Just got my chrono

[Raptor1956]

Well the CED M2 finaly arived so I went out today with my XD Tactical 357 sig and Bushmaster Varminter AR-15 and about 300 rounds of my handloads.

First the bad news -- I could not get the chrono to read the AR at all -- not one shot!

But I didn't have the problem with the XD and I tried a bunch of different bullets and loads with only an occasional failure to read the speed.

Well, my fastest was 1539fps with a 115gn Spier GD and my slowest, using a 147gn Spier GD and a lower charge was 970.5, but that looks like a flier with the rest of that string being more like 1060-1094 so I'm not sure what happened with that one shot.

I'm thinking 125gn is about the sweet spot of the 357 sig and it's looking like I'm getting around 1350-1450fps depending on charge.

Of course, all velocities were at about 5 yards so the true MV is likely to be 5-10fps faster than that.

If photobucket or something similar could handle text files I could upload the entire 21 string shoot. But I guess I can cut-and-paste so have a look.


Brian

Data Begins:

2.236068,true,true,true,false,true,false,false,915 ,
Start 6/8/2008 4:13:42 PM
Total Strings = 21
Bullet Weight = 0
Feet Per Second
String 1
1 1378
2 1409
3 1391
4 1382
5 1390
6 1406
7 1385
8 1406
9 1398
10 1397
String 2
1 1151
2 1162
3 1170
4 1173
5 1180
6 1169
7 1158
8 1177
9 1173
String 3
1 1060
2 1094
3 1073
4 1094
5 1080
6 1067
7 1093
8 1096
9 970.5
10 1064
String 4
1 1063
String 5
1 1390
2 1399
3 1400
4 1379
5 1383
6 1381
7 1376
8 1388
9 1390
10 1386
String 6
1 1435
2 1416
3 1415
4 1428
5 1449
6 1426
7 1439
String 7
1 1463
2 1427
3 1476
4 1451
5 1422
6 1432
7 1413
8 1418
9 1436
String 8
1 1441
2 1423
3 1398
4 1426
5 1419
6 1423
7 1382
8 1388
9 1426
10 1404
String 9
1 1426
2 1424
3 1388
4 1436
5 1412
6 1393
7 1411
8 1400
9 1412
10 1409
String 10
1 1442
2 1451
3 1435
4 1431
5 1446
6 1436
7 1436
8 1415
9 1444
10 1446
String 11
1 1434
2 1437
3 1421
4 1416
5 1391
6 1421
7 1409
8 1401
String 12
1 1507
2 1532
3 1524
4 1539
String 13
1 1270
2 1269
3 1262
String 14
1 1504
2 1510
3 1516
4 1532
5 1529
String 15
1 1269
2 1267
3 1248
4 1261
5 1259
String 16
1 1531
2 1518
3 1519
4 1530
5 1527
String 17
1 1254
2 1272
3 1274
4 1241
5 1245
String 18
1 1525
2 1514
3 1523
4 1519
5 1521
String 19
1 1270
2 1263
3 1262
4 1245
5 1255
String 20
1 1192
2 1177
3 1181
4 1188
String 21
1 1470
2 1473
3 1183
End 6/8/2008 4:13:58 PM

Data Ends:

[fredj338]

The Millenium (is that yours) is supposed to be pretty reliable. Make sure you set the screens at exactly the distance the manuf. suggest (usually 24"). It sounds likr you are far enough away, at least 15ft for handguns & 20ft for rifles. Sunlight plays a big part in your skyscreens ability to pick up the bullets shadow. SOme have good luck putting a piece of frosted "Scotch" tape over the skyscreen opening. You can also try using a black Sharpie & marking the bullet, sometimes helps w/ small bullets that cast a smaller shadow.

[Raptor1956]

I went through the manual last night and they indicate that for small fast bullets like the 223 you might have to shoot closer to the sensors. I guess that makes sense optically but I don't want to hit one becuase I'll probably hit both!

Yes, this is the Millenium series but the newer M2.

It looks like with the proper load I could get pretty close to 1600fps with a 115gn bullet or nearly 1500fps with a 125gn bullet.


Brian

[fredj338]

Originally Posted by Raptor1956

I went through the manual last night and they indicate that for small fast bullets like the 223 you might have to shoot closer to the sensors. I guess that makes sense optically but I don't want to hit one becuase I'll probably hit both!

Yes, this is the Millenium series but the newer M2.

It looks like with the proper load I could get pretty close to 1600fps with a 115gn bullet or nearly 1500fps with a 125gn bullet.


Brian

In a 4" bbl. you'll have to push the 357sig hard to get those vel. It's pretty easy to duplicate factory vel. in a 4" pistol though. My 115gr load runs 1450fps from my short P239.

[arizona98tj]

FWIW, I carry a rectangular piece of cardboard that I lay across the top of the skyscreen diffusers. On several occasions, this made the difference between catching the bullet and not. Here in AZ, the summer sun gets pretty intense and I believe the sensors are "squinting" so much they can't see the bullet (I don't blame them!).

[Raptor1956]

Originally Posted by arizona98tj

FWIW, I carry a rectangular piece of cardboard that I lay across the top of the skyscreen diffusers. On several occasions, this made the difference between catching the bullet and not. Here in AZ, the summer sun gets pretty intense and I believe the sensors are "squinting" so much they can't see the bullet (I don't blame them!).

Let me see if I understand what you've done here...

Does the bardboard cover both diffusers? That is, do you use a single piece that cover the whole thing?

I would think that a regular piece of cardboard would be almost completely opaque or do you use a translucient plastic type cardboard?


Brian

[arizona98tj]

Originally Posted by Raptor1956

Let me see if I understand what you've done here...

Does the bardboard cover both diffusers? That is, do you use a single piece that cover the whole thing?

I would think that a regular piece of cardboard would be almost completely opaque or do you use a translucient plastic type cardboard?


Brian

Regular piece of cardboard laid across the top of both diffusers.....yes, it covers the entire thing. With as intense as the sun gets out here, still plenty of light getting into the sensors....at least there was for me the last time I did it.

[Raptor1956]

Originally Posted by arizona98tj

Regular piece of cardboard laid across the top of both diffusers.....yes, it covers the entire thing. With as intense as the sun gets out here, still plenty of light getting into the sensors....at least there was for me the last time I did it.

Thanks, I'll give that a 'shot', perhaps this weekend.


Brian

[Raptor1956]

Well I've given the chrono a once over to see how I might improve the small fast bullet problem in blazing sun and I'll have to test this out next weekend. I think if you narrow the slit from the 0.300 inch it is now to something less you should make it easier to see the 55gr 223 bullet. Another thing I will try is to reduce the length of the slit from the current 2.16 inches to, perhaps, 1.75 inches.

So, I'm working on a quick-and-dirty test setup and if it works or not I'll post feedback.


Brian