Print Page | Close Window

Good fathers day at the range

Printed From: OpticsTalk by SWFA, Inc.
Category: Firearms, Bows, and Ammunition
Forum Name: Firearms
Forum Description: All makes, models and uses
URL: http://www.opticstalk.com/forum_posts.asp?TID=44200
Printed Date: March/28/2024 at 11:29
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com


Topic: Good fathers day at the range
Posted By: sucker76
Subject: Good fathers day at the range
Date Posted: June/18/2017 at 21:46
The good part:
A friend and I went to the range today.  Before today the farthest I have shot was 300 yards.  We went right to 600 yards and aimed for the 24x24 inch steel plate.  I was 5 for 5 on the plate first time out.  I was pretty stoked. 

My rifle was Savage 12LRP 6.5Creedmoor.  Ammo was Hornady Precision Hunter 143gr ELD-X. 
I knew velocity of 2783fps and entered into Strelok and dialed 3.5mils and was dead on.  It was a hell of a great feeling. 


The bad part:
The picture shows Prime ammo which I got because it was highly rated.  130gr BTHP.  I was using a ProChrono.  I started shooting the Prime ammo with a cooled barrel.  Here's the problem; The velocities for 10 shots have an ES of 475 and SD of 169!
I shot 4 rounds in about 6 minutes and the velocities were 2943, 2943, 2962, 2976.  I then stopped to talk to some guys at the range for about 10 minutes with ammo out of rifle and chamber flag in.  The next 6 rounds were 3182, 3220, 3418, 3129, 3384, 3212.  Velocities are in shot order. 

The case necks looked about the same for all of them.  The 3418 one did look a little more sooty.  Shot in order from left to right.


The case heads looked OK too.  No typical signs of over pressure.  Shot in order from left to right.


So my question is what happened?  Why did the velocities go way up after a short break in shooting?  Did the heat just soak into the barrel and lead to higher velocities?  Do chamber flags block enough air flow to cause this problem?



-------------
Stamp collecting since 2015



Replies:
Posted By: Dogger
Date Posted: June/19/2017 at 07:09
Sounds like you had a good day out, congrats on your shooting.  I'll defer to the experts here on your velocity questions though.


-------------
God save the Empire!


Posted By: Rancid Coolaid
Date Posted: June/19/2017 at 07:48
You went from 2900 to 3400 with no appreciable brass signs?
I would think you'd feel that difference on the gun.

If the brass looks the same, I'd wonder if it was a chrono issue. The shooting position looks to be in shade so ammo did not heat that much, right?

-------------
Freedom is something you take.
Respect is something you earn.
Equality is something you whine about not being given.


Posted By: Rancid Coolaid
Date Posted: June/19/2017 at 07:49
I would also contact Prime and ask them.

and let us know, I just bought a few boxes of their stuff!

-------------
Freedom is something you take.
Respect is something you earn.
Equality is something you whine about not being given.


Posted By: koshkin
Date Posted: June/19/2017 at 08:22
Did the POI change?

I would check the chronograph first.

ILya

-------------
http://www.darklordofoptics.com - www.darklordofoptics.com
https://rumble.com/c/DLO - Rumble Video Channel


Posted By: sucker76
Date Posted: June/19/2017 at 09:42
I thought of chrono problems too.  No large difference in feel or POI shift.  All 10 rounds were in about 1.25" at 100 yards.  The chrono was about 8' from the rifle which is about where I usually put it.  I'm trying to think back if both sensors were in the shade or not. 

I'll contact Prime later today to hear what they say.  I have looked around for anything close to my issue and have read nothing on it. 

By the answers I'll assume the consensus is not a barrel heat problem. 


-------------
Stamp collecting since 2015



Print Page | Close Window

Forum Software by Web Wiz Forums® version 12.01 - http://www.webwizforums.com
Copyright ©2001-2018 Web Wiz Ltd. - https://www.webwiz.net