Compressed loads and seating depth question

[pharmseller]

I'm trying 25.5 grains of Varget with a 70 grain RDF in my .223. At this charge the load is compressed, even with the bullet seated out a ways (2.281").

My question is, will the pressure from the powder in the case prevent me from seating to SAAMI specifications? I want to try a seating depth test but I don't know if the powder will let me get much shorter.






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[rick benjamin]

Nosler Says you are 0.5 grains above max load.
Hodgdon says you are 0.5 grains below max load.
Recommended OAL is 2.260". 2.281 suggests your case-bullet may hang up when loading from a magazine.
Single round loading may be successful.

Warning: Many factors contribute to reloading outcome, good, or bad.

 

[pharmseller]

Nosler Says you are 0.5 grains above max load.

Yes, I know.

Hodgdon says you are 0.5 grains below max load.

Yes, I know that, too.

Recommended OAL is 2.260". 2.281 suggests your case-bullet may hang up when loading from a magazine.
Single round loading may be successful.

Nope, fits in the magazine and loads just fine. Not my first rodeo.

Warning: Many factors contribute to reloading outcome, good, or bad.

Yes, I know this one, too.

Rick, I appreciate the effort, but can you answer my question?




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[Certaindeaf]

.I don't know if the powder will let me get much shorter..

I thought rick answered the question rather well.
One way to find out if it's so compressed that the charge will rebound enough to spooge out the bullet is with a good set of calipers.

 

[jordanka16]

I'm trying 25.5 grains of Varget with a 70 grain RDF in my .223. At this charge the load is compressed, even with the bullet seated out a ways (2.281").

My question is, will the pressure from the powder in the case prevent me from seating to SAAMI specifications? I want to try a seating depth test but I don't know if the powder will let me get much shorter.






P

If you're asking if the powder will physically push the bullet back out then eventually yes, it takes a lot of compression though, and if it did i would think that's more a neck tension issue.

Seat them farther in gradually, and watch for pressure signs.

 

[rick benjamin]

"Will the pressure from the powder in the case prevent me from seating to SAAMI specifications?"
Answer
No, the powder in the case won't prevent you from seating to SAAMI specs.
Will crush powder granules into air spaces between granules.
Once crushed into your desired configuration, I suspect it will remain in place until ignition.
Regards
Rick

 

[Crohnos01]

I remember reading in a reloading manual some time ago in the "Don't do this least ye earn a Darwin Award" section about a guy who was in a similar situation. In his case he was using an extruded powder and came up with the brilliant idea of smashing the grains of powder with a hammer into a fine powder and then the load would fit in the case without being a compressed load.... Needless to say the answer from the manufacturer was not exactly endorsing this idea

 

[pharmseller]

"Will the pressure from the powder in the case prevent me from seating to SAAMI specifications?"
Answer
No, the powder in the case won't prevent you from seating to SAAMI specs.
Will crush powder granules into air spaces between granules.
Once crushed into your desired configuration, I suspect it will remain in place until ignition.
Regards
Rick

Perfect, thanks.



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[DirectDrive]

Have you built a dummy round for that particular bullet ?
Smoking or marking, hitting the lands and then setting your jump where you want it.

It would be interesting to compare this to SAAMI.
Maybe you don't have to compress as much as you thought ?

 

[pharmseller]

Have you built a dummy round for that particular bullet ?
Smoking or marking, hitting the lands and then setting your jump where you want it.

It would be interesting to compare this to SAAMI.
Maybe you don't have to compress as much as you thought ?

I'm shooting a Tikka T3, so I'm constrained by magazine length. I prefer kissing the lands but that's not an option with most of my Tikkas.

So I start as long as the magazine will allow (minus a small margin) and then set progressively deeper in .020" increments. I'm looking for a depth that shoots significantly better. Then I'll fine tune that depth.




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[DizzyJ]

1) The powder charge can keep you from seating the bullet as deep as you'd like if there's too much powder in the case. Try it. Add more powder and keep dialing down the billet seating depth. At some point you'll see the bullet doesn't actually seat as deep as your micrometer dial tells you it should have. That's because at some point, the powder will give resistance to the depth the bullet can be set. I know, I've experienced this in the past. You'll know, because you'll hear a fair amount of "crunching" when it happens.

2) At some point this will cause bullet deformation. This is generally NOT conducive to accuracy.

3) Using a long necked funnel can help you to get more powder settled, and allow for more volume and less crunching when seating the bullet.

4) Never compress ball powders.

Stick powders will let you get by with some compression, not so much with the more dense powders.

 

[pharmseller]

Great advice, thanks.

Varget is a stick powder so I think I'm okay. I also loaded 25 grains of TAC and matched the seating depths. TAC is only about 95% case fill.




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[Tilos]

I'm trying 25.5 grains of Varget with a 70 grain RDF in my .223. At this charge the load is compressed, even with the bullet seated out a ways (2.281").

My question is, will the pressure from the powder in the case prevent me from seating to SAAMI specifications? I want to try a seating depth test but I don't know if the powder will let me get much shorter. P

Why not just throw charge into a fired/not resized case.
You could then push in/seat a bullet by hand and feel the resistance of powder compression at different seating depths...
True, a re-sized case would have less volume but I think this test would give some indication of the amount of compression.

 

[Member 5605]

Compressing changes the burn rate.

Assuming you are within specs and have worked up from starting point, you are good to go.

I've crunched lots of grains when my case was full to the max and it called for a compressed load.... everything went fine with those loads as they were from the book.

 

[Otter]

I'm shooting a Tikka T3, so I'm constrained by magazine length. I prefer kissing the lands but that's not an option with most of my Tikkas.P

I'm considering buying my first Tikka. Are you saying you are not able to reach the lands in most your Tikka rifles? I've found best accuracy in most my rifles is when I can seat the bullet into the lands. I don't do this with big game rifles...regardless of accuracy because you can end up pulling out the bullet if you have to remove a chambered round. Still, best accuracy in my hunting rifles are with the bullet quite close to the lands with minimal jump. Just curious...this could change my direction. Thanks for any additional info.

 

[pharmseller]

All of these are from Tikkas. None of them are close to the lands.

 

[DizzyJ]

All of these are from Tikkas. None of them are close to the lands.

View attachment 424941 View attachment 424942 View attachment 424943 View attachment 424945 View attachment 424946 View attachment 424947 View attachment 424944

View attachment 424940

Can't complain about that!

 

[pharmseller]

Yeah, but I included two pics of the same target. I tried to delete it but it didn't take.

You should see what my brother can do with his Tikka in 7mm Rem Mag. Impressive.

 

[PaulB47]

Long-necked funnel, as mentioned above. You can swirl the powder in if you pour along the sides of the funnel rather than straight down the middle. It will end up more compactly filled - at least that's what "they" say...

My long funnel is maybe 10" or 12" long.

 

[slacktide]

There is a way to test if you are over-compressing the powder. Charge the case as you would, seat the bullet as you like and measure it. Measure it again after letting it sit 24 hrs. If there is any change AT ALL you are compressing the powder way beyond what you should be. Yes you will crush and crumble the granules to some degree but there is a bit of rebound in the powder.

As a side note I avoid compressed charges at all costs because it does change the burn characteristics and there is no way to get the same compression with every round, drop tube or no.