Could you guys please evaluate the pros and cons of both, in an attempt to find which is the better system?
Thank you,
LavaRed

With striker fire if the round fails to go off you cannot just pull the trigger again the slide has to be recocked.

I've used both (Glock vs Browning Hi Power, SigP226, Colt 1911) and I much prefer hammer pistols, mainly because of the visual aspect of knowing when the hammer is back (Granted DA pistols can fire by just pulling the trigger, but it takes a harder pull obviously). On the other hand unless you have a well profiled hammer and spur, it can cause concealed draw issues (propper military spec holster is no worries though).

With striker fire if the round fails to go off you cannot just pull the trigger again the slide has to be recocked.

Same with a 1911. Maybe not the slide, but the hammer sure. I'd rather just have to work the slide in any case rather than the hammer. It's a gross motor vs. fine motor skill thing.

And I think the new Taurus striker fired pistol has a restrike feature where you can just pull the trigger again if there's a fail to fire. Course, ammo is reliable enough that pulling the trigger again won't do it. You'll need a new round in the chamber.

In short, for clearing... just rack the slide. And Glock is my gun.

I carry a 1911. I love hammer fired pistols.

That having been said, a striker fired weapon is inherentley more reliable in the real world. An exposed hammer is more likley to be retarded by dirt, clothing, or debris, leading to a misfire. The striker system is simpiler. It also takes up less room as it eliminates pieces. Hammers are extra weight as well.

I don't know about lock time and I doubt that it matters. I would speculate that striker fired weapons are quicker.

In any case, strikers are far supperior to hammers.

How about inside a rifle. Lets think select- fire rifle, just for the sake of argument. Do the same pros and cons as in a pistol apply?
Thanks,
LavaRed

I think that it would generally be the same.

Inside a rifle one must make room for the travel radius of the hammer. I suppose that is a con.

Are you talking about a semi auto, bolt action, machine gun?

I think that it would generally be the same.

Inside a rifle one must make room for the travel radius of the hammer. I suppose that is a con.

Are you talking about a semi auto, bolt action, machine gun?

Select fire.

I don't see why being striker fired would be a bad thing in a FA rifle. The imporntant thing would be (as it is with hammer fired weapons) to delay the foward travel of the striker untill the bolt is locked in it's forward battery.

Is this going to be a rifle round or a pistol round?

Its for my rifle design. Ideally, it will be able to handle all three interchangeably.
But in the meantime, lets limit ourselves to something no larger than 7.62x51mm and no smaller than 7.62x39mm.
Originally I was thinking striker-fired too (less parts), but then I realized M16's are hammer fired, which made me doubt.
I'm also about to abandon my complicated recoiling barrel locking mechanism and just stick a piston on the thing.
Its starting to look like the product of some hasty cybersex orgy between an FN SCAR and an AK-47, with the M3 Grease gun as the shemale in the middle.:p

I've used both (Glock vs Browning Hi Power, SigP226, Colt 1911) and I much prefer hammer pistols, mainly because of the visual aspect of knowing when the hammer is back (Granted DA pistols can fire by just pulling the trigger, but it takes a harder pull obviously). On the other hand unless you have a well profiled hammer and spur, it can cause concealed draw issues (propper military spec holster is no worries though).

My xd is striker and it has chamber indicator and an indicator to show the striker is charged. they are not only visual but you ca also feel the two indicators to know if the weapon is loaded. I still double check anyway to keep good habits.

The XD is also a striker fired single action only mechanism.

So it's slightly more "mushy" than a GLOCK, but it feels lighter and breaks easier.

That said, I like XDs so much I'll probably have another one in about 12 hours, really depends on what Cabelas has in stock, though.

Are you really making your own rifle? That's what I interpret after reading this thread at something like five in the morning. Do you have pictures of the project as of late?

Are you really making your own rifle? That's what I interpret after reading this thread at something like five in the morning. Do you have pictures of the project as of late?
I plan to manufacture and market my design in the future.
As of this momenr I'm still down to CAD drawings and handmade sketches. But its coming through pretty well.
As an Industrial Engineering student, it should be within my abilities to set up my production line once a working prototype can be developed.

Luger is too young to know what plans Lavared have had, in short: Everything Lava says must be taken seriously.:D

I plan to manufacture and market my design in the future.
As of this momenr I'm still down to CAD drawings and handmade sketches. But its coming through pretty well.
As an Industrial Engineering student, it should be within my abilities to set up my production line once a working prototype can be developed.

I'm interested in seeing some drawings and specs. I had a bit of inspiration to make something over the weekend as well. Unfortunately I lack machine tools. Something similar to a Steyr TMP with striker firing.

Another something I want to do is blueprint the lower on an AR-180 so I can make one out of aluminum. Plastic doesn't inspire me too much. :D

Can anyone explain how the gas system/blowback mechanism works on mordrn semiauto handguns?

Can anyone explain how the gas system/blowback mechanism works on mordrn semiauto handguns?

Blowback simply pushes the bolt or slide back due to the expansion of gases with pressure applied directly to the bullet case. The spring and bolt/slide mass is tuned so that when the case comes out of the breech the pressure won't blow something up. Gas systems vent some of the expanding gasses in the barrel to a piston or gas key which pushes the bolt carrier back.

On thing I don't understand is how recoil action is somehow different than blowback. Just looking at a slowmo of a 1911 and it looks pretty much like blowback operation where the barrel is pushing the slide back and then unlocks.

yeah I understand semi auto rifle gas systems. I just didn't get how the semi auto handguns work, thanks.

Blowback simply pushes the bolt or slide back due to the expansion of gases with pressure applied directly to the bullet case. The spring and bolt/slide mass is tuned so that when the case comes out of the breech the pressure won't blow something up. Gas systems vent some of the expanding gasses in the barrel to a piston or gas key which pushes the bolt carrier back.

On thing I don't understand is how recoil action is somehow different than blowback. Just looking at a slowmo of a 1911 and it looks pretty much like blowback operation where the barrel is pushing the slide back and then unlocks.

With recoil system, recoil takes barrel back.
Barrel hits bolt or slide, and pushes bolt or slide back.
Recoil system less accurate than blow back, barrel is fixed on bb.
Blow back has harder recoil.

Class dismissed.

The XD is also a striker fired single action only mechanism.

So it's slightly more "mushy" than a GLOCK, but it feels lighter and breaks easier.

That said, I like XDs so much I'll probably have another one in about 12 hours, really depends on what Cabelas has in stock, though.

Thats weird. I shot a glock and it had a "trigger job" and it felt worse than my factory xd.

Well, I've finally had some alone time with a GLOCK and I must say, I like the trigger better than the XD's.

It resets much faster which means I can shoot it faster.

And being a 9x19 it doesn't have any recoil.

Anyway, check my post on the W&C front page.

One advantage to a hammer lies in modularity. The trigger group and hammer can all be part of one mechanism, independent of the bolt. In handgun terms, it's the difference between a Glock and a 1911. In the former, the striker is contained within the slide, but the latter places the hammer in the frame. If ARs were striker fired, every upper would need a complete striker mechanism and some way of linking the trigger to the release mechanism. Given the less-than-exact fit of many upper/lower combos, this could be difficult to pull off.

On the other hand, strikers are much simpler and, I would imagine, more robust. They'll probably add a small amount of mass to your bolt, decreasing cyclic rate and reducing wear.

The simplest, most idiot-proof solution is an open bolt system, obviously.

Quick question: Is a 2mm diameter gas port too big?
I figured a larger gas port would improve reliability in the face of fouling, but correct me if I am wrong.

Your gas port size is dependent on too many variables. The ammo, the length of the gas tube, DI/piston choice, bolt carrier mass. You'll have to crunch some numbers, or manually tune it.

I'd leave it adjustable, like a FAL.

As to the cycling question regarding modern handguns:

Blowback: The recoil of firing drives the slide back, the recoil spring returns it to battery. Very simple. The mass of the slide and the strength of the recoil spring are tuned to keep the breech from opening until after the bullet leaves the barrel and the internal pressures have subsided to a safe level. The fixed barrel lends itself to excellent accuracy. This is mostly used for weaker cartridges. Blowback designs for something as powerful as the .45 ACP lead to positively massive slides, as in the Hi-Points. Some subguns [The Uzi being the first, IIRC] get around the size issue by telescoping part of the bolt carrier forward around the barrel.

Short recoil: Like a blowback system, recoil pushes the slide back. However, in order to avoid having very large slides and stiff springs, the barrel recoils along with the slide for a short distance, giving the chamber pressures time to subside. The barrel then stops moving rearward [via various means] and the slide continues, ejecting the spent case and chambering the next. This is used in most of your moderately powerful semi-automatics, like 1911s, Glocks, Sigs, etc.

Gas systems in pistols: Two different gas systems can be employed.

Gas retarded blowback: Heh, I said "retarded". Some HK and Steyr pistols use this. Ports in the barrel vent some of the explosive gases into a chamber inside the slide. This gas slows the recoil of the slide so that the pressures drop before it unlocks. While this is elegant, it's more complex and requires more maintenance. Like simple blowback weapons, the barrel is fixed, enhancing accuracy. You owe it to yourself to find a P7 and give it a shot.

Gas-cycled: Just like all your favorite assault rifles. AFAIK, only the Desert Eagle functions this way. It uses a gas port in the barrel to divert gases and operate a piston that moves the bolt carrier back. This allows it to operate with very powerful rounds and with excellent accuracy at the expense of added complexity and maintenance.

Quick question: Is a 2mm diameter gas port too big?
I figured a larger gas port would improve reliability in the face of fouling, but correct me if I am wrong.


Yes. Probably. It depends on the length of barrel that lies between the gas port and the muzzle. You need to figure out how much gas will be required to work the action. Then you need to figure out how much gas will pass through the gas port in the time between when the bullet passes by the port to when it leaves the barrel.

I agree about adjustable gas. At the very least, you should build the prototype with adjustable gas and figure it out from there or hire a physics/chemistry grad student to figure it out for you.

Blowback designs for something as powerful as the .45 ACP lead to positively massive slides, as in the Hi-Points. Some subguns [The Uzi being the first, IIRC] get around the size issue by telescoping part of the bolt carrier forward around the barrel.

Actually, look up the Astra 400. It's a blowback 9mm with the spring around the barrel. It's not too heavy, the slide isn't too large at all (seen cross sections and I'm surprised how small it is) and the spring is apparently comfortable to use.

Never said it was impossible. A little bit of compromise in weight and spring tension can certainly do the trick. The Hi-Points tend to exaggerate all the disadvantages of straight blowback. The slide seems even more top-heavy in contrast to the polymer frame, and the die-cast zinc alloy is less dense than steel, thus it ends up being rather large.

Never said it was impossible. A little bit of compromise in weight and spring tension can certainly do the trick. The Hi-Points tend to exaggerate all the disadvantages of straight blowback. The slide seems even more top-heavy in contrast to the polymer frame, and the die-cast zinc alloy is less dense than steel, thus it ends up being rather large.

I thought about a spring around the barrel. However, I figured it would get too hot with sustained fully automatic fire, which could lead to failure or deformation.

I thought about a spring around the barrel. However, I figured it would get too hot with sustained fully automatic fire, which could lead to failure or deformation.

Pistols are not used for sustained full auto fire, not even most sub guns are made for that. Please tell us what you are looking to design.

Pistols are not used for sustained full auto fire, not even most sub guns are made for that. Please tell us what you are looking to design.

I'm shooting for something as modular as the SCAR, as accurate as the AR platform, as relaible as the AK, and as easy to produce as the Sten gun.

Something whose barrel can be replaced in mere seconds and which can be converted from Subgun to assault rife to MG to marksman's rifle in a few minutes.
But which costs little to produce.
I may be shooting too far, but I have to aim high I guess.
In its most basic form, however, it should be an assault rifle in 7.62x39mm caliber.

I'm shooting for something as modular as the SCAR, as accurate as the AR platform, as relaible as the AK, and as easy to produce as the Sten gun.

Something whose barrel can be replaced in mere seconds and which can be converted from Subgun to assault rife to MG to marksman's rifle in a few minutes.
But which costs little to produce.
I may be shooting too far, but I have to aim high I guess.
In its most basic form, however, it should be an assault rifle in 7.62x39mm caliber.

I doubt you'd be able to make a gas piston rifle that fires a rifle cartridge as easily as a Sten. The Sten is a straight blow back if you didn't already know, whereas a gas piston driven rifle requires a bolt that stays locked up until the pressures have dropped to a safe level. You may have to sacrifice a little bit of accuracy if you want AK47 reliability as well.

I'm shooting for something as modular as the SCAR, as accurate as the AR platform, as relaible as the AK, and as easy to produce as the Sten gun.

Something whose barrel can be replaced in mere seconds and which can be converted from Subgun to assault rife to MG to marksman's rifle in a few minutes.
But which costs little to produce.
I may be shooting too far, but I have to aim high I guess.
In its most basic form, however, it should be an assault rifle in 7.62x39mm caliber.

There is no way. :(

I doubt you'd be able to make a gas piston rifle that fires a rifle cartridge as easily as a Sten. The Sten is a straight blow back if you didn't already know, whereas a gas piston driven rifle requires a bolt that stays locked up until the pressures have dropped to a safe level. You may have to sacrifice a little bit of accuracy if you want AK47 reliability as well.

Using the same rifle, you would need to change the bolt and barrel to use as a subgun, yes?

Therefore, your bolt and barrel for subgun use would be straight blowback, without a gas piston or bolt carrier, while the assault rifle barrel would have the gas ports and the bolt its bolt carrier.
It all boils down to how modular it is. I'm even thinking a removable magwell at this point.

Using the same rifle, you would need to change the bolt and barrel to use as a subgun, yes?

Therefore, your bolt and barrel for subgun use would be straight blowback, without a gas piston or bolt carrier, while the assault rifle barrel would have the gas ports and the bolt its bolt carrier.
It all boils down to how modular it is. I'm even thinking a removable magwell at this point.

Okay, I see. The upper and lower receivers may be able to be as easy as a Sten to make, but I was thinking about the rifle on the whole, barrel, bolt, operating system and all.

Okay, I see. The upper and lower receivers may be able to be as easy as a Sten to make, but I was thinking about the rifle on the whole, barrel, bolt, operating system and all.

I guess it would boil down to developing a suitable engineering process.