What to change when a load isn't working?

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tomapleleafss

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Recently purchased another 6.5 CM and started load development for it. Using FL bushing resized 1F Hornaday brass with BR2 primers. Using H4350 and RL26 with both ELDX and SMKs (142gr), I have had trouble with my sd and es. I can get 0.5 moa but the best sd is around 10 to 15 and es in the 30ish range (3 to 5 shot averages). I think I have come to the point I need to change something. Where to start, change powder or change bullet? Or what about brass. This brass was fired out of my old rifle but I did FL resize (Redding Type s bushing die)?
 
Assuming this is a factory rifle? in which case, just enjoy it for what it can do which is pretty good.

Test further and see how it groups. Velocity doesn't always tell what will happen at distance.

I would not worry about what the chrony says... trust the target.

Jerry
 
Performance can only be measured at the distance you need the performance.

If the objective is 100 yard groups, then you have arrived.

if the objective is 600 yard groups, then you have nothing, because you have not shot 600 yards. A 100 yard group (and an ES) means nothing about 600 yards.

The harmonics are so big they hide the ES (or make it worse).

As for variables to work on:

Different primer.

More or less neck tension.

More or less OAL

Polished inside neck.
 
Ganderite said:
Performance can only be measured at the distance you need the performance.

If the objective is 100 yard groups, then you have arrived.

if the objective is 600 yard groups, then you have nothing, because you have not shot 600 yards. A 100 yard group (and an ES) means nothing about 600 yards.

The harmonics are so big they hide the ES (or make it worse).

As for variables to work on:

Different primer.

More or less neck tension.

More or less OAL

Polished inside neck.
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What effect does polishing the neck have? I have never thought of doing this.
 
Mystic Precision said:
Assuming this is a factory rifle? in which case, just enjoy it for what it can do which is pretty good.

Test further and see how it groups. Velocity doesn't always tell what will happen at distance.

I would not worry about what the chrony says... trust the target.

Jerry
Click to expand...

It is a John Hancock from Patriot Valley Arms. My long range area is snowed in. Usually a farmer plows it out but he hasn't got around to it yet. I was hoping to have a solid load worked out by then. If my velocity numbers are all over (use a Labrador) I would think bullets would open up at distance.
 
tomapleleafss said:
It is a John Hancock from Patriot Valley Arms. My long range area is snowed in. Usually a farmer plows it out but he hasn't got around to it yet. I was hoping to have a solid load worked out by then. If my velocity numbers are all over (use a Labrador) I would think bullets would open up at distance.
Click to expand...

As was also mentioned above, variations in velocity are NOT a true indication of what will happen down range. Yes, tracking velocity is ubber fashionable today so we may sound nuts but we shoot at paper targets and track the results.

Trust the target, tune as far out as possible 150yds as a min. 200 to 300yds is ideal Once the load shows both good accuracy and low vertical dispersion on target, that load will shoot as far as the bullet will stay stable.

IMG_2008.jpg

Many years back, I experimented with velocity spreads in hopes it would predict LR results wrt to F class. It was not a consistent indicator and I was working for very small groups with very low vertical dispersion at distance. Often, I will complete my load tune at 1000yds on target.

When you get a chance to launch lead downrange, tune your ammo at distance. If you like to compare velocity, let us know if the best groups in your rifle also have the lowest ES/SDs.

More often then not, small double digit ES/SDs shot the best downrange... I have not bothered to velocity tune for many years

YMMV

Jerry
 

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It is winter time. Your powder may be temperature sensitive. this is especially true of RL26, which is a double base powder.
 
tomapleleafss said:
No I haven't. That is where I have decided to draw the line for how much time I can spend in shooting. I have only used Hornaday (that is the line for the financial investment in shooting) brass (another 6.5, .243, and a 7mm RM) and never had any es and sd problems.
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Since you bought once fired brass, cases may come from different lots and have wide variations in weight/Interior volume. I have experienced that with Hornady once fired brass.
 
It was my own brass. It was just fired in my previous 6.5 (RPR). I thought about the brass still forming to the chamber but again, even with new brass never had a problem before.
 
During load development, a Chrony can tell me 2 important things:

The velocity is in the range I want. For example 2800 fps plus or minus 50 fps.

Velocity is not over max. High velocity means high pressure.
 
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