Post by GLSHOOTER on May 5, 2011 12:17:42 GMT -8
I am going to post a series of tests I have done on the Consistent Crimp Tool that involved loading and shooting a series of groups with the only variation in the ammunition being the amount of crimp pressure applied with a Lee Factory Crimp Die.
These studies involved three separate rifles. The first was an SPS Varmint in 223, the second was a 243 BDL and the third was a stock AR 15 kit gun. I think that the data presented may be of interest to the board members. I warn you up front that these are pic heavy and that as long as they are I will have to add some each day. These are stock rifles with nothing done other than to adjust the trigger and to mount a target scope for shooting the groups.
I will try and make them coherent but this is a cut and paste effort from my previously posted data so if I lose anyone please feel free to chime in. If you think the work up was worthless don't hesitate to let me know how you would have changed up the test. You can make your own evaluation of the data as there will be plenty to look over.
That being said I'll get started. The first test was done in August of 2010.
I received the Consistent Crimp hardware from Precision Accuracy about 10 days ago. I borrowed an RCBS Ammo Master press for the trials as I while I own eight presses they are all progressive and I had nothing that was adaptable at that point. I wandered down to Cabela’s and picked up a Lee FCD die in 233.
I wanted to use a small cartridge for the first batch so I chose a Remington SPS 223 Varmint with about 100 rounds through it. I went to the books and evaluated load data and what I had on the shelf and decided on 25.1 grains of X-Terminator powder. Cases were all once fired Winchester commercial sized to 0.000 SAAMI specs and trimmed to 1.750, primers were Remington 7 1/2's and the COL was set at 2.255. This rifle is a shooter and the 100 yard distance does not lend itself to huge variation so knew this would be a challenge. I put a 24 X Leupold target scope on the rifle for the testing shooting off a concrete bench with the use of a very cheap front rest and some plastic bean filled rear bags.
Packaging on the wrench and temperature gauge was nice.
Instructions were adequate for assembly of the set up on to the press. The videos on the site also were helpful. The adapter needs to be threaded in to the press handle area by design. The Ammo Master that I borrowed has a smooth handle hole and is not threaded. Needles to say that was NOT GOOD!!
Being that I am the impatient type and wanted to use what I had on hand I chatted with Scott via PM and the phone. I took some measurements of the hole and found they were larger than the adapter. On a whim I screwed the tension nut for the adapter all the way to the top and put the adapter in the hole. There were a few threads left sticking out the bottom so I put on another nut and sucked it up tight in to the hole. Nice and tight we were ROCKIN!!!
I processed and loaded the ammo using a Dillon 650 and used a Sinclair expander mandrel to drop the neck tension on the sized case as much as possible yet still prevented the bullets from just sliding through the case necks. The wrench proved easy to use and I can tell you that 5 FT. lbs. is not much!! I loaded up ammo in five ft. lb. increments from 0 to 50 in groups of ten. I only loaded five of the 50's as that is a heck of a lot of pressure!!
The goal is to place groups on the target so one can review the results of varying crimp pressure. That means that you want a grid system for easy reference. I found some targets with a one inch grid, from MYTARGETS.com, for visual assessment as well as measuring them out. I wanted to eliminate any performance issues so I put a Leupold 24X target scope on the SPS.
Of course a scope change means a sight in was necessary so off I went in a balmy 109 degree temperature!! I had some OLD ammo I loaded up for my AR in 1994 with good 52 grain bullets and shot some sighters. Two rounds at 25 had me dialed in close and I moved out to 100 yards. The next group fired ran a bit under an MOA. I then fired some 40 grain VMAX that I had loaded for a different rifle on my last PD trip. Once I got settled in the rifle shot some nice groups and I found I had acceptable PD load with those bullets.
Since I intended to showcase the groups later I adjusted my scope to throw the bullets out into the non-aiming point of the target that would translate over when I evaluated the groups and allow for visual feedback as they were formed as I went for record. That worked well and I shot two, one four and one five shot, groups with the test ammo and no crimp for a baseline sight in. The rifle likes the load but still leaves room for improvement.
These are the targets that I shot that were loaded using the Consistent Crimp equipment.
These are the groups fired with the pertinent data. If you notice there seemed to be one that drifts off in several of the groups. Now you can say it's the CC at work or you can figure it's the twitchy finger of an old man at the bench. I know that I have always been able to hold four shots but that fifth one is always the bugger!!
The chrono data is shown shot to shot. These were all thrown charges on the Dillon 650 as all processes except crimping was done on it. BY and large the velocity spreads were pretty consistent except on the 25 FT/LB level. There seemed to be a wide swing that I believe was an anomaly for this test.
So here we go with the targets!!!!
Chronograph data and other information:
Looking over the groups I feel like the best four is indicative of what is going on. I looked at the chronograph numbers as I shot these and while you do see deviation in velocity the bullet impact from shot to shot from high to low never showed any correlation. The + or - of the standard deviation of the rounds still showed good grouping even though velocities did vary somewhat.
The baseline no pressure group was 0.518 with the best of four the same. Over the test looking at the best four shot groups you can see that the group was improved in five of the nine shot with pressure. Looking at the final numbers the best group with any pressure was shot at 5 FT/LBS and looking at the four shot group numbers a surprising result with the 50 FT/LBS was noted. You can see things opening up and closing as the pressure moves.
Notice that barrel temperature for each shot is to the right of the velocity readings. Barrel temp for the start of each group is directly above the set. I shot ten rounds at each level making two five shot groups and threw out the worst target in the batch as the conditions with the heat and wind were not ideal.
The data was shot over about 12 hours at the range as it takes a bit of time for the barrel to cool off. I know that I shoot a better set of targets if I just plop down and do them back to back. Shooting five and waiting 15 minutes is not conducive to my hyperactivity issues!!
Given that a guy can trickle charge his cases if he is going for the gusto the SD can be cut down quite a bit. Looking over the SD's presented you can see that the gold standard of single digit numbers was never obtained but in looking at on target results that a jump up or down did not always equate to improvement or degradation on the targets.
A good shooter, of which I am not, could really squeeze the benefit out of this tool IMHO. As I mentioned these were thrown charges. Many guys don't trickle and without benefit of a chronograph shoot some surprising groups both ways. Tools just help expand the knowledge base and can, at times, raise many questions and challenges.
Ideally with this rifle the range should be stretched out to 200 yards to really let the CC do it's thing. The short range does not really bring to light what the true potential of this set up when illustrated with a rifle that should be a tack driver from the get go. I see so much promise in the tool that I am going to pursue it in the future. In fact, I felt so strongly about this that I actually BOUGHT a Rock Chucker Supreme for my bench. This is the ONLY single stage press I will have had in use since 1977 on my bench!!
I hope this information is useful to the shooting public. Feel free to comment about what you see and if you feel the urge it's OK to rag on my lack of shooting ability. Maybe someday I'll buy one of those fancy rifle sleds and take the nut out of the equation. If you care to follow along I will be posting the results of my next test with a 243 sporter in the near future.
Greg
These studies involved three separate rifles. The first was an SPS Varmint in 223, the second was a 243 BDL and the third was a stock AR 15 kit gun. I think that the data presented may be of interest to the board members. I warn you up front that these are pic heavy and that as long as they are I will have to add some each day. These are stock rifles with nothing done other than to adjust the trigger and to mount a target scope for shooting the groups.
I will try and make them coherent but this is a cut and paste effort from my previously posted data so if I lose anyone please feel free to chime in. If you think the work up was worthless don't hesitate to let me know how you would have changed up the test. You can make your own evaluation of the data as there will be plenty to look over.
That being said I'll get started. The first test was done in August of 2010.
I received the Consistent Crimp hardware from Precision Accuracy about 10 days ago. I borrowed an RCBS Ammo Master press for the trials as I while I own eight presses they are all progressive and I had nothing that was adaptable at that point. I wandered down to Cabela’s and picked up a Lee FCD die in 233.
I wanted to use a small cartridge for the first batch so I chose a Remington SPS 223 Varmint with about 100 rounds through it. I went to the books and evaluated load data and what I had on the shelf and decided on 25.1 grains of X-Terminator powder. Cases were all once fired Winchester commercial sized to 0.000 SAAMI specs and trimmed to 1.750, primers were Remington 7 1/2's and the COL was set at 2.255. This rifle is a shooter and the 100 yard distance does not lend itself to huge variation so knew this would be a challenge. I put a 24 X Leupold target scope on the rifle for the testing shooting off a concrete bench with the use of a very cheap front rest and some plastic bean filled rear bags.
Packaging on the wrench and temperature gauge was nice.
Instructions were adequate for assembly of the set up on to the press. The videos on the site also were helpful. The adapter needs to be threaded in to the press handle area by design. The Ammo Master that I borrowed has a smooth handle hole and is not threaded. Needles to say that was NOT GOOD!!
Being that I am the impatient type and wanted to use what I had on hand I chatted with Scott via PM and the phone. I took some measurements of the hole and found they were larger than the adapter. On a whim I screwed the tension nut for the adapter all the way to the top and put the adapter in the hole. There were a few threads left sticking out the bottom so I put on another nut and sucked it up tight in to the hole. Nice and tight we were ROCKIN!!!
I processed and loaded the ammo using a Dillon 650 and used a Sinclair expander mandrel to drop the neck tension on the sized case as much as possible yet still prevented the bullets from just sliding through the case necks. The wrench proved easy to use and I can tell you that 5 FT. lbs. is not much!! I loaded up ammo in five ft. lb. increments from 0 to 50 in groups of ten. I only loaded five of the 50's as that is a heck of a lot of pressure!!
The goal is to place groups on the target so one can review the results of varying crimp pressure. That means that you want a grid system for easy reference. I found some targets with a one inch grid, from MYTARGETS.com, for visual assessment as well as measuring them out. I wanted to eliminate any performance issues so I put a Leupold 24X target scope on the SPS.
Of course a scope change means a sight in was necessary so off I went in a balmy 109 degree temperature!! I had some OLD ammo I loaded up for my AR in 1994 with good 52 grain bullets and shot some sighters. Two rounds at 25 had me dialed in close and I moved out to 100 yards. The next group fired ran a bit under an MOA. I then fired some 40 grain VMAX that I had loaded for a different rifle on my last PD trip. Once I got settled in the rifle shot some nice groups and I found I had acceptable PD load with those bullets.
Since I intended to showcase the groups later I adjusted my scope to throw the bullets out into the non-aiming point of the target that would translate over when I evaluated the groups and allow for visual feedback as they were formed as I went for record. That worked well and I shot two, one four and one five shot, groups with the test ammo and no crimp for a baseline sight in. The rifle likes the load but still leaves room for improvement.
These are the targets that I shot that were loaded using the Consistent Crimp equipment.
These are the groups fired with the pertinent data. If you notice there seemed to be one that drifts off in several of the groups. Now you can say it's the CC at work or you can figure it's the twitchy finger of an old man at the bench. I know that I have always been able to hold four shots but that fifth one is always the bugger!!
The chrono data is shown shot to shot. These were all thrown charges on the Dillon 650 as all processes except crimping was done on it. BY and large the velocity spreads were pretty consistent except on the 25 FT/LB level. There seemed to be a wide swing that I believe was an anomaly for this test.
So here we go with the targets!!!!
Chronograph data and other information:
Looking over the groups I feel like the best four is indicative of what is going on. I looked at the chronograph numbers as I shot these and while you do see deviation in velocity the bullet impact from shot to shot from high to low never showed any correlation. The + or - of the standard deviation of the rounds still showed good grouping even though velocities did vary somewhat.
The baseline no pressure group was 0.518 with the best of four the same. Over the test looking at the best four shot groups you can see that the group was improved in five of the nine shot with pressure. Looking at the final numbers the best group with any pressure was shot at 5 FT/LBS and looking at the four shot group numbers a surprising result with the 50 FT/LBS was noted. You can see things opening up and closing as the pressure moves.
Notice that barrel temperature for each shot is to the right of the velocity readings. Barrel temp for the start of each group is directly above the set. I shot ten rounds at each level making two five shot groups and threw out the worst target in the batch as the conditions with the heat and wind were not ideal.
The data was shot over about 12 hours at the range as it takes a bit of time for the barrel to cool off. I know that I shoot a better set of targets if I just plop down and do them back to back. Shooting five and waiting 15 minutes is not conducive to my hyperactivity issues!!
Given that a guy can trickle charge his cases if he is going for the gusto the SD can be cut down quite a bit. Looking over the SD's presented you can see that the gold standard of single digit numbers was never obtained but in looking at on target results that a jump up or down did not always equate to improvement or degradation on the targets.
A good shooter, of which I am not, could really squeeze the benefit out of this tool IMHO. As I mentioned these were thrown charges. Many guys don't trickle and without benefit of a chronograph shoot some surprising groups both ways. Tools just help expand the knowledge base and can, at times, raise many questions and challenges.
Ideally with this rifle the range should be stretched out to 200 yards to really let the CC do it's thing. The short range does not really bring to light what the true potential of this set up when illustrated with a rifle that should be a tack driver from the get go. I see so much promise in the tool that I am going to pursue it in the future. In fact, I felt so strongly about this that I actually BOUGHT a Rock Chucker Supreme for my bench. This is the ONLY single stage press I will have had in use since 1977 on my bench!!
I hope this information is useful to the shooting public. Feel free to comment about what you see and if you feel the urge it's OK to rag on my lack of shooting ability. Maybe someday I'll buy one of those fancy rifle sleds and take the nut out of the equation. If you care to follow along I will be posting the results of my next test with a 243 sporter in the near future.
Greg
