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Stock G20 and after market barrels, which to use for hot loads?


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#1 OFFLINE   halfglocked

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Posted Apr. 08 2014 - 01:19 AM

I have a new stock 3rd gen G20 sf and I have been doing some reading up on some hot full power loads from boutique ammo makers like Underwood and double tap, I have heard some G20's kabooming due to elevated pressures and not fully supported barrels and I was wondering ,should I look into aftermarket barrels with tighter supported chambers and my question is if I were to go to a tighter tolerance aftermarket barrel would I loose some of the reliability from the looser tolerance stock barrel? I guess what i am asking g is should i go with an aftermarket barrel or stay with a stock barrel? I would like some honest feedback ,thank you all in advance.


#2 OFFLINE   The_Shadow

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Posted Apr. 08 2014 - 04:35 PM

Well you have raised some interesting questions...let me try to work through them.

The boutique ammo is strong and higher pressure and that higher impulse is imparted to the mass of the slide during firing.  The issue with KaBoom is really a case blowout and is mainly attributed to lack of support and possibly early unlock or out of battery condition, allowing high pressure gasses to burst the casing, and jet out to affect the frame and magazine.  Frames have cracked and magazines blown out of the well suffering some damage and yes some shooter's hands were cut and bruised from the incidents I have read about.

 

First off, I think lock up of the barrel and slide in battery has to be right, with any of the guns.  Otherwise the locked dwell time needs to hold long enough to allow pressures to be contained, the imparted energy is translated to the mass of the slide and recoil system, where the recoil system is working to maintain lockup long enough.  Then it has to control the slide velocity as it is shoved rearward and it has to travel far enough to the rear in order to drag the spent casing out of the chamber, allow it to contact the ejector, and far enough and long enough to pick up a fresh cartridge from the magazine, then return it to full battery and lockup.

 

Yes, the Glock 20 factory barrels are somewhat looser chambered about 0.4340", and this adds to more reliable feeding it also allows higher pressured cartridges to swell to fill the chamber and more in cases.  Aftermarket barrels attempted to provide more support for this reason and conventional rifling for those wanting to shoot casted alloy bullets. 

 

Ammo that is of such pressure that it overfills the chamber and exceeds the containment of the brass casing, can show signs of excessive expansion and "SMILES", also in some the dreaded case blowout under certain conditions like early unlock or out of battery.

 

Handloaders typically will work up charges looking for these signs as they work with their pistols as they are setup.  My G-20SF has worked well with the factory RSA and also using the Wolff steel non-captive recoil rod system  and the 22lb spring.  I have measured about a 1.5 lb difference in between the factory RSA and the Wolff setup maintaining locked slide in battery, this added 1.5lb of the Wolff setup maybe working to hold things closed just a little longer and ejected brass a little closer.

 

The only aftermarket barrel I have for my G-20SF is chambered is LWD 6" chambered in 9x25Dillon, although I have 2 Storm Lake barrels 10mm and 40S&W and 2 LWD 357Sig and 9x25Dillon for my G-29.  However I am looking at getting a 10mm aftermarket barrel for my G-20SF, possibly 6" or even 9" just to have for range play or hunting.

 

If you are wanting to rely on your G-20SF for defensive purposes I'd stay with the factory barrel and RSA.  

 

BTW Underwood's ammo has changed up he is using Star-Line brass but now he has it with his own headstamp, as he switched from IMR800X to LongShot powder.  It does push the limits of Colt DE and the Glock factory setups it has even given my S&W1006 quite the workout with its 22lb recoil spring.  I have tested some of the Underwood loads that have blown out primers, leaving the brass in the chamber. 

 

I have seen some barrels factory and aftermarket that have split ruptured and from ammo that was not either Underwood or Double Tap but actually from other major ammo makers.

 

Aftermarket barrels can be beneficial to those who wish to reload their own ammo in the effort to control excessive expansion and working of the brass.

 

Good luck with your decision! :tap:   Also let me invite you to the 10mmFirearms Forum; http://10mm-firearms.com/index.php   :segrin:




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#3 OFFLINE   halfglocked

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Posted Apr. 09 2014 - 01:21 AM

Well The _ Shadow as everyone else I would like to run full power loads to get maximum ballistics 9th of the 10mm auto but as they say "there aren't any free lunches " do carry my G20 daily although not concealable , I was thinking about going up to a 22# rsa
Eventually, but you have given some information I greatly needed so what would you suggest for SD and hd as it is now I have both mags topped off with Winchester 175gr Silvertips I also would like to thank you for the information and the invite to forum.


#4 OFFLINE   gmor

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Posted Apr. 09 2014 - 02:21 AM

Well The _ Shadow as everyone else I would like to run full power loads to get maximum ballistics 9th of the 10mm auto but as they say "there aren't any free lunches " do carry my G20 daily although not concealable , I was thinking about going up to a 22# rsa
Eventually, but you have given some information I greatly needed so what would you suggest for SD and hd as it is now I have both mags topped off with Winchester 175gr Silvertips I also would like to thank you for the information and the invite to forum.

:dancetl6:  Welcome Aboard!!!    :piratebo5:  Don't be a stranger, stop back soon!  :pirate41:




#5 OFFLINE   halfglocked

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Posted Apr. 09 2014 - 01:00 PM

Thank you gmor I really have liked the 10mm since the '80's and I 2 as a teenager , to me my ultimate pistol was always the G20 so finally after much sacrifice from my family I finally got my dream gun a G20 sf with a Green UTAC laser /flashlight combo.Now I want to do all the upgrades. I am glad to be here and hope to learn a lot from you all.


#6 OFFLINE   devilman

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Posted Nov. 01 2014 - 11:35 PM

I just picked up a glock 20 gen 2 10mm in great condition. I put in a brass stacker 22lb guide rod, night sights, and a new lone wolf 6" ported barrel. I ordered some ammo from underwood. The 180 gr jhp and the 150 gr jhp. I was curious to know if it will be safe for me to shoot this ammo from underwood out of the gen 2 with the new lone wolf barrel. I have shot a lot of the hornady 180gr xtp ammo with no problems at all. I know this is not full house 10mm but I am upgrading this gun and would really like to shoot the real 10mm ammo from underwood. Any information will be greatly appreciated. Thank you. I always have and always will love the 10mm.




#7 OFFLINE   The_Shadow

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Posted Nov. 02 2014 - 06:07 PM

Silvertips are good to go, so are the (Bonded Defense) Gold Dot offerings from Underwood, Buffalo Bore, Georgia Arms and Double Tap if you can find them available. 




#8 OFFLINE   Retcop

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Posted Nov. 03 2014 - 07:39 AM

I am far from an expert on this, but don't the aftermarket barrels with traditional rifling produce higher pressures than Glock's polygonal rifling ? i.e the bullet is going to face more resistance from the traditional rifling than the polygonal.

Is it more important to have the round in the chamber fully supported than the type of rifling when it comes to pressures?
Are there any aftermarket Glock barrels with polygonal rifling?


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#9 OFFLINE   halfglocked

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Posted Dec. 15 2014 - 09:50 PM

I am far from an expert on this, but don't the aftermarket barrels with traditional rifling produce higher pressures than Glock's polygonal rifling ? i.e the bullet is going to face more resistance from the traditional rifling than the polygonal.Is it more important to have the round in the chamber fully supported than the type of rifling when it comes to pressures?Are there any aftermarket Glock barrels with polygonal rifling?

Wow that brings up a good point as one of Glocks advertising gimmicks is the octagonal rifling Increases muzzle velocity while reducing pressure! HMMMM anyone?





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