Determining max OAL for cast lead bullet and my barrel

[G19]

I read this excellent writeup on determining max OAL for a particular barrel with a particular jacketed or plated bullet. I'd like to adapt this method for cast lead bullets.

I've got 147gr 0.356" cast lead bullets and I'm finding they won't fit into fired cases without belling the case mouth. And once I slightly bell to allow the bullet to insert, the only tension on the bullet is at the mouth and the bullet can easily slide deeply into the fired, unsized case.

If I use resized case, the case holds the bullet tightly enough that when I push the dummy round into the chamber, the bullet gets stuck on the rifling and I need to push it out with a dowel, ruining any potential max OAL measure.

Any suggestions?

[levellinebrad]

Set your bullet seat die to seat the bullet so that your oal is 1.160. Put a very very light crimp on it, just enough so that it holds the bullet. Drop into your barrel to see if it fits. If it doesn't (and it probably will not) seat the bullet deeper and deeper until it does and then seat it about .010 deeper. That will be your max oal.

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[G19]

Set your bullet seat die to seat the bullet so that your oal is 1.160. Put a very very light crimp on it, just enough so that it holds the bullet. Drop into your barrel to see if it fits. If it doesn't (and it probably will not) seat the bullet deeper and deeper until it does and then seat it about .010 deeper. That will be your max oal.

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Using resized cases, I assume?

I guess I can compare those rounds to empty cases to find the right bullet depth that causes the cartridge to headspace on the case mouth.

[levellinebrad]

Yes, resize. Do it just like a fully loaded round except no primer and no powder. I have had some bullets that I had to do this way for the same reason.

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[HOGRIDER]

Some good info in this post:

http://www.brianenos.com/forums/index.php?showtopic=175879&p=1943959

IMO, you can rumble through several "fired" cases and find one the lead bullet will snugly slide into. Worked for me......

Or the last post from link above gives another way to get very close.

[G19]

Set your bullet seat die to seat the bullet so that your oal is 1.160. Put a very very light crimp on it, just enough so that it holds the bullet. Drop into your barrel to see if it fits. If it doesn't (and it probably will not) seat the bullet deeper and deeper until it does and then seat it about .010 deeper. That will be your max oal.

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OK, so following this suggestion, I seated a bullet to an OAL of 1.160. Crimped it to 0.378", which is just enough to remove the bell ( 0.378" = 0.356" bullet diameter + 2 * 0.011 case thickness).

And very surprisingly, it seems like that seats far enough to headspace off the case mouth.

Here's a pic of an empty case sitting in the barrel:

Here's a pic of the 1.160 OAL dummy round sitting in the barrel:

I guess I'm a little confused, as everything I've read/heard suggests that 1.160" OAL is too long for a cast lead 147gr RN, but it seems to seat in the barrel just fine (though I haven't checked it in a magazine yet).

Edited May 20, 2014 by G19

[levellinebrad]

It's all about the bullet profile and your individual barrel. Make sure the round is pushed all the way in and make sure it will spin freely. I have had bullets that would pass the plunk test at 1.190. They wouldn't even fit in the magazine. You can work down from there if you need to to find your most accurate oal. I have found that my must accurate rounds for 147gr Ln are usually around 1.135 but that is in my barrel.

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[levellinebrad]

Oh, do this with at least 10 different dummy rounds just to make sure. Individual bullets could be deformed and allow for a longer oal.

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[G19]

Oh, do this with at least 10 different dummy rounds just to make sure. Individual bullets could be deformed and allow for a longer oal.

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OK, so using a starting OAL of ~1.160, I made up 10 dummy rounds all at that starting OAL, and if they didn't pass the plunk test, I seated them farther (in small increments) until they passed.

Results - OAL at which the plunk test is passed:

1.160

1.150

1.141

1.159

1.158

1.125

1.141

1.160

1.125

1.160

Everything is above 1.140 except for two, both of which had to be seated down to 1.125 to pass the plunk test.

How do I use this to figure out the max OAL that I should be loading to? Go all the way down to 1.125? Factor in a cushion to that of maybe 0.010, so 1.115?

[levellinebrad]

I would personally use 1.125 as my max oal. You should be safe at that length.

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[G19]

I would personally use 1.125 as my max oal. You should be safe at that length.

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Thanks for the help.

Is it normal to have as much variation in OAL that plunks in the chamber when using cast lead as I experienced? I'm guessing jacketed bullets exhibit less variation?

Edited May 21, 2014 by G19

[levellinebrad]

I have seen that much variation in some cast lead. Iv have personally never used a metal jacketed bullet. I am currently using xtreme 124gr and did not notice that much variation. I am loading those at 1.130 in a cz sp01. Make sure you adjust your powder down if your load data shows a longer oal.

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[HOGRIDER]

Don't remember if you mentioned what brand of pistol your barrel is in; but I have seen many different length OALs pass the clunk test in the stock Glock barrels due to the larger specs of the chamber along with the rifling being farther away from the chamber when compared to aftermarket barrels with match grade chambers and conventional rifling.

In my case, I determined the approximate desired OAL for the Bar Sto barrel and settled on 1.120". The lead and jacketed reloads shoot just fine in either the Bar Sto or the Glock barrel though I am currently only shooting jacketed rounds in the stock barrel.

Currently loading 147gr Missouri LFP along with Zero 147gr JHP.

IMO, 1.125 should work fine if your unable to determine approximately at what length (OAL) the bullet is contacting the rifling.

Again, as levellinebrad stated, it all depends on your specific bullet profile and barrel.

HR

[G19]

Don't remember if you mentioned what brand of pistol your barrel is in;

I hadn't mentioned it. It's a M&P9L.

IMO, 1.125 should work fine if your unable to determine approximately at what length (OAL) the bullet is contacting the rifling.

Again, as levellinebrad stated, it all depends on your specific bullet profile and barrel.

Like you said, it all depends on the specific bullet profile. With some of these cast lead bullets, a cartridge of 1.160 plunks and spins freely, and with others, I need to shorten it down to 1.125 to get the same result.

I'm using a Lee seating die. Would it help to get a custom bullet seating plug from Lee?

Edited May 21, 2014 by G19

[G19]

Some good info in this post:

http://www.brianenos.com/forums/index.php?showtopic=175879&p=1943959

IMO, you can rumble through several "fired" cases and find one the lead bullet will snugly slide into. Worked for me......

Or the last post from link above gives another way to get very close.

Another data point: after sifting through a bunch of fired cases, I found one I could get the bullet into. I couldn't quite do the 'Wobbly' measurement as the lead bullet would just get stuck on the lands and not push back into the case (very tight fit of bullet in the case).

I started with an OAL of ~1.200 and using the seating die, seated it incrementally to the point where it wouldn't get stuck in the barrel (had to use a dowel to push it out each time, but because the bullet was such a tight fit in the case, pushing the bullet out of the barrel with a dowel didn't push the bullet any farther into the case). Anyway, at 1.175 OAL, the cartridge headspaces on the rim with the bullet in contact with the lands (cannot spin the cartridge) AND the cartridge can be removed by hand (so it's touching the lands, but not jammed into the lands).

Using the setback of 0.015" that Wobbly suggests in his post (linked to in my OP), that gets me to 1.160. From the earlier data, I know that some of these bullets will plunk and spin freely (no contact with lands) at an OAL of 1.160.

So if all these lead bullets were uniform, I suppose that means I could probably get away with loading to an OAL of 1.160. But since cast lead bullets (or at least the ones I have) aren't very uniform, it seems I should factor that in.

Life was a lot simpler when I just bought factory FMJ!

Edited May 21, 2014 by G19

[levellinebrad]

But it's a lot cheaper buying lead. Who's bullets are you using and what powder?

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[HOGRIDER]

G:

IMO, if your only going to be loading for the M&P9L, I would standardize my OAL for 1.150" and go from there. Next I would see if the bullet appears to be seated deep enough in the case at that OAL. As your tests have shown, you can go shorter if needed.

Maybe compare your lead load's seating depth/OAL to a factory load with similar shaped/size FMJ bullet........sometimes seating longer will expose to much of the "gripping" surface of the bullet.

I still think your on the right track! Just don't give up!

[G19]

But it's a lot cheaper buying lead. Who's bullets are you using and what powder?

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Lucky 13: http://lucky13bullets.com/index.php?main_page=product_info&cPath=2&products_id=145

Powder is IMR SR 7625.

[G19]

G:

IMO, if your only going to be loading for the M&P9L, I would standardize my OAL for 1.150" and go from there. Next I would see if the bullet appears to be seated deep enough in the case at that OAL. As your tests have shown, you can go shorter if needed.

Maybe compare your lead load's seating depth/OAL to a factory load with similar shaped/size FMJ bullet........sometimes seating longer will expose to much of the "gripping" surface of the bullet.

I still think your on the right track! Just don't give up!

After thinking about my results for a bit, I was thinking I'd load some at 1.140" and see how it goes. Didn't want to go longer at first since I'm a new reloader and I'm sure there will be more OAL variability my first few batches and wanted to give myself some leeway on both sides since I know a little above and below 1.140 will fit in the magazine and feed and fully chamber (tested with those 10 dummy rounds mentioned earlier).

If that OAL works, and once I'm a bit more familiar with operating the XL650 and (hopefully) my OAL variability shrinks, then I'll try to stretch it out to 1.150".

Nope, not giving up . . . too much invested in equipment to even afford factory ammo!

Edited May 23, 2014 by G19

[levellinebrad]

Lucky 13 makes the best lead bullets I have shot. My question would be this, why do you want to load longer? I assume that you believe that a longer oal decreases pressure which is true but only to a point. When you decrease oal, you should also decrease the weight of powder you put in the case. The 1.140 does not fit your Chamber every time so I recommend the 1.125. There is a lot of load data on the cz forum for the 7625 but I think most of it is plated which you can use. I just checked my log book. I am loading the lucky 13 124gr rn at 1.110 with 3.4gr of solo1000. I have loaded hotter but I have that listed as my most accurate and that is the load I use for uspsa. I was making 1010 fps.

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[G19]

Lucky 13 makes the best lead bullets I have shot. My question would be this, why do you want to load longer? I assume that you believe that a longer oal decreases pressure which is true but only to a point. When you decrease oal, you should also decrease the weight of powder you put in the case. The 1.140 does not fit your Chamber every time so I recommend the 1.125. There is a lot of load data on the cz forum for the 7625 but I think most of it is plated which you can use. I just checked my log book. I am loading the lucky 13 124gr rn at 1.110 with 3.4gr of solo1000. I have loaded hotter but I have that listed as my most accurate and that is the load I use for uspsa. I was making 1010 fps.

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I was thinking of loading longer for greater accuracy. But you're right, I should probably start with 1.125" and see how it goes. And I suppose loading too long and having the occasional round touch the rifling creates the potential for an overpressure situation?

I have the Lee book and the only listing for SR 7625 for 147gr bullets is for 147gr XTP. Starting grains at 2.8 with a max of 3.3gr. Even at the max, velocity would only be 844fps. But I'll load some up closer to the starting grain amount and chrono it.

Thanks for the lead, I'll check the CZ forum re: 7625.

Edited May 24, 2014 by G19

[captain037]

I use a hornady oal guage. Cheap and easy. Never used it on pistols but works great on rifles. They do work on pistols, you just have to get the dummy case for your caliber.

[tires2burn]

I got curious and tried a method that I read about somewhere. Resize a case and cut a slot with a dremel about 1/2" into the mouth of the case. Insert your bullet till it stays and then use a black marker to color the exposed part of the bullet. Push it into your barrel and the slot lets the bullet slide into the case when it hits the rifling. Carefully remove the round and measure. Reduce the length about .015 and you should be good to go.

[texasref]

I shoot 147's myself. Coated LCN. Have never had a problem.

Your OAL should be 1.160". Mine is set to 1.155" which is close enough. Don't set the bullet too deep or you'll run the risk of increasing the pressure without meaning to. Remember 35,000 is the max pressure-period.

Always resize brass and bell the mouth slightly. You can even chamfer the case if you want to help get the bullet started.

Crimp the case enough to be able to see a very small shiney ring at the mouth. This will ensure that when the round goes into battery the bullet is not seated deeper(the worst thing that can happen).

You can get in touch with Donnie at Bayou Bullets and get some .355" bullets if this problem persists. Most shoot the .356" because we need to fill the barrel as lead is soft and expands.

Good luck, and remember...........Don't seat too deep.

[G19]

I ended up loading to 1.125" OAL with Lucky13 147gr lead bullets and IMR SR7625 at various powder charges.

At 2.9 grains of powder, the rounds would not feed and would get hung up on the feed ramp. At increasing powder charges, the problem occurred less frequently. At 3.2 grains, 1 out of 10rds didn't feed. At 3.3 grains, all 10rds I had loaded fed fine, but that's obviously a small sample size.

I got curious and tried a method that I read about somewhere. Resize a case and cut a slot with a dremel about 1/2" into the mouth of the case. Insert your bullet till it stays and then use a black marker to color the exposed part of the bullet. Push it into your barrel and the slot lets the bullet slide into the case when it hits the rifling. Carefully remove the round and measure. Reduce the length about .015 and you should be good to go.

I then tried the above method of determining OAL, which gave me an OAL of 1.165". Backing off 0.015" to get the bullet off the lands gives 1.150". To be conservative, I took another 0.005" off and loaded a bunch of rounds to 1.145".

So at 1.145", 3.3gr of SR7625 and Lucky13 147gr lead bullets, I had two failures to feed out of ~110 rounds.

Any suggestions for how I should go about further reducing this FTF issue? Load to a longer or shorter OAL? More powder?