Changing col increments

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Roachclass
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Changing col increments

Post by Roachclass » Thu Apr 02, 2020 10:42 pm

At what increments should I start lengthening my cartridge by to see a difference?

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dellet
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Re: Changing col increments

Post by dellet » Fri Apr 03, 2020 1:33 am

To see a difference in what?

What are you trying to accomplish, better accuracy, lower velocity, less pressure......

What bullet and powder, sub or super
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cwlongshot
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Re: Changing col increments

Post by cwlongshot » Fri Apr 03, 2020 6:45 am

Roachclass wrote:
Thu Apr 02, 2020 10:42 pm
At what increments should I start lengthening my cartridge by to see a difference?
. Sorry man no one can answer that question. Simply said it dosent Work like that across the board for anyone to answer definitively.

As soon as some one would tell you “@ .005 off rifling you will see accuracy tighten right up!” Two guys will tell ya “HUH, then why does my 357 rifle shoot 38’s into same
Hole??

This is all guns are different. All loads cause differences that can effect every other aspect of your load.

You need to discover these things on your own with your load and your firearm. Even when you learn this or that it may or may not apply to the next recipe ya try. But that’s not a downer that’s the fun in discovering a accurate load.

Good luck
CW
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Bob the nailer
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Re: Changing col increments

Post by Bob the nailer » Fri Apr 03, 2020 9:46 am

cwlongshot wrote:
Fri Apr 03, 2020 6:45 am
Roachclass wrote:
Thu Apr 02, 2020 10:42 pm
At what increments should I start lengthening my cartridge by to see a difference?
. Sorry man no one can answer that question. Simply said it dosent Work like that across the board for anyone to answer definitively.

As soon as some one would tell you “@ .005 off rifling you will see accuracy tighten right up!” Two guys will tell ya “HUH, then why does my 357 rifle shoot 38’s into same
Hole??

This is all guns are different. All loads cause differences that can effect every other aspect of your load.

You need to discover these things on your own with your load and your firearm. Even when you learn this or that it may or may not apply to the next recipe ya try. But that’s not a downer that’s the fun in discovering a accurate load.

Good luck
CW
Agreed!
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dellet
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Re: Changing col increments

Post by dellet » Fri Apr 03, 2020 10:35 am

Bob the nailer wrote:
Fri Apr 03, 2020 9:46 am
cwlongshot wrote:
Fri Apr 03, 2020 6:45 am
Roachclass wrote:
Thu Apr 02, 2020 10:42 pm
At what increments should I start lengthening my cartridge by to see a difference?
. Sorry man no one can answer that question. Simply said it dosent Work like that across the board for anyone to answer definitively.

As soon as some one would tell you “@ .005 off rifling you will see accuracy tighten right up!” Two guys will tell ya “HUH, then why does my 357 rifle shoot 38’s into same
Hole??

This is all guns are different. All loads cause differences that can effect every other aspect of your load.

You need to discover these things on your own with your load and your firearm. Even when you learn this or that it may or may not apply to the next recipe ya try. But that’s not a downer that’s the fun in discovering a accurate load.

Good luck
CW
Agreed!
I disagree(but what's new about that). The answer is about .005"

The problem is you don't what the reason for changing length is, what it's being shot out of, or what's being shot for that matter.

So .005" will make a change, we just have no idea if it's the desired change. There is no arguing that that much adjustment will change internal ballistics enough to change external ballistics.

Being the correct answer, does not make it a helpful answer. Or Garbage input, garbage output.
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Re: Changing col increments

Post by Whole Bunches » Fri Apr 03, 2020 4:31 pm

In the case of my reloads with my various 300BLK bbls and the 125gr Nosler BT, I found a difference in accuracy at 0.1" difference in OAL. Basically, some bbls liked 2.1" OAL and some liked 2.2" OAL for best accuracy with that bullet. Also note, that for the same velocity I had to increase the H110 powder charge 0.3gr over the charge used in the 2.1" OAL.

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Re: Changing col increments

Post by Roachclass » Fri Apr 03, 2020 6:49 pm

OK I'll try .005, that seems like a very minute change but I guess once you get much longer I might have to up the charge. That's all I wanted was some opinions on what other people have done. you really don't need to know any of that other stuff to give a simple answer. If you wanna just talk about loading I'm cool with that. I'm not even loading blackout right now. I've reached my goal there for the time being with thanks to some threads here. I'm trying to get some 110gr varmageddon to shoot in my 308win Savage msr10. I got the powder load where it's shooting about 1.2" group. I'm seating at nosler book recommended 2.60 which looks kinda silly, base of bullet is past the neck into the shoulder but I tried it. I'm going to start bringing it out some to see if it makes a difference in accuracy. That's all. Gonna see what happens.

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dellet
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Re: Changing col increments

Post by dellet » Fri Apr 03, 2020 9:28 pm

Roachclass wrote:
Fri Apr 03, 2020 6:49 pm
OK I'll try .005, that seems like a very minute change but I guess once you get much longer I might have to up the charge. That's all I wanted was some opinions on what other people have done. you really don't need to know any of that other stuff to give a simple answer. If you wanna just talk about loading I'm cool with that. I'm not even loading blackout right now. I've reached my goal there for the time being with thanks to some threads here. I'm trying to get some 110gr varmageddon to shoot in my 308win Savage msr10. I got the powder load where it's shooting about 1.2" group. I'm seating at nosler book recommended 2.60 which looks kinda silly, base of bullet is past the neck into the shoulder but I tried it. I'm going to start bringing it out some to see if it makes a difference in accuracy. That's all. Gonna see what happens.
A .005” change in seated depth can/will (fact) make a measurable change, but that is a fine tuning change. A 1.2” group with a 308, unless it’s at 200 yards, is not ready for fine tuning(opinion).

A 300 blackout shooting 1.2” at 100 yards is probably closer to being ready for a .005” ladder, than a 308 shooting the same group at 200. So yes, that information matters.
300 Blackout, not just for sub-sonics.

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Re: Changing col increments

Post by Roachclass » Fri Apr 03, 2020 10:24 pm

I did 46 gr of imr 4895 and it was too hot. Vertical string like a mofo. This last try was 45.5gr that shot the 1.2 group and it kind of looks like it may be a hair slow, like a grape cluster or small buck shot pattern. So I can try 45.7 or 8 to see if it's any better. I'm using CCI 200 because I have a bunch that I'm just trying to find a use for. Really don't want to try and use up my CCI 250 mags because my supply is relatively low and probably won't be able to get some for a while. I have know hunting loads for several calibers I can use those in when that time of year rolls around again. I'm just trying to come up with something to shoot with the powders and primers I have an abundance of.

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Re: Changing col increments

Post by wildfowler » Fri Apr 03, 2020 11:01 pm

When loading for an AR in any caliber I generally start load development with my bullet seated at the maximum that it will feed reliably from my magazine, since that’s as long as you can load anyway. Depending on the brand of magazine it might even exceed 2.26 inches slightly.

Once I get where I feel like I have established the powder charge I then decrease bullet seating depth in .003” increments to see if I can notice any improvement in grouping.

I have noticed that it does not take a huge difference between the maximum length I started with and the ideal length I discovered through testing.
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