I purchased 2000 165 grain .40 cal pulled bullets last year and set down to reload a few the other day. First I discovered that these bullets are quite a bit longer than any other 165 grainers I have loaded so my first thought was to push the COAL out to 1.135 which is max. Well come to find out that the bullet OAL is all over the place and even 2 bullets that are the same OAL don't seat the same as the heavy pull marks effect the seating. I am getting COAL from 1.115 to 1.145. I shot a few with 6.8 grains of Unique my usual charge only to find some pressure problems. I am planning on backing the charge down to 6.0 grains of unique and see how this works as just a plinking load. I used the barrel of my XD and found that at 1.145 the case is making contact and the bullet is not engaging the rifling yet, I can still see the case mouth looking down the barrel with a light. The bullets have an F stamped in the nose which I would assume means there Federal. Does this sound reasonable?
.40 cal coal ?
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bigfinger76
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What do you mean by "heavy pull marks"?
LiveLife
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If the crimp cut through the copper, your bullets may be plated bullets and not jacketed. Still, this may or may not affect accuracy.
Depending on the bullet manufacturer, length of bullets may vary. For determining cartridge OAL, where the bearing surface of the bullet starts (part of bullet base that engages the rifling) is more important along with the nose tip shape (ogive).
The barrel drop test to determine the Max OAL is based on the bearing surface of the bullet and not the consistent bullet tip length (Max OAL - length of loaded round that will allow the round to fall freely into the chamber with a "plonk" and spin without hitting the start of rifling).
Once the Max OAL is determined, next you function check the dummy round (no powder/no primer) to detetmine the working OAL for your pistol/barrel/magazine by feeding the dummy round from the magazine and releasing the slide without riding it. Max OAL can also be the working OAL but sometimes working OAL is shorter than Max OAL. The variation in bullet tip length could be a factor in determining the working OAL.
Also, if the bullets are longer and get seated deeper, you need to calculate the seating depth (OAL - bullet length = max seating depth) so you are not compressing the powder charge (measured from the case mouth down to top of powder charge using the end of the calipers) which will have an adverse effect on chamber pressure.
Depending on the bullet manufacturer, length of bullets may vary. For determining cartridge OAL, where the bearing surface of the bullet starts (part of bullet base that engages the rifling) is more important along with the nose tip shape (ogive).
The barrel drop test to determine the Max OAL is based on the bearing surface of the bullet and not the consistent bullet tip length (Max OAL - length of loaded round that will allow the round to fall freely into the chamber with a "plonk" and spin without hitting the start of rifling).
Once the Max OAL is determined, next you function check the dummy round (no powder/no primer) to detetmine the working OAL for your pistol/barrel/magazine by feeding the dummy round from the magazine and releasing the slide without riding it. Max OAL can also be the working OAL but sometimes working OAL is shorter than Max OAL. The variation in bullet tip length could be a factor in determining the working OAL.
Also, if the bullets are longer and get seated deeper, you need to calculate the seating depth (OAL - bullet length = max seating depth) so you are not compressing the powder charge (measured from the case mouth down to top of powder charge using the end of the calipers) which will have an adverse effect on chamber pressure.
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oncewaslost
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I ended up buying a lee bullet sizer to run pulled 155g FMJ bullets through and smoothe the burr out somewhat. My OAL will still vary from 1.125 to 1.137 . I check every one after seating and run it through the seater again if it is over 1.135 . I know it is not necessary for my gun but it doesn't take that long and I am compulsive anyway
Sounds like two things going on. Those are plated bullets. And your seater plug doesn't fit. Are you using a round nosed seater plug with FP bullets?
Look at the tip of the bullets. Rather than getting seated as deeply as they should, the ones with the longer OAL are probably getting squished on the edge of the flat point. (This happens cuz plated bullets are dead soft lead, like a jacketed bullet, but the plating is much thinner). If you further examine the headstamps, you will find a corelation of OAL to headstamp. The thicker the brass, the more the tip of the bullet is squished, and the longer the OAL.
Buy or make a better fitting seater plug, and this problem disappears.
A Lyman M die might improve or fix the problem, too. A typical pistol flaring die expands only the first fraction of the case. The bullet displaces unexpanded case towards the bottom. So variation in brass thickness has a marked effect on seating force.
The M die expands deeper into the area where the bullet seats. Variation in brass thickness has less of an effect on seating force.
Look at the tip of the bullets. Rather than getting seated as deeply as they should, the ones with the longer OAL are probably getting squished on the edge of the flat point. (This happens cuz plated bullets are dead soft lead, like a jacketed bullet, but the plating is much thinner). If you further examine the headstamps, you will find a corelation of OAL to headstamp. The thicker the brass, the more the tip of the bullet is squished, and the longer the OAL.
Buy or make a better fitting seater plug, and this problem disappears.
A Lyman M die might improve or fix the problem, too. A typical pistol flaring die expands only the first fraction of the case. The bullet displaces unexpanded case towards the bottom. So variation in brass thickness has a marked effect on seating force.
The M die expands deeper into the area where the bullet seats. Variation in brass thickness has less of an effect on seating force.
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They are not plated bullets, I do not buy plated if I want soft I shoot cast. I purchased some Speer Gold Dots that were pulled that have the same puller marks. I sorted the Speer and saved about 500 bullets for good and loaded the other 500 for targets but didn't have the COAL issue.
I am using a SWC seater but might turn an extra SWC seater into a flat seater and see if it helps by just pushing on the nose instead of the ogive.
Brass head stamp is as much of a non issue as I can make it as I am loading by head stamp.
I am using a SWC seater but might turn an extra SWC seater into a flat seater and see if it helps by just pushing on the nose instead of the ogive.
Brass head stamp is as much of a non issue as I can make it as I am loading by head stamp.
oncewaslost
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http://www.thehighroad.org/showthread.php?t=633986&highlight=pulled+40+burr
Here was my thread with pictures of the pullmarks. Those 155g fmj are the only bullets I have ever had a variance of more than a few thousandths. They were a bargain. Lately I have been loading the pulled 135g gd, I reall like them!
Here was my thread with pictures of the pullmarks. Those 155g fmj are the only bullets I have ever had a variance of more than a few thousandths. They were a bargain. Lately I have been loading the pulled 135g gd, I reall like them!
LiveLife
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Sorry to burst your bubble. Speer Gold Dots may have thicker plating than other plated bullets but they are indeed plated bullets. Same for ATK/Speer trademarked Total Metal Jacket (TMJ) bullets - http://www.speer-ammo.com/products/gold_dot_const.aspxMuddydogs said:
BTW, I also like Gold Dot bullets for their consistent expansion performance.
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