.419" Crimp with a coated bullet

[Baynewrady]

Just wondering if anyone has their crimp set at .419" with a coated bullet, and if so what the pulled bullet looks like?

 

After experiencing some feed failures when my crimp was set to .422", I adjusted down to the factory recommendation of .419". Looking at the pulled bullet from a .419" crimp though, I'm hesitant to think I won't potentially have accuracy issues (in some spots the coating's broken and I see exposed lead). Does anyone crimp to .419" and not have this "heavy" of a pinch line? How would I achieve that?

 

TIA!

[HesedTech]

45 minutes ago, Baynewrady said:

After experiencing some feed failures when my crimp was set to .422",

Did the round "plunk test" properly at .422? If so the feed issue (you didn't write what the failure was) probably isn't the crimp size. As far as the crimp line goes, it could be worse but shouldn't cause accuracy issues. The scraping off and bare lead may cause increased barrel leading and eventually degrade the accuracy. I set the crimp based on plunk test and minimize the crimp line. Stopped worrying about trying to meet SAAMI specs years ago.

 

My 40 has a really deep throat so the only OAL restriction is magazine capability. Try different OALs and make sure the nose of the bullet is hitting about mid point on the feed ramp. The most reliable feeding in my 40 came at 1.20 OAL and required switching to 10mm magazines to achieve that. A friend who shoots 2011s uses 1.18 OAL for reliable feed.

 

Enjoy the process of customizing your loads. 

Edited June 7, 2023 by HesedTech

[shred]

That level of crimp with have zero impact on accuracy at the distances we use.

 

Possibly more leading, but accuracy, no.   

 

Here's a test I did with much more extreme bullet damage:

 

If you want to visually inspect crimp, get a 10x magnifier or a good phone camera and have a look at the gap between bullet and brass.  You want the brass near the bullet as in the top round here, not the wider gap on the bottom round.

 

Once you get there, and it measures within spec, there's rarely need to crimp any more than that.

 

[Baynewrady]

1 hour ago, HesedTech said:

Did the round "plunk test" properly at .422? If so the feed issue (you didn't write what the failure was) probably isn't the crimp size. As far as the crimp line goes, it could be worse but shouldn't cause accuracy issues. The scraping off and bare lead may cause increased barrel leading and eventually degrade the accuracy. I set the crimp based on plunk test and minimize the crimp line. Stopped worrying about trying to meet SAAMI specs years ago.

 

My 40 has a really deep throat so the only OAL restriction is magazine capability. Try different OALs and make sure the nose of the bullet is hitting about mid point on the feed ramp. The most reliable feeding in my 40 came at 1.20 OAL and required switching to 10mm magazines to achieve that. A friend who shoots 2011s uses 1.18 OAL for reliable feed.

 

Enjoy the process of customizing your loads. 

 

56 minutes ago, shred said:

That level of crimp with have zero impact on accuracy at the distances we use.

 

Possibly more leading, but accuracy, no.   

 

Here's a test I did with much more extreme bullet damage:

 

If you want to visually inspect crimp, get a 10x magnifier or a good phone camera and have a look at the gap between bullet and brass.  You want the brass near the bullet as in the top round here, not the wider gap on the bottom round.

 

Once you get there, and it measures within spec, there's rarely need to crimp any more than that.

 

 

Was having failures to chamber, sometimes a tap on the back of the slide would force the round to chamber. My previous gun would feed my loads without issue, but this is happening in a new gun. 

 

In any case, thanks for the responses guys, sounds like I'm overthinking things. I'm still going to adjust to .420" though to get rid of that indent line, based on shred's test it does look to me like damaged coating/exposed lead will lead to inaccuracy. 

[HesedTech]

9 hours ago, Baynewrady said:

My previous gun would feed my loads without issue, but this is happening in a new gun. 

There you go, new gun different chamber. One must plunk test each gun.

 

You had your answer from the beginning. 
 

 

[shred]

18 hours ago, Baynewrady said:

Was having failures to chamber, sometimes a tap on the back of the slide would force the round to chamber. My previous gun would feed my loads without issue, but this is happening in a new gun. 

 

In any case, thanks for the responses guys, sounds like I'm overthinking things. I'm still going to adjust to .420" though to get rid of that indent line, based on shred's test it does look to me like damaged coating/exposed lead will lead to inaccuracy. 

 

I don't know if this was a typo, but the takeaway is there was negligible difference in accuracy at 25 yards versus un-damaged bullets, even bullets with holes drilled into them were still 1/4 A-zone at 25.

[Baynewrady]

2 hours ago, shred said:

 

I don't know if this was a typo, but the takeaway is there was negligible difference in accuracy at 25 yards versus un-damaged bullets, even bullets with holes drilled into them were still 1/4 A-zone at 25.

Not a typo, granted it was negligible, but there WAS a difference . Obviously the crimp line I'm working with is nowhere near the damage you did to your bullets, but considering I'm spending time to reload, I'd like to have the rounds be as accurate as possible.

[HHjr]

On 6/7/2023 at 2:23 PM, Baynewrady said:

 

 

Was having failures to chamber, sometimes a tap on the back of the slide would force the round to chamber. My previous gun would feed my loads without issue, but this is happening in a new gun. 

 

In any case, thanks for the responses guys, sounds like I'm overthinking things. I'm still going to adjust to .420" though to get rid of that indent line, based on shred's test it does look to me like damaged coating/exposed lead will lead to inaccuracy. 

 First stating crimp measurement to the Thousands is highly unlikely to be repeatable for a reloader… taper crimp until the case mouth yields a shiny burnished edge and stop.  
 

Full length resizing when reloading is Utterly important with today’s open ramped barrels.  . I have three 40’s and two 10mm’s (5 40’s I guess). One stopped on my reloads…. Out of battery…    Buldged brass was the culprit… little twist on sizing die and they were All happy!  All my match ammo gets Plunk Tested…

if you pick up range Or match brass your Sizing Step Number One is Critical!!