Comments on: Determining Bullet Seating Depth http://blog.sinclairintl.com/2009/03/26/determining-bullet-seating-depth/ Sinclair International Precision Shooting Blog Mon, 02 Jan 2012 18:58:22 -0500 http://wordpress.org/?v=2.8.4 hourly 1 By: tylor http://blog.sinclairintl.com/2009/03/26/determining-bullet-seating-depth/comment-page-1/#comment-16679 tylor Tue, 01 Nov 2011 19:53:00 +0000 http://blog.sinclairintl.com/?p=147#comment-16679 Why wouldn't you seat the test bullet to Oal in dummy case Insert tip of bullet into end of barrel and rest it up against rifling Measure base of dummy case to muzzle, record measurement Now when getting new bullets seat one into a dummy case a bit long Insert tip of bullet into end of barrel, measure and subtract the first measurement. Example "1"test bullet Oal length in dummy case 2.840 touching. "2" tip in end of barrel measurement 2.159 Now I get new bullet to try, so I seat one into dummy case until it duplicates 2.159 at muzzle Now measure dummy case for new bullet Oal. Oal changes with dif bullets, but the 2.159 should stay same. Until the rifeling starts eroding. Then find updated Oal from original test bullet and start over. Lol Why wouldn’t you seat the test bullet to Oal in dummy case
Insert tip of bullet into end of barrel and rest it up against rifling
Measure base of dummy case to muzzle, record measurement
Now when getting new bullets seat one into a dummy case a bit long
Insert tip of bullet into end of barrel, measure and subtract the first measurement. Example “1″test bullet Oal length in dummy case 2.840 touching. “2″ tip in end of barrel measurement 2.159
Now I get new bullet to try, so I seat one into dummy case until it duplicates 2.159 at muzzle
Now measure dummy case for new bullet Oal.

Oal changes with dif bullets, but the 2.159 should stay same.

Until the rifeling starts eroding. Then find updated Oal from original test bullet and start over. Lol

]]> By: Nick http://blog.sinclairintl.com/2009/03/26/determining-bullet-seating-depth/comment-page-1/#comment-16300 Nick Tue, 11 Oct 2011 01:27:54 +0000 http://blog.sinclairintl.com/?p=147#comment-16300 Are Remington model 700 30-06 bullet seating depths usually longer than other brand rifles? Or does this just vary a whole lot between same model and brand/ caliper? Are Remington model 700 30-06 bullet seating depths usually longer than other brand rifles? Or does this just vary a whole lot between same model and brand/ caliper?

]]> By: Hanke http://blog.sinclairintl.com/2009/03/26/determining-bullet-seating-depth/comment-page-1/#comment-15878 Hanke Sun, 18 Sep 2011 13:02:32 +0000 http://blog.sinclairintl.com/?p=147#comment-15878 I like this article alot, and want to know. How deep must a bullet be seated? I use 155gr bullets on my 30-06 but want to test it with 110gr Hornady V max. Now the 110gr are shorter than 150gr, so the OAL will be shorter. I like this article alot, and want to know. How deep must a bullet be seated? I use 155gr bullets on my 30-06 but want to test it with 110gr Hornady V max. Now the 110gr are shorter than 150gr, so the OAL will be shorter.

]]> By: Derrill foster http://blog.sinclairintl.com/2009/03/26/determining-bullet-seating-depth/comment-page-1/#comment-15792 Derrill foster Sun, 11 Sep 2011 16:56:13 +0000 http://blog.sinclairintl.com/?p=147#comment-15792 I just read your article on bullet seating. It was very interresting. I have a question about seating. I only reload for hunting. I prefer to use a rimpe groove bullet. If I find a desired seating depth, is is ok to trim the case mouth to fit the crimp spot even though it might be less or greater than the min/max stated in the reloading manuals? thank you. I just read your article on bullet seating. It was very interresting. I have a question about seating. I only reload for hunting. I prefer to use a rimpe groove bullet. If I find a desired seating depth, is is ok to trim the case mouth to fit the crimp spot even though it might be less or greater than the min/max stated in the reloading manuals? thank you.

]]> By: wayne biggs http://blog.sinclairintl.com/2009/03/26/determining-bullet-seating-depth/comment-page-1/#comment-15656 wayne biggs Mon, 05 Sep 2011 08:59:46 +0000 http://blog.sinclairintl.com/?p=147#comment-15656 my question is i have been reloading for competition for several years now i use wilson dies stoney point oal gauge and i just recently made up some loads and after i had finished i thought i would check some of these for consistancy and found that they were all over the place i run serra match kings 155grn ,and cant work out why all checking was done from ogive to base with a comparitor ,i have checked the seater die to make sure the meplat of the projectile is not bottoming out no probs there,have got any ideas regards wayne biggs my question is i have been reloading for competition for several years now
i use wilson dies stoney point oal gauge and i just recently made up some loads and after i had finished i thought i would check some of these for consistancy and found that they were all over the place i run serra match kings 155grn ,and cant work out why all checking was done from ogive to base with a comparitor ,i have checked the seater die to make sure the meplat of the projectile is not bottoming out no probs there,have got any ideas
regards
wayne biggs

]]> By: Ramin http://blog.sinclairintl.com/2009/03/26/determining-bullet-seating-depth/comment-page-1/#comment-11712 Ramin Wed, 11 May 2011 09:01:51 +0000 http://blog.sinclairintl.com/?p=147#comment-11712 Dear Mr. Bob Blaine: Hi . As a new comer to the world of you ( reloading ) , I am in Iran. I am not sure to get any answer from you , but I myself eager to know more about reloading. My rifle caliber is 270win. with 60cm barrel length with 5 rounds magazine and it is a 4 groove right to left . Also I start to reload 5 months ago with sierra 130 pro hunter and WLR primer and RWS 11.23g. and 12.43g cases( I think the light one is for hunting and the other is military! .?) I was told to contact your line I mean your site to get more info about seating the bullet. I also installed 3-10x42 Swarovski scope. I have Chrono , range finder and pro-pack Redding press and RCBS neck size. I usually reload 41grains semi slow burn powder also with COL around 83.00mm. Some body told me about one good book by name of the ABC's of reloading by Mr. Fred Sinclair. Any how , I talk more . Your kind reply would be highly appreciated. Cheers Ramin Dear Mr. Bob Blaine:
Hi .
As a new comer to the world of you ( reloading ) , I am in Iran.
I am not sure to get any answer from you , but I myself eager to know more about reloading.
My rifle caliber is 270win. with 60cm barrel length with 5 rounds magazine and it is a 4 groove right to left .
Also I start to reload 5 months ago with sierra 130 pro hunter and WLR primer and RWS 11.23g. and 12.43g cases( I think the light one is for hunting and the other is military! .?)
I was told to contact your line I mean your site to get more info about seating the bullet.
I also installed 3-10×42 Swarovski scope.
I have Chrono , range finder and pro-pack Redding press and RCBS neck size.
I usually reload 41grains semi slow burn powder also with COL around 83.00mm.
Some body told me about one good book by name of the ABC’s of reloading by Mr. Fred Sinclair.
Any how , I talk more .
Your kind reply would be highly appreciated.
Cheers
Ramin

]]> By: Mike http://blog.sinclairintl.com/2009/03/26/determining-bullet-seating-depth/comment-page-1/#comment-11032 Mike Sat, 23 Apr 2011 16:30:49 +0000 http://blog.sinclairintl.com/?p=147#comment-11032 I've used bullet seating depth to fine tune loads many times, this works like the Browning Boss system to adjust the pressure wave. What I struggle with during load development is how much to move the bullet back from the lands for each test group. What I do is assemble ten rounds at .002" off the lands, then move back another .005" - to .007" off the lands with another 10 rounds, repeat in .005" increments until best accuracy is acheived. If an acceptable group in not found by the time you reach .050" off the lands - time to try a different powder, powder charge, primer or bullet. I often question myself is .005" the correct distance between test groups? Am I missing the best group by skipping over it? I’ve used bullet seating depth to fine tune loads many times, this works like the Browning Boss system to adjust the pressure wave. What I struggle with during load development is how much to move the bullet back from the lands for each test group. What I do is assemble ten rounds at .002″ off the lands, then move back another .005″ – to .007″ off the lands with another 10 rounds, repeat in .005″ increments until best accuracy is acheived. If an acceptable group in not found by the time you reach .050″ off the lands – time to try a different powder, powder charge, primer or bullet.

I often question myself is .005″ the correct distance between test groups? Am I missing the best group by skipping over it?

]]> By: admin http://blog.sinclairintl.com/2009/03/26/determining-bullet-seating-depth/comment-page-1/#comment-10438 admin Mon, 11 Apr 2011 19:23:11 +0000 http://blog.sinclairintl.com/?p=147#comment-10438 Hello James, You should be okay with loading this way if you are primarily loading the rifle as a single shot. If this is a concern for you personally, or you prefer to have more of the bullet in the case, you can always seat the bullet deeper. What you would do is to start at the depth that you select and then use that as your baseline. I like to shoot at least two, three shot groups to establish what the rifle will show us. You would then set the bullet back at regular intervals, while shooting two more three shot groups, to see what happens to the groups. At some point, you will see groups either opening up, or getting smaller. We are using the bullet as a weight to tune for the barrel vibrations, and the laws of physics do not care it we move the bullet closer to the rifling, or further out from the rifling. What the goal is to set the seating depth to a setting that allows the bullet to leave the muzzle at the same point that the swing of the vibration comes to a stop, at that instant, every time. This is why seating depth is such a critical dimension for consistent accuracy of our firearms. When working toward this goal, I will always use a safe powder charge. If I am using a chronograph, I will usually look for a safe load that gives the smallest SD figure, and as long as I am satisfied that I am working within safe load limits, I will then start working with the seating depth. This is the same procedure that I have used for setting up our team bench rest 6PPC rifle, and I will use it for my personal rifles as well. If you do not have access to a chronograph, then I would recommend using the load data that you have, and work within listed loads that are showing as safe in your rifle. If we can be of further service, or you have additional questions, please do not hesitate to get back in touch with me. Cordially, Bob Blaine Senior Reloading Technician Hello James,

You should be okay with loading this way if you are primarily loading the rifle as a single shot. If this is a concern for you personally, or you prefer to have more of the bullet in the case, you can always seat the bullet deeper. What you would do is to start at the depth that you select and then use that as your baseline. I like to shoot at least two, three shot groups to establish what the rifle will show us. You would then set the bullet back at regular intervals, while shooting two more three shot groups, to see what happens to the groups. At some point, you will see groups either opening up, or getting smaller. We are using the bullet as a weight to tune for the barrel vibrations, and the laws of physics do not care it we move the bullet closer to the rifling, or further out from the rifling. What the goal is to set the seating depth to a setting that allows the bullet to leave the muzzle at the same point that the swing of the vibration comes to a stop, at that instant, every time. This is why seating depth is such a critical dimension for consistent accuracy of our firearms.

When working toward this goal, I will always use a safe powder charge. If I am using a chronograph, I will usually look for a safe load that gives the smallest SD figure, and as long as I am satisfied that I am working within safe load limits, I will then start working with the seating depth. This is the same procedure that I have used for setting up our team bench rest 6PPC rifle, and I will use it for my personal rifles as well. If you do not have access to a chronograph, then I would recommend using the load data that you have, and work within listed loads that are showing as safe in your rifle.

If we can be of further service, or you have additional questions, please do not hesitate to get back in touch with me.

Cordially,

Bob Blaine
Senior Reloading Technician

]]> By: admin http://blog.sinclairintl.com/2009/03/26/determining-bullet-seating-depth/comment-page-1/#comment-10437 admin Mon, 11 Apr 2011 19:22:22 +0000 http://blog.sinclairintl.com/?p=147#comment-10437 Hello Art, The starting load is generally safe to use with the bullets up just touching the lands. I do not see any problems with this at all. To be able to determine how far you need to be to touch the lands, the use of the 59-4000 Sinclair OAL tool will allow you to determine this. Once you have determined this, you can then log this into your reloading log for future reference for loading that particular bullet in the future. Cordially, Bob Blaine Senior Reloading Technician Hello Art,

The starting load is generally safe to use with the bullets up just touching the lands. I do not see any problems with this at all. To be able to determine how far you need to be to touch the lands, the use of the 59-4000 Sinclair OAL tool will allow you to determine this. Once you have determined this, you can then log this into your reloading log for future reference for loading that particular bullet in the future.

Cordially,

Bob Blaine
Senior Reloading Technician

]]> By: Art Dominguez http://blog.sinclairintl.com/2009/03/26/determining-bullet-seating-depth/comment-page-1/#comment-8472 Art Dominguez Wed, 23 Feb 2011 03:18:27 +0000 http://blog.sinclairintl.com/?p=147#comment-8472 To Bob Blaine, I am a first time reloader. I have a Savage 10fp .308, I am using a Lee Challenger loader as well as the Lees Modern Reloader, I am interested in using Serria Matchking 150 grain HPBT bullet with CCI large rifle primers and federal fire formed cases. Load data asked for starting load Varget, 42grains, OAL 2.8" for max load. How can I measure the distance from the lands, once that is determined, will the starting load data 42grains and 2.8" OAL be safe? thanks, Art To Bob Blaine,

I am a first time reloader. I have a Savage 10fp .308, I am using a Lee Challenger loader as well as the Lees Modern Reloader, I am interested in using Serria Matchking 150 grain HPBT bullet with CCI large rifle primers and federal fire formed cases. Load data asked for starting load Varget, 42grains, OAL 2.8″ for max load. How can I measure the distance from the lands, once that is determined, will the starting load data 42grains and 2.8″ OAL be safe?
thanks,
Art

]]>