Glock - "recoil" operated???

**W.E.G.** · February 08, 2006, 07:18

One of my shooting buddies is very knowledgable about Glocks. He informed me that the correct terminology for the method of function of a Glock is "recoil" operated.

I thought the correct term was "delayed blowback."
Which is the same term that applies to a 1911 - I think.

I understand the concept of basic "blowback." I think.
Blowback is where the bolt carrier is just so damn heavy, and the recoil spring is also so damn heavy that the bullet has time to escape the barrel before the bolt can actually begin moving from the force of the shell casing pushing back aganst the boltface. That seems simple enough.

I think the "delayed-blowback" principle (and this is where I might be getting confused) is where the force of the bullet slamming its way through the rifling keeps the whole thing locked up. Once the bullet is free of the barrel, THEN the force of the shell casing moving backward causes the slide to fly back, and cycle the pistol.

If I have that much right, WTH is this "recoil" operated notion, and how does it differ from delayed blowback.

Gurus please enlighten me.

Arby · February 08, 2006, 07:41

My understanding of "delayed blowback" is that it usually involves a mechanically locked barrel and slide. The two must travel rearward in unison to a point where a cam, link, or other part of the action unlocks the two and allows the slide to travel rearward while the barrel remains stationary in the frame.

Straight blowbacks are usually of smaller calibers with less pressure involved (Mauser 1910s, PPKs, Hscs, etc.). The Astra is the only larger (9mm) caliber that is straight blowback operated, IIRC.

Windustsearch · February 08, 2006, 08:47

They are delayed blowback, which is recoil operated. Not sure what point he (Glock guy) was trying to make to you.

Diesel45 · February 08, 2006, 08:48

Quote:

Originally posted by Arby
My understanding of "delayed blowback" is that it usually involves a mechanically locked barrel and slide. The two must travel rearward in unison to a point where a cam, link, or other part of the action unlocks the two and allows the slide to travel rearward while the barrel remains stationary in the frame.

Straight blowbacks are usually of smaller calibers with less pressure involved (Mauser 1910s, PPKs, Hscs, etc.). The Astra is the only larger (9mm) caliber that is straight blowback operated, IIRC.

A Hi-point is a recent manf. arm that is large bore .45 acp w/straight blowback with a slide that weighs 12 lbs. and a recoil spring from a '63 Chevy Impala

Some sub-guns come to mind that use straight blowback that work very well IZU, MAC , Sten among others IZU uses advanced firing in the design where the round is fired before the bolt is in battery and it start to slow the bolt as the bullet is still in the barrel this is what gives the IZU its nice very controllable rhythm. Also the bolt in the IZU is called wrap around it goes very far over the barrel for even more control while firing because the weight is distributed better with the weight of the bolt forward. IIRC If I am incorrect on some termoniology sound off

Sorry I got side tracked and did not answer your question directly "Windustsearch" is dead on!

stg58guy · February 08, 2006, 10:01

Quote:

Originally posted by Arby
My understanding of "delayed blowback" is that it usually involves a mechanically locked barrel and slide. The two must travel rearward in unison to a point where a cam, link, or other part of the action unlocks the two and allows the slide to travel rearward while the barrel remains stationary in the frame.

What you are describing here is the "short recoil" system, which is the most common in self-loading pistols, like the 1911 and Glock, FN HP etc.
Delayed blowback is a different thing. In delayed blowback the barrel and slide are not locked together in this way, but there is a another force in addition to the weight of the slide. For example in the HK P7 pistol there is a "reversed" gas piston that pushes to keep the slide closed until the pressure in the barrel is released (bullet has left the barrel).
Another delayed blowback system is the roller lock also used in some HK pistols, as well as rifles.

So the main "philosophical" difference in a sense is that in short recoil systems the action is positively locked (barrel to breech=slide), whereas in delayed blowback systems there is no positive lock.

You may now ask: what's a long recoil system, then?
It's like a short recoil system but the positive lock is maintained during the whole movement of the recoiling parts (barrel moves all the way to the rear with the bolt/slide/locking device). This system was common in early light machine guns before gas operation became prevalent.

Quote:

Originally posted by Arby
Straight blowbacks are usually of smaller calibers with less pressure involved (Mauser 1910s, PPKs, Hscs, etc.). The Astra is the only larger (9mm) caliber that is straight blowback operated, IIRC.

Quite right. A "straight" blowback system has no positive lock and relies solely on the mass of the locking part (the slide in a pistol) to keep the action closed until the pressure is released through the muzzle.

FN74 · February 08, 2006, 13:45

Four basic methods of operation for automatic/semi-auto weapons as taught by the USMC and Army:

1. Gas

2. Blowback

3. Delayed Blowback

4. Recoil

1 - Everyone knows what gas operation is - same method that 90% of modern semi-auto rifles use - FAL, AK, AR-15, SKS. basically a bit of the gas is tapped off from the ignition of the round, and used to operate the system.

2. Blowback - this is mostly for small caliber pistols and sub-machine guns. Basically you are using the energy from a fired round in a FIXED barrel to push a NON LOCKING slide or Bolt to the rear for function. Classic examples are Uzi, M11, Walther PPKS, and most .22 LR rifles and pistols.

3. Delayed blowback - Probably the most difficult to describe, but it involves a combonation of a FIXED barrel with a delaying locking device to tame recoil a bit. Classic examples are just about all the HK line - HK91/93/94, MP5, and CETME. Not as commonly used in firearms, but it's out there.

4. Recoil - The principle of recoil operation involves using the energy from the exiting round to move jointly the LOCKED barrel and slide or barrel extension for a short distance to the rear and let inertia take over to finish the process as well as the recoil springs.
Classic examples are nearly all modern auto loading pistols from 9mm on up - 1911a1, Glock, Beretta, Sig, HK P2000 and USP, as well as some heavier machineguns that you may be familiar with: Ma Deuce .50 caliber MG and it's little brother the 1919 series of weapons.

So to answer your question, yes, GLOCKs are recoil operated.

HTH>

**W.E.G.** · February 08, 2006, 14:56

That's very helpful.

Thanks to all for the info!

**EMDII** · February 08, 2006, 17:45

Blowback- by definition has no locking lug or lock mechanism

mparrish · February 12, 2006, 07:00

Go to a Glock Armorer's course. It's recoil operated, per their manuals and instruction.

Excellent post explaining the various methods by FN74.

fire for effect · February 12, 2006, 08:33

All I know is that I 'recoil' from Glocks. yeck!!!

Windustsearch · February 12, 2006, 09:22

February 08, 2006, 07:18	#1
W.E.G. Administrator Silver Contributor FALaholic #: 1211 Join Date: Oct 2000 Location: Virginia Posts: 31,056	Glock - "recoil" operated??? One of my shooting buddies is very knowledgable about Glocks. He informed me that the correct terminology for the method of function of a Glock is "recoil" operated. I thought the correct term was "delayed blowback." Which is the same term that applies to a 1911 - I think. I understand the concept of basic "blowback." I think. Blowback is where the bolt carrier is just so damn heavy, and the recoil spring is also so damn heavy that the bullet has time to escape the barrel before the bolt can actually begin moving from the force of the shell casing pushing back aganst the boltface. That seems simple enough. I think the "delayed-blowback" principle (and this is where I might be getting confused) is where the force of the bullet slamming its way through the rifling keeps the whole thing locked up. Once the bullet is free of the barrel, THEN the force of the shell casing moving backward causes the slide to fly back, and cycle the pistol. If I have that much right, WTH is this "recoil" operated notion, and how does it differ from delayed blowback. Gurus please enlighten me. __________________ . . . Ask me about the Mason-Dixon FAL Collectors Association.

February 08, 2006, 08:47	#3
Windustsearch Registered FALaholic #: 10219 Join Date: Apr 2003 Location: Seattle,Wa Posts: 5,697	They are delayed blowback, which is recoil operated. Not sure what point he (Glock guy) was trying to make to you. Last edited by Windustsearch; February 08, 2006 at 08:53.

February 08, 2006, 13:45	#6
FN74 Registered FALaholic #: 220 Join Date: Jul 2000 Location: Metro New Orleans, LA Posts: 3,074	Four basic methods of operation for automatic/semi-auto weapons as taught by the USMC and Army: 1. Gas 2. Blowback 3. Delayed Blowback 4. Recoil 1 - Everyone knows what gas operation is - same method that 90% of modern semi-auto rifles use - FAL, AK, AR-15, SKS. basically a bit of the gas is tapped off from the ignition of the round, and used to operate the system. 2. Blowback - this is mostly for small caliber pistols and sub-machine guns. Basically you are using the energy from a fired round in a FIXED barrel to push a NON LOCKING slide or Bolt to the rear for function. Classic examples are Uzi, M11, Walther PPKS, and most .22 LR rifles and pistols. 3. Delayed blowback - Probably the most difficult to describe, but it involves a combonation of a FIXED barrel with a delaying locking device to tame recoil a bit. Classic examples are just about all the HK line - HK91/93/94, MP5, and CETME. Not as commonly used in firearms, but it's out there. 4. Recoil - The principle of recoil operation involves using the energy from the exiting round to move jointly the LOCKED barrel and slide or barrel extension for a short distance to the rear and let inertia take over to finish the process as well as the recoil springs. Classic examples are nearly all modern auto loading pistols from 9mm on up - 1911a1, Glock, Beretta, Sig, HK P2000 and USP, as well as some heavier machineguns that you may be familiar with: Ma Deuce .50 caliber MG and it's little brother the 1919 series of weapons. So to answer your question, yes, GLOCKs are recoil operated. HTH> __________________ DEO VINDICE! YOU! - OUT OF THE GENE POOL!!! DABTL said on 7/15/06, "I rather think it is a good idea to shut down those machine gun kits such as the MG42 from coming into this country. I cannot imagine a good use to which they might be put. I can think of many ways they could be a problem" "An MG42 has an enormous rate of fire and in the wrong hands can and will do an enormous amount of damage, some day. If not bringing in any more of those will put that day off it will be worth it."

February 08, 2006, 14:56	#7
W.E.G. Administrator Silver Contributor FALaholic #: 1211 Join Date: Oct 2000 Location: Virginia Posts: 31,056	That's very helpful. Thanks to all for the info! __________________ . . . Ask me about the Mason-Dixon FAL Collectors Association.

February 08, 2006, 17:45	#8
EMDII Evil Moderator Silver Contributor FALaholic #: 6 Join Date: Jul 2000 Location: Kennesaw, GA Posts: 13,971	Blowback- by definition has no locking lug or lock mechanism __________________ "The Spartans do not enquire how many enemy there are. The SPartans merely enquire WHERE they are." E.M. (Ted) Dannemiller II 1*

February 08, 2006, 07:41	#2
Arby Registered FALaholic #: 653 Join Date: Aug 2000 Posts: 3,492	My understanding of "delayed blowback" is that it usually involves a mechanically locked barrel and slide. The two must travel rearward in unison to a point where a cam, link, or other part of the action unlocks the two and allows the slide to travel rearward while the barrel remains stationary in the frame. Straight blowbacks are usually of smaller calibers with less pressure involved (Mauser 1910s, PPKs, Hscs, etc.). The Astra is the only larger (9mm) caliber that is straight blowback operated, IIRC.

February 12, 2006, 07:00	#9
mparrish Registered FALaholic #: 775 Join Date: Aug 2000 Location: North of Seattle, south of Canada Posts: 1,985	Go to a Glock Armorer's course. It's recoil operated, per their manuals and instruction. Excellent post explaining the various methods by FN74. __________________ Liberals and Democrats always look best when viewed through a rifle scope. Hunting liberals is a fun sport.

February 12, 2006, 08:33	#10
fire for effect Registered Bronze Contributor FALaholic #: 14188 Join Date: Apr 2004 Location: Sioux City Iowa Posts: 1,919	All I know is that I 'recoil' from Glocks. yeck!!! __________________ You cannot qualify war in harsher terms than I will. War is cruelty, and you cannot refine it; and those who brought war into our country deserve all the curses and maledictions a people can pour out. W.T. Sherman, Major General Commanding Headquarters, Army of Tennessee September, 1864

February 12, 2006, 09:22	#11
Windustsearch Registered FALaholic #: 10219 Join Date: Apr 2003 Location: Seattle,Wa Posts: 5,697

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