115 gr Zero JHP - fps?

[BigDave]

I'm building my practice ammo stockpile again. For those who shoot 115 Zero JHP .355s (not the new conical), where did you find the best accuracy? Right now I'm at 1100 fps, but I'm not thrilled. Is closer to 1200 fps better in this bullet? FWIW, I'm shooting a 6" Kart bushing barrel.

[Action Pistolero]

Dave,

The best all round velocity seems to be 1150. Before you start accuracy testing, be sure that you have fired 200 rounds. For some reason, the Zero bullets seem to do much better from a fouled barrel. When you clean it, just run a brush in and out. This will loosen the powder fouling but leave the copper.

The group that I fired a few weeks ago didn't happen until I had 200 rounds through the barrel.

[Hi-Power Jack]

For those who shoot 115 Zero JHP .355s (not the new conical), where did you find the best accuracy? Right now I'm at 1100 fps, but I'm not thrilled. Is closer to 1200 fps better in this bullet? FWIW, I'm shooting a 6" Kart bushing barrel.

Dave, I don't think you'll find the answer to your question on this

Forum:(

Each gun is different. Just possible that your gun will be more

accurate with a heavier bullet, or a different powder.

Only experimentation is going to answer your question.

My gun prefers 147 grain bullets - and seated as short as I can

make them feed ??? Everyone else loads as long as possible -

my gun is more accurate shorter.

While you're experimenting with velocity, don't forget the possible

factor of OAL for the same load - can make an accuracy difference.

Good luck,

Jack

[BigDave]

Dave, I don't think you'll find the answer to your question on this

Forum:(

Thanks. There a lot of folks I know, have met, and have shot with here. All of them of tons more experience with this bullet than I do.

This is a start, though. The proof is over the chrono and the score sheet.

[kimmbeckwith]

Kevin you are dead on about the fouling. I never shoot a clean gun for a match or for testing a load!!! Also, when shooting for group make sure you use the same lot of powder, primers and brass. I have an indoor chronograph, so I test the load for consistency before heading to the range. If you have very extreme spreads you may need to check your powder drop. Some extreme spreads shoot OK, but I have found Standard Deviation a help in developing a load.

Kim

[Greg in VA]

In my KKM barreled 1911, the 115's started shooting good at 1150, and got really good at 1200.

[gm iprod]

Having to shoot a dirty gun could kill Kevin.

1050fps to 1250fps my gun shoots groups way smaller then the X ring.

Certainly stay away from 1045fps especially at the Cup and if the chrono is 13feet away , that could get you DQ'd.

I run at just over 1150fps and that keeps them supersonic all teh way to the target. Best accuracy at 50 is above 1130fps and under 1090fps. That middle ground will shoot good at 25Y and crap at 35Y / 50Y. Bullets are transonic and not at their best.

Keep the speed of all shots in a chrono test group outside those parameters and you will be sweet.

I think the newer bullet likes to be going faster. But I have an older barrel and have found I can slow them right off. Not too much though or I am playing with chrono hell.

BTW how is Travis????

[Action Pistolero]

Having to shoot a dirty gun could kill Kevin.

1050fps to 1250fps my gun shoots groups way smaller then the X ring.

Certainly stay away from 1045fps especially at the Cup and if the chrono is 13feet away , that could get you DQ'd.

I run at just over 1150fps and that keeps them supersonic all teh way to the target. Best accuracy at 50 is above 1130fps and under 1090fps. That middle ground will shoot good at 25Y and crap at 35Y / 50Y. Bullets are transonic and not at their best.

Keep the speed of all shots in a chrono test group outside those parameters and you will be sweet.

I think the newer bullet likes to be going faster. But I have an older barrel and have found I can slow them right off. Not too much though or I am playing with chrono hell.

BTW how is Travis????

Yea, it's going to drive me nuts shooting a dirty gun. I will be running a brush through it once to clean the crown. By the time I get done shooting the short distances the barrel will be fouled enough for the longer shots.

I'm starting to believe that this speed of sound stuff is a bunch of hooey with pistol bullets. I need to shoot through a chrono at 50 yards to make a believer out of me. All I know is that 1150 fps works very well in my guns. I would tend to think that by the time the bullet gets to 50 yards it has passed through the sound barrier.

Travis is busy arresting drunk drivers and other fecal matter. I believe he enjoys it though. He hasn't been shooting much but he did manage to kill a few Deer this fall. He is also finding out just how far a paycheck goes. I don't know if you have heard but he is now engaged. Date is June 2013.

[BigDave]

Well...it helps when you are dropping what you think you're dropping in terms of powder. Turns out that that was off by 0.3gr or more. Chrono'd again on Friday and I'm averaging 1165 fps with Zero, Sierra, and XTP 115 gr heads with mixed fired brass. The Sierra and XTPs were the most consistent and had the lowest SDs.

Now I just need to learn how to shoot accurately.

[shooter1911]

Richard,

I am fine like Kevin said been busy at work arresting drunk drivers and such. Also as Kevin said I am engaged and it will be around June 2013 after the Cup of course. I haven't shot much at all, but that will change. I just put in a order in to zero. I will be back on the shooting circuit in 2012. Hope everyone is doing well on your end.

Travis

[gm iprod]

Travis,

Get married two weeks before the Cup and go to it as the Honeymoon, start out like you intend to carry on. Let me know how that works out?

Keep those bastard drunks off the roads. We have had a horrific holiday period with morons in cars over here. I have taken to driving the Dodge to make sure if they hit me they lose.

When in June, is there a Match nearby I can shoot for the excuse of staying longer?? See thats how you have to think!

OK back to reality. Looks like I may have misread or misremembered my notes on the muzzle velocity theory, checked them today and found the following.

Sierra 115gr at 1200fps at muzzle is doing 1086 at 50Y. This proved to be less accurate than 1150fps in my gun.

1150fps at muzzle and 1070fps at 50Y. much better accuracy at 50Y until I dropped the load a little.

1100fps at muzzle is doing 1017 at 50Y. So all well into the zone of being back at very accurate. In fact more accurate than I recall.

I tested some of this with a chronograph at those ranges, some data was stolen out of the Sierra Manual

Now the spanner in the works. 1250fps. Very accurate at all ranges until I got to 50y then ugly. Velocity at 50Y according to Sierra is 1120fps. Right at that nasty area in my mind.

1300fps. 1150fps at 50Y, great accuracy but hard to manage recoil wise prone and for mover. Barricade and plates Ok as in barricade you can hang onto something. Plates are just big enough to not matter. But even a nick on the side low down would go right over real good.

I think 1150fps (and less) at muzzle is best because by the time the bullet is at 25Y (the first real test of how accurate you are shooting) it is just under 1090fps therefore well subsonic and just slightly slowing down at each next step. Shooter error is way bigger than group error at less than 25Y.

According to the 2nd Sierra Manual, they tested 44Magnum bullets at various speeds at muzzle and at a variety of target ranges and found that the best chance of accuracy was if the bullet stayed over the speed of sound or stayed under the speed of sound at muzzle and target. Better accuracy was achieved at target once the bullet went well below the speed of sound (if exiting at super sonic) at the target, the bullet had some time to re-establish (restablise for want of a better description) itself. This little trick is used at estreme range by a lot of guys. I have yet to finalise proper testing data for this phenomena, but from limited time at various ranges I prefer to keep everything as simple as I am.

I have found that to get the best groups at 50Y I stay super sonic all the way which means launching 115gr at 1300fps. Or stay around that 1150fps. As I have some issues with my weakhand wrist at present (along with all the other aches & pains) I am working on dropping the loads back under 1100fps with the new Zero. I ahve had some very positive results with this laod and shooting mover is very nice.

One big issue with lighter loads. If you are not spot on with your technique the groups will open up. I have noticed a habit of giving the gun a flick as I fire and this has caused some odd number scoring shots of late.

BTW if anyone has a Sierra #2 Manual, check out page 639. A very suave looking Mr Bernosky, with wide collars and nasty nasty moustache.

[Action Pistolero]

There is a monthly match in Bedford the first Sat. in June. We get burned out after Bianchi so there are no bigger matches in June. The first regional after Bianchi is the middle of July. Even then, just ask George Martin how hard it is to get the entries for the match in July.

I did some chrono testing the other day. Set up the chrono at 10ft from the muzzle and then 50 yards.

10ft

High 1147

Low 1123

Extreme spread 24

Average 1136

Stnd. dev 9

50 yards

High 1047

Low 1030

Extreme spread 17

Average 1038

Stnd dev 5

Air temp was 60 degrees so speed of sound was around 1117.

I have been doing a bunch of reading on the speed of sound stuff. Since bullets are spinning the effect of the bullet passing through the sound barrier causes minimal effect on accuracy. This pertains to pistol calibers and is a completely different story for rifle calibers at long ranges. At long range, the bullet spin slows down enough that the sound barrier does have an effect on the bullet.

[Spangler]

Being a research statistics guy...I absolutely agree with Kevin, It is very unlikely that the speed of sound is having any significant affect on bullet flight at 50 yards. Here is some data I've put together. some of it is from these posts, one of Kevin's tests, and others from manuals. First note...it appears all the major ammo manufacturers use the same book. Their numbers are exactly the same, likely from calculation, not testing (see Rem and HDY data). This is only part of the spread I put togehter and bullet weight does not seem to do anything but change the % slightly...What I did see in the data is that bullets starting out faster will slow at a faster rate and the effect is nearly linear. What this means is you get more variance in speed from 1300fps than if you start at 1150, and the difference is VERY significant. This shows up both in % reduction and real FPS change. I suspect it's largely that change which has created the perception that transonic causes issues. Again, with a fast spinning projectile, there would be little "flutter" in any case. Maybe able to argue less so in a 1/24 than a 1/32 barrel since it spins faster, but that's going pretty deep...

Also, MOST of our loads go transonic inside 50yds as pretty much anything starting out under 1250 will be subsonic before 50yds at 90F. Assuming speed of sound between 1095fps(40F) and 1149fps(90F), I would guess most our best loads fall through this range at some point during the year. The next question is WHERE they go transonic. If we do beleive transonic impacts flight there would be a significant difference between going transonic 2 feet from the barrel VS 2 feet from the target. Do our best loads change through the year as temp and SOS change (taking aside temp sensitive powders)?

I think the general rule here as most of you are hitting on is to simply find the best load for YOUR gun setup and don't worry about speed as long as you're over PF. I shot a 1.5" group yesterday at 100yds (yes, I load test at 100) with my Gilmore (pics to come)that I'm sure went subsonic in the first 50yds. The temp was ~40 so SOS should have been ~1090. Muzzle Vel was 1117 making 50yds vel ~1040 and 100yds vel well below SOS.

hope this helps...

muzzle 50Yds Diff. % Diff

1300 1150 150 11.54% Post

1250 1120 130 10.40% Post

1250 1113 137 10.96% 115 FMJ REM +P

1200 1086 114 9.50% Post

1155 1047 108 9.35% 115 XTP HDY

1155 1047 108 9.35% 115 FMJ REM

1150 1070 80 6.96% Post

1136 1038 98 8.63% Kevin

1130 1067 63 5.58% 115JHP-FED

1100 1017 83 7.55% Post

Edited January 3, 2012 by Spangler

[DWFAN]

Cameron Cup is in June if you consider that "Bigger".

[Action Pistolero]

Cameron Cup is in June if you consider that "Bigger".

Forgot about that one. 2nd Sat. in June?

[DWFAN]

Cameron Cup is in June if you consider that "Bigger".

Forgot about that one. 2nd Sat. in June?

2nd sounds pretty soon after the Cup, I think it's the 3rd.