Pressure / barrel speeds?

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Originally Posted by Happy

Sorry Brads I m confused now ,,, If Im right you saying just the one was over the safety mark. Yes agree you could get caught out.


so did you pull and weigh one of the loads and it was ok within limits.. or ??? :thumbsup:

Inattentive reloading could be dangerous for sure. Our machine has so far never had a fail or over beep. We check it and recheck it during the process but others may not for sure.

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I checked 3 or 4 that where all as the should be, the one in the photo obvisiouly wasn't:(
The guy seemed very trustworthy and was a family man but people do funny shit like drinking while reloading, different powders out at once etc.

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Originally Posted by veitnamcam

Backed off half a grain and called it good? :D

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That's what I did to start with, shot a deer and then the bolt still would open that easy. Just as will the stag went down straight away!

Backed off another half grain after that.

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Originally Posted by BRADS

Someone will no the proper answer:) but this is my basic understanding.
Some of the longer double banded (Barnes pills?)create way more pressure than the same weight in other pills,
Has caught a few out:)

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Other way mate likes of Barnes and gs custom projectiles with more grooves have less engraving pressure so can load higher go faster for same pressures.

Gmx have a couple in them and nosler etips have none hard projectile engraves hard and puts pressure back up.

Sent from my SM-G900F using Tapatalk

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Originally Posted by tui_man2

Other way mate likes of Barnes and gs custom projectiles with more grooves have less engraving pressure so can load higher go faster for same pressures.

Gmx have a couple in them and nosler etips have none hard projectile engraves hard and puts pressure back up.

Sent from my SM-G900F using Tapatalk

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Thanks Abe that does make sense.

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Originally Posted by Gibo

Ok guys im trying to get my head around a few things.

Firstly pressure. Why is it lighter pills in the same cal can use more of the same powder than heavier pills. Is it to do with resistance?
How can this effect the case differently (pressure wise) ?

Secondly barrel speed?? If someone has told me my barrel is slow (tikka) how could a magnum of same cal same (tikka) go any faster?

Just getting my head around the basics of reloading so keen to learn. Hope these even make sense: D

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Heavier pills = bigger pills = more surface area touching the rifleing = more friction = more pressure

Here's some ejector marks I got in my 6.5-55ai. I have lapua brass now though so will see if I can go back to that charge of powder and not get the marks

Attachment 28112

Edit: What you can't see also is loose primer pockets, Fresh primers can be put in by hand and knocked out just as easy. I did measure it but forgot how much bigger they were but it was by a bit

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Originally Posted by Smiddy

another sign is the roundness of your primer after being fired, compare it to a unfired round - it should look the same and not flat

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Disagree Smiddy, It should have a dent from the firing pin:thumbsup:

Are those marks indented toby?

Yup, not just a shine but a small gouge

Trying to reach ..260 Ackley speeds eh?:p

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Originally Posted by R93

Trying to reach ..260 Ackley speeds eh?:p

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Was on a mission to get to 3000 with 140's haha dreaming of course but got close to 2,900. I think. I can check what my top speed was if you want?

I thought the 6.5 x 55 ai was faster than the .260 ai
I get 2950 easy.
What length barrel Toby?

What kind of charge was that with Toby?

I'll start another thread

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Originally Posted by Nick-D

Heavier pills = bigger pills = more surface area touching the rifleing = more friction = more pressure

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Mmm not sure about that, different shaped pills have different surface area. The weight is the key.