barrel length and pressure signs

[dagwood]

The load I found to work best for my Sig/Sauer SSG3000 1/12 twist 22.5 inch barrel loaded with 45.5gr of H4895 and nosler custom comp 155gr bullet with no pressure signs and nice clean cut holes. Now I'm shooting a Rem 700-V with 26 inch barrel and 1/12 twist also. But now I'm getting ragged holes at 100 yards and signs of overpressure on the primer.
The only difference other than the guns was it was 105 degrees the day I shot the Rem. Any ideas on what is going on???

 

[0481]

Re: barrel length and pressure signs

What was the temp the days you shoot the 3000?

 

[BobinNC]

Re: barrel length and pressure signs

Describe your overpressure signs on the primer, cause primers are a notoriously bad indicator of pressure, except when blown or pierced.

As to your problem: Different rifle, barrel, chamber, throat, and 105 degrees is bloody hot....

 

[dagwood]

Re: barrel length and pressure signs

I'm getting a ring around the firing pin detent that I was not getting on the Sig. Maybe the firing pin opening is larger than the Rem 700. Also getting alot of black soot on the neck this time. The cases were full sized, not just neck sized. The ragged holes bother me at that close of a distance.

 

[Fred_C_Dobbs]

Re: barrel length and pressure signs

PMax occurs in the first few inches of bullet movement so I don't think anything that happens another 20 inches down the barrel will change it much.

With that charge weight of 4895, using the default dimensions, QuickLoad predicts a 2600 psi increase in Pmax between 80°F and 105. Besides excessive chamber pressure, too large a firing pin hole (which you already mentioned) and too weak a firing pin spring also can tend to cause more pronounced cratering. Without stepping up the charge weight gradually and watching its progression, it's difficult to tell whether it was high or excessive pressure that caused it.

 

[dagwood]

Re: barrel length and pressure signs

The temps I normally shoot at during the summer is mid 80's to high 90's. The 105 was not the typical temps we get here and that wasn't heat index. That was 115 degrees. This year is a different story, alot of heat, humidity and brush fires.
The current 1000 acre fire is close to our sub-division. We had heavy smoke and hot ash falling about an hour ago, but now its raining.

 

[BCP]

Re: barrel length and pressure signs

Maybe that load is a little much for your rifle in that heat? Also (at the risk of sounding stupid) what is a "ragged" hole?

 

[MitchAlsup]

Re: barrel length and pressure signs

Remmington firing pins are routinely bushed to get rid of primer cratering issues.

 

[dagwood]

Re: barrel length and pressure signs

BCP
looks like the bullet is starting to tumble a little. I know 100 yards is real close for that, but they look different from when I shot the same rounds from the SSG 3000.

 

[TimResin]

Re: barrel length and pressure signs

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MitchAlsup</div><div class="ubbcode-body">Remmington firing pins are routinely bushed to get rid of primer cratering issues.</div></div>

I think I am having the same issue with my reloads. Is it that big of a deal if this is happening? Cause there is no way I am getting over pressure with 42 grains of varget in a Winchester case .308

And if it is a problem what will fix the problem or who?