. Red Dot.

I don't know what my wife's 17 slugs at, but it appears to behave the same.

What die are you using to flare? I ask because the Lee 9mm die basically just flares and doesn't expand, a 38S&W expander will drop right in and expand much further down and may help with the swaging. Seating out a bit longer may help too. I pretty much always seat longer than 1.1, prefer 1.135-1.15.

[adam_mac84]

What die are you using to flare? I ask because the Lee 9mm die basically just flares and doesn't expand, a 38S&W expander will drop right in and expand much further down and may help with the swaging. Seating out a bit longer may help too. I pretty much always seat longer than 1.1, prefer 1.135-1.15.

Lyman m die. I size and deprive before loading on the turret. It's for 9mm/38

In keeping with scientific method of one change at a time. I went back to my unsized boolits. Which seem to be cased down to .357 anyhow. Loaded to 1.060 as before. Only crimp applied is to de flare case to plunk in glock. (Very close to a case gauge fit anyhow).

My change was increasing charge to 3.9gr hp38. Did not get chrony data on it but previously was at or just under 1k with 3.4 grains same length. (Still 50/50 RS/COWW)

115 down the pipe. Seemed a bit better.

Pics are of a rescued bullet (sand berm) and my barrel after a wet patch to remove carbon etc.

Next change is alloy. I have some coww I sized initially for my smith at .356. And am going to throw some range scrap only boolits and size to .357.

Igolfat8 also helped and sent me some of his 120 TC that he knows work. I'm going to try to replicate his load with some great advise he offered. (WSF power)



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[adam_mac84]

Seating out a bit longer may help too. I pretty much always seat longer than 1.1, prefer 1.135-1.15.

Will add that to the list of try's. I have done 1.120 with my .357 tests. Some depends on what I know will plunk. (Advise from the great 9mm thread to determine max OAL)



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