Question Answered

[nhglyn]

Question answered, please delete post

Edited February 24, 2006 by nhglyn

[RacerX1166]

I will defer to the experts as I'm new to open but I played around with loads, working my way up the scale (with Bob's guidance) until I found one I liked. You have to be the judge of how the dot jumps relative to your style of shooting.

I actually found my Pro Sx (I think a previous generation comp) liked much hotter loads better than softer ones. I switched to N105 which has stabilized the dot in a big way. Those two powders are the ones that Bob recommends to stay under pressure.

[Shadow]

nhgln-

There's no "reliable" test since dot movement is subjective to the individual. Your grip (how tight or loose) will make a big difference. I also don't believe you will be able to tell a difference from .2 grains.

With that said, I like to start by shooting a target at seven yards with about five shots at a slow cadence (about a second apart) and just watch the dot movement. Then I shoot two shots on three targets at my normal speed. To me a consistent, straight up and down dot is more important than flat (although flat is good). I pick the load that feels best to me. You need to pick what feels best for you and shoot a lot of it. You will adapt to the load.

You might also want to ask a more experience open shooter to shoot your gun and give you his opinion (your gun may be flatter than you think). Also try others' guns if you get a chance. A lot of shooters talk about how flat their gun and load are, but when you shoot it, you wonder what their perception of flat is.

Racerx1166-

Did you initially have problems with up/down movement or sideways oscillation (like an infinity symbol? I've recently purchased a similiar comp and am having problems with sideways oscillation with my current load (7625).

Edited February 26, 2006 by Shadow

[Flexmoney]

The shooter is a big part of the system.

make sure you try the timing drills that Matt Burkett has in his free tips section: http://www.mattburkett.com/html/10.html

[AWLAZS]

You might also want to ask a more experience open shooter to shoot your gun and give you his opinion (your gun may be flatter than you think). Also thry others guns if you get a chance. A lot of shooters talk about how flat their gun and load are, but when you shoot it, you wonder what their perception of flat is.

Glyn I can help you out with this lets get together

[benny hill]

If you don't have any holes in the barrel/slide you need 2 or 3. Also a slower powder & last you will need to shoot 115 gr. bullets

[blackdragon]

Flex,

+1

Ivan

[XRe]

I recently did something similar to what Shadow describes... I did the following:

Loaded up 6 different powders w/ one bullet weight and found 170PF for each. I discarded two powders outright from that testing - one started to show pressure signs, and the other was more obviously flippy and harsh in the hand during chrono testing.

Then I loaded up loads of each of the four remaining powders at 170PF, and shot them in a blind comparison during a match, and took notes on which ones I liked. Then, I went out a second day, and shot another blind comparison shooting some drills. I had two other shooters - one a complete noob to Open guns, and another more experienced shooter - do the same, and took their info as additional points to consider. That narrowed it down to two powders. I then went out a third day and shot 4 Bill Drills (at 50, 25, 15, and 7 yards) with each, and half a Vice Pres (2 on each at 7 yards) and took notes - I did this with all four powders, and knowing which one was which (ie, not blind), so that I could compare. I then shot the previous "best two" with some movement drills and off balance stuff, to evaluate subjective recoil.

The result? I still eliminated the same 4 powders, in the end, and was left with two that consistently cycled the gun straight up and down. The only difference was how flat it shot. The flatter one had about 50% less dot rise, and is about 50% more expensive.

So, for 125 HAPs in my gun, 3N38 worked best, followed by 7625. I consistently was able to shoot faster, more accurate drills at all yardages with these two powders. Out of the powders I eliminated, I liked them in this order: N105 (less predictable, but very soft), N350 (relatively harsh, and inconsistent movement), 3N37 (pressure signs), 4756 (flippy and quite harsh).

The next test?? Try 121s and 115s with 3N38, 7625, and N350 (cause I've got a good amount of it left)

(edited to add in the movement drills, which I'd forgotten about....)

Edited February 22, 2006 by XRe

[Shadow]

If you don't have any holes in the barrel/slide you need 2 or 3. Also a slower powder & last you will need to shoot 115 gr. bullets

Benny-

Was your reply to nhglyn to get a flatter dot, or to me to cure the oscillation in the Brazos ProSX comp?

Or both.

[Jake Di Vita]

Dave,

Don't forget to add shooting groups from a rest into your testing pattern. Some loads group better than others.

[XRe]

Dave,

Don't forget to add shooting groups from a rest into your testing pattern. Some loads group better than others.

Quite right... It was really windy out the day I did the first batch of shooting tests. I shot a 10 shot group w/ each one at 50 yards using my bag as a rest. Being as it was gusting in the 30+ mph range, I didn't take them *too* seriously, cause I didn't shoot them too well, relatively speaking. But, 7625 was the largest group at 3", including whatever might count as a flier. 3N38 was the best, at 2 9/16", and N105/N350 were both at 2 3/4". That's pretty close across the board. However, most of the 3N38 rounds were clustered in a 1.5" group, with four outliers - I'm not reading too much into that, but it had the impression of being slightly more consistent.

Also - the gun was sighted in for N350. 7625 and N350 shot to same POA. 3N38 and N105 grouped about 4-5" lower at 50. I attribute this to the greater volume of gas in both of those loads keeping the muzzle slightly flatter until the bullet has exited the barrel - maybe that's hooey, but...

[benny hill]

Reply was to you shadow

[JRBean]

Don't forget you can also tune your dot movement with different weight recoil springs. If you find a load that is to your liking but not quite perfect try a lighter or heavier spring and see what that does for you.

[Shadow]

Reply was to you shadow

Thanks Benny. I understand the slower powder but not the requirement to use 115s.

Edited February 26, 2006 by Shadow

[benny hill]

Lighter bullet's get more powder so the comp has more pressure to shoot flater. In my experience about 20% flatter. Also freezes the comp from moveing.

[Shadow]

Lighter bullet's get more powder so the comp has more pressure to shoot flater. In my experience about 20% flatter. Also freezes the comp from moveing.

Thanks Benny.