How much bullet set back is exceptable in auto loaders

[Metal God]

I've been reloading centerfire rifle for years but just started loading for hand guns . This question started out regarding crimping lead bullets and how much is needed . It now has moved to a general question to any bullet style . I started doing some test with different crimp strengths to see what holds the bullet best .

I was using the 45acp 200gr XTP bullet in the test . First I'll ask which of these bullets do you think has the right crimp ?



Ok now that we have a base line to work with . I seated a bullet and gave it a medium crimp . Likely something like the center bullet above . I then placed it in a mag and chambered it by releasing the slide on a Springfield 1911 and letting the slide fly home . I got .005 in bullet set back and was surprised at that . I really did not think I'd get any .

Now I have a couple threads going about 45acp reloading and this crimp thing has come up and I have received some good info . Some say my flare was to much and others feel it may be my COAL . . I thought I start a fresh thread dedicated to this point .

Now that I know I was getting bullet set back with my current method of flaring , seating & crimping I thought I'd try a couple more test all still using the same 200grXTP bullets ( each new test with new case and bullet ) and Springfield 1911 .

First I re-sized some cases then adjusted the flare to just barely give enough to seat the bullet with out shaving copper off . I then seated the bullet to my COAL of 1.240 and gave it a medium crimp . I then did the chambering test and the bullet set back .007 .

Ok no problem I do all that agian with new case and bullet but this time I crimp it as much as my die will crimp, VERY VERY heavy crimp . I then do the chambering test . I get bullet set back of .006 . I chamber it 4 more times in a row for a total set back of .037 . Now this is measuring with my .400 comparator .

OK no problem lets see if it's my seating depth so I do all the sizing , flaring etc but seat the bullet to Hornady's per manual 1.210 . I then give the cartridge a medium heavy crimp . I then chamber test the round . Any guesses what happen -------------- yep got a set back of .007 . So I chambered that round another 4 times for a total set back of .031 .

Either I'm doing something very wrong or set back is a normal thing . Now everything I've read about crimping says you crimp to AVOID set back . I don't ever remember reading anything that said you crimp to keep set back to a MINIMUM .

Is this just something you can't stop with out a crimp groove ?

How many of you get set back and are ok with it and how many have actually tested for bullet set back ?

[stilly]

Setback can be a normal thing in autoloaders. Is it a new gun? Maybe it is a bit harsher until things settle in.

But when EVERYONE is done talking, here is what you will realize. So your pill is .007 back more than normal. IT only (99%) happens once and you are shooting it so who really gives a damn about setback as long as it cycles and works for you.

Do not get me wrong, I TOTALLY get what you are saying; I was so ****ing anal and I still AM but my god I am sure I would have a heart attack if I started measuring setbacks on some of my stuff and then tried to fix it with NO foreseeable results.

Am I wrong? No. There WILL be setback, but if it bothers you, then by all means, keep loading a tad longer to compensate for that. And, try it in a different gun. The other thing you can do is very gently plop the round into the chamber with the barrel pointed down and THEN let the slide go home, but then what about the rest of your shots?

Setback happens...

So act like some crazy scientist for a multibillion dollar corp and DEAL with it.

[h.charlie]

The crimp on the left looks like it deformed your bullet you only need a light crimp to remove what was done by the expander in my opinion, other then that stilly delt with this pretty well

[J-cat]

Try seating without belling the case. Skip the expander step. Then crimp minimally. A lot of these bullets have enough roundness at the base that expanding and belling is not necessary.

Second, like Stilly said, so what if you get setback? Why do you feel the need to load and unload the gun so many times?

FWIW, I get a little setback, not as much as you, with minimal crimp and I skip the expander/bell step unless I'm loading lead. For bullets with sharp bases, I bell slightly using a Lee universal expander. It's a straight cone without an expander. It bells only. That way I get maximum case tension on the bullet.

[pacrat]

Is this just something you can't stop with out a crimp groove ?

No, you can't stop it without a crimp groove to lock the bullet to the case. And if you had a crimp groove, you can't use it in a 45acp. They headspace off of the case mouth.

I use a taper crimp and don't worry about no steeenk'n setback. On HD ammo that gets cycled into the chamber but not fired. If when I rotate ammo it shows a little set back [by eye] not mic. Load it into the mag last so it chambers first. Ride the slide into battery gently and then bump the slide with heel of hand to assure full forward slide position with lugs locked.

If you repeatedly slam factory ammo into the chamber from the mag it will show setback. BTDT.

Also since you are fairly new to pistol loading. Don't drop one in the chamber of a 1911 and let the slide slam forward off of the slide lock. You can break or damage your extractor doing that. It is designed for the round to "slide up" into the extractor. Not "snap over" the extractor groove.

In the REAL world, .004" is the thickness of the average human hair. Even .007" is still shy of the thickness of 2 human hairs. It is not humanly possible for a flesh and blood person to ever hold steady enough to discern this tiny amount of variance in seating depth on a target. Unless your name is Mr. Ransom Rest.

Start enjoying and quit stressing.

JM2c

[AGunNut2]

You could probably stop it with a cannelure under the base of the bullet. I noticed that Magtech's CBC-stamped cases in .45 Colt have a second cannelure at the bullet's base, loaded ammo and even new cases (which may or may not match your projectile and depth).

[stilly]

No, you can't stop it without a crimp groove to lock the bullet to the case. And if you had a crimp groove, you can't use it in a 45acp. They headspace off of the case mouth.

I use a taper crimp and don't worry about no steeenk'n setback. On HD ammo that gets cycled into the chamber but not fired. If when I rotate ammo it shows a little set back [by eye] not mic. Load it into the mag last so it chambers first. Ride the slide into battery gently and then bump the slide with heel of hand to assure full forward slide position with lugs locked.

If you repeatedly slam factory ammo into the chamber from the mag it will show setback. BTDT.

Also since you are fairly new to pistol loading. Don't drop one in the chamber of a 1911 and let the slide slam forward off of the slide lock. You can break or damage your extractor doing that. It is designed for the round to "slide up" into the extractor. Not "snap over" the extractor groove.

In the REAL world, .004" is the thickness of the average human hair. Even .007" is still shy of the thickness of 2 human hairs. It is not humanly possible for a flesh and blood person to ever hold steady enough to discern this tiny amount of variance in seating depth on a target. Unless your name is Mr. Ransom Rest.

Start enjoying and quit stressing.

JM2c

OOPS. My way is ONLY for operators. If you do not operate then yes, do not do that.

BTW, the ONLY other way to limit or remove setback is to get the shells with the cannelures (what else are they called?) ON THE BRASS or get the machine to MAKE YOUR OWN but this is a VERY extreme way of dealing with setback and that machine is kinda on the expensive side. I have seen it for sale at Corbin or somewhere though.

It is TOTALLY cool, but also totally expensive for being a one trick pony and I bet ONE or TWO people in this forum MIGHT have ever seen one in real life.

The good news is that you can order online from their secure shoppingcart... (LoL)

http://www.corbins.com/pcm-2.htm

http://www.corbins.com/pr-4070.htm

[pacrat]

OOPS. My way is ONLY for operators. If you do not operate then yes, do not do that.

Like the "operators" in the movies who FLIP open their DA revolvers to check the load?

No Thanx

[stilly]

I am in an elite group of operators. We only know the type of drug that we have confiscated by pulling out an illegal switch blade or stiletto, cutting it open and then licking a small amount of powder off the blade...

If you do not operate on THAT level, then you do not operate on my level and if you do not operate on my level then you can consider yourself a NON-operating operator...

[Metal God]

Alrighty then lol .

I guess I had put to much thought into seating depth and handgun rounds . I kept reading seating the bullet deeper effects pressure a lot . That's why I was concerned about my bullet set back . I guess I'll just have to DEAL WITH IT . It took me quite a bit of testing before I was comfortable not crimping my AR loads .

I'm still surprised I can't stop my bullet from moving . I wonder if the cartridge were to sit awhile it would lock into place . I know I've had rifle rounds that were much harder to pull after they had been sitting around for a year then I remember they were the first time I pulled them .

[silas3d]

I was concerned about crimp when I started loading plated bullets (200gr SWC Rainier) for warm 45lc loads. I did some experiments and found that I only needed ~1/2 turn of the Lee FCD (i.e. "light crimp") and they worked perfectly. The 6th round's COL had not budged after firing the first 5 rounds in my Blackhawk.

I know it was a different use case, but after my experience I'm not all that surprised at what you found if the copper on your bullets was as thin as the Rainiers which would mean that you're basically hammering the back of a lead bullet and the real mechanism for holding it in place is the side wall friction.

[silas3d]

p.s. "light crimp" with the Lee FCD leaves even less of a grove in the copper than the one on the left in our picture...

[Metal God]

FWIW those bullets in the pic are Hornady 200gr XTP JHP not plated as well as all bullets in the test .

[stilly]

Alrighty then lol .

I guess I had put to much thought into seating depth and handgun rounds . I kept reading seating the bullet deeper effects pressure a lot . That's why I was concerned about my bullet set back . I guess I'll just have to DEAL WITH IT . It took me quite a bit of testing before I was comfortable not crimping my AR loads .

I'm still surprised I can't stop my bullet from moving . I wonder if the cartridge were to sit awhile it would lock into place . I know I've had rifle rounds that were much harder to pull after they had been sitting around for a year then I remember they were the first time I pulled them .

I am glad to see that you are not going to beat yourself to death trying to fix this. It is like jumping into a pool and trying to push the water away so you do not get wet. But you know what happens if you can do that successfully? You break a leg from hitting the floor on the pool... So you are gonna get it one way or another. Best just to do what you can to control everything else as best you can.

AND, if you want to shell out the big bucks for a dry suit that WILL allow you to jump into a pool and not get wet, then here you go: http://www.corbins.com/pr-4070.htm

As a bonus, LOOK for some of these shells that are already out there. I believe thre are a LOT of range pickups that I have come across that have those cannelure marks around the case and THOSE will prevent the bullet from setting back too much.

But I am glad to see you now know how to DEAL WITH IT!

Now, go buy yourself an XM42 because you earned it!

[TKM]

Some of us shoot 460Rowland and have no issues with regular 45acp regardless of chamber depth.

We also don't get bullet setback, which is nice.