Open Gun Design Questions

[JoeC]

Greetings Everyone,

 

I'm about to build another open gun and wanted to ask you a question or three.

 

If you were buying or building a new open gun, what key features would you desire?

What caliber would you prefer?

What kind of red dot would you run?

 

Thank you.

[Aircooled6racer]

Hello: Full length pistol 5 1/2". 1:32 twist barrel, lightened slide, C-More slide ride 6MOA, 9mm, my comp, wide body frame, vertical two sided setback scope mount, Roupe grip. That will be my next build for me. Thanks, Eric

[Sarge]

RTS2

9MAJOR

Hard chrome

[Ultimo-Hombre]

Haven't really been impressed with popple holes.  Cmore gets all funky with no real improvement in performance. At least not perceptible at my level. 

[d_striker]

5 hours ago, Aircooled6racer said:

Hello: Full length pistol 5 1/2". 1:32 twist barrel, lightened slide, C-More slide ride 6MOA, 9mm, my comp, wide body frame, vertical two sided setback scope mount, Roupe grip. That will be my next build for me. Thanks, Eric

 

Why a wide body frame?

[scooterj]

2 hours ago, d_striker said:

 

Why a wide body frame?

Capacity 

[Hi-Power Jack]

3 hours ago, d_striker said:

 

Why a wide body frame?

 

You don't want to run a single stack in OPEN.

[Desmo412]

he may be referring to a short wide frame vs a standard width 2011 style frame

[Sarge]

2 hours ago, Desmo412 said:

he may be referring to a short wide frame vs a standard width 2011 style frame

I would say that's what he meant as well. 2011 can be standard or wide frame

[Aircooled6racer]

Hello: I was tired yesterday after the match. Yes, I will be using a wide frame since I have it already and wanted a little more weight down low in my hand. It is a 2011 long wide 5" frame I will cut back to a mid length frame. Thanks, Eric

[caspian guy]

I like the wide frame for an open gun anyway, thicker area to drill and tap for scope mount holes.

[zzt]

27 minutes ago, caspian guy said:

I like the wide frame for an open gun anyway, thicker area to drill and tap for scope mount holes.

+1

[3gunDQ]

I like a heavy to medium weight gun with a SV signature grip. I prefer 38 supercomp , RHT gas pedal, RTS2 optic... in the SV IMM variety. 

[theWacoKid]

Yea, let's see how confusing we can make this.

 

Modified length build, hybrid, 2 port comp, 3/16" holes until my favorite load makes 170-172 pf, 9x19, RTS2 6 moa.

[Shmella]

I'll play. This. Steel pt evo grip, deltapoint pro 2.5 moa dot, long dust cover, shortened slide,2 port sv comp with three holes in the barrel. 9major and I have done the unthinkable so far and only ran blue bullet coated 125s so far at 170pf (800 rds) with no hiccups and so far no leading I have noticed. The plot thickens. 

This is a heavy gun btw at 53oz empty. 

Edited February 26, 2017 by Shmella

[tanfoglio1911]

3 hours ago, Shmella said:

I'll play. This. Steel pt evo grip, deltapoint pro 2.5 moa dot, long dust cover, shortened slide,2 port sv comp with three holes in the barrel. 9major and I have done the unthinkable so far and only ran blue bullet coated 125s so far at 170pf (800 rds) with no hiccups and so far no leading I have noticed. The plot thickens. 

This is a heavy gun btw at 53oz empty. 

 

How does those 2 port and 3 holes works? How's the recoil? I am putting new upper to my open gun with the same number of holes. Thanks.

[d_striker]

6 hours ago, Sarge said:

I would say that's what he meant as well. 2011 can be standard or wide frame

 

Yup.

 

I'm new to 2011's.  I bought a used Open gun a few months back that was built on an STI wide frame.  Wasn't sure why people used wide frames over standard.  

 

I guess more material for tapping scope mount holes makes sense.  Any other reasons people use wide frames for Open 2011's?

[Shmella]

2 hours ago, tanfoglio1911 said:

 

How does those 2 port and 3 holes works? How's the recoil? I am putting new upper to my open gun with the same number of holes. Thanks.

I'm not really a huge believer in chasing ultimate flatness and shyed away from trying to achieve that, but I really like this setup so far. The holes are rather large and angled backwards. It feels pretty flat but I haven't done any load experimenting or slomo video to check it. I just loaded up some 125s with 7.1-2 grains of silhouette and ended up hitting 168-170 pf first load testing so I settled there and loaded up a bunch more. This setup is relatively soft in the hand and is easy to track the dot and in my limited amount of time shooting it I like it. 

[digi531]

Hi JoeC, answering your question is difficult because open guns are so subjective in how they " feel " from one person to another.  I feel most decent built open guns do the job and reduce felt recoil, after that the load development has a big role.  Atlas Gunworks (guys in VT.) have an interesting youtube video on open gun design and what they feel is " state of the art "  and Adam mentions that there is so much that can be done to open gun design.  As a twenty year competitor and hobbyist builder I have come full circle building shorty's ( which are terrible ) mid-length, Infinity IMM size ( which are good for younger people )  and now back to full size.  Like many, I have experimented with part selection, hybrid/barrel porting and comps, seeking that "magic" combination.  Guess what ? I'm still looking.

[SWprotected]

I don't have the experience digi531 has but I agree, the subjective nature makes it different for each shooter. I have a shorter heavy gun and a longer lighter gun and the feel is completely different. I am still trying to decide for myself what works best for me.

[BeerBaron]

For me there are a few key elements:

 

must haves:

titanium comp that works (there are a few good ones)

2-4 popple holes

slide racker on the weak hand side which is fitted with ball detents for easy removal

i also think a slower twist rate like a 1:24 or 1:32 is worthwhile. 

Steel grip (though this is user preference)

cmore rts2 or deltapoint pro. The new mini dots are small, low and light. 

 

So mine would be either 4.5inch (imm length) or 5 inch (5.4inch barrel). Wide frame but cut short of being full length. 3 x 3/16 popple holes, decent titanium comp (cheely, sv, Eric's, binary etc). Cmore rts2 8moa on single sided mount. Racker retained with ball detents. Pt evo or sv steel grip.  A nice trigger is a good thing too.

[JoeC]

For those of you wanting a 1-32" twist barrel...how many of you have actually tested one vs. a 1-16"?

 

Hint...I have.

 

Also, how many of you have tested the RTS2 for deflection at 25 yards?

 

Again, I have...

[Steelix]

What does the twist rate do to the gun. Slow rate vs fast rate. And what gram bullets work the best in each. 

[BeerBaron]

Generally speaking if you want to shoot lighter bullets fast (i.e. Open gun) you want a slower twist rate. For heavier bullets at slower speeds a faster twist rate is desirable. There's a lot more to it but that's the very basic theory. 

 

Joe: yes I have 1:16 barreled gun as well as a 1:24 and have tried 1:32 as well. I'm by no means an expert on barrels but I can understand the theory of why the slower twist would be desirable with a short 115gn pill going 1400 fps. 

 

Im not sure what you mean by 'deflection' with rts2 at 25 yards? Do you mean a height over bore issue? Or some kind of parallax error? 

 

Id like to hear what you've found?

[rishii]

I'll play

full size, steel frame or sti with steel grips

lightened slide, but not too light, around 11oz, I've had slides that were lighter and cracked both of them

light steel comp similar to the brazos thundercomp 2, I've had 2 ti comp before and cracked both of them, I've also liked the  trubores I've fired 

bull barrel with 2 popple holes in 38 supercomp

With a C-more rts2, 8moa, the ejection port is clear of the scope and you don't need to do anything fancy for ejection, and you don't need a racker

Other than that, it's gotta run, sparkling clean or after 1000 rounds

i also chased the perfectly flat shooting open and I had one, heavy steel comp, 4 port hybricomp barrel, it didn't rise, it dipped and I couldn't shoot it worth a damn

as long as the dot tracks straight up and down, I'm good