|
|
Joined: Jul 2001
Posts: 60,153 Likes: 13
Campfire Kahuna
|
Campfire Kahuna
Joined: Jul 2001
Posts: 60,153 Likes: 13 |
A few comments:
Again, the directions for the RCBS Casemaster suggest measuring runout approximately .1 inch in front of the case mount, or about where the ogive typically begins. As somebody else already stated, this is the area where the bullet typically enters the rifling.
Annealing after every shot certainly helps, especially when searching for the finest accuracy--which is why I typically anneal the 6mm PPC brass for my benchrest rifle after every firing.
With hunting rifles I typically anneal after every four firings, but keep the brass separated in Ziploc bags, with how many times they've been fired written on the bag with a Magic Marker. Have gotten fine accuracy by using only brass that's been fired the same numbers of times after the last annealing when loading a box or two of ammo. (I anneal after four firings because even with "ordinary" brass that's soon enough to prevent necks from cracking. But have found that even "premium" brass results in more consistent accuracy when annealed regularly, even if not after every firing.)
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
|
|
|
|
|
Joined: Jul 2001
Posts: 60,153 Likes: 13
Campfire Kahuna
|
|
Campfire Kahuna
Joined: Jul 2001
Posts: 60,153 Likes: 13 |
Might also mention "experiment" I made with factory ammo around 20 years ago. Had a custom rifle built in a well-known but not super-common chambering, and shortly thereafter was invited on a Coues deer hunt in Sonora. Didn't have time to work up a load, but lucked upon some factory ammo that had received great reviews--and not just in gun magazines. Since Coues deer aren't very big (in general smaller than pronghorns), I wanted all the accuracy possible.
Bought several boxes, then sorted them according to bullet run-out, measured as described above, about .1 inch in front of the case mouth. The batches were those with at most .003 run-out, .003 to .005, and over .005, which ran up to .008.
The .003 or less rounds averaged 3 shots in around .5 inch at 100 yards, the .003-005 rounds around an inch, and the over-.005 rounds about 1.5 inches. Now, even the >.005 rounds would certainly work fine on most big game at "normal" ranges, but I used the <.003 rounds. The buck I eventually got was only 220 yards away, but I was very confident at twice that range--or more.
Apparently that variation in accuracy potential would be meaningless to some here, and my field experience indicates it is--on animals considerably larger than Coues deer. But I was indeed happier and more confident with the best accuracy.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
|
|
|
|
|
Joined: Jun 2004
Posts: 44,860 Likes: 4
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Jun 2004
Posts: 44,860 Likes: 4 |
That's closer to what I've seen. The other fellow's comment that he hasn't seen runout up to .008" make any difference is in direct contradiction to the blind test shoot I did with my friend.
|
|
|
|
|
Joined: Jun 2020
Posts: 791
Campfire Regular
|
|
Campfire Regular
Joined: Jun 2020
Posts: 791 |
I can truly state that I have NEVER measured round out on any cartridge, nor do I plan to in the future. I do believe that if you are a benchrest competition shooter, that it would be a critical factor, BUT for 99% of big game hunters I believe it is a waste of time and energy. I am a hunter primarily elk and deer, and believe that one should do the best job possible in developing a hunting load, I do not believe that weighing cases, weighing bullets, or primers, will make a difference in your ability to get the job done. Load them carefully with good components and don't worry about the minutia.
|
|
|
|
|
Joined: Jun 2004
Posts: 44,860 Likes: 4
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Jun 2004
Posts: 44,860 Likes: 4 |
For conversation, what falls under the headings of doing the best job possible and loading them carefully?
|
|
|
|
|
Joined: Mar 2021
Posts: 2,427 Likes: 3
Campfire Regular
|
|
Campfire Regular
Joined: Mar 2021
Posts: 2,427 Likes: 3 |
Well that's just great... .003 or less runout =1/2 inch groups, and .005 or more = 1 to 1 1/2 inch groups... now i want a slant bed concentricity gauge to check my load test ammo (before i taint the data with crooked necks)... And a teslong bore scope from that other thread (so i can be sure what my barrels look like)... You guys are kill'in me ($$$)... You know that, Right!... A bunch of Enablers for sure... lol
Last edited by 7mm_Loco; 02/14/22.
|
|
|
|
|
Joined: Sep 2010
Posts: 4,001
Campfire Tracker
|
|
Campfire Tracker
Joined: Sep 2010
Posts: 4,001 |
Well that's just great... .003 or less runout =1/2 inch groups, and .005 or more = 1 to 1 1/2 inch groups... now i want a slant bed concentricity gauge to check my load test ammo (before i taint the data with crooked necks)... And a teslong bore scope from that other thread (so i can be sure what my barrels look like)... You guys are kill'in me ($$$)... You know that, Right!... A bunch of Enablers for sure... lol Both those items are nice to have but not necessarily required.
I am continually astounded at how quickly people make up their minds on little evidence or none at all.
Jack O'Connor
|
|
|
|
|
Joined: Dec 2003
Posts: 4,950
Campfire Tracker
|
|
Campfire Tracker
Joined: Dec 2003
Posts: 4,950 |
With all the discussion about cartridge run-out, has anyone ever delved into how precisely rifle chambers are aligned with barrels, and that effect on accuracy?
|
|
|
|
|
Joined: Feb 2014
Posts: 2,621
Campfire Regular
|
|
OP
Campfire Regular
Joined: Feb 2014
Posts: 2,621 |
I can truly state that I have NEVER measured round out on any cartridge, nor do I plan to in the future. I do believe that if you are a benchrest competition shooter, that it would be a critical factor, BUT for 99% of big game hunters I believe it is a waste of time and energy. I am a hunter primarily elk and deer, and believe that one should do the best job possible in developing a hunting load, I do not believe that weighing cases, weighing bullets, or primers, will make a difference in your ability to get the job done. Load them carefully with good components and don't worry about the minutia. I hear ya - in general however with the reduced a availability of components I’ve started elevating my quality standards if only to reduce my use of materials. To me, checking runout is an easy way to make more sure that a loader isn’t just churning out substandard stuff and testing more loads than necessary chasing better accuracy. It’s nice to qualify what different die sets or combination of dies creates the best ammo or not. So I guess, for me, this step helps me determine what my quality components indeed are then I can load more freely without worrying about every single cartridge etc.
Last edited by PintsofCraft; 02/14/22. Reason: Spelling
|
|
|
|
|
Joined: Feb 2014
Posts: 2,621
Campfire Regular
|
|
OP
Campfire Regular
Joined: Feb 2014
Posts: 2,621 |
Might also mention "experiment" I made with factory ammo around 20 years ago. Had a custom rifle built in a well-known but not super-common chambering, and shortly thereafter was invited on a Coues deer hunt in Sonora. Didn't have time to work up a load, but lucked upon some factory ammo that had received great reviews--and not just in gun magazines. Since Coues deer aren't very big (in general smaller than pronghorns), I wanted all the accuracy possible.
Bought several boxes, then sorted them according to bullet run-out, measured as described above, about .1 inch in front of the case mouth. The batches were those with at most .003 run-out, .003 to .005, and over .005, which ran up to .008.
The .003 or less rounds averaged 3 shots in around .5 inch at 100 yards, the .003-005 rounds around an inch, and the over-.005 rounds about 1.5 inches. Now, even the >.005 rounds would certainly work fine on most big game at "normal" ranges, but I used the <.003 rounds. The buck I eventually got was only 220 yards away, but I was very confident at twice that range--or more.
Apparently that variation in accuracy potential would be meaningless to some here, and my field experience indicates it is--on animals considerably larger than Coues deer. But I was indeed happier and more confident with the best accuracy. Thanks for adding so much solid data to the thread - helps us all evolve in a more thoughtful manner
|
|
|
|
|
Joined: Jun 2020
Posts: 791
Campfire Regular
|
|
Campfire Regular
Joined: Jun 2020
Posts: 791 |
For conversation, what falls under the headings of doing the best job possible and loading them carefully? I start by case exam, i look for red fingernail polish on primer, if it's red it goes in trash, check, for cracks, then size, length, clean and chamfer. I load powder with spoon, and measure each amount ( especially on full loads), then seat bullet. Done except for running through magazine.
Last edited by elkmen1; 02/14/22.
|
|
|
|
|
Joined: Jan 2003
Posts: 3,444 Likes: 4
Campfire Tracker
|
|
Campfire Tracker
Joined: Jan 2003
Posts: 3,444 Likes: 4 |
With all the discussion about cartridge run-out, has anyone ever delved into how precisely rifle chambers are aligned with barrels, and that effect on accuracy? Sure have.  -Al
Forbidden Zoner
|
|
|
|
|
Joined: Jun 2007
Posts: 7,914 Likes: 2
Campfire Outfitter
|
Campfire Outfitter
Joined: Jun 2007
Posts: 7,914 Likes: 2 |
With all the discussion about cartridge run-out, has anyone ever delved into how precisely rifle chambers are aligned with barrels, and that effect on accuracy? Sure have. -Al Great. Can you describe the process?
GOA
|
|
|
|
|
Joined: Feb 2014
Posts: 2,621
Campfire Regular
|
|
OP
Campfire Regular
Joined: Feb 2014
Posts: 2,621 |
Dialogue on this thread is outstanding- thank you all!
|
|
|
|
|
Joined: Jan 2010
Posts: 956
Campfire Regular
|
|
Campfire Regular
Joined: Jan 2010
Posts: 956 |
Seems like what I've learned so far is, the people who say there's no need to measure, do in fact measure, just maybe not as often. That's not the same as not measuring.
Still want to know more about fixing problems (not necessarily the rounds themselves) and what are you doing with the culls? Breaking them down and starting over? Saving them to "shoot out" for a just cleaned barrel?
|
|
|
|
|
Joined: Sep 2009
Posts: 3,007
Campfire Tracker
|
|
Campfire Tracker
Joined: Sep 2009
Posts: 3,007 |
After reading a lot of Mule Deer's writings on this subject, I now check my rifle rounds for runout and adjust as necessary with the Tru Angle tool. The result has been more consistent accuracy from my rifles. The extra effort is definitely worth it to me.
|
|
|
|
|
Joined: Jun 2004
Posts: 44,860 Likes: 4
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Jun 2004
Posts: 44,860 Likes: 4 |
Could you refine your components and processes so adjustments to runout become unnecessary?
|
|
|
|
|
Joined: Sep 2009
Posts: 3,007
Campfire Tracker
|
|
Campfire Tracker
Joined: Sep 2009
Posts: 3,007 |
Could you refine your components and processes so adjustments to runout become unnecessary? I've worked on that some but am not there yet.
|
|
|
|
|
Joined: Mar 2006
Posts: 14,518 Likes: 1
Campfire Outfitter
|
|
Campfire Outfitter
Joined: Mar 2006
Posts: 14,518 Likes: 1 |
Could you refine your components and processes so adjustments to runout become unnecessary? I've worked on that some but am not there yet. I’ve done the same over the years. Starting with consistent necks (either from the factory or turned), I found that a combination of the LCD, Redding BD, and Forster BR dies is almost guaranteed to produce 0.0015” or less of TIR, indicated on the ogive. Cheap dies can give good concentricity performance, as well, but it’s not such a sure thing, IME.
|
|
|
|
|
Joined: Feb 2006
Posts: 1,309 Likes: 2
Campfire Regular
|
|
Campfire Regular
Joined: Feb 2006
Posts: 1,309 Likes: 2 |
Well that's just great... .003 or less runout =1/2 inch groups, and .005 or more = 1 to 1 1/2 inch groups... now i want a slant bed concentricity gauge to check my load test ammo (before i taint the data with crooked necks)... And a teslong bore scope from that other thread (so i can be sure what my barrels look like)... You guys are kill'in me ($$$)... You know that, Right!... A bunch of Enablers for sure... lol Amazon will put a very serviceable Teslong borescope on your doorstep for $55.99.
Al
Spend your life wisely.
|
|
|
|
|
556 members (1234, 160user, 219 Wasp, 10Glocks, 1beaver_shooter, 1Akshooter, 60 invisible),
2,439
guests, and
1,200
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
Forums81
Topics1,192,459
Posts18,489,777
Members73,972
| |
Most Online11,491
Jul 7th, 2023
|
|
|
|
