A few weeks ago I noticed I couldn't see the cannelure on 2 of my sd rounds anymore. I measured the length with my calipers and wrote it in sharpie on the case to track it. They are hornady 9mm critical duty 135 gr. they aren't +p so they weren't recalled. I probably strip and clean my ccw too often but whatever, that explains the cycling. Has anyone ever noticed this before? Do you think I should get a box of gold dots now?
Sd ammo bullet setback
- Thread starter Okcafe86
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That will happen eventually with any ammo that is continually rechambered. I rotate the rounds at the top of my mags for this very reason. Pressures can increase rapidly when the bullet is seated too low. Generally speaking I replace my SD ammo 3 or 4 times a year. After a few months I just shoot up my SD ammo and buy a fresh pack or three.
Since factory ammo comes in boxes of 20, 25, 50 or 100 you always have extra rounds since magazines capacity seldom evenly divides those numbers. If this setback bothers you just replace the bullet with one of those "extra" rounds left over.
Personally the only time I worry about setback in factory ammo is when it may cause failure to feed. My solution has been to keep the setback round in the chamber knowing that when it fires the successive rounds of standard length will subsequently feed.
The setback caused by the bullet being shoved against the feed ramp during chambering will eventually stop when the base of the bullet contacts the powder. While some worry about possible increase in pressure the fact is that there has never been any incidences where the pressure in factory ammo has increased dramatically enough to cause damage or failure in firearms, if it had there would be many posts on the internet and customer complaints to the ammo manufacturers.
I have over the years fired rounds that where set back without any resulting problems or issues. I have also pulled some of the bullets from setback ammo and then seated and crimped the bullets in back place with heavier crimp to produce a round that no longer would set back.
Personally the only time I worry about setback in factory ammo is when it may cause failure to feed. My solution has been to keep the setback round in the chamber knowing that when it fires the successive rounds of standard length will subsequently feed.
The setback caused by the bullet being shoved against the feed ramp during chambering will eventually stop when the base of the bullet contacts the powder. While some worry about possible increase in pressure the fact is that there has never been any incidences where the pressure in factory ammo has increased dramatically enough to cause damage or failure in firearms, if it had there would be many posts on the internet and customer complaints to the ammo manufacturers.
I have over the years fired rounds that where set back without any resulting problems or issues. I have also pulled some of the bullets from setback ammo and then seated and crimped the bullets in back place with heavier crimp to produce a round that no longer would set back.
I reload, bullets seated an deeper lengths WILL produce higher pressures according to just about every reloading manual publisher. If using +p or +p+, things can produce massive spikes in pressure from the already high pressure 9mm. Listen to the manufacturers.
This is one of the primary reasons I went back to a revolver.
Autoloaders even if you don't shoot your carry ammo will eventually ruin it if you shoot them with other ammo.
IMO every person who ccw's an automatic needs to have a way to measure, keep track of and a plan to limit bullet setback
Autoloaders even if you don't shoot your carry ammo will eventually ruin it if you shoot them with other ammo.
IMO every person who ccw's an automatic needs to have a way to measure, keep track of and a plan to limit bullet setback
HisSoldier
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C&H makes a nifty canneluring tool that mounts on the bench, I used to roll them into the cases just below the bullet bases, problem solved.
Since then I've spent a lot of money on reloading gear and have learned to take care for bullet tension, ie case mouth size. But there is no downside to having the cases cannelured unless you go to much heavier bullets, the cannelures would make them stick out farther, however, they can still be seated deeper, it just pushes the cannelure back out.
The cannelures are not affected by shooting in my experience, so they are there for the next time too.
Since then I've spent a lot of money on reloading gear and have learned to take care for bullet tension, ie case mouth size. But there is no downside to having the cases cannelured unless you go to much heavier bullets, the cannelures would make them stick out farther, however, they can still be seated deeper, it just pushes the cannelure back out.
The cannelures are not affected by shooting in my experience, so they are there for the next time too.
Next time you buy a box off SD ammo.
Mark a ring around the bullets at the the case mouth with a Black Sharpie pen.
When the black ring disappears inside the case?
That immediately becomes range practice ammo before it gets any worse.
rc
Mark a ring around the bullets at the the case mouth with a Black Sharpie pen.
When the black ring disappears inside the case?
That immediately becomes range practice ammo before it gets any worse.
rc
Trunk Monkey
member
Any time I unload my SD ammunition I place the round I unchambered at the bottom of the magazine and bump the rest of the rounds up one. When each round has cycled twice I shoot them and buy new
Hornady is the ONLY brand that I personally have experienced setback with in SD ammo. I've switched to Federal HST's in my .45's and I've run Speer Gold Dot's 124's in my 9's with no issues. But I've had issues with both Hornady XD and Critical defence in .45 (don't know if it's just a 1911 problem or not). 
I've had terrible bullet set back with Hornady's lineup of SD ammo. I tried the Critical Defense, TAP, and one other I don't recall the name of. I had problems with each one. In some cases I would get bullet setback after one chambering.
I carried Winchester PDX1 for a long time, no problems. I carry Gold Dots now, and no problems still.
I carried Winchester PDX1 for a long time, no problems. I carry Gold Dots now, and no problems still.
I had the same problem with Critical Defense. I noticed that on my 1911 the problem was that the polymer tip would catch slightly on the feed ramp, causing it to hang up and absorb more of the impact than it should have, causing setback. Although I will say that I never had that problem with my M&P.
I tested the Critical Duty 135gr std pressure in my own 9mm's and it took 25 rechamberings before there was measurable setback.
Tomac
Tomac
Some rounds are more resistant to bullet setbacks than others. I noticed some substantial setback in 230gr .45 by Blazer after just 5 chamberings. But my 155 gr .40 Golden Saber carry ammo has had about 20 chamberings with no noticeable difference. When I clean my carry, I take out the +1 round and place it next to a fresh round on a flat surface. If I can see any difference, I break out the calipers. Depending on how much the setback is I either toss it, fire it, or rotate it toward the bottom of the mag.
One thing that struck me odd was the cannelure to begin with. I'm pretty sure 9mm head spaces on the case mouth...so crimping would screw with proper head spacing. Also, it wasn't even crimped into the cannelure...what's the point of the cannelure if it's not even crimped?
Crimping won't necessarily screw with the headspace on a 9mm round. A roll crimp certainly would, but a mild taper crimp should not cause you any problems.
Not really. Crimp grooves can certainly give you the option of roll crimping into said groove, but a cannelure on a semi auto round is not meant for roll crimping. Taper crimp only.
mljdeckard
Member
The best solution I have come up with is to minimize repeated loading and unloading. In my house, with my life situation, I find it best to just leave it loaded most of the time. When I clean, I empty the magazine and reload it again in no particular order. I have never had noticeable setback on a .45 HST. And if it was ME, I would try a lot of different options before I start messing with factory defensive ammo.
Just wanted to clear up a couple of misconceptions about crimping ACP / rimless cartridges, and the serious risks associated with set back on these type cartridges, such as 9mm.
First off, the taper crimp utilized on 9mm shouldn't really be considered as a crimp at all. It's only purpose is to remove any belling of the mouth used during seating, and isn't really a crimp function at all.
And crimping beyond what's necessary to remove the bell would reduce the diameter of the case mouth, thus posing some serious issues. One being that the cartridge head spaces on the case mouth, so there would be a risk of the mouth getting pinched in the throat of the firearm, which could cause extreme pressure spikes. And for those who reload, over crimping swags the bullet down, which also reduces neck tension / bullet hold.
Bullets intended for auto loading cartridges, ACP types, rimless, do not have canelures. There are however a number of factory ammunition manufacturer's that will place a canelure on the brass right at the point where the base of the bullet is seated, and also sometimes between the case mouth and the bullet base, in other words crimped into the bullet shank. This is to help prevent / reduce the possibility of bullet set back, but the bullet it's self will not have a canelure that the mouth crimps into.
As far as asset back in cartridges such as 9mm, it's a very bad thing. As little as .010" of set back can cause a noticeable spike in pressure, and when you get to .030" set back, you can expect to see the effects of pressure doubling, or higher. It doesn't matter if your referring to factory ammunition or reloads, set back is very bad, and can cause catastrophic pressure events. For those who don't reload, .030" would be difficult to visually detect.
GS
First off, the taper crimp utilized on 9mm shouldn't really be considered as a crimp at all. It's only purpose is to remove any belling of the mouth used during seating, and isn't really a crimp function at all.
And crimping beyond what's necessary to remove the bell would reduce the diameter of the case mouth, thus posing some serious issues. One being that the cartridge head spaces on the case mouth, so there would be a risk of the mouth getting pinched in the throat of the firearm, which could cause extreme pressure spikes. And for those who reload, over crimping swags the bullet down, which also reduces neck tension / bullet hold.
Bullets intended for auto loading cartridges, ACP types, rimless, do not have canelures. There are however a number of factory ammunition manufacturer's that will place a canelure on the brass right at the point where the base of the bullet is seated, and also sometimes between the case mouth and the bullet base, in other words crimped into the bullet shank. This is to help prevent / reduce the possibility of bullet set back, but the bullet it's self will not have a canelure that the mouth crimps into.
As far as asset back in cartridges such as 9mm, it's a very bad thing. As little as .010" of set back can cause a noticeable spike in pressure, and when you get to .030" set back, you can expect to see the effects of pressure doubling, or higher. It doesn't matter if your referring to factory ammunition or reloads, set back is very bad, and can cause catastrophic pressure events. For those who don't reload, .030" would be difficult to visually detect.
GS
People worry too much about bullet setback. The only practical problem is a shortened round may fail to feed properly however if it still feeds from the magazine, no problem.
There is a lot of nonsense regarding the danger of pressures being increased by shortening OAL, this may be a problem with some particular powder bullet combination, most likely a very fast powder.
My opinion FWIW is that its a non issue, if it was you would see lots of complaints regarding damaged handguns, pictures of blown up barrels, and other general whining. BTW over the years I've shot many factory shorted 9mm and other caliber rounds, generally after I've decided they may cause a feed problem, and have not experienced any signs of over pressure on the primers, cases or damage to a gun. I've looked for it many times to see if the OAL warning in the Speer Manuals has any real world factual basis.
The way I look at it is that manufacturers produce literally billions of rounds of ammo that is shot every year. Of those rounds many are likely to have been shortened by subsequent multiple chambering.
In the last 50 years reading gun mags and now the internet I've never read a factual KB or other damage to any firearm that's attributed to high pressure from a shortened OAL of a round. Can't find one on Google either.
There is a lot of nonsense regarding the danger of pressures being increased by shortening OAL, this may be a problem with some particular powder bullet combination, most likely a very fast powder.
My opinion FWIW is that its a non issue, if it was you would see lots of complaints regarding damaged handguns, pictures of blown up barrels, and other general whining. BTW over the years I've shot many factory shorted 9mm and other caliber rounds, generally after I've decided they may cause a feed problem, and have not experienced any signs of over pressure on the primers, cases or damage to a gun. I've looked for it many times to see if the OAL warning in the Speer Manuals has any real world factual basis.
The way I look at it is that manufacturers produce literally billions of rounds of ammo that is shot every year. Of those rounds many are likely to have been shortened by subsequent multiple chambering.
In the last 50 years reading gun mags and now the internet I've never read a factual KB or other damage to any firearm that's attributed to high pressure from a shortened OAL of a round. Can't find one on Google either.
During the ammo "crisis" I got out of the practice of 3 and out.
I write the OAL of the new rounds on the box and occasionally check the ones I carry. I deactivate any round 0.010 shorter than new.
Much cheaper than blowing up a gun or a trip to the ER
YMMV
I write the OAL of the new rounds on the box and occasionally check the ones I carry. I deactivate any round 0.010 shorter than new.
Much cheaper than blowing up a gun or a trip to the ER
YMMV
RetiredUSNChief
Member
If this were actually a "non issue", then the subject would not be a matter of concern for loading or reloading ammunition. But it IS a matter of concern.
Nobody says that bullet setback WILL cause a catestrophic failure in a firearm, they say it MAY cause such an event because setback DOES result in increased, and possibly dramatically increased, chamber pressures.
How much of an increase in chamber pressures is a function of the amount of setback, the type of powder used, and how the round was loaded in the first place.
Rounds that are already loaded to +P pressures or higher will necessarily have less margin for error. Rounds that are compression loaded likewise will have less margin for error. This is because such rounds are already loaded in such a fashion as to run them closer to the allowable limits for a given bullet and changing bullet seating depth can cause a dramatic increase in chamber pressures.
While I grant you that most bullet loadings are not likely to be much concern for some nominal amount of setback, you cannot say that the concern is "a lot of nonsense".
Setback happens, especially for excessive multiple chamberings of the same round. When it becomes noticable in a bullet, it should be rotated out of stock as a round routinely loaded in their SD weapon to avoid further setback and complications. Whether one uses it in target shooting or otherwise disposes of it I leave up to the individual.
Bullet setback is a real and serious concern, especially in newer high pressure semi autos. This applies to factory and handloads. Manufactures have gotten a lot better at minimizing it, and sometimes partially eliminating it. Earlier on Rem 185 grain 45 acp plus p could be downright dangerous if chambered too many times (sometimes more than once).
Learned this the hard way, having personally experienced mags being blown out the grip in 1911 45 acp (earlier Rem plus p) and .40 BHP (handloaded rem brass).
When loading higher pressure rounds, am really careful with certain combinations of brass and jacketed bullet dia.
When buying factory rounds, am checking for setback in the pistols it is intended for .
Learned this the hard way, having personally experienced mags being blown out the grip in 1911 45 acp (earlier Rem plus p) and .40 BHP (handloaded rem brass).
When loading higher pressure rounds, am really careful with certain combinations of brass and jacketed bullet dia.
When buying factory rounds, am checking for setback in the pistols it is intended for .
Mainsail
Member
Why are so many of you unloading and reloading your handguns so much?
I pretty much unload mine when I get to the range and shoot the magazine for function. Then clean & reloaded, and stays that way until next time.
I pretty much unload mine when I get to the range and shoot the magazine for function. Then clean & reloaded, and stays that way until next time.
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