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Posted: 5/4/2015 11:11:55 PM EDT
| So my head to ogive touching the lands is 3.287 should I go .282 .277 .272 or .277 .267 .257 fo my seating depth. Thanks folks. |
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If it is a hunting rifle I would stay about .020" off of the lands if your magazine will allow it. This will give you enough tolerance so you don't accidentally stick one in the barrel when you go to unload at the end of the hunt.
If you are going shoot them single shot you can load them touching the lands. Loading single shot also allows you to seat shallower in the case than if they have to withstand the rigours of feeding from a magazine. Motor1 |
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Quoted:
So my head to ogive touching the lands is 3.287 should I go .282 .277 .272 or .277 .267 .257 fo my seating depth. Thanks folks. If the bullets are plain cup and core types, start with the bullets touching the lands, then .010", .020", .030" and .040" back. If the bullets are solid shank types, e.g., Nosler Ballistic Tips, then start your ladder at about .020". If you are using solid bullets like the Barnes TSX etc., then start at .040" then .050". The huskier bullets need some room to get going before hitting the lands, otherwise excessive pressure can result. good luck - CW |
| Yes it does have a mag but there's no way I can use it and have a good seating depth. The bullets I've chosen for testing are Berger 200gr match hybrid target. Berger sent me load data starting at 54gr of h4350 with a max of 60gr. I have loads made at 54gr 3.282 .277 .272 .267 and the same for 55 and 56gr. 3.287 was touching the lands with my hornady oal gauge. Does what I have going sound good to start or should I take those .282 to .257? I'm going for elr target with this poor dude setup,I get a 1/2 to 1/4 moa load I'm gtg. I'm hellbent to get a 36" plate at 1600 lol,the rifle is a f&n tsr xp. |
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So I went to sportsmans and measured a bunch of ammo
Fed 180gr sp 3.205 Fed 165 partition 3.200 Nos 180 accubond 3.181 Rem corlokt 150 3.225 And the stuff I fired Winchester 180 pp 3.230 so dam .057 off the lands and some .100 off the lands. Am I going to be safe starting .010 off with these 200gr Berger,they have a huge bearing surface. |
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This is straight from Berger.
The folks at Berger Bullets have just released an interesting technical bulletin that describes methods for optimizing bullet seating depths with Berger VLDs. The document explains how to find the OAL “sweet spot” for VLDs in your rifle. Interestingly, while VLDs commonly work best seated into the rifling .010? or more, Berger’s research indicates that, in some rifles, VLDs perform well jumped .040? or more. This is a significant finding, one that’s backed-up by real-world testing by many shooters. The key point in Berger’s report is that: “VLD bullets shoot best when loaded to a Cartridge Overall Length (COAL) that puts the bullet in a ‘sweet spot’. This sweet spot is a band .030? to .040? wide and is located anywhere between jamming the bullets into the lands and .150? jump off the lands.” CLICK HERE to download Berger VLD Tuning Tips Writing in the report, Berger’s Eric Stecker observes: “Many reloaders feel (and I tend to agree) that meaningful COAL adjustments are .002 to .005. Every once in a while I might adjust the COAL by .010 but this seems like I am moving the bullet the length of a football field. The only way a shooter will be able to benefit from this situation is to let go of this opinion that more than .010 change is too much (me included).” For target competition shooters (for whom it is practical to seat into the lands), Berger recommends the following test to find your rifle’s VLD sweet spot. Load 24 rounds at the following COAL: 1. .010? into (touching) the lands (jam) 6 rounds 2. .040? off the lands (jump) 6 rounds 3. .080? off the lands (jump) 6 rounds 4. .120? off the lands (jump) 6 rounds Berger predicts that: “One of these 4 COALs will outperform the other three by a considerable margin. Once you know which one of these 4 COAL shoots best then you can tweak the COAL +/- .002 or .005.” OBSERVATION and WARNING Berger may definitely be on to something here, and we applaud Berger’s testers for testing a very broad range of seating depths. However, we want to issue a STRONG WARNING to reloaders who may be inclined to try the 4-step method listed above. Be aware that, as you load your cartridge progressively shorter, putting the bullet deeper into the case, you will be reducing the effective case capacity dramatically. With smaller cases, such as the .223 Rem and 6mmBR, moving from .010? into the lands to .080? and .120? off the lands can CAUSE a dramatic pressure rise. So, a load .010? into the lands that may be safe can be WAY OVERPRESSURE with the bullet seated .120? off the lands (i.e. .130? deeper in the case, the difference between .010? in and .120? out). To illustrate, using a QuickLOAD simulation for the 6mmBR cartridge, moving the bullet 0.130? deeper into the case can raise pressures dramatically. With the Berger 105 VLD seated .010? in the lands (with 0.220 of bearing surface in the neck), and a charge of 30.0 grains of Varget, QuickLOAD predicts 60,887 psi. (This is using ADI 2208 data, and a 5500 psi start initiation value). If we move the bullet back 0.130? further into the case, QuickLOAD predicts 64,420 psi (even after we drop start initiation pressure to the “default” non-jammed 3625 psi value). The 64,420 psi level is way higher! Cartridge & LoadCOALJam/Jump*Start PressureMax Pressure 6mmBR, 30.0 Varget Berger 105 VLD2.354?+0.010? in lands5500 psi60,887 psi 6mmBR, 30.0 Varget Berger 105 VLD2.324?-0.20? JUMP3625 psi59,645 psi 6mmBR, 30.0 Varget Berger 105 VLD2.264?-0.80? JUMP3625 psi62,413 psi 6mmBR, 30.0 Varget Berger 105 VLD2.224?-0.120? JUMP3625 psi64,420 psi * As used here, this is the variance in OAL from a load length where the bullet ogive just touches the lands (first jacket to barrel contact). Loading bullets to an OAL beyond that point is “jamming” (seating bullet into lands), while loading to an OAL shorter than that is “jumping” (seating bullet away from lands). NOTE: This is only a software simulation, and the real pressures you encounter may be different. But, the point is that moving the bullet 0.130? further down in a 6mmBR case can raise pressures more than 3,000 psi! Therefore, you must employ EXTREME CAUTION when moving your bullets that much in a relatively small case. Remember that going from .010? jam to a very long jump will probably increase pressures in your cartridge so you MUST adjust your load accordingly. |
| Good info so with my start load of 54gr should I try the test not as dramatic so .010 .030 .050 off the lands? They say 54gr is the start load should I reduce by 5gr to perform this method? If someone thinks the loads I worked up are good to test I'll do it. I'll have it on the chrony so ill verify my velocity and watch for pressure signs. So in other words how would you work a load for this projectile? And I made that oal gauge with a dummy and indeed it is 3.292 jammed so I believe the 3.287 is a light touch to the lands. |
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