How flat is flat?!?

[Aircooled6racer]

Hello: All guns move, just some do it flatter than others. Finding the right load and comp design does alot. I know, I have tested a bunch of both. Thanks, Eric

[gianmarko]

i have run tests with different loads, ranging from commercial ammo to 175PF, with a friend who shoots also a Czechmate.

cant say i could see any difference in barrel flip.

the sensation is that going up in power the flip even increases and not decreases.

i am starting to think that it depends a lot on the strenght of the shooter's grip on the gun.

also, watching some slowmo of pistols, my impression is that the flip is generated mostly by the slide hitting the back stop

which occurs long after the gases have escaped barrell and compensator

therefore it could be that a very light slide with very weak spring might make the slide hit the back stop so quickly that the gases can still eliminate the (or some of ) barrell flip

but i am really just speculating here

[earthshine402]

First of all, look at the targets we shoot and the shape of the A zones. The A zone is tall and thin, and tolerates some vertical error, but does not tolerate much lateral error. When you remove the vertical movement from the gun, the gun basically oscillates in a random (unpredictable) circular pattern after it fires. An un-aimed second shot can get you a C or D that is vertically in the middle of the target. If the same error had been vertical, both hits would have easily been A's. Introducing some vertical movement makes the gun's movement predictable laterally and eliminates the randomness of the movement. The inconsistency is not cause by the gun, rather by the grip and arms that are holding the gun.

I'm not an open shooter, but I call BS on this. The presence or absence of vertical movment is not neccesarily correlated to lateral movement. How can vertical movment make the lateral movement predictable? Isn't lateral movement controlled more by the shooter?

[Supermoto]

I'm not an open shooter, but I call BS on this. The presence or absence of vertical movment is not neccesarily correlated to lateral movement. How can vertical movment make the lateral movement predictable? Isn't lateral movement controlled more by the shooter?

I agree that lateral movement is caused by the shooter. I find that if I shoot iron sighted guns for a while, my grip becomes lazy, which causes the dot to circles. It takes me about 100 rounds to really get the dot to track only vertically again.

I like some vertical movement, makes calling shots easier, make tracking the dot easier. Too much movement causes slow spits on targets were I need to wait for the dot to settle. But at close range, I just shoot the bottom of the red line. At this point I prefer a gun that shoots softer than flatter, they are more comfortable to shoot and since I can't run splits faster than .18s, I don't feel like I am losing any time. So far the softest gun I have shot was my 5" bedell in super and a Akai 9 that was stroked. My current open gun is kinda light and has a short Trubor comp. It is a little more flippy then I like. Hoping that adding popple holes will tame some of the flip

First run is with the bedell. second with the Trubor barrel

[JeffWard]

Since joining the dark side I have had a lot of fun building my own guns on the platform I love CZs/Tanfoglios), but since I had never shot an Open gun until I built one, it seems I'm never quite satisfied with how flat it runs. The more guns I build and the more comps I try I'm beginning to think guy who claim their dot never leaves the glass are imagining things. I poked around for some videos today and say these two and thought, "my gun's flatter than that!"

My M&P Limited gun shoots "flatter" than the second video.

GRIP STRENGTH.

JeffWard

[L9X25]

First of all, look at the targets we shoot and the shape of the A zones. The A zone is tall and thin, and tolerates some vertical error, but does not tolerate much lateral error. When you remove the vertical movement from the gun, the gun basically oscillates in a random (unpredictable) circular pattern after it fires. An un-aimed second shot can get you a C or D that is vertically in the middle of the target. If the same error had been vertical, both hits would have easily been A's. Introducing some vertical movement makes the gun's movement predictable laterally and eliminates the randomness of the movement. The inconsistency is not cause by the gun, rather by the grip and arms that are holding the gun.

I'm not an open shooter, but I call BS on this. The presence or absence of vertical movment is not neccesarily correlated to lateral movement. How can vertical movment make the lateral movement predictable? Isn't lateral movement controlled more by the shooter?

Gotta like that, I have no experience with the topic but I call BS.

When you have made the gun totally flat, it still has recoil, it is just not upward. The gun usually comes back into your hand (like a rifle) and you have to absorb that recoil with your stance, grip and arm position. When standing still, with perfect posture, you can create a stable and balanced platform to absorb the recoil and the gun barely moves. When you are shooting on the move, or from various positions, you cannot keep that perfect (balanced) posture to absorb the recoil without shifting the gun. Your arms and grip absorbing the recoil are what cause the gun to move from side to side, not the gun itself.

When you have a gun that is not flat, the majority of the recoil impulse goes upward, and there is little coming backward, into your hand, and causing the lateral movement.

[earthshine402]

First of all, look at the targets we shoot and the shape of the A zones. The A zone is tall and thin, and tolerates some vertical error, but does not tolerate much lateral error. When you remove the vertical movement from the gun, the gun basically oscillates in a random (unpredictable) circular pattern after it fires. An un-aimed second shot can get you a C or D that is vertically in the middle of the target. If the same error had been vertical, both hits would have easily been A's. Introducing some vertical movement makes the gun's movement predictable laterally and eliminates the randomness of the movement. The inconsistency is not cause by the gun, rather by the grip and arms that are holding the gun.

I'm not an open shooter, but I call BS on this. The presence or absence of vertical movment is not neccesarily correlated to lateral movement. How can vertical movment make the lateral movement predictable? Isn't lateral movement controlled more by the shooter?

Gotta like that, I have no experience with the topic but I call BS.

When you have made the gun totally flat, it still has recoil, it is just not upward. The gun usually comes back into your hand (like a rifle) and you have to absorb that recoil with your stance, grip and arm position. When standing still, with perfect posture, you can create a stable and balanced platform to absorb the recoil and the gun barely moves. When you are shooting on the move, or from various positions, you cannot keep that perfect (balanced) posture to absorb the recoil without shifting the gun. Your arms and grip absorbing the recoil are what cause the gun to move from side to side, not the gun itself.

When you have a gun that is not flat, the majority of the recoil impulse goes upward, and there is little coming backward, into your hand, and causing the lateral movement.

I didn't say "I never shot a gun before" I've shot production and limited plenty. I understand recoil.

I also understand statistics. Claiming that lack of movement in one dimension is correlated to more movement in another dimension is what I felt was not founded. It is still on the shooter to control the left-right motion, regardless of the up-down motion.

[L9X25]

It's the fact that you have a lot less of the force that induces the left-right movement when you allow the gun to recoil upward. When you restrict the upward movement, all of the recoil is channeled backward, toward the shooter.

[kneelingatlas]

I also understand statistics.

Physics will probably be more help here

Edited May 13, 2014 by kneelingatlas

[eric nielsen]

"Calling BS" is something my friends & I did when comparing stories about girls we kissed at summer camp.

[rishii]

I want on a similar quest a long time ago, I kept changing out comps looking for the perfect set up, and

I had a gun once that did shoot dead flat, it actually dipped on recoil, 4 port hybricomp barrel, heavy and long steel 5 chamber, 9 port comp with sp2 powder, and 124gr jhp, and the dot never left the A zone

And I couldn't shoot it worth a damn, the recoil impulse was all wrong the fastest split I could do was a .20, because I was waiting for the dot to settle

I took it to the range with a vice, a hacksaw and started to cut off baffles until I got some vertical movement in the dot, and I ended up right where I started, with a 3 port comp with a couple of small side drafts

[kneelingatlas]

I don't want to lose any of my precious SP2 out of popple holes!

[L9X25]

Around 1993 (when Rob convinced Dillon to make a few sets of 9x25 dies) we started working on the caliber. We experimented with projectiles from 88 grains through 147. We tried all sorts of powders, comps, barrel ports, etc. One of my personal favorite combos was a 108gr JSP over 18grs of H-110. It is the closest thing to an AR-15 for the 1911. It was incredibly loud but extremely well behaved. USPSA eventually stepped in and eliminated that from being an option, making 115's the best option. At that time we were running 4 or 5 chamber comps and a couple of small holes in the barrel.

[BSeevers]

Around 1993 (when Rob convinced Dillon to make a few sets of 9x25 dies) we started working on the caliber. We experimented with projectiles from 88 grains through 147. We tried all sorts of powders, comps, barrel ports, etc. One of my personal favorite combos was a 108gr JSP over 18grs of H-110. It is the closest thing to an AR-15 for the 1911. It was incredibly loud but extremely well behaved. USPSA eventually stepped in and eliminated that from being an option, making 115's the best option. At that time we were running 4 or 5 chamber comps and a couple of small holes in the barrel.

They made my old Hybrid with 3n37 and 115 gr at the old PF of 175 sound kinda wimpy and with that combo I used to ask RO's if they had a pacemaker before I shot. Liability reasons ya know

[L9X25]

Old story involving Paul Whitacre (local GM and fixture on this board for years): We were shooting on the same squad at a match near Orlando and Paul asked to shoot my gun. We went to an unused berm and I handed him my gun. He fired a few quick shots and was in the process of saying how nice it felt when he fired a shot with his mouth open. The concussion hit the roof of his mouth and stopped him in his tracks ...it nearly made him lose his balance. He handed it back with something like 'feels very nice, but no-thanks!"

[staudacher]

This is the flattest shooting gun I have run across. This is a friends 38 Super open gun. I shot the video at 600fps.

There was a smudge on the C-More lens so the dot isn't real clear.

Edited June 3, 2014 by staudacher

[kneelingatlas]

That's pretty awesome staudacher, do you know all the particulars on his pistol/load?

[staudacher]

That's pretty awesome staudacher, do you know all the particulars on his pistol/load?

Afraid I don't. I think the gun was built by a local guy around Nashville

It is Brad Griffin's gun. (moverfive)

Edited June 3, 2014 by staudacher

[earthshine402]

can you post the gun firing at full speed?

That is really neat seeing the optic flex during the firing cycle.

[38supPat]

Around 1993 (when Rob convinced Dillon to make a few sets of 9x25 dies) we started working on the caliber. We experimented with projectiles from 88 grains through 147. We tried all sorts of powders, comps, barrel ports, etc. One of my personal favorite combos was a 108gr JSP over 18grs of H-110. It is the closest thing to an AR-15 for the 1911. It was incredibly loud but extremely well behaved. USPSA eventually stepped in and eliminated that from being an option, making 115's the best option. At that time we were running 4 or 5 chamber comps and a couple of small holes in the barrel.

I shot the '98 North Americans with someone shooting a load like this. It was either H110 or 296 with 108 gr bullets. It was setting off car alarms!

[staudacher]

can you post the gun firing at full speed?

That is really neat seeing the optic flex during the firing cycle.

Here it is at half speed.

https://www.youtube.com/watch?v=Ja14UFQcP5A&list=UUzln5-8dz8CZSYdtCYN-I_A

Edited June 4, 2014 by staudacher

[thompsoncustom]

That is amazing if I build an open gun I'm gonna shoot for something like that.

[moverfive]

Here is the scary part........I didn't have the best grip/stance on the gun as I was having to keep his camera between me and the gun while looking through the camera's lens to see the dot. So the dot movement could have been a bit better. :-)

[moverfive]

The 9x25's were very popular when I was in Hawaii (of all places). Some of those crazy characters tried 88gr bullets.....and this was with the old power factor. Obnoxious doesn't begin to describe what those guns sounded and felt like as a bystander.

[Flatland Shooter]

And fwiw watch this video of Max and see how much the gun moves, yet its an awesome performance

I think its often the Indian and not the arrow.

I ran the chrono stage at the 2014 Texas Open last March and got the opportunity to shoot over 200 OPGs (Other People's Guns). While there were a lot of flat shooting guns out there, Max's was not one of them. I was actually surprised at how much it jumped.

I don't know if its the same gun and load as in the video but the gun I tested sure didn't keep him from winning the match.

Bill

Edited June 4, 2014 by Flatland Shooter