Testing Different Powders in Same Cases?

[BigDMT]

Just wanted to get opinions from some of the accomplished and experienced shooters on whether or not you have ever given any thought to separating cases where you only burn one type of powder in them while load testing?

I personally have always just used the same cases to test multiple powders, sometimes I burn 3 or more different powders in the same cases finding what a rifle really likes. I often wondered if it would be wise and beneficial to accuracy to separate cases during testing where they are only subject to one type of powder while testing different charge weights. Only reason I have not tried it is because I always seem to find a load that is acceptable to me. What are your thoughts on this theory? Do you believe different types of carbon residue can have an effect, whether good or bad, on load development? Thanks.

 

[dmoran]

In any testing, it is fairest to conduct test from/with equal parameters.
With that said, if your testing one powder from a clean barrel and 10-shots, to be a fair comparison test to the next powder, the barrel conditions should also start clean and the same amount of shots (fouling).
That is how I go about testing powders, by cleaning/equalizing the barrel/bore between the powder types.
D

 

[BigDMT]

In any testing, it is fairest to conduct test from/with equal parameters.
With that said, if your testing one powder from a clean barrel and 10-shots, to be a fair comparison test to the next powder, the barrel conditions should also be repeated - IMO.
That is how I go about testing powders, by cleaning/equalizing the barrel/bore between the powder types.
D

I do the same with my bore when testing loads, so I totally agree with you there. But in this instance I am asking about the brass. Thanks D.

 

[Shynloco]

In any testing, it is fairest to conduct test from/with equal parameters.
With that said, if your testing one powder from a clean barrel and 10-shots, to be a fair comparison test to the next powder, the barrel conditions should also start clean and the same amount of shots (fouling).
That is how I go about testing powders, by cleaning/equalizing the barrel/bore between the powder types.
D

Big+1 !

 

[dmoran]

Guess I miss understood the question.... sorry
If using the same Lot and equally prepped cases (sizing, specifications, volume), you should have case equality - IMO

D

 

[jo191145]

I would assume your concerned with the carbon inside the neck and it's attributes toward bullet release.
It's a valid concern but the effect of carbon in the bore is much larger.
If your barrel likes a powder you'll see it there first. As your necks carbon up with your chosen powder things will only get better assuming your not one of those shooters that need the neck ids all shiney.

 

[Alex Wheeler]

Just wanted to get opinions from some of the accomplished and experienced shooters on whether or not you have ever given any thought to separating cases where you only burn one type of powder in them while load testing?

I personally have always just used the same cases to test multiple powders, sometimes I burn 3 or more different powders in the same cases finding what a rifle really likes. I often wondered if it would be wise and beneficial to accuracy to separate cases during testing where they are only subject to one type of powder while testing different charge weights. Only reason I have not tried it is because I always seem to find a load that is acceptable to me. What are your thoughts on this theory? Do you believe different types of carbon residue can have an effect, whether good or bad, on load development? Thanks.

Nope. Bullet release is related to neck tension not seating force, they are not the same thing. Lube the neck on the case and will have a lower seating force but the same neck tension. The neck expands to release the bullet, the bullet does not slide out of the case, if it did it would not expand.

 

[Shynloco]

Just wanted to get opinions from some of the accomplished and experienced shooters on whether or not you have ever given any thought to separating cases where you only burn one type of powder in them while load testing?

I personally have always just used the same cases to test multiple powders, sometimes I burn 3 or more different powders in the same cases finding what a rifle really likes. I often wondered if it would be wise and beneficial to accuracy to separate cases during testing where they are only subject to one type of powder while testing different charge weights. Only reason I have not tried it is because I always seem to find a load that is acceptable to me. What are your thoughts on this theory? Do you believe different types of carbon residue can have an effect, whether good or bad, on load development? Thanks.

Nope. Bullet release is related to neck tension not seating force, they are not the same thing. Lube the neck on the case and will have a lower seating force but the same neck tension. The neck expands to release the bullet, the bullet does not slide out of the case, if it did it would not expand.

Z,
I agree with your statement and am curious as to your opinion (or anyone else's). Employing Donovan's practices which he wrote about and that I use when reloading for testing and comparing loads in the same brass rifle, etc, IF you maintain and set a neck tension of .001 or .002..... is there really a need to even worry about carbon or any lubricate inside the necks? The reason I ask what seems to be a silly question, is that I tumble, clean and prep each casing I reload in great detail, which includes using a brass bore brush on the inside of each casing neck to get out any grime, brass filing (caused by chamfering) and relying on that aforementioned light neck tension for a smooth and easy bullet release. I've heard some dip the base of their bullet in various dry lubricants. But I wonder if that REALLY has any valuable effect that hasn't already been accomplished via a light neck tension. Thx.

Alex

PS: Sorry BigDMT...not trying to hijack your post.

 

[Alex Wheeler]

Alex,
I leave the carbon inside my necks, I use a stiff nylon brush to clean off the loose stuff. I would not use light neck tension just to get a smooth release. You need to experiment with neck tension to see what the load wants.

 

[BigDMT]

OK, every one is still missing my point in question...
I always clean my necks with a brush to remove carbon, just so that's clear, but I never clean the inside of the case body. I don't even own a tumbler anymore.

What I am really getting at is whether or not the residue left behind by a different powder will effect the performances of other powders?

For example; say I have 5 cases that recently had RL15 fired in them during load testing, Then I had 5 cases that had 8208XBR fired in them. Then I try to test a 10 shot group using all of those cases, but now I am loading them with Varget.

Do you believe that the chemical make up of the carbon residue left behind can effect how a different powder performs? Is it possible that even though they are all identical and loaded with Varget now, the cases with RL15 residue could perform differently than the cases with 8208XBR residue in the bodies?

 

[jo191145]

Just wanted to get opinions from some of the accomplished and experienced shooters on whether or not you have ever given any thought to separating cases where you only burn one type of powder in them while load testing?

I personally have always just used the same cases to test multiple powders, sometimes I burn 3 or more different powders in the same cases finding what a rifle really likes. I often wondered if it would be wise and beneficial to accuracy to separate cases during testing where they are only subject to one type of powder while testing different charge weights. Only reason I have not tried it is because I always seem to find a load that is acceptable to me. What are your thoughts on this theory? Do you believe different types of carbon residue can have an effect, whether good or bad, on load development? Thanks.

Nope. Bullet release is related to neck tension not seating force, they are not the same thing. Lube the neck on the case and will have a lower seating force but the same neck tension. The neck expands to release the bullet, the bullet does not slide out of the case, if it did it would not expand.

Not to derail the thread but I disagree. Ever forget to charge a reload with powder? The primer will drive the bullet forward into the lands without expanding the brass. There's no reason to believe as the powder begins to ignite and expand that bullet isn't moving before enough pressure is developed to expand the brass.
Perhaps if loading hard into the lands everything moves at once, otherwise I doubt it.
I've seen necks not expand in long throated rifles with hard brass and Viht powders. It has something to do with the power curve of Viht I believe. Other powders worked fine but all Viht would leave some to most of the necks un expanded.

 

[jo191145]

BigDMT

Generally I would say no to your question.
Since you added 8208XBR to the mix I would say anything is possible. Not a fan of XBR.

 

[Alex Wheeler]

Just wanted to get opinions from some of the accomplished and experienced shooters on whether or not you have ever given any thought to separating cases where you only burn one type of powder in them while load testing?

I personally have always just used the same cases to test multiple powders, sometimes I burn 3 or more different powders in the same cases finding what a rifle really likes. I often wondered if it would be wise and beneficial to accuracy to separate cases during testing where they are only subject to one type of powder while testing different charge weights. Only reason I have not tried it is because I always seem to find a load that is acceptable to me. What are your thoughts on this theory? Do you believe different types of carbon residue can have an effect, whether good or bad, on load development? Thanks.

Nope. Bullet release is related to neck tension not seating force, they are not the same thing. Lube the neck on the case and will have a lower seating force but the same neck tension. The neck expands to release the bullet, the bullet does not slide out of the case, if it did it would not expand.

Not to derail the thread but I disagree. Ever forget to charge a reload with powder? The primer will drive the bullet forward into the lands without expanding the brass. There's no reason to believe as the powder begins to ignite and expand that bullet isn't moving before enough pressure is developed to expand the brass.
Perhaps if loading hard into the lands everything moves at once, otherwise I doubt it.
I've seen necks not expand in long throated rifles with hard brass and Viht powders. It has something to do with the power curve of Viht I believe. Other powders worked fine but all Viht would leave some to most of the necks un expanded.

Exactly my point, if the bullet is pushed out of the case the neck wont expand. But, you may be right that it moves some before the neck opens.

 

[jpretle]

BigDMT, I think residual burnt powder is moot, in successive loadings, provided there was a clean, complete burn on the previous firing.

 

[Shynloco]

Alex,
I leave the carbon inside my necks, I use a stiff nylon brush to clean off the loose stuff. I would not use light neck tension just to get a smooth release. You need to experiment with neck tension to see what the load wants.

Z,
I guess I sounded like I was using light neck tension to get a smooth release...that isn't what I do. Perhaps its a by-product when my casings are prepped properly. And as you suggest, I have "played" with Neck tensions of .001, ,002 and tighter with all my calibers. I was just more interested (and perhaps to darn anal) about cleaning for leaving the carbon inside the necks.

BigDMT,
For what it's worth as was stated by someone else, I do believe a small residual amount of powder against the insides of the casings are a moot issue when a casing is loaded with a normal load of another powder. I also have long doubted that just because casings are cleaned in a tumbler, that the inside walls of casing are cleaned in a substantial manner. Just my thoughts.

Alex

 

[BigDMT]

Thanks guys. I often wondered about the possible negative effects with cross contamination of powders, but I suppose if the burn is complete like jpretle stated, then there is nothing to contaminate the new charge.

The reason I brought this question up is because I have noticed in the past that after cleaning cases (which I don't do anymore) the rifle doesn't quite group as good as it does after the cases have had a charge or two fired through them. So if that seems to change things, I wondered about cross contamination. Thanks again for all the input so far.

 

[mikegaiz]

Neck tension will be different between a clean case neck or not clean case neck when sized with the same size neck bushing. Clean metal to clean metal tension is higher.

 

[Shynloco]

....... I have noticed in the past that after cleaning cases (which I don't do anymore) the rifle doesn't quite group as good as it does after the cases have had a charge or two fired through them.

Well I guess that opens the door to further debate and perhaps a rehash of the practices serious Benchrest shooters use to be able to repeat their finite accuracy with their loads. For a person like me, who shoots and reloads strictly for enjoyment and who loves the accuracy, I've noted over time, that certain practice are key in providing the repeatable accuracy, while others, focus more on say the life of the brass. Whether that is an economic decision or just the fact that small groups satisfy some wants, others may reject any notion of economic savings via such practices such as FL resizing after each firing. And cleaning case may be just the start of a series of steps and it depends on the path you follow thereafter, whether you can repeat the accuracy you had yesterday that made your day. And I can relate to what BigDMT is talking about when he says he's noted a slight decline in accuracy in his loads. I dare say, maintaining a constant consistency on my targets, is oft times no easy feat. But for me, its the challenge of starting anew each time at my reloading bench, that I've found hold the keys to starting the process to personal success. And all that doesn't even address sitting down at the shooting table and moving to the next step of putting those carefully made handloads to work trying to put together a "personal best" target that you might put on the wall as reminder that it can be done.

Alex

 

[jo191145]

Thanks guys. I often wondered about the possible negative effects with cross contamination of powders, but I suppose if the burn is complete like jpretle stated, then there is nothing to contaminate the new charge.

The reason I brought this question up is because I have noticed in the past that after cleaning cases (which I don't do anymore) the rifle doesn't quite group as good as it does after the cases have had a charge or two fired through them. So if that seems to change things, I wondered about cross contamination. Thanks again for all the input so far.

That's the carbon in the necks I'd bet. Usually life is better when it's in there. The biggest benefit for bushing dies is losing that expander ball that can mess with that lovely carbon layer.
Most might not agree with my biggest benefit comment but in the tests I've ran it was hands down.

 

[langenc]

OK, every one is still missing my point in question...
I always clean my necks with a brush to remove carbon, just so that's clear, but I never clean the inside of the case body. I don't even own a tumbler anymore.

What I am really getting at is whether or not the residue left behind by a different powder will effect the performances of other powders?

For example; say I have 5 cases that recently had RL15 fired in them during load testing, Then I had 5 cases that had 8208XBR fired in them. Then I try to test a 10 shot group using all of those cases, but now I am loading them with Varget.

Do you believe that the chemical make up of the carbon residue left behind can effect how a different powder performs? Is it possible that even though they are all identical and loaded with Varget now, the cases with RL15 residue could perform differently than the cases with 8208XBR residue in the bodies?

WOW--

I dont shoot that weel to know if those conditions would make a difference. Maybe Ill tighten the nut and see if I can determine if all the parameters you mentioned makes a difference. Good idea.