would like to know the pros and cons of the lee factory crimp die
canuck4570 said:would like to know the pros and cons of the lee factory crimp die
2506 said:I shoot a lot of old military rifles and they have looooooog throats. No way to get close to the lands and still work through the magazine. I have found that the use of the Lee Factory Crimp Die really increases accuracy over rounds not crimped for me. It also improved accuracy in my AR and M1 Garand. Even heavy crimps on match bullets DID NOT ADVERSELY EFFECT ACCURACY.
The Lee Factory Crimp Die for pistol round is great. It makes for almost no malfunctioning problems in semi-autos for me.
jlow said:2506 said:I shoot a lot of old military rifles and they have looooooog throats. No way to get close to the lands and still work through the magazine. I have found that the use of the Lee Factory Crimp Die really increases accuracy over rounds not crimped for me. It also improved accuracy in my AR and M1 Garand. Even heavy crimps on match bullets DID NOT ADVERSELY EFFECT ACCURACY.
The Lee Factory Crimp Die for pistol round is great. It makes for almost no malfunctioning problems in semi-autos for me.
Ok, but has anyone actually done a study to test whether it affects ES and/or SDEV which to me is different than accuracy at least in terms of what is normally done i.e. at 100 yards? It seems that a Lee crimp will likely change the diameter of the bullet bearing surface at least the area inside the case. Not making a judgement call as to whether this is good or bad but asking whether someone has actually done a through study and what are the results?
jlow said:Thanks! An interesting study. Not quite sure what that first set of numbers are , not labeled? The N-size of the study is pretty small (5) and at least looking at the three main numbers – average MV, ES, and SD, does not seem to have any significant effect one way or the other – thanks!
steve4102 said:jlow said:Thanks! An interesting study. Not quite sure what that first set of numbers are , not labeled? The N-size of the study is pretty small (5) and at least looking at the three main numbers – average MV, ES, and SD, does not seem to have any significant effect one way or the other – thanks!
From the test.
I loaded 50 identical rounds for each rifle, 25 of which were crimped and 25 were left without crimps. I tried to put a reasonably heavy crimp on, although none of the bullets had a crimp groove. I fired all of the them as 5 shot groups, over an OEHLER Model 43 PBL.[/i
The test size was 25 rounds crimped and 25 rounds not crimped for each cartridge for a total of 50 rounds per cartridge.
The first numbers are group size for five rounds. In the 223 un-crimped five shot group 1 measured .523 inches, Group 2 .596 inches etc. for a 25 round average of .618 inches.
steve4102 said:jlow said:Thanks! An interesting study. Not quite sure what that first set of numbers are , not labeled? The N-size of the study is pretty small (5) and at least looking at the three main numbers – average MV, ES, and SD, does not seem to have any significant effect one way or the other – thanks!
From the test.
I loaded 50 identical rounds for each rifle, 25 of which were crimped and 25 were left without crimps. I tried to put a reasonably heavy crimp on, although none of the bullets had a crimp groove. I fired all of the them as 5 shot groups, over an OEHLER Model 43 PBL.
The test size was 25 rounds crimped and 25 rounds not crimped for each cartridge for a total of 50 rounds per cartridge.
The first numbers are group size for five rounds. In the 223 un-crimped five shot group 1 measured .523 inches, Group 2 .596 inches etc. for a 25 round average of .618 inches.
jlow said:2506 said:I shoot a lot of old military rifles and they have looooooog throats. No way to get close to the lands and still work through the magazine. I have found that the use of the Lee Factory Crimp Die really increases accuracy over rounds not crimped for me. It also improved accuracy in my AR and M1 Garand. Even heavy crimps on match bullets DID NOT ADVERSELY EFFECT ACCURACY.
The Lee Factory Crimp Die for pistol round is great. It makes for almost no malfunctioning problems in semi-autos for me.
Ok, but has anyone actually done a study to test whether it affects ES and/or SDEV which to me is different than accuracy at least in terms of what is normally done i.e. at 100 yards? It seems that a Lee crimp will likely change the diameter of the bullet bearing surface at least the area inside the case. Not making a judgement call as to whether this is good or bad but asking whether someone has actually done a through study and what are the results?
Did you write that article?