MUZZLE / RED DOT JUMP- HOW TO TAME IT?

[Hopper]

Finally got the Sti DVC Open gun to run consistently.  It took a 9mm Major load at a 167 pf to make it run consistently.  The load is 6.6 gr of Win AutoComp behind a 124gr Montana Gold JHP.  CCI 500 primers.  Now I have to deal with muzzle jump.  The recoil spring is an original factory spring with a green color code. Any good ways to deal with this ?  Thanks

[niroth81]

I would suggest to try a heavier pill. It's a different sort of felt recoil. I used to run 135gr but I've even heard of people running 147gr and having great results. This is usually with 38 super so I'm not sure if you can fit enough powder to get them going at the right speed.

[open17]

You will get LOTS of replies on this one!    My 2¢--up your load to 172 or so to get the comp working better.  Maybe even

go to a slower powder to get a bit more gas.  I'm using HS-6, but there are several others. Nothing wrong with AutoComp,

lots of people prefer it.    

Recoil spring will influence how flat it runs.  9 lbs is a dandy starting place, go up or down as needed.  Regular or variable?

Mainspring affects the timing a bit.   17 lbs is sort of standard, I have one gun that runs flatter with a 18.  

And the radius on the firing pin stop can do more than you would think----

Welcome to the wonderful world of "Open gun tuning to fit your personal preferences"

Edited November 15, 2016 by open17

[jcc7x7]

124 or 115gr bullets

Get your PF between 168-172 , that is GENERALLY where they start to flatten out.

I like 8lbs springs Wolfe variables seem to close the slide softer causing less dip .

Play with grip pressure until you get the movement straight up and back  on target.

Then shoot it until you have muscle memory to grip the same and then the wonderful world of open starts opening up LOL

[Aircooled6racer]

Hello: Try a ISMI 8lb recoil spring and 17lb ISMI mainspring. Up your powder charge to 6.8 grains of Auto Comp, that should give you about 171-173PF loading to 1.170" OAL. Next will be to shoot it a lot and then try some different loads using different powder like HS-6 and 115 JHP Montana Golds. Thanks, Eric

[JMike]

My experience is you have to run the rounds a bit hotter than a 167 PF. I would stick with a 124-125 gr projectile. I currently run a 124 gr projectile out to a PF of about 175 PF. My dot behaves much better at higher power factors than at lower power factors. I know this might sound counter-intuitive but keep in mind, you want gas and a lot of it. This is what makes the comp worth more having on the end of the barrel. 

YMMV but play around with it and see what works best for you. 

[gerritm]

I am running my DVC at about 170pf and it is flat with little rise or dot jump. IMHO it could be the powder. Maybe others will know better, but I have a couple of shooting buddies that tried autocomp & did not like it in similar guns. Have gone to HS-6 or 3n38. Mine is 38 super with 8.5 of HS6 and 124 JHP PD @ 170pf.

I am running all stock springs that came with gun.

gerritm

Edited November 16, 2016 by gerritm
more info

[teros135]

Different guns like different loads.  I have one that likes WAC, has more dot bounce with HS6; the other one is the opposite.  Both like 3n38 best.  

[Hi-Power Jack]

Little more WAC will help ...  

[zzt]

My experience has been that if you do not have barrel ports or "poppels" to help tame muzzle rise, you need more powder and slower to work the comp.  Examples:  on one gun I had a 172PF bunny fart load that was so soft you would not believe it made major.  However, muzzle rise was considerable.  To get that gun, with 3 up ports and 4 small side bleeder ports, to shot flat required 188PF.  It was flat, but harsh and violent.

On another gun with a 4-chamber comp (3 up ports, 2 side ports) and two 3/16" poppels, I have no trouble getting the gun to shoot flat with some of the "faster" powders in the WAC, Silhouette, HS-6 range.  Recoil is harder on the hands than with the first gun, at 172PF, but it shoots way flatter.

If you cannot get it as flat as you like with bullet and powder choices, consider having at least one poppel added.

[theWacoKid]

Develop a high grip with a solid lock on the gun and get stronger. 

When it comes to springs, comps, popples, pf, and powder there are a zillion combos that work well.  You'll never get a magic do-all answer.  If you're a tinkerer, tinker. If you're not, load something that runs and go practice shooting. 

Edited November 16, 2016 by theWacoKid

[Dwampler22]

I am running into the same issues. I will be testing more hs6 here shortly. I have a 5.5in barrel and a cheely comp. no poper holes. 

[rishii]

I'm kinda numb on recoil and on how soft the gun feels, what's important to me is the dot has to track up and straight down in a predictable manner

now having said that, in my experience, I've never found a powder that was significantly better than others

playing with spring weight does affect how the dot tracks, the heavier the spring will reduce muzzle rise, but will cause muzzle dip  as the slide returns to battery, lighter spring will have the opposite effect. The trick is to find a spring weight that balances both muzzle rise and muzzle dip that's acceptable to you, and here's the kicker, there is no right answer, you have get springs from 7-11 lbs and try them all by running drills

also bullet weight makes a difference, lighter bullets take more powder to make PF, more powder=more gas to work the comp

but more gas=more muzzle blast, again you gotta find a balance that works for you

work up loads for 115, 121 & 124 and run drills

oh and welcome to the darkside