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> Re-using crimped bullets.
Re-using crimped bullets.
@ 04:59 pm (GMT) |
Tom DixonCan I re-use a crimped (deformed) bullet?I recently loaded up a pressure ladder of 130gn Speer BTSP,s. The load data suggests that this would be a nice flat load out to around 300 yds in my 7-08.. Once i got to testing i found velocities were lower than the book suggests, so I worked up the loads firing one bullet from each load at a different POI checking for pressure signs with each one. The plan was to then go back and shoot each load out at its respective target. I got to 43.8gn, Which was as high as I had loaded. This is .2gn over book max and still showed no pressure signs and also about 150fps lower than I was expecting / hoping for. The group size for the three shots at 43.8 was not great and neither was the ES. so I am going to load up some more working up over book max in the hope of finding a nice load with better velocity. I saw little point in shooting the rest of the lower loads so I brought them home, I can pull the bullets easy enough but they are crimped, the crimp has squeezed the bullets a little so now I'm not sure if I can re-use them. I can't think of a logical reason as to why not but thats not to say that there isn't one.. The crimp has created a cannelure in the bullet going in .006" and has expanded the bullet by .001" at either side of the cannelure.. |
Replies
@ 06:15 pm (GMT) |
Chris MurphyRe: Re-using crimped bullets.Yes you can use them maybe not for load development or past 500 without confirming they shoot the same first |
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@ 06:25 pm (GMT) |
Tom DixonRe: Re-using crimped bullets.Thats kind of what I thought, this is not really a long range bullet, I have the 145gnBTSP and Amax for longer ranges, I just wanted these for point and shoot stuff at moderate ranges. I'm shooting hill reds next month which aren't that big so I think that these 130gn jobs might be pretty good. I was thinking that if I can get these shooting in the 3000-3100fps range then they will duplicate some of the 130gn 270 factory loads. If I reload them to the exact same depth as they were before is should be fine. |
@ 06:55 pm (GMT) |
Nathan FosterRe: Re-using crimped bullets.Hi Tom, the main issue is the cases. They get a bit beaten up during this work and lose concentrity so that by the time they are loaded twice, the alignment may be poor. Not the best for load work.This is a very soft bullet, the jacket being very thin. Fast expanding but not deep penetrating. It will reach to and destroy vitals but may not exit depending on exact body weights. Quite true, it will behave like the .270 with regards to killing performance with like weight / construction bullets. |
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@ 07:38 pm (GMT) |
Tom DixonRe: Re-using crimped bullets.So should I do a full re-prep on the brass? |
@ 07:44 pm (GMT) |
Bryan WebsterRe: Re-using crimped bullets.What I have done is inside neck ream, laod and shoot and then outside neck turn next time.worked for me |
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@ 07:55 pm (GMT) |
Nathan FosterRe: Re-using crimped bullets.For sake of accuracy load work, you might just have to fire off these loaded rounds and then reload (prefer neck sizing if possible). Its a waste but its the easiest way to ensure the next batch is concentric and with even neck tension (not just at the crimp).The ammo could be used for standing shot practice which makes this less wasteful. |
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@ 08:50 pm (GMT) |
Tom DixonRe: Re-using crimped bullets.I think I'll pull them but use fresh brass for the rest of the load development. I'll use the pulled bullets and cases as hunting loads once I've found a load I like. As these are intended for moderate ranges that shouldn't be a problem..I'll let you know how they perform. |
@ 03:46 am (GMT) |
Mike DavisRe: Re-using crimped bullets.why are you crimping a non cannalured pill?????thats if Ive read post right.... maybe part of your accuracy issue????? |
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@ 10:51 am (GMT) |
Tom DixonRe: Re-using crimped bullets.Quote: why are you crimping a non cannalured pill?????thats if Ive read post right.... maybe part of your accuracy issue?????
Its fine to crimp a non cannelured bullet, just as you don't have to crimp at the cannelure on a bullet that has one. In theory its giving a more uniform tension and allowing the combustion to really get going before the seal is broken. This should improve the ES... Wether it will or not is a different matter. |
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@ 06:10 pm (GMT) |
Bryan WebsterRe: Re-using crimped bullets.I experimented with this using my 308 Win and the Lee crimping die.Could see no benefit so stopped doing it unless shooting really short bullets with a cannelure as in the 130 grain Barnes TSX. Observed no significant accuracy or velocity advantage in my limited tests of 50 rounds. |
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@ 06:18 pm (GMT) |
Tom DixonRe: Re-using crimped bullets.Interesting Bryan, once I find a load I like Ill load a few with and without the crimp and see if it makes any difference. I'm using the Lee collet dies so concentricity is nigh on perfect anyway. Since there is no way of seating close to the lands on the 7-08, with most bullets anyway, I thought the crimp might help things... |
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@ 09:11 pm (GMT) |
Tom DixonRe: Re-using crimped bullets.Well I shot another 7 groups going up .2gn at a time, still no pressure signs, got to around 3000fps. Groups tightened up a little but still nothing to write home about. Going to have to load up some more. Now that I have recorded some decent data I'm guessing I'll hit 3100fps at nearly 3gn above book max which seems pretty excessive. That's assuming I don't hit pressure before then.Does anyone find that Vihtavuori powders are conservative in their max loads? The Vihtavuori max load for N540 is 43.7gn and gives around 3100fps with a 130gn bullet. I'm getting about 2890 from that charge. 44.1 gives 2900, .3 gives 2911 .5 gives 2937 .7 gives 2941 .9 gives 2972 And 45.1 gives 2994 I should point out that it was cold during testing, about -2C but that shouldn't make that big a difference should it? |
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@ 04:25 pm (GMT) |
Tom DixonRe: Re-using crimped bullets.Well 3rd time lucky I got some better results today, went up to 46.1gn which is well over 2gn above book max, best groups came around the 45.5-45.7 mark. These are giving around 3030fps which is quick enough. Still no pressure signs to speak of even at 46.1, maybe a very slight resistance on bolt lift but still nothing else. I could probably get past 3100fps if I kept going but the 45.7 group was .3moa and the 45.5 was also a single hole for two shots and a high flyer which I fucked up.I should have followed the advice in the reloading book and gone up in .5 gn intervals instead of .2 as I could have saved a whole load of ammo and time. Thing is I have found in the past that some bullets hit pressure early on, the swift scirocco for one, that was locking the bolt well below book max.... Still, I now have a load I am happy with. |
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