Macinaw Posted March 23, 2018 Share Posted March 23, 2018 I am using Summers Enterprises 124gn poly coated lead bullets wit 4 grns of Red Dot. The bullets sometimes tumble (hit the paper sideways). I was told that Red Dot is a "fast" powder that is not allowing the bullet to engage the rifling of the barrel causing the bullet to tumble. I was told to switch powder to Tight Group. Will TG be a slower burning powder that will solve the tumbling issue? Thanks for any help! Link to comment Share on other sites More sharing options...
GrumpyOne Posted March 23, 2018 Share Posted March 23, 2018 Red Dot is 7th on the burn rate chart, Tite Group is 15...I run VV N320 which is 25. I do not know if there is a correlation between fast powders and tumbling bullets, but I wouldn't think so. Link to comment Share on other sites More sharing options...
bowenbuilt Posted March 23, 2018 Share Posted March 23, 2018 99% of the time bullet tumbling is caused by undersized bullets rattling down the barrel and exiting unstabilized. This could be caused by a number of things. I would check the diameter of the bullets you are using against slugging the bore to find its diameter. Over crimping is also one of the main causes of unstabilized bullets. If your bullet checks out, if your bore is not over sized I would look at the amount of crimp being applied. Red Dot has nothing to do with this. Changing powder types is most likely not the answer. Link to comment Share on other sites More sharing options...
Service Desk Posted March 23, 2018 Share Posted March 23, 2018 Excessive crimp causes a bullet to be partially sized to a smaller diameter, effectively making a bullet undersize if your barrel has a tendency towards a more generous bore dimension. Barrel leading usually accompanies an undersize bullet problem. Link to comment Share on other sites More sharing options...
stick Posted March 23, 2018 Share Posted March 23, 2018 do you know your crimp? if you have a bullet puller. pull a bullet. it shouldn't have more than a faint line where it was held by the case mouth. What is your loading setup? Link to comment Share on other sites More sharing options...
Macinaw Posted March 23, 2018 Author Share Posted March 23, 2018 I am almost positive that I am over crimping. I did this originally because I was using a revolver. JM 929. I did this to avoid bullet jump. Thanks for the help! Link to comment Share on other sites More sharing options...
M1A4ME Posted March 23, 2018 Share Posted March 23, 2018 Was the load developed in/for the revolver? I have/had a favorite 140 grain lead bullet load for my M&P 9MM. Shot pretty good. Moved from the M&P to the CZ pistols and those loads tumbled like crazy in the CZ's. Every one of them (P09, CZ 85, two or three CZ 75's). I just kept shooting them till all of them were used up (I think). I never did slug a barrel on the CZ's. I loaded up some of the same bullets (have a few boxes of them) with a different powder at a charge weight that increased the velocity and saw no tumbling. Groups are nothing to brag about, but the bullets didn't tumble at the higher velocity. Have you tried (if you can for that powder) increasing the velocity? Link to comment Share on other sites More sharing options...
Steve RA Posted March 23, 2018 Share Posted March 23, 2018 Bullet hardness will also have some bearing on the issue. A harder bullet is less likely to obturate, especially with low pressure loads. Main thing is to have the bullet .002 larger than the bore diameter. Also no crimp, just straighten the case walls to remove the belling. Link to comment Share on other sites More sharing options...
10X Posted March 23, 2018 Share Posted March 23, 2018 Overall length of the loaded cartridge can also be a big factor. If the bullet has too long of a jump before it engages the rifling, it can cause problems. I've solved tumbling problems just by increasing cartridge length to near the maximum that the chamber will accommodate. Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted March 23, 2018 Share Posted March 23, 2018 2 hours ago, Macinaw said: I am over crimping. You actually "crimp" bullets only for revolvers ... For semi-autos, you simply remove the bell that enabled you to seat the bullet. Your case should be straight up and down when you finish "crimping" ... Link to comment Share on other sites More sharing options...
CrashDodson Posted March 23, 2018 Share Posted March 23, 2018 In my .40 limited guns I had to run a .400 bullet in a barrel I had that was TIN coated. These same bullets will tumble in a new gun with a schuman hybrid, I have to run .401 bullets or they will tumble. Some bullet companies will send you some raw lead bullets, that are softer, that you can use to swage your barrel with to determine the size you need. The crimp can also be an issue, but so is bullet to barrel fit. Link to comment Share on other sites More sharing options...
72stick Posted March 23, 2018 Share Posted March 23, 2018 I was fascinated with the accuracy issues that plague the 9mm and played around with this a few years ago by slugging barrels, chasing powder, different weight bullets and COAL. I finally looked at what the AMU uses. When I started using 115g bullets at 1150 fps, all my accuracy issues went away . Link to comment Share on other sites More sharing options...
stick Posted March 23, 2018 Share Posted March 23, 2018 8 minutes ago, 72stick said: I was fascinated with the accuracy issues that plague the 9mm and played around with this a few years ago by slugging barrels, chasing powder, different weight bullets and COAL. I finally looked at what the AMU uses. When I started using 115g bullets at 1150 fps, all my accuracy issues went away . Interesting response. Link to comment Share on other sites More sharing options...
Macinaw Posted March 23, 2018 Author Share Posted March 23, 2018 Thank you! All of you have helped me. Link to comment Share on other sites More sharing options...
223to45 Posted March 23, 2018 Share Posted March 23, 2018 I had a similar problem, turns out I had too much crimp.And I run a much faster powder, so I doubt powder has anything to do with it.Sent from my SM-G930V using Tapatalk Link to comment Share on other sites More sharing options...
tcazes Posted March 23, 2018 Share Posted March 23, 2018 there are so many better powder options out there smh. you should use just enough "crimp" to remove the flare from the powder funnel. no need to crimp in and grab the bullet Link to comment Share on other sites More sharing options...
IDescribe Posted March 24, 2018 Share Posted March 24, 2018 On 3/22/2018 at 8:41 PM, Macinaw said: I was told that Red Dot is a "fast" powder that is not allowing the bullet to engage the rifling of the barrel causing the bullet to tumble. As others have said, this is nonsense. Tumbling is typically poor bullet to barrel fit or damage to the bullet, OR the bullet simply not moving fast enough to remain gyrostabilized all the way to the target, with this last option almost certainly not the case (just possible). What is your crimp measurement? Take one of your loaded cartridges and measure right at the case mouth, and measure with the thin, bladed tips of the calipers, not the wider part further into the jaws. The 9mm case is tapered, so if you center the thick part of the jaws over the case mouth, you're actually taking a measurement behind the casemouth. Use the thin bladed tips right at the case mouth. There are a number of different ways to determine the "proper" case mouth diameter for a particular bullet, but you can use .379 for every bullet you load for 9mm and be fine. Also, what is the measured diameter of the bullet? Link to comment Share on other sites More sharing options...
Macinaw Posted March 24, 2018 Author Share Posted March 24, 2018 I am using polymer coated lead sized to .357. I know that I have crimped them too much. I will change that ASAP. Thanks for your help. Link to comment Share on other sites More sharing options...
zzt Posted March 24, 2018 Share Posted March 24, 2018 (edited) I disagree with the no crimp for semi autos idea. With no crimp I get bullet setback. If I lightly crimp so there is an indentation in poly and plated bullets, I get no setback and have no problems. My bullseye buddies who shoot 9mm for the Center Fire leg tell me they have to drive the bullets fast to get acceptable accuracy. Dardas Bullets sells soft lead balls for slugging your bore. They will even measure them for you if you send them back. Edited March 24, 2018 by zzt Link to comment Share on other sites More sharing options...
12glocks Posted March 24, 2018 Share Posted March 24, 2018 Nothing wrong with a small amount of taper crimp or circumferential crimp like from a Lee FCD. My experience is that coated and plated, and lead bullets for that matter, are more sensitive to "issues" related to crimp. It may be possible that simply changing to a jacketed bullet you may be fine. I usually pull a couple of bullets looking for excess crimp and make a couple of dummy rounds that I chamber repeatedly to see if they lengthen. Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted March 25, 2018 Share Posted March 25, 2018 (edited) 5 hours ago, zzt said: With no crimp I get bullet setback. If it feeds, and is accurate, there is now problem. Lots of times, a little crimp in a semi-auto will cause either malfunctions or inaccuracy, or both You shouldn't need "crimp" to solve bullet setback - that's a matter of neck tension, which can be addressed with an undersized sizing die - then you don't need a "crimp". Edited March 25, 2018 by Hi-Power Jack Link to comment Share on other sites More sharing options...
IDescribe Posted March 25, 2018 Share Posted March 25, 2018 (edited) Crimping past flush with a straight-wall or tapered case like 9mm designed for a taper crimp can actually reduce neck tension and make the matter worse. As you bend the metal at the case mouth inward, the case walls below it want to bow out in response. They don't visibly bow out, but tension is reduced as they try to. Just flush is what you want. I would recommend never using a Lee FCD on lead bullets. It will swage the bullet shank and can lead to tumbling. I should have asked that already. If you are perchance using a Lee FCD with these bullets, that's likely part of your problem. Use a regular taper crimp die and crimp to flush, not past. Edited March 26, 2018 by IDescribe Link to comment Share on other sites More sharing options...
bowenbuilt Posted March 25, 2018 Share Posted March 25, 2018 What he said...... Link to comment Share on other sites More sharing options...
9x45 Posted March 26, 2018 Share Posted March 26, 2018 Crimp is a misnomer. It should properly be called de-bell. Only only bell from the powder thru die to seat the bullet, and only enough de-bell to case gage. Crimp does not hold bullets in place, that is neck tension (interference fit between the bullet OD and the case ID). Notice there is almost no perceptible crimp on my 357SIG Major loads, which has the shortest neck tension of all semi autos. Link to comment Share on other sites More sharing options...
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