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Post by guncollector on Dec 17, 2011 23:51:49 GMT -8
I have been reloading for over 40 years but I guess I have been what the precision shooters and reloaders call a hobby reloader. Since I have retired I have become interested in getting to the next level in reloading.
I just put together an AR in 6X45 with a BHW barrel so I decided I would try to produce some high quality ammo. I have several thousand PMP 223 cases so I decided to give them a try. I took 500 cases and sized them in the 6x45 sizer die and carefully trimmed them all to exactly the same length. Then I thought I should pay some attention to the flash holes. I bought a flash hole deburring tool and a flash hole reaming tool form Sinclair's. When I started reaming the flash holes to make sure they were all uniform I noticed that about 10% of the cases had slightly off center flash holes. It was hard to see with the naked eye but was easy to spot using the reaming tool. This finally brings me to my series of questions which I hope some of you precision reloaders can answer for me. First, should I even be using PMP brass? It seems to be good quality other than 10% of them having off center flash holes. The weight of the cases is consistent. My second question is how are the flash holes put in the case and how can it be done off center? Last but not least, what effect do off center flash holes have on accuracy?
Any help form you accuracy experts out there will be greatly appreciated.
Bob
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Post by GLSHOOTER on Dec 18, 2011 10:50:03 GMT -8
I have been reloading for over 40 years but I guess I have been what the precision shooters and reloaders call a hobby reloader. Since I have retired I have become interested in getting to the next level in reloading. I just put together an AR in 6X45 with a BHW barrel so I decided I would try to produce some high quality ammo. I have several thousand PMP 223 cases so I decided to give them a try. I took 500 cases and sized them in the 6x45 sizer die and carefully trimmed them all to exactly the same length. Then I thought I should pay some attention to the flash holes. I bought a flash hole deburring tool and a flash hole reaming tool form Sinclair's. When I started reaming the flash holes to make sure they were all uniform I noticed that about 10% of the cases had slightly off center flash holes. It was hard to see with the naked eye but was easy to spot using the reaming tool. This finally brings me to my series of questions which I hope some of you precision reloaders can answer for me. First, should I even be using PMP brass? It seems to be good quality other than 10% of them having off center flash holes. The weight of the cases is consistent. My second question is how are the flash holes put in the case and how can it be done off center? Last but not least, what effect do off center flash holes have on accuracy? Any help form you accuracy experts out there will be greatly appreciated. Bob Interesting issue. I'll give you my thoughts. I have used very little PMP brass over the years. I just have access to more of the Win/R-P, FED stuff and just throw it in the blasting ammo bucket. Just my personal thing. If I had bunch of it I would certainly use it but probably not if I wanted to "match" prep it. The flash holes are punched and that is why you get the burrs up inside the case. The good guys like Lapua drill theirs so the burrs just don't happen. I figure they form the case and primer pocket then run the brass through a punch set up for the holes. I would imagine QC is not the strong point on that operation. I don't think that any of us will recognize a group influence with the of center flash holes in these particular rifles. Perhaps Ritch can chime in as while I am decent he IS a world class BR guy and will be able to speak intelligently to this issue. Greg PS: Welcome to the quest for bug holes!!  |
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Post by Deleted on Dec 18, 2011 14:22:52 GMT -8
I have been reloading for over 40 years but I guess I have been what the precision shooters and reloaders call a hobby reloader. Since I have retired I have become interested in getting to the next level in reloading. I just put together an AR in 6X45 with a BHW barrel so I decided I would try to produce some high quality ammo. I have several thousand PMP 223 cases so I decided to give them a try. I took 500 cases and sized them in the 6x45 sizer die and carefully trimmed them all to exactly the same length. Then I thought I should pay some attention to the flash holes. I bought a flash hole deburring tool and a flash hole reaming tool form Sinclair's. When I started reaming the flash holes to make sure they were all uniform I noticed that about 10% of the cases had slightly off center flash holes. It was hard to see with the naked eye but was easy to spot using the reaming tool. This finally brings me to my series of questions which I hope some of you precision reloaders can answer for me. First, should I even be using PMP brass? It seems to be good quality other than 10% of them having off center flash holes. The weight of the cases is consistent. My second question is how are the flash holes put in the case and how can it be done off center? Last but not least, what effect do off center flash holes have on accuracy? Any help form you accuracy experts out there will be greatly appreciated. Bob Interesting issue. I'll give you my thoughts. I have used very little PMP brass over the years. I just have access to more of the Win/R-P, FED stuff and just throw it in the blasting ammo bucket. Just my personal thing. If I had bunch of it I would certainly use it but probably not if I wanted to "match" prep it. The flash holes are punched and that is why you get the burrs up inside the case. The good guys like Lapua drill theirs so the burrs just don't happen. I figure they form the case and primer pocket then run the brass through a punch set up for the holes. I would imagine QC is not the strong point on that operation. I don't think that any of us will recognize a group influence with the of center flash holes in these particular rifles. Perhaps Ritch can chime in as while I am decent he IS a world class BR guy and will be able to speak intelligently to this issue. Greg PS: Welcome to the quest for bug holes!! Greg is right. Off center flash holes are more common than people think. Unless you are after everything your rifle will give you and then some, your brass prep technique will be fine. |
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Post by guncollector on Dec 19, 2011 12:07:01 GMT -8
Greg and Ritch,
Thank you both for taking the time to help me. Can either one of you recommend a book that might help me in my quest for very small groups?
Bob
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Post by GLSHOOTER on Dec 19, 2011 12:34:24 GMT -8
Greg and Ritch, Thank you both for taking the time to help me. Can either one of you recommend a book that might help me in my quest for very small groups? Bob Two books. One general top level competition loading for various disciplines: Precision Shooting Reloading Guide Edited by Dave Brennan. Available from Sinclair and Amazon Second book is Handloading for Competition by Glen Zediker. Available from him and Amazon Glen has several books on the AR that are great reading and his work is translatable to actually in the field hunting besides various shooting disciplines. Some don't like his more or less down home writing style but as long as the info is good I have no issues like that. Only hits count and misses don't pay off. Greg |
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Post by Deleted on Dec 19, 2011 12:39:20 GMT -8
There are several books out there. One of the best in my opinion is : The Ultimate In Rifle Accuracy by Glenn Newick. It is geared more to benchrest but contains a lot in information that can be applied to other rifle venues.
If you are after the tightest groups possible, your components are everything. In order of most important first.
#1 Brass: For small groups your brass has to be perfect.
#2 Primers: They have to be seated exactly the same depth to have consistent ignition.
#3 Bullets: Good bullets are a must, but are not as important as the first two. I have shot some impressive groups with bullets look sub par.
#4 Powder: Believe it or not powder has the least to do with short range accuracy. 300 yards or less.
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Post by GLSHOOTER on Dec 19, 2011 13:22:23 GMT -8
You would name the very first true book on accuracy I ever bought. Now I have to go back and reread it!! Thanks for the priority of your components. My forte has always been IPSC matches that at times demanded very good accuracy for the average Joe but never truly challenged the sub-0.5 MOA barrier. Perhaps the realistic expectations on the equipment for once actually took some precedence!!  Greg |
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Post by Deleted on Dec 19, 2011 18:43:16 GMT -8
I have seem PMC brass do that for quite some time. I don't think that it is a huge concern. I am loading with care but not so much for match accuracy and still get sub moa groups pretty consistently with different type of brass and bullets (not in the same strings of course). Sometimes I have time to load for match accuracy, sometimes I don't and still get pretty good results with this nice round. If you want to give it a go find out maximum accuracy potential you might want to consider all the previous great recommendations and also the following but again it depends how far you really want to go in terms of finding out the accuracy potential of your rifle. Get some lapua cases  and for starting segregated LC x1 fired have been great performers for me. Prep the brass. Use this brass once with a mild load in the same chamber. Could be used to brake in and to test accuracy loads but this will not be the actual accuracy test, it is more like fire forming the brass to your chamber. Then is ready to be trimmed to the precise same length, segregate and only neck size, do not full re-size. Make sure you end up with carbon copies for each 1 or 2 strings. Primer pockets must be the same depth and same flash hole. Again the main thing is consistency. Weight the bullets and segregate. You have some pretty decent match bullets that do not need precision swagging. For example 80gr Berger is a top performer in consistency. There are many others. Check for brass thickness and neck tension. Lapua is very consistent. Neck turning might be needed specially with the LC brass. Finally loads must be consistent to one 1/10 of a grain, seating depth, overal length and specially concentricity of the round. A bullet that is not perfectly centered is one of the reasons to ruing all the other work. In the end we wan rounds that are virtually identical. A solid Stand, preferably a Bench REst slider is a pretty good idea. One of those clamp-on sliders is as good as it gets to measure the accuracy potential of a rifle. See if you can borrow one if you do not have one. This might be over doing but I might cancel the gas block or get one of those with a cancel function in the same place and then when I am testing for accuracy potential use single feed. This would be unpractical for normal use AR but for finding out the potential it is a better way. In the end an autoloader cycling and stripping rounds from a magazine is a very violent movement and depending on the round and ramps might throw the concentricity and all the hard work away with it. These are things you might already know better than anyone but anyway I hope there is something here that helps. |
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Post by Deleted on Dec 19, 2011 19:21:11 GMT -8
I have seem PMC brass do that for quite some time. I don't think that it is a huge concern. I am loading with care but not so much for match accuracy and still get sub moa groups pretty consistently with different type of brass and bullets (not in the same strings of course). Sometimes I have time to load for match accuracy, sometimes I don't and still get pretty good results with this nice round. If you want to give it a go find out maximum accuracy potential you might want to consider all the previous great recommendations and also the following but again it depends how far you really want to go in terms of finding out the accuracy potential of your rifle. Get some lapua cases and for starting segregated LC x1 fired have been great performers for me. Prep the brass. Use this brass once with a mild load in the same chamber. Could be used to brake in and to test accuracy loads but this will not be the actual accuracy test, it is more like fire forming the brass to your chamber. Then is ready to be trimmed to the precise same length, segregate and only neck size, do not full re-size. Make sure you end up with carbon copies for each 1 or 2 strings. Primer pockets must be the same depth and same flash hole. Again the main thing is consistency. Weight the bullets and segregate. You have some pretty decent match bullets that do not need precision swagging. For example 80gr Berger is a top performer in consistency. There are many others. Check for brass thickness and neck tension. Lapua is very consistent. Neck turning might be needed specially with the LC brass. Finally loads must be consistent to one 1/10 of a grain, seating depth, overal length and specially concentricity of the round. A bullet that is not perfectly centered is one of the reasons to ruing all the other work. In the end we wan rounds that are virtually identical. A solid Stand, preferably a Bench REst slider is a pretty good idea. One of those clamp-on sliders is as good as it gets to measure the accuracy potential of a rifle. See if you can borrow one if you do not have one. This might be over doing but I might cancel the gas block or get one of those with a cancel function in the same place and then when I am testing for accuracy potential use single feed. This would be unpractical for normal use AR but for finding out the potential it is a better way. In the end an autoloader cycling and stripping rounds from a magazine is a very violent movement and depending on the round and ramps might throw the concentricity and all the hard work away with it. These are things you might already know better than anyone but anyway I hope there is something here that helps. The weight of the bullet will not matter at close range.( Under 300 yards.) As long as they came from the same pointup die. I had to prove this to a fellow benchrest shooter. I had him load 10 rounds, 5 with 68 gr bullets made with .790 length jackets and 5 with 62 gr bullets made with .680 jackets. He kept track of which were 68's and 62's I shot the target, it ended up a .090 the final count was 3 68 gr and 2 62 gr all in the same group. Also this was all done with 52 1/2 clicks of military 8208 out of a Harrell powder measure. So you can also see why powder is at the bottom of the list of components. Remember brass is everything, with out good brass you can not shoot good groups. |
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Post by GLSHOOTER on Dec 19, 2011 20:54:50 GMT -8
Given that the brass is the foundation of accuracy do you think that the abuse that the AR dishes out to this major component almost eliminates the potential of a consistent top level shooter using the same cases over a period of time.
I know that a good BR guy might only use 20 cases in an entire match year but I don't think many AR shooters will live long using 20 cases. I know that I started with 200 Grendels for the LBC and am down to 146 as I type this. Of course I have ruined some working up the loads with the gas block and crushed a mouth or two from not doing the proper adjustments.
I guess what I am saying is if we can get 0.5 MOA or less out of an AR would you consider this a success and not bother burning the barrel out in the quest for CONSISTENT 3's?
Greg
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Post by guncollector on Dec 20, 2011 2:01:31 GMT -8
Greg and Ritch,
Thank you very much for the information and the book recommendations. I have them on order.
1shotzero,
Thank you for your great information.
I think I will see what I can do with the brass I have prepped. Then I will order some Lapua brass and see what I can do with that. This is probably all moot because I am sure my BHW barrel can shoot better that I can but I'll give it my best shot.
Bob
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Post by GLSHOOTER on Dec 20, 2011 9:06:38 GMT -8
Greg and Ritch, Thank you very much for the information and the book recommendations. I have them on order. 1shotzero, Thank you for your great information. I think I will see what I can do with the brass I have prepped. Then I will order some Lapua brass and see what I can do with that. This is probably all moot because I am sure my BHW barrel can shoot better that I can but I'll give it my best shot. Bob My first exposure to Lapua brass was like having an out of body experience.....breath taking!! The good thing is that if you start with BHW quality barrel it will usually be an issue of how well you can hold up your end of the bargain!! Keep us posted. Greg |
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Post by bcspider on Feb 25, 2012 11:22:40 GMT -8
I have never had an issues using brass with the flash hole a little off center.
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Post by joebush on Feb 27, 2012 15:03:18 GMT -8
Awesome information guys, thanks.
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and for starting segregated LC x1 fired have been great performers for me.