Area 8 chrono question

[chrisa006]

My ammo averaged 987 through the chrono at Area 8. The same batch at home was 928. Did any one else have unexpected readings?

[Kingman]

mine was hotter there than it was at the SC sectional and I backed it off a tenth of a grain.

[Matt Cheely]

I had it slightly high.

My gun chono'd at 170.8 at home. 172.5 at A8

In the past my chrono has been quite close to most major match chrono's.

[chrisa006]

Matt,

Mine had been close too, which is why I was so surprised

[GTOSHootr]

Mine was slower at home. 168ish at home, 172pf there.

[Scout454]

I got 170 at home over the same setup (CED with IR in a closed, blackened box) on 3 different occasions. At A8, ammo loaded at the same time, same bullets, same lot of primers, same jug of N310 went 168. Elevation, temperature and humidity were about the same.

[vluc]

My usual runs between 136-138 PF. Was 141 at A8.

[Seth]

I thought so. I've chrono'd 3 times in the last 2 months and came out with about a 168pf consistently. Area 8 had it at 179pf. I figure some was temp, some was elevation gain, but that was a big jump.

[BNorth]

Mine loads were slightly slower at A8 than the previous weekend. Stage 7 was my first stage so we were the first to chrono on Sat morning. It was definitely cooler than the previous weekend.

[dirty whiteboy]

Higher elevation maybe?

I bumped mine after SC, 165,500 a little too close!

[RacerX1166]

One more yes...all same components (same lot in fact) was running 170-171 at home and got 173 at A8.

[wide45]

I had 172 at home, 165.4 at A8

[Glen517]

Wow was it. A6 169.5 same run off the press 174.8 A8

[Brazos SC Shooter]

I had 172 at home, 165.4 at A8

This was my experience as well. I didn't make major with my first three shots. Fortunately I did with the second group but it was barely. I think I was 165.7 average. Way to close for my taste.

[Chris Keen]

Which gun did you shoot that out of Drew ?

[wide45]

I had 172 at home, 165.4 at A8

Just got in from rechronoing.

165ish with the leftover ammo from A8.

Switched powder lot.

Need to bump up .2+gr. of Longshot for A7

[Ed Deegan]

Mine was actually down. I was chrono'd 2x in the month before and it was about 2 pf slower than the others. (FYI, 1 was at ssn and one at our club match)

[mikegot38]

This is the same batch of ammo I shot last year and it had been 173 at home, 166 at last years

Area 8, 170+ at SC Sectional and 170+ at this years Area 8.

[Sestock]

Elevation Change?

Danbury, CT 397 Ft

Alverton, PA 1181 Ft

[GENE S]

At Area 8, mine was 178, and the Summer Blast, 169.

Same loads, out of the same box.

[SA Friday]

Elevation Change?

Danbury, CT 397 Ft

Alverton, PA 1181 Ft

I really doubt that elevation had anything to do with the chrono reading differences. I shot ammo at summer blast from a lot I loaded and shot regularly in CO. It chronoed 130-132pf in CO and it chronoed 131pf at summer blast. Thats about a 6000ft change in elevation.

Chrono's are funny insturments, and virtually impossible to calibrate. There are just too many factors that could be in play for a different chrono reading from both the chrono and the ammo. Just control what you can, shoot hot enough that you don't miss your mark and use good reloading practices for consistant lots of ammo. Know what readings on your chrono are compared to other chronos. Get a base line from shooting over as many chrono's as possible with the same lot of ammo. It's all you can really do.

[Ed Deegan]

FWIW

Mine was factory federal, same lot numbers.

SS Classic 197 and change

A8 195 and change

Summer Blast 188 and change

[Franklin D Wolverton]

Most of these changes can probably be attributed to differences in temp between when you test fired it, and where you shot it.

I test my ammo in a temp controlled indoor range (72). It does not take a very significant change in temp to mess a little with your loads. 10 deg either way will make a very noticeable change. Kind of need to watch the time of day you crono. If you crono early in the morning before the temp has come up (and before you have fired your gun for the day) your fps will be a lot lower than if you crono at noon, after putting 100 rounds through your barrel.

Ahh... here I am preaching to the choir.

Frank

[vluc]

Now that we have brought Summer Blast into this, let me post my results. Using the same ammo bunch made at the time of A8, at Summer Blast I came in at 139PF. So my load usually runs at 136-138 (closer to 138), was 139 at SB and 141 at A8. Still in the ball park. Works for me. Original calibration on a Master Beta Shooting Chrony at an indoor range.

I could tell no difference in the feel of the gun between A8 and SB other than that I did much better at SB.

Edited July 24, 2008 by vluc

[Vlad]

Mine was 136.x at A8 (no idea how big x was) and 136.4 at the Blast. It comes in at 135 at home. They weren't loaded in the same batch, but they were the same recipe.