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Posted: 2/20/2010 2:40:25 PM EDT
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Ok, so I have been doing some load developement with various powders & bullets.
I think I have a couple of promising loads. Seating depth/OAL is the final step for a pet load (from what I have been told) What increments should I start playing around in OAL? Do you start a maximum magazine length & just leave it there? Do you start at max OAL & work down in ? increments until minimum? The 2 loads I will be developing are... Varget with Hornady 55 gr FMJ's TAC with Nosler 69 gr HPBT They are both for an AR 16'' w/ 1/9 |
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I have had my best luck with 22-250, 308 and 30-06 by measuring the closed bolt. Easy to do too!
Just make up a dummy round (no powder or primer) with an empty case and your bullet. Set the bullet into the case and put it in your rifle. Close the bolt and let the bolt push the bullet into the case. Remove the dummy round and measure it with your calipers and record it in your notes. Now, unscrew your bullet seater die and run the bullet up into the die. Screw the seat down until you fell it touch the bullet. Let the ram down and then give the seater another very slight turn down. Measure the bullet again and record this in your notes. You should now have a bullet that will be seated just behind the rifling. Sometimes when you are making the dummy round the bullet might stick in the rifling when closing the bolt. No problem, jusr very carefully run a rod down the muzzle to push it out. |
| Hornady 55 FMJ's just load to recommended length. Seat them from 2.200" out to 2.230". I seat them to 2.218-2.220" and it puts the cannelure where I want it for crimping. I've seen no difference in accuracy trying to seat them longer. Now some other military and commercial 55 FMJ's have a longer sharper tip profile and they are designed to be seated to an oal at 2.250" but the Hornady's have a blunter tip shape. As far as the 69 or 77 match hollowpoints, I'd load them to a maximum length at 2.260", which because of the irregular hollowpoint tip, some will be shorter than the 2.260". 2.250" up to a max of 2.260" for your 69 bthp's. This is for AR's and their magazines. For a bolt rifle then you could try seating them at longer lengths. |
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Quoted: s. You should now have a bullet that will be seated just behind the rifling. There are many ways to get there, but that's the key right there. Setting the distance between the bullet and the rifling. In some cases the magazine would limit you, which is why you've heard many people say they run theirs out to max magazine limits. IMHO, Cartridge OAL should be the FIRST step, not the last. Because as you change the seating depth, you're changing the pressure (all else being equal)...which changes *everything* about how that round will fire in your weapon. |
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Quoted:
I have had my best luck with 22-250, 308 and 30-06 by measuring the closed bolt. Easy to do too! Just make up a dummy round (no powder or primer) with an empty case and your bullet. Set the bullet into the case and put it in your rifle. Close the bolt and let the bolt push the bullet into the case. Remove the dummy round and measure it with your calipers and record it in your notes. Now, unscrew your bullet seater die and run the bullet up into the die. Screw the seat down until you fell it touch the bullet. Let the ram down and then give the seater another very slight turn down. Measure the bullet again and record this in your notes. You should now have a bullet that will be seated just behind the rifling. Sometimes when you are making the dummy round the bullet might stick in the rifling when closing the bolt. No problem, jusr very carefully run a rod down the muzzle to push it out. Thats pretty much the same thing as using a Hornady OAL guage. It will measure to the lands from the bullet's ogive. I have been told thats pretty useless to try in a AR |
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Quoted:
Thats pretty much the same thing as using a Hornady OAL guage. It will measure to the lands from the bullet's ogive. I have been told thats pretty useless to try in a AR Loading to mag length pretty much guarantees that you're going to have a bunch of jump before the lands. You can't seat them just off the lands and still have them anywhere close to fitting in a magazine. |
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Quoted:
Quoted:
Thats pretty much the same thing as using a Hornady OAL guage. It will measure to the lands from the bullet's ogive. I have been told thats pretty useless to try in a AR Loading to mag length pretty much guarantees that you're going to have a bunch of jump before the lands. You can't seat them just off the lands and still have them anywhere close to fitting in a magazine. So, is it or is not possible to just "kiss'' the lands in an AR without going over mag length? |
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Quoted:
Quoted:
Quoted:
Thats pretty much the same thing as using a Hornady OAL guage. It will measure to the lands from the bullet's ogive. I have been told thats pretty useless to try in a AR Loading to mag length pretty much guarantees that you're going to have a bunch of jump before the lands. You can't seat them just off the lands and still have them anywhere close to fitting in a magazine. So, is it or is not possible to just "kiss'' the lands in an AR without going over mag length? No, like I said above. Mag length max is 2.260, or thereabouts. I did a test with some Hornady 75gr BTHP's. In order to have them loaded to .005" off the lands, they'd have to have an overall length of 2.343'" in one of my AR's and 2.357" in another. WAY over mag length. On the bright side, that ammo shoots sub-moa for me loaded to mag length, so it clearly tolerates the jump pretty well. |
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