I think I have a problem with diameter

[nueces5]

Today I went to shoot the new boolits in my G17. Approximately after about 40 shots I started making keyholings.
The diameter is .3555, the slug of my glock is .355 and they are PC.
The armed bullet does not pass the plunk test satisfactorily, because if I do more crimp, I reduce its diameter. It falls well in the bedroom but does not rotate with the fingers.
Should I try to increase the diameter of my boolits? I think this week I got the expander that Lathesmith did to me, that I hope it's a help.
Or should I respect the plunk test?
Six months into this, I still can not find the way to be precise with this gun.
Inside barrel.


My boolit

[toallmy]

Contact a member named Doug guy , see if he can work his magic on your chamber , then you can plunk a little fatter Boolit .

[waksupi]

I would say you need a bigger bullet. You might try shooting softer alloy, but it probably won't slug up enough to solve the problem.

[toallmy]

Possibly reducing over all length it might help with the plunk test also , your throat might be catching on the shoulder of your cast boolits .

[nueces5]

Contact a member named Doug guy , see if he can work his magic on your chamber , then you can plunk a little fatter Boolit .

I live in Argentina! I think I'm going to try first to broaden my boolits and reduce the OAL

[Dieselhorses]

According to Hodgdon Reloading your bullet needs to be .356 and your alloy, as mentioned, should be softer. Don't know what the weight is of yours is but a 125 gr LCN OAL is 1.125" with HP-38 and TG. Also maybe it's my imagination but your loaded round looks like the either the case isn't square or the bullet didn't seat right. Just speculation.

[Dave W.]

In my opinion you have two problems; the OAL is too long. The straight side of the bullet, just before the taper should stick out the end of the case about the thickness of your thumb nail. With the124 grain truncated boolits that I cast the OAL is 1.050.

Secondly the barrel is leading - getting fouled. There are several different things that can cause leading - fouling. Once you correct why the barrel is not staying clean, the gun will shoot accurately.

The rule of thumb is to size lead boolits .001 over the barrel diameter.

[Walks]

Seat the bullet deeper in the case.
Use a harder alloy.
Buy a Wolf bbl with conventional rifling.

[RED BEAR]

I would try to increase bullet size first i usually go a full .001 to .002 over the bore.

[DougGuy]

That barrel has ZERO throat, so you can't even load boolits to spec in the load data or they won't chamber. That is also a hardened barrel which requires a carbide reamer to put any freebore in there. To be honest I think you would have better results with an aftermarket barrel if you can get one where you are.

[Hickory]

I would try to increase bullet size first i usually go a full .001 to .002 over the bore.

Yes, I would try this first. A few thousands of an inch might be all you need.

[williamhemmings]

Today I went to shoot the new boolits in my G17. Approximately after about 40 shots I started making keyholings.
The diameter is .3555, the slug of my glock is .355 and they are PC.
The armed bullet does not pass the plunk test satisfactorily, because if I do more crimp, I reduce its diameter. It falls well in the bedroom but does not rotate with the fingers.
Should I try to increase the diameter of my boolits? I think this week I got the expander that Lathesmith did to me, that I hope it's a help.
Or should I respect the plunk test?
Six months into this, I still can not find the way to be precise with this gun.
Inside barrel.


My boolit

Glock recommends not using lead bullets in their weapons.

Sent from my moto g(6) using Tapatalk

[williamhemmings]

Today I went to shoot the new boolits in my G17. Approximately after about 40 shots I started making keyholings.
The diameter is .3555, the slug of my glock is .355 and they are PC.
The armed bullet does not pass the plunk test satisfactorily, because if I do more crimp, I reduce its diameter. It falls well in the bedroom but does not rotate with the fingers.
Should I try to increase the diameter of my boolits? I think this week I got the expander that Lathesmith did to me, that I hope it's a help.
Or should I respect the plunk test?
Six months into this, I still can not find the way to be precise with this gun.
Inside barrel.


My boolit

Also Glock Chambers are on the large size to facilitate chambering and some died (Dillion) size cases tight to facilitate chambering. This works the brass and can cause a Brite ring near the base. If reloaded to often the case can fail.

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[Tom W.]

I shot that same boolit when I had my Glocks, a 17 and a 19, and still use it in my Ruger and CZ. I used a Lee .358 sizer and it barely touched the boolit, but the thing shot wonderfully.No leading in the Glock factory barrels, no FTF, stovepipes or anything. I knew that if I needed to shoot something the Glocks would go Boom. You do need to seat the boolit deeper. I saw your picture and looked at one of my loaded rounds and you have way too much side of the boolit showing. I seat mine to the end of the straight side and it does well. The others I'll size to .357 and they also do well, but right now I'm saving those for the CZ.

[sigep1764]

Gents, if we look at the rifling in that barrel it is definitely not a stock Glock barrel. It has cut rifling.
Nueces, I would shorten the overall length and reduce the powder charge appropriately for the new length. I would also size before PC and load without sizing after PC. See where this leads you.

[Sig556r]

You do need to seat the boolit deeper. I saw your picture and looked at one of my loaded rounds and you have way too much side of the boolit showing. I seat mine to the end of the straight side and it does well.

I think you mean the boolits needs to seat deeper so casemouth coincide with the start of the taper...

[gnostic]

I've shot buckets of those 120 grain TC Lee bullets out of 3 or 4, 9mm pistols. Size them .358, lube with Lyman Super Moly, seat them a bit deeper and taper crimp. You didn't say where the bullet was contacting the barrel when you plunk test. Seat the bullet deep enough that it doesn't contact the barrel. Also, the loaded case in the photo still has a bit of flare from your expander die, use a taper crimp die to remove it...

[atr]

Looks like your barrel is leading...try a larger diamenter

[waksupi]

Seat the bullet deeper in the case.
Use a harder alloy.
Buy a Wolf bbl with conventional rifling.

Harder alloys are not a good thing for most handguns.

[reddog81]

Sounds like a number of issues. Seat the bullets at the longest OAL that allows for them to fit the magazine, feed, and chamber with 100'% reliability. Just stick with loads closer to starting loads while trying to figure out the best OAL.

It looks like your powder coat is failing. Leading like that shouldn't happen with a correctly cured powder coat finish. Accuracy will drop off sharply once your barrel starts to lead.

A .356 or .357 sizing die will probably work better than a .3555 die, but unless you fix the PC problem it won;t make much difference,