Checklist/Steps to Prevent KB in Glocks

[LiveLife]

DISCLAIMER/CAUTION: Glock does not endorse use of any reloads (jacketed/plated/lead/Moly coated/etc.) and not all suggested load data may be currently published for the particular bullet/type, so use reloads and load data suggestions at your own risk. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.



While discussing a recent Glock KB thread with other reloaders, a general consensus was reached as to what factors may contribute/lead to a Glock KaBoom (KB):

- Double charge of powder (exceeding max chamber pressure)
- Overcharge of powder due to inaccurate/misuse of powder measure, scale, load data, etc. (exceeding max chamber pressure)
- Use of inaccurate/mixing up load data for bullet weight/powder (exceeding max chamber pressure)
- Inadequate neck tension/reduction of OAL during feeding from magazine/bullet nose bumping on ramp (exceeding max chamber pressure)
- Weakened/work hardened/damaged/defective case (case failure)
- Obstruction in barrel (squib round in barrel)
- Obstruction in chamber (excessive fouling buildup or foreign object in chamber to prevent full chambering of round/firing-out-of-battery)
- Especially for 40S&W, lack of full case support at ramp area of chamber (case failure)



There have been several threads on Glock KBs in recent years on THR, so how about developing a checklist or steps to prevent KB in Glocks to benefit new/old reloaders to Glocks? I have shot several hundred thousand rounds of reloads in Glocks (mostly 40S&W) using mixed range brass with jacketed/plated/lead bullets and use the following steps and Quality Control (QC) checks. Feel free to add QC checks, reloading steps or comments.


QC check - Regardless of scale type used (beam or digital), use check weights to ensure accuracy of scale/powder measure for powder charge range used.

Reloading step - Triple check load data for bullet type/weight/powder used. Only one container of powder on the reloading bench at any time.

Reloading step - Do not start at published max powder charge. Always conduct full powder work up from published start charge or 10 percent below max charge and work up in .1-.2 gr increments. Never exceed published max load data.

QC step - During powder work up from start charge, if significant bulging of case is noticed, consider reducing powder charge, changing powder (I recommend W231/HP-38 or slower burn rate powder for 40S&W) or using aftermarket barrel with fully supported chamber at the ramp area.

Reloading step - If using mixed range brass with unknown reloading history, use mid-to-high range load data. Reserve near max/max load data for "known" once-fired cases without damage/defects.

Reloading step - Adhere to plated bullet manufacturers' recommendations for load data, velocities and amount of taper crimp, etc:
Rainier Ballistics - Use lead load data, 1200-1250 fps max, slight taper crimp, Lee FCD OK.
Berry's MFG - Use lead load data/start-to-mid range jacketed load data, 1200 fps max (850-900 fps for 45ACP), 1450 fps max for Thick Plated bullets (TP), no tight roll crimp.

QC check - During sorting of brass, visually inspect all cases for damage/defect and discard/recycle as necessary

QC check - During full-length resizing of cases, if significantly greater effort is needed on the ram lever or bottom of resizing die does not "kiss" the shell holder/plate, inspect the case for "guppy or overly bulged" case base. If bulge is slight, rotate case 90 degrees and attempt to resize the case. Check if resized case pass the case gauge or fall freely into the tightest barrel chamber you have. Discard/recycle case as necessary.

QC check - If resizing cases separately, check to see if resized cases fall into case gauge/tightest barrel chamber freely. If not, resize case again and recheck. Discard/recycle case as necessary.

Reloading step - Use minimal amount of case neck flare to prevent reducing neck tension of resized case.

QC check - Press on the finished round's bullet nose against the reloading bench top and manually feed/chamber initial rounds from the magazine by releasing the slide to check for bullet set back (measure OAL before and after).

Reloading step - If loading single stage, double check for powder charge inside cases to prevent squib rounds.

QC check - Visually inspect case for powder charge before seating bullet or mount a small mirror/light to visualize powder inside the case to prevent squib rounds.

Reloading step - If progressive loading process is interrupted for any reason, visually inspect case for powder charge before seating bullet to prevent squib round or clear the shell plate and start over with station #1 if there is further concern/doubt.

Range QC - Field strip pistol and inspect barrel before each range session.

Range QC - If shooting lead reloads, inspect inside of barrel near chamber area for fouling/leading build up and clean as necessary every 200-300 rounds. If shooting a lot of lead reloads, consider using an aftermarket barrel with conventional square cut land/groove rifling for reduced fouling/leading and greater accuracy.

 

[gahunter12]

If I have to stop the process for any reason on my RL550b, I always make sure the next step is pulling the handle. Example: If I need to stop I will advance the shellplate so I have a case in Station 1 that needs resized, Station 2 that needs belled and charged, Station 3 has a charged case with a bullet setting on top, and Station 4 has a seated bullet that needs a taper crimp. So that way I know that my next step when I get back is pulling the handle. I do a quick check of the case in ST 2 and lift the bullet in ST 3 then pull the handle

 

[rsrocket1]

I really think this recent kaboom would have happened in any gun, but for the exact reason you are stating here bds, thank you.

The barrel of this gun was split in half and peeled open like a banana. I don't think that would happen just from a weak case in an unsupported chamber. The belly blew out only because it was another weak spot in a severe overpressure which would not happen with a normal charge in a properly chambered cartridge.

My guess is that there was either an over/double charge or too much crimp allowing the case mouth beyond the chamber and getting trapped between the bullet and barrel (hence the 1/10th inch ring of brass he later pulled out of the blown up barrel). These are probably the result of interruptions he had while teaching his son the workings of the press, then resuming without rechecking everything twice.

Any time I have an interruption whether from people, the press (primer problem), "nature" or anything else, I take all cases out of the press and finish them off one at a time, then start over. When starting a session or changing calibers, I remeasure and reset everything as if the dies are being used for the first time.

It only takes a couple of extra minutes, but my hand, face and gun are worth it.

 

[Jeff H]

I really think this recent kaboom would have happened in any gun, but for the exact reason you are stating here bds, thank you.

The barrel of this gun was split in half and peeled open like a banana. I don't think that would happen just from a weak case in an unsupported chamber. The belly blew out only because it was another weak spot in a severe overpressure which would not happen with a normal charge in a properly chambered cartridge.

Your reasoning is sound, but you have the wrong barrel. The barrel for the gun that started the thread is on page 2. The one you are describing is on page 3 and posted by someone else.

IMHO, it was probably a slight overcharge with already weakened brass.

 

[LiveLife]

Although different barrel/KB was referenced, since this thread discussion is about general Glock KB prevention, what factors/practices would have prevented these KBs?

I think we have a vast combined wealth of knowledge from various KB threads discussed on THR. I think each identified KB contributing factor/practice warrants appropriate corrective action/reloading practice change to benefit THR members/guests from not experiencing another KB in the future.

In the "High Road" fashion, admitting that improperly using reloads in Glocks can result in KBs is the first responsible step in addressing/resolving this issue. Second and logical next step would be to discuss proper "root cause analysis" and appropriate resolutions I am suggesting on this thread.

I believe such a "Best Practices" Glock KB prevention checklist can be drafted here on THR with the combined participation and experience of THR members so shooting reloads in Glocks can be a safer experience for all.

 

[GLOOB]

If I have to stop the process for any reason on my RL550b, I always make sure the next step is pulling the handle.

I only load on a single stage press, but I suggest you try this instead:

I stop when the ram is all the way up. When the ram is down, there's 2 possible states for the case to be in. Either it hasn't been processed yet. Or it has already been processed. If the ram is up, then there's only one possible state for that case to be in. I bet this works the same way on an RL550b. If the ram is up, then you know that all the cases have already been done for that station. After you lower it your next thing is to move the cases round the merry go round.

 

[Varmiter]

Your checklist just touched on the ‘Unsupported Chamber’ which is good, but that item needs to be highlighted.

Too many reloaders will process their brass with a brief visual glance and fail to notice a bulged case. The sizing die will iron this out, but the case was weak in the first place, and the additional working of the case, in producing the bulge, and then ironing the bulge out weakens it even further. Anyone who reloads a bulged case is just asking for a KB.

Chris

 

[rsrocket1]

I looked again through the thread and you are absolutely right Jeff, thanks for the correction. The barrel was intact.

 

[Nomad]

Very good write up bds - the only thing I would add is, if I am using a factory barrel with unsupported chamber, I only reuse brass of a known origin 5 times before disregarding it. IMO it just adds a measure of safety. On my USPSA gun I went to a custom fully supported chamber to reduce my risk.

 

[Certaindeaf]

1: use a Hi-Point.. did you see those videos?

 

[ny32182]

Looks like a good list of thinks to keep an eye on, but in what way is it Glock specific? A bad round is a bad round, and you don't want to shoot it in any gun, Glock or otherwise.

 

[Nomad]

ny32182 - You are correct a bad round is to be avoided. However, the Glock, along with a few other brands, have an unsupported chamber which leaves less margin of error where excessive pressure is concerned.

 

[ny32182]

I've always thought that the term "unsupported" Glock barrel is meaningless. "chamber support" is a sliding scale... some chambers are tighter than others, and some barrels have a deeper feed ramp cut than others; "unsupported" conveys little to no real information. Some generations of Glock barrels have a deeper feed ramp cut than others.

Personally, with only a very few possible exceptions, if I did not feel a round of ammo was safe in a Glock I would not be shooting it in any other gun either.

 

[GLOOB]

Not to mention that the Glock hasn't had an "unsupported barrel" in over 12 years. The Gen 3's and later have about as much or more support as a lot of other modern 40SW semiautos, none of which I've ever read about having unsupported chambers. Maybe it's time to wake up and look at the calendar. It's 2012, not 1997.

 

[popper]

bds - add to your list: DO NOT reload FC marked 40 SW cases. Fracture cracks at extractor groove. I know it's old but we need reminders. Also, novice reloaders should NOT use fast powder; yes that is in your list, but I see a lot of experienced reloaders recommending (on THR) stuff novices shouldn't try..

 

[mboylan]

A big part of the problem in the recent KB was the choice of powder. TG is great for building bunny fart loads. However, it is not a forgiving powder. The pressure curve has an obscene spike at just over the max in tight cases like 9mm and 40. Way too many newer reloaders think pressure is linear. They don't hit the books enough.

A slower burning powder has a much more forgiving pressure curve.