Bullets are keyholeing on target

[Bench]

1 hour ago, HesedTech said:

Bench

 

Your pictures really don't tell us much. You have to make sure the bullets "plunk" or drop in, spin and fall out of the chamber freely. Go to this link for the best info on the subjects: https://www.egglestonmunitions.com/articles

 

Also (as the link will instruct you about) the diameter of the bullet is a function of the size of the barrel.

 

There's a lot of personal opinions in reloading, but a few ring true and MephisMechanic's info is something worth remembering.

 

At this point, personally I think you have the wrong bullet for your gun.

 

 

The images were requested by someone that has been following this thread so hopefully they are of benefit to him. Thanks for the URL for Eggelston. I may need to look them up since I see that they are in my area.

[Bench]

29 minutes ago, lgh said:

There's an old adage, "Match the bullet to the barrel and the powder to the bullet". It looks like you have the wrong bullet.

Guess I'd better find more about matching the bullet to the barrel, and making sure the barrel is the way it should be.

[HesedTech]

Bench

 

looking at your loaded bullet I noticed the brass is pretty straight and without the “coke bottle” taper and bulge from the seated bullet. Which sizing and seating dies are you using? Additionally do you have a case gauge like Dillon or another well known brand? The resized brass should easily drop into barrel and seem a bit loose. 

 

I’m having a bit trouble thinking Precision coated bullets won’t work in your gun. 

Edited May 6, 2018 by HesedTech

[Bench]

9 hours ago, HesedTech said:

looking at your loaded bullet I noticed the brass is pretty straight and without the “coke bottle” taper and bulge from the seated bullet. Which sizing and seating dies are you using? Additionally do you have a case gauge like Dillon or another well known brand? The resized brass should easily drop into barrel and seem a bit loose.

I'm using a Dillon SDB press with all the stock dies.

No case gauge at this time.

Resized brass (no bullet) does easily drop into the barrel and turns easily, and falls out no problem when the barrel is inverted. It does seem loose when in the barrel.

This batch of Precision 147 FN measures .661x.355. Seems just a bit narrower than it should be (?).

[IDescribe]

Okay, so those pictures actually tell us quite a bit.  And it turns out to have been quite helpful you posted the pick of the case with no bullet at all.   

I've cut out the relevant part of each pic and combined them into one picture for comparison.  The different pictures are not at precisely the same angle every time, and they're not at exactly the same distance from the lense each time, leading to slightly different scales, so keep that in mind, but the pics are very revealing. 

 

In the first pic with no bullet seated, we may assume that the case is headspacing on the casemouth at the chamber's headspacing step, as it was designed to do.  Note where the top of the chamber is relative to the case.  The top face of the chamber lines up with the crease/transition between the bevel in the extractor groove and the narrowest section of the extractor groove.  I've noted this alignment in the first and second pics with dotted lines to show how much seating a bullet at 1.15 lifts the case out of the chamber as a result of the cartridge headspacing by the bullet hitting the rifling lands.

So look at the 1.15 pic.  The difference between no bullet and a bullet at 1.15 is the height of that bevel in the extractor groove.

Now look at the 1.13 pic.  Shortening to 1.13 seems to drop it right back to the level with no bullet at all, or VERY VERY close, suggesting it's headspacing on the casemouth again, or ALMOST on the case mouth. 

Now look at the 1.11 pic.  It's no deeper into the chamber.  Or if it is deeper, it's barely deeper, certainly not the same difference as 1.13 vs 1.15.  Hard to say exactly because of slightly different camera angles, but IF there is any difference at all, it's nowhere near the difference between 1.13 and 1.15, which it would be if it were still headspacing by the bullet hitting the rifling lands.

Now look at 1.09.  It's the same again.  No difference.

Now look at 1.06.  It's the same again. No difference.

Now look at 1.045.  It's the same again.  No difference.

[IDescribe]

I would suggest that your bullet is probably headspacing on the case mouth as it should at 1.13, with the bullet out of the rifling, and if not, definitely by 1.11.  If you want to confirm this, assemble the pistol and chamber the round that is 1.045.  Make a vertical pencil mark from the slide onto the receiver.  That shows where the slide sits relative to the receiver when fully into battery.  Maybe chamber that round from the magazine a couple of times to make sure your pencil mark lines up consistently each time.  Then chamber the 1.13 round.  Do the marks still line up?  If the bullet is hitting the lands at 1.13, the marks should no longer line up.  If the bullet is just barely hitting the lands, it could jam the bullet into the lands or setback the bullet a little into the case and the marks still line up, BUT if that's happening, it will stick, and you'll be able to feel it when you cycle the slide by hand to clear the dummy round.  And if that is the case, if the bullet is hitting and sticking, but the marks are lining up, I'd bet the problem goes away at 1.12.

Give it a shot and see what happens.     And if you haven't done it already, scrub out that chamber and run this test with a clean chamber.   

 

Edited May 6, 2018 by IDescribe

[IDescribe]

Assuming your cartridge is headspacing properly at 1.13 or 1.12 or 1.11, what is the difference in plunk testing at those OALs vs 1.048 that led you to believe that the bullet was NOT into the rifling at 1.048 but WAS into the rifling at longer OALs?  If it works out that your cartridge is fine at longer OALs, you'll need to figure out where you were going wrong with determining that 1.048 is where it started to work right.

In general, if the bullet is hitting the lands, the cartridge will go in further every time you shorten it.  Shorter than the length short enough that it's not hitting the lands, it will headspace on the casemouth at the headspacing step in the chamber, and it will not go in any further.  NOW, that is NOT how you want to test max OAL in the future.  You want to be able to test it with your fingers and by feel.  But the fact that the cartridge was not going any further into the chamber once you pass 1.13 means your bullet is out of the lands.

I would suggest that you need to play with the 1.045 cartridge in the chamber.  Hold it in with just a little pressure and twirl it between your fingers.  The 1.13 or 1.11 would feel the same if they're out of the lands.  You can also take the 1.15, which we know is too long, insert that, hold the case head between your fingers, and hold it back out of the rifling a little and twirl it between your fingers to see what that feels like, then insert it a little deeper, a little deeper, until it hits the rifling and grabs, and you can feel the resistance, then press in a little harder until it grabs hard and you can't twirl the case at all.  Your not being sure what to feel for may have led you astray in evaluating your max OAL.

 

[IDescribe]

Also, just to make sure you're visualizing what's going on inside the chamber, I threw together a diagram. 

 

 

Edited May 6, 2018 by IDescribe

[IDescribe]

Also noteworthy, look at the top image of just an empty chamber.  The "free bore" is the space between the headspacing step and the rifling of just smooth bore, larger than the diameter of the bullet.  When someone talks about "reaming" a barrel, they're talking about using a reamer to cut out rifling, effectively lengthening the freebore.  Personally, I find the practice unnecessary, even in short-throated pistols like CZ.  But I thought I'd point out what people mean when they talk about reaming.   

[Bench]

9 hours ago, IDescribe said:

I would suggest that your bullet is probably headspacing on the case mouth as it should at 1.13, with the bullet out of the rifling, and if not, definitely by 1.11.  If you want to confirm this, assemble the pistol and chamber the round that is 1.045.  Make a vertical pencil mark from the slide onto the receiver.  That shows where the slide sits relative to the receiver when fully into battery.  Maybe chamber that round from the magazine a couple of times to make sure your pencil mark lines up consistently each time.  Then chamber the 1.13 round.  Do the marks still line up?  If the bullet is hitting the lands at 1.13, the marks should no longer line up.  If the bullet is just barely hitting the lands, it could jam the bullet into the lands or setback the bullet a little into the case and the marks still line up, BUT if that's happening, it will stick, and you'll be able to feel it when you cycle the slide by hand to clear the dummy round.  And if that is the case, if the bullet is hitting and sticking, but the marks are lining up, I'd bet the problem goes away at 1.12.

Give it a shot and see what happens.     And if you haven't done it already, scrub out that chamber and run this test with a clean chamber.   

 

I'll need to clean out the barrel and gun following the match today. I'll try the 'line' test after all is cleaned up.

 

7 hours ago, IDescribe said:

Also noteworthy, look at the top image of just an empty chamber.  The "free bore" is the space between the headspacing step and the rifling of just smooth bore, larger than the diameter of the bullet.  When someone talks about "reaming" a barrel, they're talking about using a reamer to cut out rifling, effectively lengthening the freebore.  Personally, I find the practice unnecessary, even in short-throated pistols like CZ.  But I thought I'd point out what people mean when they talk about reaming.   

Thanks for that bit of information.

[Bench]

8 hours ago, IDescribe said:

Assuming your cartridge is headspacing properly at 1.13 or 1.12 or 1.11, what is the difference in plunk testing at those OALs vs 1.048 that led you to believe that the bullet was NOT into the rifling at 1.048 but WAS into the rifling at longer OALs?  If it works out that your cartridge is fine at longer OALs, you'll need to figure out where you were going wrong with determining that 1.048 is where it started to work right.

In general, if the bullet is hitting the lands, the cartridge will go in further every time you shorten it.  Shorter than the length short enough that it's not hitting the lands, it will headspace on the casemouth at the headspacing step in the chamber, and it will not go in any further.  NOW, that is NOT how you want to test max OAL in the future.  You want to be able to test it with your fingers and by feel.  But the fact that the cartridge was not going any further into the chamber once you pass 1.13 means your bullet is out of the lands.

I would suggest that you need to play with the 1.045 cartridge in the chamber.  Hold it in with just a little pressure and twirl it between your fingers.  The 1.13 or 1.11 would feel the same if they're out of the lands.  You can also take the 1.15, which we know is too long, insert that, hold the case head between your fingers, and hold it back out of the rifling a little and twirl it between your fingers to see what that feels like, then insert it a little deeper, a little deeper, until it hits the rifling and grabs, and you can feel the resistance, then press in a little harder until it grabs hard and you can't twirl the case at all.  Your not being sure what to feel for may have led you astray in evaluating your max OAL.

I've been plunk testing by letting the cartridge fall into the barrel from about a cartridge length above the barrel. Usually I will then invert it to see if it falls freely from the barrel. I'll replunk it and lightly test for free rotation without forward pressure. I did write some notes as I was making up the range of dummy rounds and at 1.11 I noted that the test was still negative but was loosening up. My parameters for that usually involve an inverted barrel resulting in a fall of the cartridge but that it didn't immediately fall out, there was a hesitation. Rotation usually was only partial where it would rotate only so far and then stop. The lengths that followed showed a 'diminishing' negative plunk test but all portions of the plunk test were positive at 1.045 that is the bullet fell freely from the inverted barrel and rotated freely...even with some forward pressure. Crimps were all at .378/.379 and I did measure the bullets: .661x.355

[ddc]

I think you are getting excellent guidance by IDescribe.

That diagram he drew up is worth it's weight in gold in helping to describe what is going on with different cartridge lengths and how they affect chambering/plunk test/etc.

I found that once I was able to visualize the issues it really helped the debugging process.

One thing I thought I'd ask although maybe it was covered earlier in the thread: Are you doing your development and debugging with the same headstamps or is this with mixed brass?

[Bench]

51 minutes ago, ddc said:

I think you are getting excellent guidance by IDescribe.

That diagram he drew up is worth it's weight in gold in helping to describe what is going on with different cartridge lengths and how they affect chambering/plunk test/etc.

I found that once I was able to visualize the issues it really helped the debugging process.

One thing I thought I'd ask although maybe it was covered earlier in the thread: Are you doing your development and debugging with the same headstamps or is this with mixed brass?

I second the above about IDescribe!!! Regarding head stamps I haven't taken that step yet and use random brass.

[njl]

Has anyone mentioned yet that Precision’s web site has for as long as I can remember recommend against using their bullets with titegroup? It may be burning hot enough to compromise the coating.

https://precisionbullets.com/2017/11/14/reloading-powders/

[IDescribe]

11 hours ago, Bench said:

Rotation usually was only partial where it would rotate only so far and then stop.

This shouldn't be happening.  Everything -- the bullet, the case mouth, every part of the chamber -- they're all round.  The finishing reamer that set the length of the freebore -- round.  Everything is round.  So even if you had a single burr in there, it should make contact and cause problems no matter what rotational orientation the cartridge was in.  There should be no "turns freely" then hits a point where it stops.

[IDescribe]

If you haven't tested if the pistol goes fully into battery yet with the longer bullets, I was thinking a piece of scotch tape would have a finer edge and might work better than a pencil mark.  Just lay a piece of scotch tape across the slide and receiver, then cut it carefully with a razor.

 

Do cut the coating on your pistol.   

 

Edited May 7, 2018 by IDescribe

[IDescribe]

8 hours ago, njl said:

Has anyone mentioned yet that Precision’s web site has for as long as I can remember recommend against using their bullets with titegroup? It may be burning hot enough to compromise the coating.

https://precisionbullets.com/2017/11/14/reloading-powders/

 

I don't think that has been mentioned.  I thought when Precision moved to their new coating, that it was tougher, and that powder concerns were no longer supposed to be an issue, but I see that their site still recommends against it.

Definitely something for him to consider going forward, though not the root cause of his current problem. 

[IDescribe]

Your next step here is to see if the gun goes fully into battery with the longer bullets using the test with the scotch tape/pencil mark.    And make a couple of dummy rounds at 1.12, as well.  OAL 1.12 puts your seating depth somewhere in the range of .290-.295, which is the max you want it.  If you're going into battery at 1.12 without putting the bullet into the rifling, and I'm pretty sure you will be, that's your new OAL. 

Also, with the plunk test, I don't personally plunk.  If you're chamber checking a few hundred bullets for a match, that's the way to go because it's quick and easy.  To check for max OAL, though, I just insert it as far as it will go, then grab it at the base with my thumb and ring finger like pincers, with the fingernails of those two fingers inserted into the extractor groove, so I can get a grip on it, otherwise it's not easy to spin it, even when it's head-spaced on the case mouth.  And then I spin it.  

 

At this point, I'd also want to make absolutely sure your crimp is less than .380, and sometimes measuring crimp can be a bit tricky.  The safest way to be sure it's in that range is to first -- close your caliper jaws and make sure they're calibrated to read 0.000.  Then open them and use the set screw on your calipers to set the calipers to .380, and lock down the set screw there, so the calipers won't move.   Will the case mouth fit in between the jaws?  If not, you're not crimping to .378/.379 as you intend to.   If so, you could also set to .378 and make sure the case mouth will NOT slip inside, showing it's .378 or bigger.

 

Let us know.   

Edited May 7, 2018 by IDescribe

[Bench]

10 hours ago, njl said:

Has anyone mentioned yet that Precision’s web site has for as long as I can remember recommend against using their bullets with titegroup? It may be burning hot enough to compromise the coating.

https://precisionbullets.com/2017/11/14/reloading-powders/

But they do give a load for it, curious.

[IDescribe]

TItegroup's issues are a bit exaggerated.  There are better powders, but I wouldn't worry about that right now.  That's not your root issue.   

[Bench]

8 minutes ago, IDescribe said:

TItegroup's issues are a bit exaggerated.  There are better powders, but I wouldn't worry about that right now.  That's not your root issue.   

Thanks, I'm going to address bullet profile issues before any powder considerations. I'll be in touch regarding 'better powders' once other issues are ironed out.

[IDescribe]

3 hours ago, Bench said:

Thanks, I'm going to address bullet profile issues before any powder considerations. I'll be in touch regarding 'better powders' once other issues are ironed out.

 

I no longer think you have a bullet profile issue.  I think you have a testing procedure issue.  If that cartridge is not descending deeper and deeper into the chamber as you seat the bullet deeper and deeper into the case (and it appears not to be in the photos), then the bullet is not contacting the rifling.  I suspect you'll be fine at 1.12 or 1.13.

NOW, it is also probable that that .355 diameter bullet is not going to be a good fit for your barrel, and you'll certainly be better off going to .356, and probably .357 even better, but that's a different issue, and again, that can be dealt with on the next bullet purchase. 

[Bench]

5 hours ago, IDescribe said:

 

I no longer think you have a bullet profile issue.  I think you have a testing procedure issue.  If that cartridge is not descending deeper and deeper into the chamber as you seat the bullet deeper and deeper into the case (and it appears not to be in the photos), then the bullet is not contacting the rifling.  I suspect you'll be fine at 1.12 or 1.13.

So what might my testing issue be? Some of the cartridges will fall out when placed in a certain position and will rotate most of the way 360 degrees but will find a sticky spot and stop. A friend gave me some 147 Xtreme RN and at 1.1 the cartridge will rotate to a certain spot and stick and rub Sharpie off the bullet. I haven't Sharpied all of the dummy rounds yet but the rounds that plunk well are down in the 1.075 to 1.08 range. Can that still be my testing procedure? Sharpied bullet get scraped off starting at about 0.076 up from the case mouth and continues down toward the case mouth.. This really indicates to me that there is something amiss with the barrel...or in the reload...or what am I missing here? My next step is to make reference marks on the cartridge and barrel to see if different cartridges of the same OAL reveal the same Sharpie scratch location. This might shed some light on barrel vs reloading direction.

Edited May 7, 2018 by Bench
More specific info added.

[IDescribe]

Picture your bullet turning.  Relative to the axis around which it's rotating, it's circular.  I get that there could be something in the chamber to catch something protruding laterally from the cartridge, but there are no lateral protrusions on the cartridge.  Everything is circular.  So if there's something contacting some part of the cartridge at some orientation, it should also be catching the corresponding spot on the cartridge at every orientation.  It should be a consistent level of drag, or no drag. 

 

The only way I can see what you're describing happening is if you had a horrible degree of runout -- runout being the deviation in alignment between the axis of the bullet and the axis of the case when loaded.  If you take one of your loaded cartridges, and roll it across the table, it's tapered, so it's likely to turn a little, but can you see a wobble of the bullet relative to the case?  That's the only way I can see what you're describing happening -- if the bullet axis and case axis are very poorly aligned.  And to be clear -- I'm not saying you're not experiencing what you're experiencing.  I just don't think it is as you are interpreting it.

Have you checked yet with the scotch tape or pencil mark to see if the slide and receiver line up at the same spot with the 1.045 vs the 1.11 vs the 1.13 vs the 1.15?

[IDescribe]

Go back to an empty but sized case and insert it all the way and spin it.  Does it spin 100% freely?