7mm-08 reloading problem

• Apr 2, 2018

• #1

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lock-n-load

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I am reloading for my son's Remington Model 7, 7mm-08. The rifle is a youth model, so the barrel is very thin. No matter what loads I try, the 1st shot (the one that counts on a deer stand) is consistently ~100 fps faster than shots 2 & 3. I've tried Varget & Win 748 powder, and 120 grain Nosler BT & Speer 130 grain boat tails. Same results with various loads. At 100 FPS faster than all subsequent shots, the 1st shot is consistently 1.25" - 1.5" higher at 100 yards than the rest. Anyone have any ideas, or just sight the rifle in with all cold shots, waiting ~10 minutes b/t each shot?

 

• Apr 2, 2018

• #2

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Blue Diamond

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I would sight somewhere in the middle if you are THAT worried about it. Unless you're trying to shoot them in the eye or the ear hole you should be GTG.

 

• Apr 2, 2018

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Barry J

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did you check the gun? Screws tight and barrel free floated?

 

• Apr 2, 2018

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bowhtr1

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Sounds like the barrel is touching something after the first shot. What happens with a clean barrel first shot? I have the same gun in 7mm08 and I did put a thin piece of rubber at the very front between the stock and barrel to make contact. It will still walk some but after the barrel has about 4 quick rounds through it.

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• Apr 2, 2018

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DaSouthernYankee

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I doubt every first shot is 100fps faster. Cold bore shots are usually off from the rest of the group, dont know why.

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• Apr 2, 2018

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Yes. All screws tight. Had to shim the barrel a bit to float it, but all good now.

 

• Apr 2, 2018

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lock-n-load

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Verified with chrono. Every first shot without fail.

 

• Apr 3, 2018

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highstandard40

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The "first" shot you are speaking of, is this from a clean barrel? Is there residual gun oil in the barrel for the first shot? If so, you may want to make a fouling shot before doing any accuracy and chrono testing. I have seen several guns that refuse to behave with a squeaky clean bore. After a shot or two they then settle down and act right. 22LR is notorious for this trait.

 

• Apr 3, 2018

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highstandard40 said:

The "first" shot you are speaking of, is this from a clean barrel? Is there residual gun oil in the barrel for the first shot? If so, you may want to make a fouling shot before doing any accuracy and chrono testing. I have seen several guns that refuse to behave with a squeaky clean bore. After a shot or two they then settle down and act right. 22LR is notorious for this trait.

Click to expand...

No - Not from a clean barrel. I will shoot 3 shots, wait about 30 minutes for the barrel to cool, and shoot another 3 shots. Same results - shot #1 from each string will be 100 fps faster and about 1.25" - 1.5" higher at 100 yards. No cleaning between strings.

 

• Apr 3, 2018

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twinin

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The only other thing not mentioned that I can think of is that you load a detachable magazine, and the first round sits at the top of the magazine and is in the sun and warms up for the 30 minutes? 100 fps seems like too much for that though.

 

• Apr 3, 2018

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Blue Diamond

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What is the spread like between #2 and #3?

 

• Apr 5, 2018

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twinin said:

The only other thing not mentioned that I can think of is that you load a detachable magazine, and the first round sits at the top of the magazine and is in the sun and warms up for the 30 minutes? 100 fps seems like too much for that though.

Click to expand...

That can't be it either since the Model 7 has the spring swing plate, not a detachable mag. All cartridges stay in the same box until I put them in the gun. It has been frustrating for me.

 

• Apr 5, 2018

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Blue Diamond said:

What is the spread like between #2 and #3?

Click to expand...

Shot on different targets, but looking at both side by side, all 1st shots within 3/4" of one another, and all subsequent shots within about 1" of one another.

 

• Apr 5, 2018

• #14

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Tboy

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Just a thought but Have you verified it’s not the chrono with that FPS spread?

An interesting and related read dealing with the same caliber. 9 pages worth

https://www.thehighroad.org/index.php?threads/why-is-my-first-shot-high.711904/

 

• Apr 5, 2018

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Blue Diamond

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lock-n-load said:

Shot on different targets, but looking at both side by side, all 1st shots within 3/4" of one another, and all subsequent shots within about 1" of one another.

Click to expand...

That may be the best you can achive with a light weight free floated barrel. Take your shims out and place a thin rubber cushion under the barrel where it leaves the fore end to bed the barrel somewhat and stop some of the harmonic vibrations. It will probably settle down or not. You've tried everything else.