6mm Creedmoor reloading......SRP or LRP?

Formidilosus

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If it's a hunting rifle, I would go LRP. More ignition foe colder weather.


I have heard this my whole life. The last few years I have used a lot of Creedmoor and 308 sized cases that use SRP’s, for months at below 0°F, down to -18° and have seen no issues at all. And the ammo and rifles have been left outside the entire time cold soaking.
 

sndmn11

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I didn't know this was a thing......? Please tell me more
I am regurgitating very loosely here, so bear with me.

The two gunsmiths I know who I use and pester for advice both separately told me that firing pin diameter was very important when I asked them about their preference in 6.5creed brass. My understanding is that when you are using a larger (most likely "standard") firing pin diameter with small rifle primers there is an increased likelihood of having primer issues when near max pressure; cratering, ruptures, for example. Something about the firing pin indenting too much of the available surface area of the primer...could be wrong

I think one solution if it became a problem was to reduce the diameter of the firing pin and bush the firing pin hole.

Their explanations were consistent and I found similar in the very brief research I did.

HOWEVER, I shoot small rifle primers in my Tikka 22BR without an issue, It was originally a 30-06. It very well could be a moot point.
 

Formidilosus

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I am regurgitating very loosely here, so bear with me.

The two gunsmiths I know who I use and pester for advice both separately told me that firing pin diameter was very important when I asked them about their preference in 6.5creed brass. My understanding is that when you are using a larger (most likely "standard") firing pin diameter with small rifle primers there is an increased likelihood of having primer issues when near max pressure; cratering, ruptures, for example. Something about the firing pin indenting too much of the available surface area of the primer...could be wrong

I think one solution if it became a problem was to reduce the diameter of the firing pin and bush the firing pin hole.


That is a thing with Remington based actions, and some others, not with Tikkas. The firing pin hole is not oversized on T3’s.
 

MThuntr

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Personally I wouldn't mess with using 6.5CM brass and just buy a bunch of 6CM from Shooter's Pro Shop for $33/50. I believe they use LRP.

This would also resolve any headstamp issues with putting the wrong ammo into a rifle. I know the likelihood is almost 0 but it wouldn't take much for some to pick up a round and try to shove a round where it's not supposed to be.
 
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Lawnboi

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Have SRP ever been an issue with tikka standard bolt face bolts?
Not in my last two barrels.

The firing pin in a t3x is the same for all bolt faces fwiw


Add me as another with no issues with srp creedmoor brass in cold temps. I’m mainly shooting extruded temp insensitive powders. Down to 0.

You can buy cci 450s everywhere, not so much with LRP.

If you have Lapua on hand that’s the answer regardless of primer size
 
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Harvey_NW

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I'm trying to justify this project by telling myself that this will be a great rifle for my 15 year old son and using some components I already have. I didn't think it would be much of an issue to neck down some brass I already had, but haven't looked into it much. I could be talked into buying proper brass if it makes more sense.
It will be, 6 creed is awesome. But as far as the brass if it's not a no-turn chamber, you'll have to neck turn, then probably need a bushing die with a SAC bushing to avoid a donut. Might be the cheaper option to buy 1-200pcs of brass and a standard FL die set, and be on your way to killing shit. I use Peterson brass in 2 creeds now, positive results in both.
 

amassi

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I'm trying to justify this project by telling myself that this will be a great rifle for my 15 year old son and using some components I already have. I didn't think it would be much of an issue to neck down some brass I already had, but haven't looked into it much. I could be talked into buying proper brass if it makes more sense.
It absolutely can be. That's what my first 2 were. Necked down 6.5 brass and went to town. Carbon six and preferred barrel blanks fwiw
 
OP
Jimbee

Jimbee

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It absolutely can be. That's what my first 2 were. Necked down 6.5 brass and went to town. Carbon six and preferred barrel blanks fwiw
Did you use a bushing die, or? Tell me your neck down process if you don't mind. I thought I could just lube the brass and ease it into a 6CM full length die (like a gentleman) and seat a bullet and check neck width. Then if need be, I could do some neck turning....?
 

amassi

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Used a bushing die and 2 steps( essential 264-257-243) just because I happened to have the bushings on hand. Then ran them over a 242 mandrel and shot them.
You can lube the necks and run them in a 6mm cm neck die and it'll work, you may sacrifice a case or 2 to the lapua gods for the indiscretion. It helps if you have perfectly round necks to start with. Then Just check oal length when your done, may need to trim.
 
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Jimbee

Jimbee

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It seems OP is planning on necking down 6.5 brass he already has on hand.

@Jimbee - I assume you've looked into neck clearance and the possibility of needing to turn necks if things are too tight after necking down? I'd definitely just source 6CM headstamp brass if you can.
What's the ideal or necessary neck clearance? I necked down a couple pieces of brass, seated a bullet and measured a diameter of .272. I believe the saami chamber is supposed to be .2770.
 
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What's the ideal or necessary neck clearance? I necked down a couple pieces of brass, seated a bullet and measured a diameter of .272. I believe the saami chamber is supposed to be .2770.

0.005" should be enough clearance.
 
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Oh I’ve seen -45 here in WY. Probably the coldest I’ve hunted coyotes is -10 deg F. Sorry I didn’t specify, cold can mean different things to different people.


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Thanks for clarifying.

-45 ambient? I’ve seen cold but never that cold without windchill. The coldest I’ve hunted coyotes was -31 ambient. A coyote actually trotted right down the road by my truck. He wanted the rabbit really bad haha
 

4ester

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Thanks for clarifying.

-45 ambient? I’ve seen cold but never that cold without windchill. The coldest I’ve hunted coyotes was -31 ambient. A coyote actually trotted right down the road by my truck. He wanted the rabbit really bad haha

Yes that’s ambient….Will freeze your nose shut in short order. Now it’s been a few years since we’ve had a good cold winter like that. I’ve found when it’s that cold coyotes stick their nose up their butts and recirculate air to stay warm. And are more active towards noon when it warms up.


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