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Low Presure signs


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Hi I have been reloading my 223 & 243 for a few years now I have had to change powder due to not being able to get varget anymore.

In my 243 I am using 38.3gn of Vihtavuori N140 with a 70gn Sierra Blitzking I am getting signs of low pressure around the neck and top of case black soot type marks. The rounds group clover leaf at 100yrds.

Sierra say max load is 38.8 and minimum load 37.4.

So I can not see why I am getting soot on my cases any idea please????

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Don't worry about sooting. Normally this is the unburnt residue often from the graphite coating of the powder grains. If you are full length sizing then don't set the die to touch the shell holder you only need enough resizing on the case body (inclusive of shoulder) to allow the brass to chamber without causing the bolt to bind.

 

I personally only neck size and even then I sometimes see soot so it could be a characteristic of Vihtavuori as this is also my choice of powder at this time.

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There is every chance you pushed the shoulders back to far on sizing hence my previous questions, have you some un-sized from that batch or even the same brand? if your under max I should step it up some 0.2 progressions carefully watching for pressure sign and the sooting suddenly disapearing - some new data is getting a bit conservative, I tend to just get on with it and look for my own guns limit with a load, then back off! But I am not suggesting you do this,

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Don't worry about sooting. Normally this is the unburnt residue often from the graphite coating of the powder grains. If you are full length sizing then don't set the die to touch the shell holder you only need enough resizing on the case body (inclusive of shoulder) to allow the brass to chamber without causing the bolt to bind.

 

I personally only neck size and even then I sometimes see soot so it could be a characteristic of Vihtavuori as this is also my choice of powder at this time.

Now the brass has been fire formed I only neck size I use N130 on my 223 but have never seen any signs of shooting as I moved over to N140 as varget became unavailable I worked my loads up to near max and then dropped back again as grouping spread still had sooting at higher end so I think you must be right re the type of powder.

I have been reloading for around 4 years but never seen this so I thought I would ask.

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Dont worry...every one got you thinking there is an issue and there is not...forget it. Just different powder from what your use to.

 

U.

 

I don't agree, the gasses are not sealed- for one reason or another the shoulder isn't being blown out to create this seal. its not a big thing if he is oversizing the brass- he will just wear it out quick and get a dirty chamber

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Now the brass has been fire formed I only neck size I use N130 on my 223 but have never seen any signs of shooting as I moved over to N140 as varget became unavailable I worked my loads up to near max and then dropped back again as grouping spread still had sooting at higher end so I think you must be right re the type of powder.

I have been reloading for around 4 years but never seen this so I thought I would ask.

 

I use varget in some of my .243 loads I don't get sooting, but I do at the low end and if I push a shoulder back to far I get ejector marks in the base of the brass at times also (this is always scrapped off)

 

Sorry got muddled then your on vhit, I only use vhit in 160 with heavier bullets scratch that - I still doubt its the powder coz the shoulder should seal

Edited by kent
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Hi kent I have no changed my proses since I've changed powder nothing else has changed so how just because I've changed powder can I be over sizing my brass I only neck size anyway if I am doing something wrong then feel free to explain but as I say my proses have not changed my sizing dies have not been adjusted only my seating die.

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This might well be the last time I ever say this but that load in the Sierra manual is researched and proven in ONLY ONE BARREL and has realistically, very little to do with your barrel.

 

I'm not one for pushing loads OTT in any way shape or form BUT WHAT ARE YOUR PRIMERS AND BRASS TELLING YOU?

Thanks Fister totally agree Sierra used a 1 in 9 twist barrel my primers and the brass are coming out in good condition I have know thighs rounds they all eject fine primers are well pocketed and no splits to neck and no damage to brass at all

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Dont worry...every one got you thinking there is an issue and there is not...forget it. Just different powder from what your use to.

 

U.

I didn't suggest a problem,I simply asked if a chrono had proven low pressure by a significant drop in velocity.Also If zero (elevation) hadn't dropped an appreciable amount and recoil was similar then I can't see why/how or where there is evidence of low pressure.

 

In my 6mm Br I use 55gr Nosler BT along with 33.3 gr of H 4895. Velocity = 3800 with a shot to shot deviation of less than 10fps,using Lapua brass and CCI match s/r primers it's a great varmint round, and yes there's a nice 'sine wave type powder pattern' on the case neck, all it proves is that you're operating in the 'sweet spot' of the powder.

 

Regards remmyman

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I didn't suggest a problem,I simply asked if a chrono had proven low pressure by a significant drop in velocity.Also If zero (elevation) hadn't dropped an appreciable amount and recoil was similar then I can't see why/how or where there is evidence of low pressure.

 

In my 6mm Br I use 55gr Nosler BT along with 33.3 gr of H 4895. Velocity = 3800 with a shot to shot deviation of less than 10fps,using Lapua brass and CCI match s/r primers it's a great varmint round, and yes there's a nice 'sine wave type powder pattern' on the case neck, all it proves is that you're operating in the 'sweet spot' of the powder.

 

Regards remmyman

You have a 6mm BR, uber cool B)

 

U.

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:thumbs:

You have a 6mm BR, uber cool B)

U.


It's a great calibre, mine's throated out for the big 105gr A-max for a thousand yd target, but shoots anything weight wise sub 1/4 inch groups @ 100yds.(rifle built by Border Barrels, Remmy 700 action, AI stock,26 inch heavy,heavy SS barrel,(1inch at muzzle) Jewel trigger, MYM mod. Glass is a 9-36x56 IOR, as a Vermin/fox/deer rifle it takes some beating. :good:

 

Regards remmyman

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:thumbs:

 

It's a great calibre, mine's throated out for the big 105gr A-max for a thousand yd target, but shoots anything weight wise sub 1/4 inch groups @ 100yds.(rifle built by Border Barrels, Remmy 700 action, AI stock,26 inch heavy,heavy SS barrel,(1inch at muzzle) Jewel trigger, MYM mod. Glass is a 9-36x56 IOR, as a Vermin/fox/deer rifle it takes some beating. :good:

 

Regards remmyman

Cool. I would prefer a light sporter my self being fat n' old gettin' lol.

Efficient cartridge, I like the 22 also.

 

ALB.

 

U.

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