Load to Coal or Ogive ?

[owdnorthener]

Hi,  I have loaded 69gr tmk with 22gr N140 and after measuring (i previously had cut a slot plus drilled a hole in brass to check) the brass looks full, so am concerned I would compress powder if I loaded more powder.

Maybe if I loaded to ogive and be over coal, I would have more space and hence could load more powder, so, do I follow the manual and stop at 22gr or ?

Fingers crossed I over thinking this, and as you see I need a hand.  Thanks.

[Popsbengo]

25 minutes ago, owdnorthener said:

Hi,  I have loaded 69gr tmk with 22gr N140 and after measuring (i previously had cut a slot plus drilled a hole in brass to check) the brass looks full, so am concerned I would compress powder if I loaded more powder.

Maybe if I loaded to ogive and be over coal, I would have more space and hence could load more powder, so, do I follow the manual and stop at 22gr or ?

Fingers crossed I over thinking this, and as you see I need a hand.  Thanks.

The Viht load data for SMK 69gr (I don't have TMK data to hand) indicates 25.9gr N140 max.  I'm very surprised that 22gr is filling the case.

What's your loaded COAL ?

[owdnorthener]

Thanks for getting back to me .... I loaded to Coal 2,260, in Hornady brass.

As said, looking, it appears the bullet touches powder at 22gr, hence my concerns. 

 

[Popsbengo]

Your COAL is longer by a few thou' than the suggested COAL listed by Viht for a similar bullet, I would say you're going to be ok using the powder charge as recommended.  

When I used 77gr Scenar in .223, I loaded 23.5gr N140 and it crunched on bullet seating.

[owdnorthener]

Thanks. That sounds promising.   I don't have lots of experience, as you can see, so other views are quite reassuring.

I shouldn't have tried to see what contact the powder makes with the bullet and trusted the manual.

[Popsbengo]

1 hour ago, owdnorthener said:

Thanks. That sounds promising.   I don't have lots of experience, as you can see, so other views are quite reassuring.

I shouldn't have tried to see what contact the powder makes with the bullet and trusted the manual.

Curiosity is a good thing when tempered with judgement.  Powder does settle, try tapping the case and you may find the powder level drops.

[owdnorthener]

Thanks. I think that's it. A little to wary, so I'll stay at recommended coal and work up my powder slowly, ready for the range to see just what I have to play with.

Thanks for taking time and trouble to help me out.

 

Regards Alan.

[Richiew]

Hi there 

Vihtavuori web can be misleading on some combinations, my 60 g bergers are rather hot and not at the max quoted but the 73 g bergers are over max by a smidge and have no signs of over pressure at all and they do crunch . Start in the middle of the powder range and work up to max if ok could go up in smaller increments till you find ejector marks etc . I’m a full 2 grain s over max in 308 for the Berger 155.5s with no problems. There’s some articles on the web that are saying that lightly compressed loads are a good thing. Load to standard spec to start with find a good powder combo then experiment with a longer loading depending on your max mag length . Enjoy 

[Richiew]

Have a look at my posts on ,,, what’s your favourite 223 fox bullet. Think you’ll find some of it useful 

cheers

[Timbo1963]

A little bit of compression is quite often what reloaders go for (good case fill is supposed to be better), but normally VIHTAVUORI tells you when it is compressed. I have always found there max is quite conservative compared to what some people are loading (I’m not recommending going over there max though). Always start lower and work your load up looking for signs of pressure. And because you can see the powder might not mean it’s compressed, there is normally a crunching sound when you are compressing. 22gr seems quite low to be compressing, I’ve loaded 77SMK with 24.5gr of N140 for my AR with no issues.

[Laurie]

Compressed loads  are endemic in 223 at magazine COAL with longer, heavier bullets, especially with the slower burning powders such as N140. Some loading data sources use a compressed load indicator, some don't, and some seem to do so only when they remember the issue.

Viht lists 25.9gn N140 as maximum for the 69gn Sierra MK at 2.26-inch COAL which implies that is for the standard SAAMI chamber with its very short freebore. That is in Lapua brass and is a hot load. Remember, published loads data applies solely to the listed components, so the Hornady cases you're using may have more or less internal capacity. If less, that increases the case-fill level, also peak pressures. If more, the reverse.

The SMK and TMK are also different enough to change things. The ogive / neck radius and central shank are pretty well the same, but the TMK has a longer less sharply angled boat-tail section, and of course has the acetyl tip stuck on the front end lengthening, in conjunction these factors producing a greater bullet OAL. Seated to the same COAL, 2.26", it is seated necessarily deeper than the SMK so there is less space for powder and higher fill-ratios with any charge weight.

QuickLOAD gives Viht's maximum N140 charge a 106% fill-ratio with the SMK, rising to nearly 110% with the TMK seated to the same COAL. Compression in itself doesn't raise pressures but creates various other problems. First, just getting the stuff in. If you regularly load this or similar bullets to magazine length, you really need a powder funnel with a longer drop tube. The Forster universal funnel with 5.5-inch tube is very good but expensive. It and a slow angled pour will let you get another 1.5 or so gn powder into the case through better settling. But even so, using top loads with this powder will see compression, and that nasty feeling / sounding 'crunch'. It's then important to subsequently check COALs, as heavily compressed charges can push bullets back out increasing COALs depending on the degree of neck tension being created by the sizer die.

Then we get into rifle type (Bolt or straight-pull) and chamber type / freebore as single-loading with long-throated factory chambers, even more so competition ones like the Wylde or those with longer freebores allow bullet seating to longer COALs.

Be VERY wary of comments that suggest Viht gives 'mild' max loadings. QuickLOAD says this charge weight exceeds the US SAAMI 55,000 psi limit and is much closer to the CIP / NATO ceiling of 62,000 psi in Lapua brass. Those sort of pressure levels from Viht powders from factory loads are in line with what I see in loading the 223 with heavier bullets.  

[English Rifleman]

Wow Laurie

That was a very detailed explanation, and i for one would like to say thanks..

[Richiew]

Hi Laurie 

nice info fella , much appreciated . This is why we measure to the lands so our long pointy bullet can be seated to the ogive measurement and still feed from the mag if it’s a bolt rifle and the magazine allows it . 
cheers 

[owdnorthener]

This post/question has turned into a very detailed explanation of processes involved.  I'm learning much more than I imagined.   Much better than just a "do this" list.

Thanks to all, for your input. Its much appreciated.

Alan.

[Andrew]

Laurie might be the only person old enough on this thread to remember when "seating depth" was the standard measurement given in load manuals.  It was how I learned to reload. My uncle tried to promote a tool that would allow a shooter to make a dummy round measuring the setting depth via a collared spring steel rod that slipped into the empty primer pocket of a prepped case. It never caught a whiff of interest but he was right when he opined that the distance from the base of the bullet to the ignition source was ballistically more important than any other measurement. Which is what this thread is about. ~Andrew