G20 - Mysterious FTE's [Archive] - Glock Talk

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Bubbba
04-16-2010, 18:37
Just spent an hour typing this post, clicked "Post" and everything diappeared... Oh well, ill try again.


Recently bought a brand new G20 SF. Gun is 100% stock
Tried loading some ammo for it:

1F FC Brass (purchased as 1F from a gunshop)
CCI 300 Primer
9.0gr Blue Dot
200gr TMJ bullet (Copper plated)
1.260 OAL

Gun fails to eject every 15 rounds or so.
Sometimes the empty casings get stuck in the ejection port somewhere, sometimes half way in the chamber.

Then i tried 175gr TMJ bullets with 9.7gr BD.. Same thing..

Most of you are probably thinking to themselves by now: "Ah, hes limpwristing". I can assure you that this is not the case. After the first couple of failures, i made sure to hold the gun rock hard, the FTE's kept comming...

My second through was underloaded ammo. I dont see this being the case either, as 9.0gr Blue Dot should be hot enough to cycle the action reliably (Min recommended for this bullet is 8.0gr, per my manual)

Now comes the strange part. I dont know if it is related to the FTE's, but once every 20 shots or so, cases come out looking like this:
http://i39.tinypic.com/111tkw2.jpg
I dont see how 9.0gr of Blue Dot could split cases like this. What could be the cause? Bad brass?

Here are a couple of shots of primers. They look weird to me, but i've seen similar looking primers posted before and people said it was normal.
http://i42.tinypic.com/qrj5l4.jpg
http://i40.tinypic.com/16hixs0.jpg
What is the rectangular mark around the primer strike? Is that the primer pushing itself into the firing pin channel?!? :shocked: Could this really be happening with such a weak load?

I suppose i could buy some factory ammo and see if the problem goes away. At $70/box though, i was hoping i wouldnt have to.
If it is my reloads that are causing the FTE's, what could it be?! Im new to loading pistol ammo (all the ammo was loaded on a single stage press).. Is there something that stands out?
If not the ammo, what could be the problem?

Thanks!

Taterhead
04-22-2010, 21:03
First of all, welcome to the Glock 10mm and to handloading for it!

If not limpwristing a stock G20, then I would look to the ammo as the problem. G20s don't typically have trouble cycling ammo.

First the primers: The rectangular marks are normal. Also, the primer condition seems ok (not flattened). Although primer condition is not a reliable indicator of pressure.

Now on to your load data: 9.0 grains of is right at max, if not higher, for a 200 gr plated bullet. Plated bullets should be treated like cast lead when looking at recipes.

Lyman lists a max charge of Blue Dot for a 200 gr cast bullet at 9.0. Plated bullet manufacturers state that you can also use recipe data for jacketed bullets by backing off max loads by 10%. Using Hornady's 200 gr JHP max of 9.4 grains implies that you may be in excess of max pressure when adjusting that max down by 10%. Alliant's data for a jacketed 200 gr bullet is a max of 8.9 grains. Adjusting that down by 10% for plated bullets suggests an over-charge as well.

My guess is that you have high pressure problem. Secondly, you have second hand brass of who-knows-what condition. It may be brittle. Excess chamber pressure could be causing the brass to expand sufficiently that it is sticking in the chamber. Split brass says, "you probably have excess pressure." If not, you have really troublesome brass.

I would pull the bullets from any remaining 200 gr loads that you have. My next move would be to get some new brass, back off the loads, and start working your charges back up. Starline Brass is great and inexpensive. I don't think they charge for shipping either if you buy directly from their site.

If you decide to go with Starline, I'd suggest to get a box of Buffalo Bore factory ammo (about $26 for a box of 20). They also use Starline Brass. Fire those. You can then measure the max expansion of the spent BB brass. Since BB is a hot factory load, it can be assumed to be near max pressure. The max case expansion of BB can be a reasonably good reference point for comparing the case expansion of your load workups. You'll begin to identify trends in max case expansion for loads that approach max pressure in your firearm. This can be a useful clue about what is going on pressure wise.

Kegs
04-23-2010, 09:26
How's your crimp look? :headscratch:

I had one failure on all the hundreds of handloads I made and I think it may have to do with a little wider than typical mouth flare - and none of them (so far) have had any crimp that I am aware of - just the flare was minimal and did not protrude from the rest of the brass since the bullet was seated.

Also - I noted that factory ammo COAL was set at 2.242".

HOV
04-23-2010, 09:48
How's your crimp look? :headscratch:

I had one failure on all the hundreds of handloads I made and I think it may have to do with a little wider than typical mouth flare - and none of them (so far) have had any crimp that I am aware of - just the flare was minimal and did not protrude from the rest of the brass since the bullet was seated.

Also - I noted that factory ammo COAL was set at 2.242".

2.242"?? Two rounds put together?

IMO, not enough crimp may cause feeding problems, or slide stopping just out of battery during feed, but I don't think it would cause FTE.

_The_Shadow
04-23-2010, 14:50
Bubbba, Welcome to Glock Talk!

I think you have some FC brass that is brittle and splits are common even with factory loaded Federal Brass aswell. Judging the looks of your load, by the primers and data given your pressures should be within the working designs of the pistol.

About your "FTE" issue...Does it eject properly with factory rounds? If YES the problem is probably with your handload to some degree. If NO it maybe a weak spring or broken extractor...Use your finger nail to pull the extractor to the outside as to check for tension, this should be fairly stiff if it is not then suspect extractor issue.

Be sure to look or compare the extractor shape and compare with another Glock to be sure it is not broken or damaged in any way...new parts can and do break from time to time.

Looking at the head stamps of those FC casings shows many dents along the rim these appear to have been loaded/shot a few times each. The splits shouldn't hurt your chamber but it can cause inconsistant ballistic performance.

Try and speak with Glock about the extractor if it feels weak or get with a Glock armor to change out the extractor and or spring.

Best regards!

hill billy
05-21-2010, 14:46
If that's once fired brass, I'll eat my shorts. Are your FTE's happening in conjunction with the cases expanding?

_The_Shadow
05-24-2010, 15:24
What is happening is that the casing splits(Federal is prone to this), more than normal amounts gas pressures slip by the chamber walls and hampering the ejection cycle.

If he used different brass he should see the problem disappear, if it doesn't I would suspect extractor issues.