Loads running faster than published data

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tac_driver

New member
Pistol: Glock 21SF StormLake Match BBL
Powder : Unique
Weight : 6.7
Bullet : Midstates
Weight : 200gr. LSWC
Brass: Winchester
Primer: WLP
COL: 1.248"
Crimp 0.471
Comments : 242 fps higher than published
My Average - 1072
Published AVG - 830
No pressure signs at all.
Spoke to alliant and sent them a fired case and a few rounds.
They won't be back till the 4th.
Wondering if someone else could shed some light on my problem.
 
F

farmerboy

Moderator
Problem? What's :)the problem? Is it too fast? or if is was slower than the test barrel performed, would the problem be too slow? Again, your load and the published load from the test barrel may shoot the same or they may not. Your gun shot that particular load at that speed and the OTHER gun shot at a different speed. What's the problem? If it shoots good for you without showing pressure signs, then keep shooting.
 
J

Jim Watson

New member
That is a lot of difference the wrong way.
What is your chronograph setup? 1072 fps is suspiciously close to the speed of sound and shockwave detection can screw up velocity readings.
 
S

Shoney

New member
I first had to do a search for the Glock 21SF to make sure it was a 45ACP. I next checked 3 Alliant references for a 200 LSWC

Pre 2005 data - - 200 gr Speer LSWC _ 5.4gr Unique _ 790fps
2007 data - - - - 200 gr Speer LSWC _ 5.1gr Unique _ 810fps
2008 data - - - - 200 gr Speer LSWC _ 5.4gr Unique _ 790fps

Pre 2005 data - - 200 gr Speer GDHP _ 7.3gr Unique _ 984fps
2007 data - - - - 200 gr Speer GDHP _ 7.1gr Unique _ 975fps
2008 data - - - - 200 gr Speer GDHP _ 7.3gr Unique _ 984fps

It appears that you have used jacketed data for the lead. That would account for some of the velocity gain. Your aftermarket barrel is probably much tighter for tolerances, and could give you a higher pressure/velocity. If you were at a much higher altitude than that where the Alliant company did their tests, then you can get higher velocities. Your chrono may be off.

Add up these factors cumulatively with probably more, and that will give you a good idea why it is high.

Did you get any leading?
 
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tac_driver

New member
I first had to do a search for the Glock 21SF to make sure it was a 45ACP. I next checked 3 Alliant references for a 200 LSWC

Pre 2005 data - - 200 gr Speer LSWC _ 5.4gr Unique _ 790fps
2007 data - - - - 200 gr Speer LSWC _ 5.1gr Unique _ 810fps
2008 data - - - - 200 gr Speer LSWC _ 5.4gr Unique _ 790fps

Pre 2005 data - - 200 gr Speer GDHP _ 7.3gr Unique _ 984fps
2007 data - - - - 200 gr Speer GDHP _ 7.1gr Unique _ 975fps
2008 data - - - - 200 gr Speer GDHP _ 7.3gr Unique _ 984fps

It appears that you have used jacketed data for the lead. That would account for some of the velocity gain. Your aftermarket barrel is probably much tighter for tolerances, and could give you a higher pressure/velocity. If you were at a much higher altitude than that where the Alliant company did their tests, then you can get higher velocities. Your chrono may be off.

I know it's not my chrono because titegroup, power pistol and universal were right on.
I used this data

Lyman Pistol&Revolver 3rd edition
Unique start 6.0 717 Max 7.5 913 COL 1.235
Add up these factors cumulatively with probably more, and that will give you a good idea why it is high.

Did you get any leading?
No Leading and no pressure signs
Thanks for your input Shoney
 
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tac_driver

New member
We don't know anything about your reloading set up. What are you using to weigh your charges?

Using a Dillon 550B press, and a Dillon Terminator reloading scale, using RCBS check weights to calibrate. Probably has nothing to do with my set up because Power Pistol, TiteGroup and Universal were all on the money when chronographing. Which leads me to believe it is the powder. Midstates 230gr LRN was running 152fps higher than published data.
When I originally spoke to Alliant they checked the lot# and found it to be 20fps faster well within the normal range.
 
S

Shoney

New member
tac_driver wrote
Lyman Pistol&Revolver 3rd edition
Unique start 6.0 717 Max 7.5 913 COL 1.235
Click to expand...
What was the exact bullet listed with this load? You haven't stated that yet.
 
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tac_driver

New member
What was the exact bullet listed with this load? You haven't stated that yet.
Same one that is listed in the 48th and 49th edition of the lyman manuals.
#452630
200gr. (#2 Alloy) 1.235" OAL
 
D

Dragon55

New member
Apologies for sort of a hijack but...

Posted by wncchester "Have you verified that your chronograph is correct?"

I know that Sport, Shoney, and Tacdriver all know more about this than I do but....

I've only been reloading a little over a year now. My son gifted me a Chrony for

Christmas. I too wonder how to verify. Heck I've chronied (is that the term?)

everything I can that's not loud until I can get out to the range.

Using instruments a lot at work we always have a 'known' we use to calibrate an

instrument.

I too wonder how to verify my new Chrony. I'm thinking I'll use my .22 as

time goes on for a recheck.
 
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J

Jim243

New member
Tac-Driver

I have the same data in the 49th edition that you have. It is strange since you are midway on the powder. The only thing I could think of is that since they are lead bullets, they (the bullet) may have been sized or manufacturered too small for the caliber. If you have some still unloaded check to see if they are .451 or smaller. That could account for the increase in FPS you encountered.

Jim
 
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tac_driver

New member
Tac-Driver

I have the same data in the 49th edition that you have. It is strange since you are midway on the powder. The only thing I could think of is that since they are lead bullets, they (the bullet) may have been sized or manufacturered too small for the caliber. If you have some still unloaded check to see if they are .451 or smaller. That could account for the increase in FPS you encountered.

Jim
Powder : Unique Weight : 5.4
Bullet : Zero Weight : 230grs.
Type : FMJ
String: 36
HI 838.8
LO 752.4
AVG 725
ES 86.35
SD 34.56
My Avg. 794

Powder : TiteGroup Weight : 4.2
Bullet : Zero Weight : 230grs.
Type : FMJ
String: 53
LO 680.1
HI 698.7
AVG 710
ES 18.61
SD 6.63
My Avg. 688.8

Powder : Universal Weight : 5.0
Bullet : Zero Weight : 230grs.
Type : FMJ
String: 46
LO 623.1
HI 663.2
My AVG 636.9
ES 40.15
SD 17.97

Powder : Bullseye Weight : 4.1
Bullet : Zero Weight : 230grs.
Type : FMJ
String: 60
LO 706.6
HI 727.7
AVG 710
ES 21.03
SD 9
My Avg. 714.9
LSWC measures .452
LRN measures .452
 
W

wncchester

New member
"I too wonder how to verify my new Chrony. I'm thinking I'll use my .22 as time goes on for a recheck."

That's about as good as we can get. Any chronograph that is accurate at one speed is most likely to be accurate at others.

It would be ideal if you can find a few boxes of .22RF to set aside for that purpose. Only some "standard" such as that can give us comfort when things look weird. Run it it through both your's and as many other chronograps, with the same firearm, as possible to obtain a fairly good idea of the speed it produces IN that firearm.
 
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tac_driver

New member
Well alliant finally got around to testing those rounds i sent. They were getting the same velocities and verified nothing was wrong with the powder charge, crimp, OAL. He said it might be because i'm using winchester primers (total bull****).

The last testing i did was:
Caliber : 45ACP Barrel Length : 4.6 Firearm : Glock 21SF
Load 4
Date : 1/28/10 Temp : 45 Conditions : sunny
Case : Winchester Crimp : 0.471 PF: 157
Trimmed :0.893 Primer : WLP COAL: 1.248
Powder : Unique Weight : 4.9 PD: 0.88 Shots: 5
Bullet : Midstates Weight : 200grs. BOAL: 0.649
Type : LSWC
Comments :
String: 3
LO 764.2
HI 809.2
AVG 785.2
ES 45.01
SD 17.17

The lowest starting charge i could find for unique was in the .45ACP load book in the speer section at 4.9grs. However the book say it should be a velocity of 716fps, which is still giving me 69.2fps faster than published data but i'm going to have to live with it. Just going to load it all up and shoot it, but won't be buying any more of this powder again.
 
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Shoney

New member
I had an incident where my velocities were showing much higher than book data, yet showing no pressure signs at max loads. Since I didn't understand what was going on, I called the chrono factory.

The chrono company asked what elevation I was shooting at, because at higher elevations the air is less dense and higher velocities could be expected. Since I wasn't at high elevation, they told me to calibrate my chrono using high quality .22 LR, where the expected velocity is on the box (Federal 900B for example).

The quality ammo was to be fired out of a 24" bolt action or lever action .22, and should achieve the stated velocity within 50 fps or closely thereabout. The .22's usually vary less from the stated velocity than most commercial and handloaded centerfire cartridges. I was also told that the escaping gasses with unburned powder and residue particles of the cenerfire ammo crossing the chrono can give false high readings.
 
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