Crimping bullets for bolt action?

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Crimping bullets for bolt action?

Post by whert » 13 Oct 2013, 12:49 pm

Hi guys,

I'm working up some loads with Hornady SST's which have the crimp groove.

Whether the bullet actually crimps obviously varies depending on seating depth, whether case is trimmed or not etc.

I know bullets a typically crimped for more, er, energetic? guns like full auto and that kind of setup where the cartridges are really getting rattled around in the firearm before being fired.

For a bolt action though, is there anything to be gained by crimping the bullet?

Should I be aiming so that they do crimp? I'm a bit slack on trimming my brass so there is a little mix at the moment. Just want to make sure I'm not shooting myself in the foot for some reason by not crimping them,

Thanks
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Re: Crimping bullets for bolt action?

Post by Lorgar » 13 Oct 2013, 2:29 pm

Unless you're shooting very high calibre stuff, dislodged bullets wont be an issue.

Inconsistency in crimping will though. If you're cases are trimmed unevenly and some are crimped and others are not that could only effect your groups negatively.

You should get in the habit of trimming them consistently.
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Re: Crimping bullets for bolt action?

Post by Warrigul » 14 Oct 2013, 7:23 pm

If you have a Lee factory crimp they definately improve .303 accuracy.
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Re: Crimping bullets for bolt action?

Post by inspector » 14 Oct 2013, 9:11 pm

Warrigul wrote:If you have a Lee factory crimp they definately improve .303 accuracy.


Bit of a mixed bag thought isn't it?

Crimping improves accuracy for some loads & rifles, decreases it for other combos...
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Re: Crimping bullets for bolt action?

Post by Warrigul » 15 Oct 2013, 8:28 am

inspector wrote:
Warrigul wrote:If you have a Lee factory crimp they definately improve .303 accuracy.


Bit of a mixed bag thought isn't it?

Crimping improves accuracy for some loads & rifles, decreases it for other combos...


Dunno, I go by results. and the .303 and the .223 are the only ones I Lee crimp. The .223 I was seating .010" off the lands so crimping didn't make much difference but it didn't decrease the accuracy.

I don't shoot .303 past 600m, but up to that distance there is a noticeable difference. Three years ago I did a lot of development at 100m off the bench with three rifles (when I had to change to commercial projectiles) and every one benefitted.

In my case there is a benefit I can't speak for others. They make batching for length redundant which is good. As long as they are under max length you don't have to trim to get a good crimp.
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Re: Crimping bullets for bolt action?

Post by ailar » 15 Oct 2013, 9:08 am

Gah, sometimes I hate shooting.

It shouldn't be so hard to throw a little bit of metal down range accurately :lol:
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Re: Crimping bullets for bolt action?

Post by Westy » 24 Oct 2013, 8:14 pm

ailar wrote:Gah, sometimes I hate shooting.

It shouldn't be so hard to throw a little bit of metal down range accurately :lol:

If this frustrates try 3D Archery LOL!!! :D :lol: :D
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Re: Crimping bullets for bolt action?

Post by ailar » 25 Oct 2013, 7:52 am

Westy wrote:If this frustrates try 3D Archery


No no no, noooo.

Adding strings and elastic to this could only end in more trouble :lol:
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Re: Crimping bullets for bolt action?

Post by Hardcast » 27 Oct 2013, 1:15 pm

whert,

Crimping, like seating bullets right out to the lands, or seating with a lot of neck tension, can add pressure to the load.

Crimping isn't just to hold the projectile in place.

If you have worked up a load without crimping, no probs, leave it that way.
And Vica Versa, but if you're having trouble getting a load just right when you know it could be better, as long as you're not at the max end of the powder scale, then try a crimp. Personally I don't crimp anything other than the lever action with full loads, I do think it tends to wear the case mouth a bit.
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Re: Crimping bullets for bolt action?

Post by whert » 27 Oct 2013, 2:42 pm

Cheers Hardcast.

I have a load at the moment which is good, and just by chance it is crimped.

I'll leave well enough alone here I think.
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