Open Major 9

[ssg2]

Hello people,

I need your advice. I have an STI Open Major 9 with a 4/5 chamber compensator with two holes.

When should I charge to use a slow powder. But I still have a high impact. She shoots are not really flat.

Since I shoot IPSC in Germany, I have to use bullets over 120 gr.

I've emailed a couple of gunsmiths in the U.S., but received no reply.

What a load I have to assume that the gun shoots flat?

I read that you used in the United States and SUPERCOMP Winchester HS 6

The factor is not as important as it is only open during the IPSC 160.

A flat shooting behavior is more important to me.

DVC Stefan for Germany

[Desmo412]

Try Vihtavuori 3N37 and 3N38. I managed to make 172PF with 8.9gr of 3N38 with a 124gr CMJ at 1.165. This powder seems to work especially well in guns with hybrid or popple holes. I currently use a 115gr JHP with Hodgdon HS6 at a 176PF. Typically, the higher you go in Power Factor, the flatter the gun shoots. Keep in mind, every gun is different and every shooter's perception of what "flat" and "soft" feel like is different.

[Flexmoney]

You will want to search this forum, lots of load data that should apply to your setup.

Do you have available Vectan (Nobel) SP2 ? If so, give it top consideration.

[NogNog]

I have to agree with Flexmoney. Since you are from Germany you should have no prolem getting the most sought after Vectran powder here I US for open loads

[ssg2]

I am currently using SP2, 8.9 gr Factor 180 Is my feeling but not flat enough.

[NogNog]

In my STI match master with T2 comp, I run VV N350 7.4 grains 125 zero jhp-c, it chronoed 169-170 PF

[CocoBolo]

I shoot major 9, 124gr CMJ with 7.7gr of Silhouette (that is from Ram Shot) OAL 1.165. This produces about 172 pf, you won't be short on power. This is a full size gun (5") with a Dawson DP-2 comp no poppel holes, 9# recoil spring and 17# hammer spring. The firing pin stop is radiused, slide weight is 10oz.

So comp designs need more gas to work correctly. One of my guns was a horrible bouncey snowgoose shooting at about 170 pf, I put another .3gr of powder behind the 125gr bringing it up to 175pf, that tamed the beast! With the 175pf it shot flat and soft!

So sometimes you have to try something to find out if it works.

SP2 should be good but a friend of mine was using it and went to the Silhouette after trying my load. YMMV

[Flexmoney]

I am currently using SP2, 8.9 gr Factor 180 Is my feeling but not flat enough.

Wjhy are you running 180 power factor? To get the gas up?

Grip the gun more firmly with your support hand and it will flatten out.

In fact, try the Matt Burkett Timing Drills (I think they are on Saul's website, but you can find them with a search)

[ssg2]

Yes, the last measurement at the chrono on the Infinity-Open Match it´s a factor 180

[diehli]

And did you try loads between 160 and 180? You could simply be overriding the effectiveness of the comp at this stage. If you have tried different loads, then it's a good idea to try a different comp since you're likely pushing the pressure limits for 9mm at 180 PF.

[CocoBolo]

Ok, I think I got it. Time for a tungsten guide rod and a lighter recoil spring an 8# or 9#. Plus back the load off to about 165-170pf. 180pf is pushing it but I've been to 190pf without incident. I don't recommend it.

Sometimes its not about the speed of the powder sometimes it is just a different powder. Take for instance N105 vs AA#7 they are about the same speed a gun will shot a bit flatter with N105 but the slap in the palm is harder than AA#7. 3N38 is right there as well, and by the way it works well in 9 major, as does AA#7. I've heard of N105 in 9 major just have not done it personally.

Is the comp clean? I just spent two hours cleaning a friends comp with a drimmel tool, it was so clogged that his bullets were tumbling, yes it had a lead accumulation all the way up and into the bore line of the comp. You would thin a GM would know better.