Slow Model 700 7mm Rem Mag?

[geraldhawaii]

Sockey66, if you find the problem, could you please post it. I have the same issue with my 7mm Rem Mag. I shoot an older model Tikka T3 Lite in stainless steel barrel. I believe the barrel is 23 inches. I shoot a Nosler Partition 160 grain with 63 grains of H4831sc and Federal 215 mag primers, and get consitant groups of 5/8 inches at 100 yards. However, the velocity is similar to yours, and I tried adding more powder in .2 grain increments, but got some pressure signs.

Thank you.

 

[Sockeye66]

Sockey66, if you find the problem, could you please post it. I have the same issue with my 7mm Rem Mag. I shoot an older model Tikka T3 Lite in stainless steel barrel. I believe the barrel is 23 inches. I shoot a Nosler Partition 160 grain with 63 grains of H4831sc and Federal 215 mag primers, and get consitant groups of 5/8 inches at 100 yards. However, the velocity is similar to yours, and I tried adding more powder in .2 grain increments, but got some pressure signs.

Thank you.

Absolutely I will, I gave him some RL23, new Federal 215's along with a half dozen different brands and weights of .284 bullets to try. Be patient, he teaches welding at the college in Great Falls so he'll probably get to this on Friday or Saturday.

 

[sodakota]

I'd try RE 26. It's the most accurate powder in my early 700 BDL 7mm RM for heavier bullets.

 

[Sockeye66]

I'd try RE 26. It's the most accurate powder in my early 700 BDL 7mm RM for heavier bullets.

I'm down to my last lb of 26, not enough to work up a load for him and be able to depend on getting more, that would've been my #1 recommendation as well.

 

[Rflshootr]

Do you have any RE-22 or RE-19? Those should work as well.

 

[Sockeye66]

Do you have any RE-22 or RE-19? Those should work as well.

Some RE22, no RE19 (strangely, have never even bought any) and a lb of MRP which is now dedicated to my 6.5x284.

 

[baldhunter]

I load 66.0grs of Reloader 22 with 160gr bullets in my 7mags.I've used this load in five different rifles and all of them grouped well with that load.

 

[Taylorbok]

I'd just like to mention that powder doesn't have the same burn rate from lot to lot and moisture content has an affect on that also. IIRC most manufacturers shoot for <10% variance between lots but your speeds seem to be in that "window" I've had to vary powder charges between lots of powder substantially. Food for thought.

 

[MagnumManiac]

Unfortunately, if you have a rough chamber, burrs or a rough bore, you are going to pressure out before reaching top velocity…it happens.
My Win Mod 70 EW in 338WM is just like your 7RM, slow and pressures out remarkably quickly and ran a good 200fps slower than any of my 4 other 338WM rifles. The bore in it was very rough, so I ran a lead plug with fine lapping compound for 5 strokes one way and 5 back. This is what the borescope showed before lapping it and after.

Cheers.

 

[MagnumManiac]

I'd just like to mention that powder doesn't have the same burn rate from lot to lot and moisture content has an affect on that also. IIRC most manufacturers shoot for <10% variance between lots but your speeds seem to be in that "window" I've had to vary powder charges between lots of powder substantially. Food for thought.

No manufacturer shoots for 10% variance in burn rate…not one.
Burn rate, as stipulated by both SAAMI and CIP must be held within 3% +/- of the ORIGINAL stats, otherwise it CANNOT be sold as a canister powder. It gets relegated to BULK powder lot. I know this because I used to work at ADI, the manufacturer of such powder as Varget, H1000 & Retumbo, amongst others.
Now, what many quote as a 10% difference in burn rate in their rifle is solely based on their VELOCITY outcome, this is NOT burn rate % correlation mathematically.

Cheers.

 

[TXTrained]

You said you hit pressure with H1000..That makes me think your Chroino is faulty. You should be at 3,000 FPS. On the other I'd say maybe your powder is bad..Sucked up moisture and weighs more because its dense...soyoure really not at the right weight because its heavier.Im ran into that prior to using a Dehumidifier in my reloading room years ago.Get a NEW bottle of powder and try that load.

 

[Taylorbok]

No manufacturer shoots for 10% variance in burn rate…not one.
Burn rate, as stipulated by both SAAMI and CIP must be held within 3% +/- of the ORIGINAL stats, otherwise it CANNOT be sold as a canister powder. It gets relegated to BULK powder lot. I know this because I used to work at ADI, the manufacturer of such powder as Varget, H1000 & Retumbo, amongst others.
Now, what many quote as a 10% difference in burn rate in their rifle is solely based on their VELOCITY outcome, this is NOT burn rate % correlation mathematically.

Cheers.

Thanks for the clarification. I can't seem to find the info anywhere but I knew there was tolerable variance and under ten seemed to ring a bell.
+/- 3% is still a variation of up to 6% which is <10%

 

[MagnumManiac]

Thanks for the clarification. I can't seem to find the info anywhere but I knew there was tolerable variance and under ten seemed to ring a bell.
+/- 3% is still a variation of up to 6% which is <10%

It is not 6%… it is minus 3% of original, or it is plus 3%, you don't add the 2 together.

Cheers.

 

[Taylorbok]

It is not 6%… it is minus 3% of original, or it is plus 3%, you don't add the 2 together.

Cheers.

I'm genuinely asking how is that's not a 6% variance?
You have your original lot,
then you produce the next one, it's 3% slower than the original, ship it out.
Now you produce a 3rd lot and it's 3% faster than the original.
If you got powder from the 2nd and 3rd lot they would be 6% different.