Compaction load vs regular loads

CHRIS MCBRIDE

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Loading my 7mm stuff up and have few different 7mm calibers. &mm-08,7mm mauser and 7mm Mag. Noticed the 08 has few compaction loads and almost all the mauser stuff is compacted since it fills case the the neck if not overflowing.

Wondering if any accuracy gain or lost between fully filled case and one with little room left like most my 7 mag loads. Just one of those got me thinking things and yes I do tend to over think at times.
 

FEENIX

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memtb

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There are likely many factors (cartridge, case capacity, case shape, bullet weight) that may play into the results. I don’t think that there is a “one size fits all” answer. I’ve worked with exactly what exactly what you described with success.....but that was with one cartridge/bullet/powder! memtb
 

Savage 12BVSS

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I shoot several 7mm-08's and a 260 and it can be a struggle with some powders that case fill too far and you hear that distinctive crunching sound as you seat the bullet. With light neck tension you can find the bullets pushing out some which can lead to feeding issues and moving into the lands if seated close. The nosler reloading manual's give case fill of various powders and all aren't equal for sure. Using Fed 210M and CCI BR2 primers I never had any ignition problems but with H4350 I did have a bullet stick in the lands (.008 off) while hunting and had the choice of unloading with the trigger or using a cleaning rod down the muzzle at home to avoid dumping powder into the action and magazine.

Solution for me came when I tried a powder that didn't fill the case as full (Varget) and it shot better as a bonus. Slowly switched two different cartridges and four guns over to the new powder and haven't had a compressed load since.

Now I'll go get a plate of fresh deer steaks out of the slow cooker and sit back and watch :)
 

Jud96

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My most accurate loads in my .308 Norma Magnum are about 90% case fill. There’s a good bit of powder shake in the case. I don’t mind though because the velocity standard deviations are single digits and it shoots 1/4” groups. I like to have 90% case fill but I don’t think you need compressed loads for accuracy or low ES and SD.
 

110len

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Loading my 7mm stuff up and have few different 7mm calibers. &mm-08,7mm mauser and 7mm Mag. Noticed the 08 has few compaction loads and almost all the mauser stuff is compacted since it fills case the the neck if not overflowing.

Wondering if any accuracy gain or lost between fully filled case and one with little room left like most my 7 mag loads. Just one of those got me thinking things and yes I do tend to over think at times.
My biggest fear with compacted loads is possibly having it cause concentricity issues. Not sure if it would but still..
 

DUSTY NOGGIN

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let me try to help. i gotta say ,that is one of the most opened questions you could ask, so much so some may not take the post serious, if you are sincere in your post please please please understand that what you are doing is dangerous , and read a manual before loading ... if your powder charges are over flowing i would also consider checking your scale

look up a VMD chart here https://leeprecision.com/files/instruct/VMD.pdf

"C" stands for compressed , not compaction ... generally speaking, that is one reason why there are so many choices of powder ... if you have one that is too full, you pick another one that is also listed in the data book , that is more dense with the same/similar max pressures ( check the pressure differences ) BUT !! keep in mind different types of powder react differently at different volumes and different case capacity's

no offence intended , you sound new , go by the book data and use a powder listed that doesn't use a compressed load ( " * " or a "C" ) ... the hotter the load the more wear to the rifle

what bullet weight did you want to use for your 7mm mauser
 
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CHRIS MCBRIDE

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Far from new. Only been reloading for 35 years. I am always curious as to what others find or try. As for the mauser I have 2 one is 20" barrel 1893 that I made a brazilian cherry stock for the other is 1895 that I made into a pistol on other half of the brazilian cherry has 14" barrel. In rifle I run 150 or 162 grain bullets in the pistol I run 162 gr bullets. Various types since always looking for better

Rifle is pretty good shooter out to 400,longest shots I have had to test it. The pistol is good to about 200 yrds,but shooter is only half *** that far out and better to stay 150 or less for while. At 150 pistol is about 1.25" 3 shot group and has gone 1" when I am doing everything right on my part.
 

FEENIX

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Messing around with compressed loads has ‘typically’ presented me more headaches than benefits. I try to steer clear of compression if at all possible.
Agreed! More often than not, in "my" experience, the group opens up. I end up backing it down and find the best compromise between accuracy and velocity goal.
 

Savage 12BVSS

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Messing around with compressed loads has ‘typically’ presented me more headaches than benefits. I try to steer clear of compression if at all possible.

Agreed! More often than not, in "my" experience, the group opens up. I end up backing it down and find the best compromise between accuracy and velocity goal.
These posters are giving good advice........usually you can find a powder that will fill the case less and often it will be as or more accurate. The nosler loading manual is online and you can bring it up and quickly find alternatives to try. I used to vibrate the powder level down and that can help but with less neck tension it can and will push your bullets up some and change distance off lands or maybe not fit the magazine and feed as well. Besides I always hated that sound of powder crunching :( Good Shooting :)
 

QuietTexan

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The "overflowing the case" part is what concerns me. What specific powder and charge weight is resulting in that? I've heard the crunch before, but never wasn't able to fit the charge into the case to compress.

Quick look at the Nosler book for 7mm Mauser does show a 115% chage of Viht N165 under a 175gr pill, but if that's where I was at I would change to an IMR powder and get back down into the 80-90%s for fill.

Amongst people who compress, is overflowing normal? Just a sign to use a drop tube funnel? Or something concerning.
 

DUSTY NOGGIN

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try some h414 at .661

compared to
h4350 at .725

could likely use h414 for all of your 7s if you absolutly had to .. might not even have to change your existing bullet weight choice

full , but not compressing is the best powder pick IMO
 
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