The Firing Line Forums - View Single Post - Squib load- could use some help in the diagnosis

bozhoz · May 23, 2009, 03:22 PM

Thanks for the followup Ozzie. Here are some answers to your questions:

1) I am sure that the weight is correct for 2 reasons... a) I weighed each charge on a digital scale b) upon loading all cartridges (7.0, 7.4, 7.8) I weighed each assembled bullet again, the total variance was give or take 2 grains (assuming bullet weight/case weight and obviously powder weight variances). So I am sure the charge was correct.

2) Did not notice any unburnt powder in the barrel, however I can see a section of rifling that appears to have been dinged up pretty good. Trying to examine this more carefully to see if this is copper fouling or damage to the steel barrel (which it looks like).

3) I agree with you on the "Mag" designation, I believe it is a thicker jacket, and also agree that the bullet alone should not have been the cause of the squib load.

4) Overcrimping- There was no major deformity in the case after the crimping. My heavy crimp rolled over the edge and did cause some minor bulging where it meets the bullet, but all round chambered into the cylinder fine. My concern was if I was crimping too tightly, yes it may raise the pressure, but would the tight crimp slow the bullet down... (or is the raise in pressure a net offest with the heavier crimp).

So I guess my next question would be, if I am starting at the starting load, but my OAL length was .05" longer than OAL, could this be getting me down into very low territory, thus causing the squib load?

My next obvious step is to try shooting the 7.8 grain bullets and see how they perform.

May 23, 2009, 03:22 PM	#4
bozhoz Member Join Date: March 15, 2009 Posts: 82	Thanks for the followup Ozzie. Here are some answers to your questions: 1) I am sure that the weight is correct for 2 reasons... a) I weighed each charge on a digital scale b) upon loading all cartridges (7.0, 7.4, 7.8) I weighed each assembled bullet again, the total variance was give or take 2 grains (assuming bullet weight/case weight and obviously powder weight variances). So I am sure the charge was correct. 2) Did not notice any unburnt powder in the barrel, however I can see a section of rifling that appears to have been dinged up pretty good. Trying to examine this more carefully to see if this is copper fouling or damage to the steel barrel (which it looks like). 3) I agree with you on the "Mag" designation, I believe it is a thicker jacket, and also agree that the bullet alone should not have been the cause of the squib load. 4) Overcrimping- There was no major deformity in the case after the crimping. My heavy crimp rolled over the edge and did cause some minor bulging where it meets the bullet, but all round chambered into the cylinder fine. My concern was if I was crimping too tightly, yes it may raise the pressure, but would the tight crimp slow the bullet down... (or is the raise in pressure a net offest with the heavier crimp). So I guess my next question would be, if I am starting at the starting load, but my OAL length was .05" longer than OAL, could this be getting me down into very low territory, thus causing the squib load? My next obvious step is to try shooting the 7.8 grain bullets and see how they perform.