Why I Crimp

[Blackhawk]

I finally finished one of the test I wanted to do and here are the results.
This test was conducted at 50 Yards to minimize wind problems that could effect the 30 grain bullet of the 22 WMR. (Gusting up to 20 MPH)

All test were with the best AMMO for my rifle to hopefully get the best test differences.

Factory loadings were very close to the results of the last test without crimping 160 ft/sec difference in velocities compared to 161 ft/sec earlier test.

Crimping was done in a lee FCD with Schell holder I built to hold the 22 WMR without crushing the fragile case.

The first amount of crimp was .004 thousandths smaller than the parent case diameter at the bullet. Group size was .101 (At 50 yards) SD's were 27.9 and velocity stayed close to the factory velocities.

Next was the .007 thousandths crimp. group size went to .377 and SD's up to 31.2 velocity increased by an average of 20 ft/sec.

Then came the .010 thousandths crimp. Group went to .675 and velocity increased by 50 ft/sec.
The interesting thing was that the group POI also shifted1" to the left.

The final test was .012 thousandths and the group opened up to almost .925 and velocity exceeded 2300 ft/sec.

I feel the test was successful in that It did show that different crimps can effect the group, SD's, POI and velocities. It also showed me that .004 to ,006 thousandths crimp appears to be the best performer in accuracy in my rifle.

Now to shoot the rifle at 100 yards to see what it will do.

J E CUSTOM

Totally agree with your last statement, as well as your testing.

 

[West Calamus]

I finally finished one of the test I wanted to do and here are the results.
This test was conducted at 50 Yards to minimize wind problems that could effect the 30 grain bullet of the 22 WMR. (Gusting up to 20 MPH)

All test were with the best AMMO for my rifle to hopefully get the best test differences.

Factory loadings were very close to the results of the last test without crimping 160 ft/sec difference in velocities compared to 161 ft/sec earlier test.

Crimping was done in a lee FCD with Schell holder I built to hold the 22 WMR without crushing the fragile case.

The first amount of crimp was .004 thousandths smaller than the parent case diameter at the bullet. Group size was .101 (At 50 yards) SD's were 27.9 and velocity stayed close to the factory velocities.

Next was the .007 thousandths crimp. group size went to .377 and SD's up to 31.2 velocity increased by an average of 20 ft/sec.

Then came the .010 thousandths crimp. Group went to .675 and velocity increased by 50 ft/sec.
The interesting thing was that the group POI also shifted1" to the left.

The final test was .012 thousandths and the group opened up to almost .925 and velocity exceeded 2300 ft/sec.

I feel the test was successful in that It did show that different crimps can effect the group, SD's, POI and velocities. It also showed me that .004 to ,006 thousandths crimp appears to be the best performer in accuracy in my rifle.

Now to shoot the rifle at 100 yards to see what it will do.

J E CUSTOM

Very good info. So could I extrapolate That a crimp will add more resistance and therefore increase pressure? Something I have often wondered.

 

[J E Custom]

Very good info. So could I extrapolate That a crimp will add more resistance and therefore increase pressure? Something I have often wondered.

Yes It will increase the pressure but the main improvement I saw was consistency/accuracy if the right amount of crimping pressure is used. If you noticed, at some point the accuracy fell off due to to much crimp. It also improves powder burn but that can cause pressure to rise. So start testing the minimum crimp in your rifle should be considered a must.

J E CUSTOM

 

[Tac-O]

Yes It will increase the pressure but the main improvement I saw was consistency/accuracy if the right amount of crimping pressure is used. If you noticed, at some point the accuracy fell off due to to much crimp. It also improves powder burn but that can cause pressure to rise. So start testing the minimum crimp in your rifle should be considered a must.

J E CUSTOM

With your results, it would appear that the more crimp there is, the larger group size becomes.

But, surely that is just because you're keeping all other variables the same. I know at some point it will deform the bullet and very likely decrease accuracy regardless of load parameters. I would think that if you haven't made it to the bullet deformation point, one of the tighter crimp settings could be made more accurate again by altering either seating depth or charge weight.

Thoughts?

 

[West Calamus]

Yes It will increase the pressure but the main improvement I saw was consistency/accuracy if the right amount of crimping pressure is used. If you noticed, at some point the accuracy fell off due to to much crimp. It also improves powder burn but that can cause pressure to rise. So start testing the minimum crimp in your rifle should be considered a must.

J E CUSTOM

Thx JE. Always respect your input. Now I will try to figure out all this roll crimp stuff from old treads posted.

 

[Laguna Freak]

I finally finished one of the test I wanted to do and here are the results.
This test was conducted at 50 Yards to minimize wind problems that could effect the 30 grain bullet of the 22 WMR. (Gusting up to 20 MPH)

All test were with the best AMMO for my rifle to hopefully get the best test differences.

Factory loadings were very close to the results of the last test without crimping 160 ft/sec difference in velocities compared to 161 ft/sec earlier test.

Crimping was done in a lee FCD with Schell holder I built to hold the 22 WMR without crushing the fragile case.

The first amount of crimp was .004 thousandths smaller than the parent case diameter at the bullet. Group size was .101 (At 50 yards) SD's were 27.9 and velocity stayed close to the factory velocities.

Next was the .007 thousandths crimp. group size went to .377 and SD's up to 31.2 velocity increased by an average of 20 ft/sec.

Then came the .010 thousandths crimp. Group went to .675 and velocity increased by 50 ft/sec.
The interesting thing was that the group POI also shifted1" to the left.

The final test was .012 thousandths and the group opened up to almost .925 and velocity exceeded 2300 ft/sec.

I feel the test was successful in that It did show that different crimps can effect the group, SD's, POI and velocities. It also showed me that .004 to ,006 thousandths crimp appears to be the best performer in accuracy in my rifle.

Now to shoot the rifle at 100 yards to see what it will do.

J E CUSTOM

Thanks for posting that. I have a Lee FCD in my .44 Mag/Spl dies. Cant wait to see how it affects bullet flight.

I roll crimp rifle loads and have found variability that I think is determined by bullet material. Eg; Accubond cannot take as much crimp as Scirocco II. Both .308". Accubond in .30-06 and Scirocco II in 300 WSM. Accubond can take about 15 degrees and Scirocco II takes about 22 degrees. Both shoot sub-half moa at 100 and the 06 holds it out to 300 if I do my part. Haven't shot the WSM that far yet as I am still proving the load.

 

[Calvin45]

I know this is going to start the age old battle of crimp or not to crimp and that's not what I'm trying to do so I'm stating "This is why I crimp", This is my opinion so take it for that, I'm just sharing my personal experience and what works for me I am not a competition shooter nor do I claim to be Just a LRH . This is the second time this has happened to me in the past thirty years, the first was an Elk hunt in Oregon where I mailed my rifle and ammo out and then spent a week Horseback and the second time was yesterday, I will tell you that I do not abuse my guns, with that being said I use them for what they are intended for and I do not own anything that hasn't been "Well Used" No safe queens here, Now why I crimp, My Coyote Rig is a Rem 700 in 270 with 90 gr Sierra's, I loaded some rounds last month and got sidetracked and didn't crimp ( I use the Lee FCD on everything I load ) 10 rounds, I just let it go cause I wanted to get in the woods,these were loaded into a 5 rd Magazine two weeks ago, i hunt every evening an twice a day on the weekends 2 to 3 sets a trip and last Saturday my gun slipped off of my shoulder and landed on the Butt stock in a field and didn't hurt anything, fast forward to last night, I shot a ground hog ejected and chambered a new round and while unloading the weapon i saw the bullet in the second round in the mag was gone, upon examination I found the bullet had fell back in to the case, as i said this is the second time this has happened to me and why " I crimp" As for a side note this was 3X fired brass annealed, trimmed and FL resized every loading with a measured .0023 neck tension

Totally unrelated but it sounds like you're an Elmer Kieth disciple...he once disdainfully described the 270 as "a fine coyote round I suppose" .

 

[ButterBean]

Totally unrelated but it sounds like you're an Elmer Kieth disciple...he once disdainfully described the 270 as "a fine coyote round I suppose" .

It's awesome on Yote's and anything else for that matter, I'll never be without one

 

[Outdrmn]

Here's how I use the Lee FCD for accuracy, I'm not trying to push it on anybody or saying that what anyone is doing is wrong, I love reloading and I have spent a small fortune on the latest and greatest and 30 years later I have come full circle and am almost where I started finding I can do a lot with a little. Anyway The Lee FCD, It comes with instructions and they work fine set to those specs but here is how I use it to "Fine Tune", Back the die way off and raise a round, screw the die in until it tightens up against the round, (Hand tighten really snug and I take a fine line sharpie and mark the die, lock nut and press at this point for reference), lower the round and give it a 16th to 1/8th or so of a turn, ( I prefer to cam over doing this with the Rock Chucker press so I know I'm consistent ) it may not look like it did anything but I assure you it did, crimp a string of however many you want and see if it helps, if it didn't give it another 16th to an 1/8th of a turn in and repeat. You can take bigger swings if you like but I don't .The way I use the Lee FCD its the same as finding a powder charge or seating depth. Once again I'm no professional and I'm not a competition shooter I'm a hunter who loves fast accurate rifles and this works for me and i use it on everything I load for, I have seen it help various calibers and I will say that I personally have never seen it hurt one in any way, , I do a lot of unconventional things from the Case Lube or the Dies I like to use some folks think I'm crazy I reckon, Once again this is just how I do things, I just want to say this again so it doesn't get all twisted,

ButterBean

Thanks BB for the detailed info! I have to try this now, I've learned so much form this site over the years! It's folks like you that really make a difference, sharing your experience, time and effort.

 

[ButterBean]

Thanks BB for the detailed info! I have to try this now, I've learned so much form this site over the years! It's folks like you that really make a difference, sharing your experience, time and effort.

If you need any help just give me a call 812-264-6183

 

[ButterBean]

Thanks BB for the detailed info! I have to try this now, I've learned so much form this site over the years! It's folks like you that really make a difference, sharing your experience, time and effort.

Shinbone put this together and is much clearer than the way I tried to explain it

 

[cboom]

Will definitely give this a try. Thank you for the great information ButterBean!

 

[ButterBean]

Will definitely give this a try. Thank you for the great information ButterBean!

No problem Bud

 

[Outdrmn]

Shinbone put this together and is much clearer than the way I tried to explain it View attachment 231263

Wow thanks for more info, but you did explain it great. I've never been accused of being the sharpest rake in the elevator, so for me to understand your directions, you done good.