Do I need to worry about this

[constable79]

Forum newbie with first post.  Have been reloading rifle/pistol for 40 years but this is my first foray into 10mm and the 1911.

Have a brand new, never fired Springfield RO Elite Operator.  Ready to start load development and was going to start with Power Pistol in the 8gr - 9gr range and possibly Blue Dot since i have both on hand.

I made a dummy round with new Starline brass and Montana Gold 180gr JHP loaded to a COAL of 1.249.  Dummy round passed the plunk test; freely dropped in, spun freely in chamber and freely fell out when turned up.  The round also passed the case guage test.  I thought i was well on my way since my reload setup fit.  I also took measurements of my dummy reload as well as several commercial rounds i had on  hand for comparison (see first table in attached spreadsheet).

I then performed my last test which was to chamber the round from a magazine to check feed.  Dummy round chambered easily and the slide was in full battery.  This is where my concern comes in.  After ejecting the dummy round i re-measured the round and determined the bullet had setback .0015.  Since the round freely passed the plunk test i can only assume the setback occurred as the round traversed the feed ramp and bounced off the top of the chamber.  I also did the same feed check test with my commercial rounds and with all but one of them there was no setback (see second table in the attachment).

Since this issue is new to me i have come to the forum experts for advice, suggestions, and/or education.
1.  Is some setback normal in the 1911 and I can safely ignore this small setback?
2.  If i need to correct the setback issue is the solution to increase my crimp?
3.  If i need to increase my crimp from current .4225 would you suggest .4220, .4215 or .4210?

I would appreciate any and all suggestions.

Apologize for the long post but wanted to give you as much data as i could.

Thank you.  Have a great weekend and stay safe out there.



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[sparkyv]

Interesting, I would never have thought to remeasure my dummy round after chambering test.  I test for setback by firing the gun with the dummy round on board.

[Graybeard]

That's a pretty tiny amount of setback and probably won't be an issue. It would probably be a good idea to chamber and eject that same dummy round multiple times and see if it continues to setback farther. If it starts to really setback noticeably, you might have a sizing/expander issue. I doubt that you do. Just my opinion, but I would fire them. Starline brass work hardens, so you may get better case neck tension after a couple of loadings.

Power Pistol and BlueDot are both excellent powders for 10mm. Virtually everyone on this forum has chimed in that 10.4gr of BlueDot with various 180gr bullets can produce a very accurate round. PP can, too, but usually at a little hotter loadings.

I wouldn't go nuts on increasing the crimp since case neck tension is more important to avoiding setback and over crimping may interfere with proper headspacing. Why beat up the extractor on a nice 1911 over a problem that might not exist?

Lastly, it could be the gun. Break it in with a few hundred rounds and the bullets may not impact the feed ramp, or the top of the chamber, as hard. New and unfired is the tightest that gun is ever going to be.

Good luck with it and congrats on the new gun!

[The_Shadow]

constable79, welcome to the forum and the 10mm world!
My first question is did you test the bullet fit in the New Starline brass?  What die set are you using?  It shouldn't need to be sized as new but it may help.
Did you use an expander die on the new brass?  What was the inside measure of the casing after passing the expander inside.  Did the bullet seem to seat too easily?

Given the bullet had a good amount of tension as seated, the next point would be crimping.  Did you seat the bullet fully before crimping?  The 10mm being a straight wall case and bullets have no cannelure you need to be careful that crimping isn't actually loosening the tension.

Seating bullets to proper depth with out crimp being applied helps with many things especially cast & plated bullets to prevent bullet material from being shaved or snagging the case enough to buckle it.  I work single stage and use a die spacer to raise my RCBS seater/crimp die up 1/8" (this is so I do not need to adjust the locking nut that is set for the perfect crimp) to do all my bullet seating with no crimp closing the case against the bullet in motion.  After all bullets are fully seated to the proper COL, I then remove the spacer and place the die back in the press.
Then back the bullet seater stem out so it doesn't touch the bullet and run the cartridges back through to only apply the crimp that is pushed against the bullet.

With finished cartridges mine measure 0.4215" - 0.4220" on the very edge of the case mouth.

If using the LEE FCD, I have noted that it can resize and squeeze the case and bullet down leaving the bullet tension less than desirable!

Good luck!

[Kenk]

Welcome constable79, you will find extremely knowledgeable folks here, Not to mention an overall great bunch of guys, enjoy!

Ken

[Bimmer]

Have been reloading rifle/pistol for 40 years...

After ejecting the dummy round i re-measured the round and determined the bullet had setback .0015...

Since this issue is new to me i have come to the forum experts for advice, suggestions, and/or education.
1.  Is some setback normal in the 1911 and I can safely ignore this small setback?
2.  If i need to correct the setback issue is the solution to increase my crimp?
3.  If i need to increase my crimp from current .4225 would you suggest .4220, .4215 or .4210?

You say you're an experienced reloader, so please don't take offense, but...

1.  I don't think 0.0015" is measurable.  That's only one and a half of the little ticks on my micrometer... 

My reloads vary that much without me adjusting anything...  Example, I'm in the middle of a batch of .40S&W, and they measure 1.135" or 1.137".  No big deal. 


2.  You didn't say whether you tested neck tension... 

Push your dummy round down on your workbench as hard as you can.  If you can move the bullet back in the case, then you don't have enough neck tension. 


3.  You're talking about crimping...  No.  Just no no NO.  It's neck tension that holds the bullet in place, not crimping. 

Crimping is only to remove the bell that enabled seating the bullet.  If your dummy round is at 0.423 or less (SAAMI spec) and/or your rounds chamber easily, then you have enough crimp. 


My guesses:

1.  You're jumping at shadows.  The setback you think you measured is negligible, or...

2.  If you are seeing real set-back, and/or your neck tension is not enough, then you're not sizing your cases down enough. 

[constable79]

That's a pretty tiny amount of setback and probably won't be an issue. It would probably be a good idea to chamber and eject that same dummy round multiple times and see if it continues to setback farther. If it starts to really setback noticeably, you might have a sizing/expander issue. I doubt that you do. Just my opinion, but I would fire them. Starline brass work hardens, so you may get better case neck tension after a couple of loadings.

Thank you Graybeard for the feedback.  Apologize i left this information out.  Yes i did cycle the round several times after the initial setback and it did not setback any further than the initial loading.

[constable79]

constable79, welcome to the forum and the 10mm world!
My first question is did you test the bullet fit in the New Starline brass?  What die set are you using?  It shouldn't need to be sized as new but it may help.
Did you use an expander die on the new brass?  What was the inside measure of the casing after passing the expander inside.  Did the bullet seem to seat too easily?

Given the bullet had a good amount of tension as seated, the next point would be crimping.  Did you seat the bullet fully before crimping?  The 10mm being a straight wall case and bullets have no cannelure you need to be careful that crimping isn't actually loosening the tension.

Seating bullets to proper depth with out crimp being applied helps with many things especially cast & plated bullets to prevent bullet material from being shaved or snagging the case enough to buckle it.  I work single stage and use a die spacer to raise my RCBS seater/crimp die up 1/8" (this is so I do not need to adjust the locking nut that is set for the perfect crimp) to do all my bullet seating with no crimp closing the case against the bullet in motion.  After all bullets are fully seated to the proper COL, I then remove the spacer and place the die back in the press.
Then back the bullet seater stem out so it doesn't touch the bullet and run the cartridges back through to only apply the crimp that is pushed against the bullet.

With finished cartridges mine measure 0.4215" - 0.4220" on the very edge of the case mouth.

If using the LEE FCD, I have noted that it can resize and squeeze the case and bullet down leaving the bullet tension less than desirable!

Good luck!

Shadow, thank you for the comments and recommendations.

I am loading on a Rock Chucker single stage using Dillon dies.  Yes i sized the case before using it and i seat and crimp in separate operations with specific/separate crimp and seat dies.  I did not think to measure the ID after expanding but i will do so and report back.  The bullet seating did not seem excessively easy.

I see your crimp is just slightly more than mine so i might minimally increase mine to get in your range which is where my  .40s&W is.

Edited to add additional measurements.

Sized case, measurements at case mouth:
OD:  .418
ID:  .2415

Expanded case, measurements at case mouth:
OD:  .425
ID:  .242

Sized case, bullet seated, no crimp applied, measured at case mouth:
OD:  .426

Sized case, bullet seated, crimped, measured at case mouth:
OD:  .422

Bullets measure .3995

Would appreciate any additional feedback/suggestions if you have any.

[constable79]

1.  I don't think 0.0015" is measurable.  That's only one and a half of the little ticks on my micrometer... 

My reloads vary that much without me adjusting anything...  Example, I'm in the middle of a batch of .40S&W, and they measure 1.135" or 1.137".  No big deal. 

2.  You didn't say whether you tested neck tension... 

Push your dummy round down on your workbench as hard as you can.  If you can move the bullet back in the case, then you don't have enough neck tension. 


3.  You're talking about crimping...  No.  Just no no NO.  It's neck tension that holds the bullet in place, not crimping. 

Crimping is only to remove the bell that enabled seating the bullet.  If your dummy round is at 0.423 or less (SAAMI spec) and/or your rounds chamber easily, then you have enough crimp. 

My guesses:

1.  You're jumping at shadows.  The setback you think you measured is negligible, or...

2.  If you are seeing real set-back, and/or your neck tension is not enough, then you're not sizing your cases down enough.

Bimmer,  Thank you for the response, no offense taken whatsoever.

Just to clarify, i understand there are variances when loading ammunition and that the COAL will vary due to many factors including varying bullet length and seating die plug.  I was trying to explain i loaded my round and then chambered the round.  After chambering the round the COAL was reduced.  It might not be the most correct way to do things but I am using a caliper to measure my COAL and not a micrometer.  I only use a ball micrometer to measure case neck thickness.

Yes i did do the bench push test as hard as a i could and did not see any setback.  Obviously a steel gun with a stout recoil spring has more force in chambering a round to cause setback than my hands and a wood reloading bench.

Agree i might be chasing shadows which is why i asked for the experts opinions on this forum before i moved forward with load development.  I was taught to avoid setback in any round but especially in .40s&W and 10mm because it could significantly increase pressures.  I realize .0015 change in bullet seating depth probably would not be an issue as i don't plan on shooting nuclear loads.

Thank you for your input.

[The_Shadow]

That small amount of setback is not going to affect anything.  The process you are using sounds great  , with the bullets being 0.3990" 0.3995" a little more crimp could be applied.
You have a great understanding of what's happening and dealing with it.  The 10mm usually has a standard COL of 1.2500" - 1.2600", however bullets with WFN meplats over 0.300" sometimes need to be seated slightly deeper to function in some guns to change the tipping angle to the chamber.  I have seen these measured at 1.2420" with meplats of 0.3200"...
Good luck! 

[constable79]

Thank you very much Shadow.  I appreciate all of your help and advice.  Have a great weekend and stay safe out there.

Now to find an open range..............

[Bimmer]

Bullets measure .3995

Would appreciate any additional feedback/suggestions if you have any.

Like Shadow said, I don't think this is anything to worry about... 

Aren't bullets s'posed to be 0.400 or 0.401"? 

[Graybeard]

Bullets measure .3995

Would appreciate any additional feedback/suggestions if you have any.

Like Shadow said, I don't think this is anything to worry about... 

Aren't bullets s'posed to be 0.400 or 0.401"?

Typically, yes, .400" for fmj or jacketed and .401" for lead, plated, softer bullets. The difference between .3995" and .400" is only 5 ten thousandths of an inch. That's a really tiny manufacturing tolerance.

IIRC, from my college days, that's called the degree of unknown certainty. Meaning how many decimal places your measurement is accurate to based on the capabilities of your measuring instrument and the level of accuracy necessary. For example constable79's micrometer may be able to measure these bullets accurately to .3995" but a more accurate device could come up with .3995898" which would round to .400".  That's basically what calipers that go out to 3 decimal places are doing all the time, showing you accuracy to one thousandth of an inch.

[constable79]

Bullets measure .3995

Would appreciate any additional feedback/suggestions if you have any.

Like Shadow said, I don't think this is anything to worry about... 

Aren't bullets s'posed to be 0.400 or 0.401"?

Typically, yes, .400" for fmj or jacketed and .401" for lead, plated, softer bullets. The difference between .3995" and .400" is only 5 ten thousandths of an inch. That's a really tiny manufacturing tolerance.

IIRC, from my college days, that's called the degree of unknown certainty. Meaning how many decimal places you measurement is accurate to based on the capabilities of you measuring instrument and the level of accuracy necessary. For example constable79's micrometer may be able to measure these bullets accurately to .3995" but a more accurate device could come up with .3995898" which would round to .400".  That's basically what calipers that go out to 3 decimal places are doing all the time, showing you accuracy to one thousandth of an inch.

Thanks Graybeard, agree 100%.  On my Starret caliper the 10/1000 digit is either "0" or "5" which means all it's telling me is my  bullet is between .3995 and .4000.  As you stated the difference is insignificant and equates to .400 in my mind.