albinomonki
12-17-2011, 11:33 PM
Greetings community,
I've been a lurker for a few months now. Haven't had too much to contribute beyond the wealth of knowledge already here. However, today I went out and performed, what I’ll call my take on, an OCW method test. This time I got some interesting results I think. I decided instead of trying to interpret it myself, which does not always seem to work out perfectly, I would pool the vast resources of this forum and ask for any and all opinions and advice you can offer.
I put “intro” in the subject as this is my first post here so a bit about me: Grew up in MA shooting BB guns. I am now a PA resident and can finally fully enjoy owning and shooting firearms. In the last year I started reloading and shooting IDPA and am now chasing bugholes with my .223--- my white buffalo, but I certainly enjoy pulling my hair out, kicking myself, chasing the unobtainable, and an endless challenge. What could be more entertaining?
In order to keep this post manageable I’ll save you all some reading and get to my question. If you need more info about rifle, loading techniques, etc, I’ve included it at the end of this post. Without further adieu… My testing procedure: I loaded (10) 3-rnd groups, increasing powder charge by 0.2grns between each group. Feeling adventurous because my COL is so much greater than the book value, I started at a medium charge according to Lyman and Hornady so that I could hit the Lyman accurate load, which is also their max charge weight.
Firing Process: In order to minimize barrel fouling variables, I sprayed barrel with ballistol and ran boresnake through 5 times. I then fired 5 factory rounds to see if POI settled down as well as determine firing rate for temperature to have relatively consistent barrel temp for each shot. This first image shows my 5 factory rounds in the top left fired first. The center image shows my pre test sight-in. Where I then fired 3 out of 6 reloads that I whipped through the progressive in order to get close to target with this bullet/case/powder combo. First round was low, adjusted 3 clicks up (1/4 MOA /click) next two rounds hit low bull. Begin OCW test.
http://farm8.staticflickr.com/7024/6528346673_23bb790785_z.jpg
The following image is a composite I made of the OCW (optimum charge weight for anyone wondering) groups. These groups were fired in a round robin, with ~1 – 2 min between rounds depending on how long it took me to completely rebuild firing position after single-loading the next round. These were all shot on a bench, with harris bipod front rest, and rear squeeze sock. I was wearing 4 layers on torso and gloves.
(CAVEAT: If there is one thing I can contribute it is a rear sand-sock that has been working really well for me. I just took a nice wool sock and filled it with brown lentils. It has been working great, nice and smooth hold and the lentils are far lighter than sand and do not escape thru the sock. The shape of them also seems to work really well in supporting the butt of the rifle. Give it a shot, worth a try in a pinch.)
http://farm8.staticflickr.com/7034/6528758373_c02993070b_b.jpg
I do everything in my power to try and be consistent with my shooting, but of course I’m sure there is still some piloting issues. But I figure, “if this is how I’m gonna shoot, might as well get some practice while I test. Who cares if all my data is erroneous?” I’m only partially kidding when I say that. I hope that the results of this test and my control groups can illustrate that I’m a decent enough shot to at least have a hope and a prayer at figuring some of this out. I guess now is as good a time as any to say that I don’t have a chrono, so my apologies, I cannot give you velo data or SDs at this time.
The main reason I was inspired to post this was because of some of the unique patterns I saw in the groups. I won’t go too far into what I see because the main purpose of this post is to get your input, however some things just jump off the page for me. Vertical on groups 4, 7, 8 with the horizontal of 5 in between !?! Very similar pattern on groups 1 & 6 with ~0.5” elevation change? Almost perfect doubles plus fliers on 8 & 9. FYI, round 1 of the tenth group exhibited pressure signs I was not a fan of and did not continue to shoot them. Even if it were accurate I would not want to shoot that regularly in my rifle, so it’s moot.
I’ve also included some overlays, mostly for fun, although it was neat to assemble. The bottom left two targets are a compilation of all shots fired. The leftmost one I’ve erased all outlines as if they were fired on as single group. The second from the left shows the outlines of the bullet holes. The bottom two right targets show the groups 1-4 and 5-7, respectively. While the aggregate is an OK group, I’m still looking for a single hole. Perhaps I need to dump some more money into this rig and/or tighten up my reloading skills.
After the 9 groups were fired, I fired 3 more of the 24 gr loads at the center target of the first image to confirm that accuracy did not go to heck due to a fouled barrel. They were still very near the first 2 post-sighter shots. Finally, I shot 5 more rounds of the factory BHA to re-confirm that fouling was not a problem and to prove to myself that after 2 hours my shooting didn’t go to hell in a handbasket. Aslo, FWIW, the final rounds in the top right target of the first image were loaded in magazine and fired as fast as I could, under 20 seconds.
Well, I apologize for the extremely long post. I look forward to hearing what you guys have to say. And thought that at least maybe someone would be entertained in a cruel, sick, twisted way in my results as I am.
Thanks in advance for your help and reading the obnoxiously long post, I really enjoy this forum, I don’t have a flame suit but I do have access to one rated for 50KVA,
Andy
About the stick: Savage 10 FCP, .223 Rem, almost completely stock, riding in a Choate tactical stock, slight trigger clean up (by me), harris bipod, Hawk 6.5-20 x42mm Optic. Approx 300 rnds through factory 1:9” twist varmit contour 24” bbl. Action/barrel has been removed from stock once to clean up trigger. Action screws re-tightened hand tight in increments to attempt even torque; I do not have a torque rench—this is not an accustock, think this one is as picky about torque as the accustock? Action is pillar-bedded and appears to have very solid bedding contact.
…because I know it doesn’t count if there aren’t pics ;) (this was not the day of test but during the freak Oct. snow storm)
http://farm8.staticflickr.com/7026/6529000461_20bd7bff4d_b.jpg
About the rounds: 69gr Nosler Custom Competition BTHPs in Black Hills Ammo reloaded cases. FL resized, trimmed to length, chamfered, deburred, primer pocket cleaned, flash hole deburred, neck brushed, and weight sorted so that all 3 rnd groups are within 0.1 grn. Primers and bullets NOT weight sorted.
Rounds loaded on RCBS progressive press w/ standard RCBS dies. No crimp. Run through press one by one i.e. used as a single stage. Primed cases are tared on scale, charge is dropped from uniflow measure, then weighted on a cabela’s electronic scale in case. I’m meticulous in gauging/avoiding the scale’s drift, sometimes re-weighing charges 4-7 times while re-zeroing scale.
COL is determined with Hornady gauge off ogive to be 0.002” – 0.003” back from where bullet hits in chamber/barrel. I don’t want to say the lands because when I pull the bullet from the rifle I do not see marks from the lands.
I've been a lurker for a few months now. Haven't had too much to contribute beyond the wealth of knowledge already here. However, today I went out and performed, what I’ll call my take on, an OCW method test. This time I got some interesting results I think. I decided instead of trying to interpret it myself, which does not always seem to work out perfectly, I would pool the vast resources of this forum and ask for any and all opinions and advice you can offer.
I put “intro” in the subject as this is my first post here so a bit about me: Grew up in MA shooting BB guns. I am now a PA resident and can finally fully enjoy owning and shooting firearms. In the last year I started reloading and shooting IDPA and am now chasing bugholes with my .223--- my white buffalo, but I certainly enjoy pulling my hair out, kicking myself, chasing the unobtainable, and an endless challenge. What could be more entertaining?
In order to keep this post manageable I’ll save you all some reading and get to my question. If you need more info about rifle, loading techniques, etc, I’ve included it at the end of this post. Without further adieu… My testing procedure: I loaded (10) 3-rnd groups, increasing powder charge by 0.2grns between each group. Feeling adventurous because my COL is so much greater than the book value, I started at a medium charge according to Lyman and Hornady so that I could hit the Lyman accurate load, which is also their max charge weight.
Firing Process: In order to minimize barrel fouling variables, I sprayed barrel with ballistol and ran boresnake through 5 times. I then fired 5 factory rounds to see if POI settled down as well as determine firing rate for temperature to have relatively consistent barrel temp for each shot. This first image shows my 5 factory rounds in the top left fired first. The center image shows my pre test sight-in. Where I then fired 3 out of 6 reloads that I whipped through the progressive in order to get close to target with this bullet/case/powder combo. First round was low, adjusted 3 clicks up (1/4 MOA /click) next two rounds hit low bull. Begin OCW test.
http://farm8.staticflickr.com/7024/6528346673_23bb790785_z.jpg
The following image is a composite I made of the OCW (optimum charge weight for anyone wondering) groups. These groups were fired in a round robin, with ~1 – 2 min between rounds depending on how long it took me to completely rebuild firing position after single-loading the next round. These were all shot on a bench, with harris bipod front rest, and rear squeeze sock. I was wearing 4 layers on torso and gloves.
(CAVEAT: If there is one thing I can contribute it is a rear sand-sock that has been working really well for me. I just took a nice wool sock and filled it with brown lentils. It has been working great, nice and smooth hold and the lentils are far lighter than sand and do not escape thru the sock. The shape of them also seems to work really well in supporting the butt of the rifle. Give it a shot, worth a try in a pinch.)
http://farm8.staticflickr.com/7034/6528758373_c02993070b_b.jpg
I do everything in my power to try and be consistent with my shooting, but of course I’m sure there is still some piloting issues. But I figure, “if this is how I’m gonna shoot, might as well get some practice while I test. Who cares if all my data is erroneous?” I’m only partially kidding when I say that. I hope that the results of this test and my control groups can illustrate that I’m a decent enough shot to at least have a hope and a prayer at figuring some of this out. I guess now is as good a time as any to say that I don’t have a chrono, so my apologies, I cannot give you velo data or SDs at this time.
The main reason I was inspired to post this was because of some of the unique patterns I saw in the groups. I won’t go too far into what I see because the main purpose of this post is to get your input, however some things just jump off the page for me. Vertical on groups 4, 7, 8 with the horizontal of 5 in between !?! Very similar pattern on groups 1 & 6 with ~0.5” elevation change? Almost perfect doubles plus fliers on 8 & 9. FYI, round 1 of the tenth group exhibited pressure signs I was not a fan of and did not continue to shoot them. Even if it were accurate I would not want to shoot that regularly in my rifle, so it’s moot.
I’ve also included some overlays, mostly for fun, although it was neat to assemble. The bottom left two targets are a compilation of all shots fired. The leftmost one I’ve erased all outlines as if they were fired on as single group. The second from the left shows the outlines of the bullet holes. The bottom two right targets show the groups 1-4 and 5-7, respectively. While the aggregate is an OK group, I’m still looking for a single hole. Perhaps I need to dump some more money into this rig and/or tighten up my reloading skills.
After the 9 groups were fired, I fired 3 more of the 24 gr loads at the center target of the first image to confirm that accuracy did not go to heck due to a fouled barrel. They were still very near the first 2 post-sighter shots. Finally, I shot 5 more rounds of the factory BHA to re-confirm that fouling was not a problem and to prove to myself that after 2 hours my shooting didn’t go to hell in a handbasket. Aslo, FWIW, the final rounds in the top right target of the first image were loaded in magazine and fired as fast as I could, under 20 seconds.
Well, I apologize for the extremely long post. I look forward to hearing what you guys have to say. And thought that at least maybe someone would be entertained in a cruel, sick, twisted way in my results as I am.
Thanks in advance for your help and reading the obnoxiously long post, I really enjoy this forum, I don’t have a flame suit but I do have access to one rated for 50KVA,
Andy
About the stick: Savage 10 FCP, .223 Rem, almost completely stock, riding in a Choate tactical stock, slight trigger clean up (by me), harris bipod, Hawk 6.5-20 x42mm Optic. Approx 300 rnds through factory 1:9” twist varmit contour 24” bbl. Action/barrel has been removed from stock once to clean up trigger. Action screws re-tightened hand tight in increments to attempt even torque; I do not have a torque rench—this is not an accustock, think this one is as picky about torque as the accustock? Action is pillar-bedded and appears to have very solid bedding contact.
…because I know it doesn’t count if there aren’t pics ;) (this was not the day of test but during the freak Oct. snow storm)
http://farm8.staticflickr.com/7026/6529000461_20bd7bff4d_b.jpg
About the rounds: 69gr Nosler Custom Competition BTHPs in Black Hills Ammo reloaded cases. FL resized, trimmed to length, chamfered, deburred, primer pocket cleaned, flash hole deburred, neck brushed, and weight sorted so that all 3 rnd groups are within 0.1 grn. Primers and bullets NOT weight sorted.
Rounds loaded on RCBS progressive press w/ standard RCBS dies. No crimp. Run through press one by one i.e. used as a single stage. Primed cases are tared on scale, charge is dropped from uniflow measure, then weighted on a cabela’s electronic scale in case. I’m meticulous in gauging/avoiding the scale’s drift, sometimes re-weighing charges 4-7 times while re-zeroing scale.
COL is determined with Hornady gauge off ogive to be 0.002” – 0.003” back from where bullet hits in chamber/barrel. I don’t want to say the lands because when I pull the bullet from the rifle I do not see marks from the lands.