Compression

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bear-kodiak
Posts: 24
Joined: Thu Oct 16, 2003 6:11 pm
Location: central pa

Compression

Post by bear-kodiak »

Hello List
Was wanting to know how much compression
I should use for my 45-70 rounds with a Postell
bullet and Goex cartridge powder 62 grains ?
Thank you for any advice...jim
jackrabbit
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Location: Carpenter Wyoming

Re: Compression

Post by jackrabbit »

I am not sure what you are wanting to know. If you seat your bullet a bit off the lands, that will give you your overall cartridge length. Compression will be whatever it is with 62 grains of powder and that length.

Personally, I don't pay any attention to compression. I find the cartridge length I want to use with that specific bullet and then mess with powder charges until I find one that works. Many of my loads smash the crap out of the powder charges, and do well at matches in-spite of the fact that common internet knowledge says it shouldn't work. Of course, if you are heavily compressing, you need to do it with a compression die and not the bullet.

Hope this helps, please ask if you have more questions.
Cody
rdnck
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Re: Compression

Post by rdnck »

Pay close attention to what jackrabbit just wrote. He is dead on about compression.

The Lyman Postell is one of the best bullets you will find, and it will shoot very accurately with 62 grains of Goex Cartridge out to the pig line. You will have to use 69 to 70 grains to have consistent success on turkey and rams with the Postell because at 535 grains it will come in to the longer targets at such a steep angle with the lighter powder charge that it leaves little if any room for error. Shoot straight, rdnck.
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gunlaker
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Re: Compression

Post by gunlaker »

I do the same as Cody. It works great :-)

Chris.
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bear-kodiak
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Location: central pa

Re: Compression

Post by bear-kodiak »

[quote=rdnck post_id=316095 time=1590287213 user_id=94]
Pay close attention to what jackrabbit just wrote. He is dead on about compression.

The Lyman Postell is one of the best bullets you will find, and it will shoot very accurately with 62 grains of Goex Cartridge out to the pig line. You will have to use 69 to 70 grains to have consistent success on turkey and rams with the Postell because at 535 grains it will come in to the longer targets at such a steep angle with the lighter powder charge that it leaves little if any room for error. Shoot straight, rdnck.
[/quote]

So do you think I should use a 69 - 70 charge
for all ?
jackrabbit
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Location: Carpenter Wyoming

Re: Compression

Post by jackrabbit »

Your powder charge will depend on what you want to do with the load and what is most accurate. Sometimes the smaller charges can be quite accurate at the closer ranges, but they don't have enough power to shoot well at long ranges. Minimum powder charge would be one that leaves no air space under the bullet, while maximum would be the most you can compress without bulging the case. I would find the minimum charge, add one grain and load 10 shells, then up one grain and load 10 more, continuing until you are near maximum. Now go shoot groups with these and keep track of which load shoots the best. If you are just wanting to mess around, most any powder charge will do, but if you are wanting to be competitive, it will take some time developing a load.

We are not trying to be vague about an appropriate powder charge, you just have to figure it out for yourself. Different brands of brass have different volumes, as well as different lots of powder have different densities, and most guns are individuals that like different loads. We are not able to just say "use this much powder and all will be perfect." Load development is all part of the fun in learning to shoot these rifles.
Good luck, Cody
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Don McDowell
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Re: Compression

Post by Don McDowell »

FWIW 69 grains of Cartridge with the postel bullet is usually a very accurate load in most 45-70's. The velocity it gives is a bit lower and the fouling a bit thicker than other powders available today, but it's a good one. Primers may make a differnence in your rifle, but the 4 of them that live here get along well with cci 200 or ww large rifle.
AKA Donny Ray Rockslinger :?
John Bly
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Re: Compression

Post by John Bly »

You've gotten good advice here. Spend some time and get to know your rifle. No one can tell you the best bullet or powder or compression for your particular rifle. Only your rifle can tell you. The learning curve is all part of the experience. When it all comes together you'll be amazed. My nephews are surprised when my shooting at 200 yards with iron sights beats their modern rifles with expensive scopes.
"Perfection consists not so much in doing extraordinary things as in doing ordinary things extraordinarily well"
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