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LittleLebowski
05-28-2018, 01:27 PM
I’m seeing consistently slow velocities with all handloads out of my 20” 700 as recorded by my MagnetoSpeed Sporter (https://www.brownells.com/shooting-accessories/range-gear/chronographs/sporter-chronograph-prod78977.aspx), as in 2625fps for Hornady 178gr ELDM over 45.0gr of Varget. Might this be my CCI 200 primers? I’m guessing I should switch to magnum primers.

mtnbkr
05-28-2018, 02:13 PM
Slow compared to what exactly? The same load but with different primers? Compared with the loading manual? Varget is a fastish rifle powder and shouldn't need a mag primer.

308win?

The 175gr HPBT load on Hodgdon's reloading site uses a non-mag match primer with a compressed 45gr charge of Varget.

Chris

LittleLebowski
05-28-2018, 02:30 PM
Yeah, 308. I can’t break 2500fps with 195s and JV can with the same powder and bullet weight.

mtnbkr
05-28-2018, 02:44 PM
Yeah, 308. I can’t break 2500fps with 195s and JV can with the same powder and bullet weight.

Same charge as well? What about the gun?

Guns are weird. I've had guns that run slow (GP100 and Winchester 70 FWT 6.5x55) and others that run fast (Ruger Redhawk and Savage Hog Hunter 308). If you're confident your load is not overpressure (and vice versa for his), try them in each other's guns and see if the same trend holds.

It won't hurt to try another primer, but I would be surprised if it made a big difference.

Chris

LittleLebowski
05-28-2018, 03:55 PM
Same charge as well? What about the gun?

Guns are weird. I've had guns that run slow (GP100 and Winchester 70 FWT 6.5x55) and others that run fast (Ruger Redhawk and Savage Hog Hunter 308). If you're confident your load is not overpressure (and vice versa for his), try them in each other's guns and see if the same trend holds.

It won't hurt to try another primer, but I would be surprised if it made a big difference.

Chris

Same rifle, same charge. I should be hitting 2600ish with the 178s and 45.0gr of Varget.

mtnbkr
05-28-2018, 04:24 PM
Same rifle, same charge. I should be hitting 2600ish with the 178s and 45.0gr of Varget.

But different primer or same? Any idea on round count for the two rifles? Wear changes how a gun reacts to a load.

Chris

JohnO
05-28-2018, 06:21 PM
Same rifle, same charge. I should be hitting 2600ish with the 178s and 45.0gr of Varget.

Meaning? Same make and model?

No two rifles are going to have identically cut chambers, leads and bores. All that will factor into how a particular load performs.

mtnbkr
05-28-2018, 07:11 PM
LL, if you're not married to Varget, give RL17 a try. I'm getting 2800fps with a 180gr SPBT in my 20" 308win. That's a book load. Apparently RL17 has a flatter pressure curve, so it "pushes" longer, giving you more velocity at a given pressure. It might solve your velocity problem.

Chris

LittleLebowski
05-28-2018, 07:59 PM
Meaning? Same make and model?

No two rifles are going to have identically cut chambers, leads and bores. All that will factor into how a particular load performs.

Same rifle. One rifle.

mtnbkr
05-28-2018, 08:18 PM
Same rifle. One rifle.

oh! Well, that's different.

ok, same gun, same powder charge.

Safe to assume same brass and same bullet? What about brass prep and seating depth?

Since you asked about the primer, are you using different primers?

Chris

LittleLebowski
05-29-2018, 06:35 AM
oh! Well, that's different.

ok, same gun, same powder charge.

Safe to assume same brass and same bullet? What about brass prep and seating depth?

Since you asked about the primer, are you using different primers?

Chris

Same rifle. Same brass, primer, and charge. I load both the 195s and the 178s to 2.87" (as long as I can).

mtnbkr
05-29-2018, 07:17 AM
Same rifle. Same brass, primer, and charge. I load both the 195s and the 178s to 2.87" (as long as I can).

To what depth does JV load them?

Are you using powders from the same lot? Test environmentals (ambient temp, humidity, etc) the same (or close, as in not a 30+ deg difference)? Are you using the same chronograph?

Are you *sure* the charge is the same? Maybe pull one loaded by each of you and measure the charge on the same scale. Your individual tools may be off. Digital scales have a .1gr variation in either direction for example.

Chris

LittleLebowski
05-29-2018, 09:04 AM
Excellent questions, answers inline.


To what depth does JV load them? I think he pushes it to mag length like me. I'll run over to his office and find out.

Are you using powders from the same lot? Yes, same keg. Test environmentals (ambient temp, humidity, etc) the same (or close, as in not a 30+ deg difference)? Yes, all the same. Are you using the same chronograph? Yes.

Are you *sure* the charge is the same? I checked on two digital scales and an RCBS beam scale, they are all within .08 of each other.

mtnbkr
05-29-2018, 09:37 AM
Excellent questions, answers inline.

If the components are the same, you're using the same charge (verified by multiple scales), and your seating depth is the same, the ONLY other thing that comes to mind is brass prep (trimming, chamfering, sizing, etc) and age (new vs N-Fired). To be honest, I'd expect brass prep and age to have more of a factor on accuracy than velocity, though I suppose old brass with non-elastic necks could reduce velocity since the bullet wouldn't be held long enough for appropriate pressures to develop. I'm not sure that's a rifle issue as much as it is with handguns.

What about loading dies? Same brand? Maybe the brass is being worked slightly differently (tighter/looser necks, shoulders bumped back more or less, etc).

Aside from velocity concerns, how is accuracy?

Otherwise, I'm at a total loss to explain the difference in velocity.

Chris

LittleLebowski
05-29-2018, 10:22 AM
JV figured it out, I was checking velocity with the can on. I'm going to chrono sans the can and report back, but I bet that's it (the Magnetospeed "bayonet" needs to be close to the muzzle, within 1 centimeter). Of course this negates me running the chrono in my back yard now :(

mtnbkr
05-29-2018, 10:54 AM
Have him chrono his loads with the can and see if his loads react accordingly.

Chris

LittleLebowski
05-29-2018, 12:26 PM
Have him chrono his loads with the can and see if his loads react accordingly.

Chris

He's a busy guy, I'll just figure it out with my can and my loads, I doubt he'd deign to shoot my ammo :D

Trigger
05-29-2018, 06:57 PM
German Salazar performed an extensive primer test, and posted the results on his old website: riflemansjournal.blogspot.com. He has since take the site down. Some of his photos are still available at: http://www.6mmbr.com/PrimerPix.html

LittleLebowski
05-30-2018, 05:55 AM
German Salazar performed an extensive primer test, and posted the results on his old website: riflemansjournal.blogspot.com. He has since take the site down. Some of his photos are still available at: http://www.6mmbr.com/PrimerPix.html

I regret missing that site, I see so many references to excellent work on it.

Hambo
05-30-2018, 06:08 AM
So if I understand this you and JV have similar rifles, and using the same data your loads were slower in your rifle than his were in his rifle. That it?

If you want to compare his chrono data to yours, you really need to shoot his ammo in your rifle. Otherwise there are rifle variables you can't account for. If his ammo hits X velocity in yours, but your ammo doesn't reach X, it's something in your ammo.

mtnbkr
05-30-2018, 06:13 AM
I regret missing that site, I see so many references to excellent work on it.

This is the first time I've heard of it and I've been reloading since the late 90s. Been a long time member of a number of reloading-oriented sites too.

Not sure how it flew under my radar...

BTW, if you don't have it yet, Ken Waters' Pet Loads is a good resource. You're welcome to peruse my copy if you want a preview.

Chris

mtnbkr
05-30-2018, 06:14 AM
So if I understand this you and JV have similar rifles, and using the same data your loads were slower in your rifle than his were in his rifle. That it?

If you want to compare his chrono data to yours, you really need to shoot his ammo in your rifle. Otherwise there are rifle variables you can't account for. If his ammo hits X velocity in yours, but your ammo doesn't reach X, it's something in your ammo.

Per and earlier post, it sounds like they're using the same physical rifle. That sounds odd, but was what he said.

Chris

Hambo
05-30-2018, 06:20 AM
Per and earlier post, it sounds like they're using the same physical rifle. That sounds odd, but was what he said.

Chris

I took it to mean he was shooting the 175 and 195 in the same rifle, but you could be right. The string of posts is confusing.

mtnbkr
05-30-2018, 06:26 AM
I took it to mean he was shooting the 175 and 195 in the same rifle, but you could be right. The string of posts is confusing.

Per post #9, "Same rifle. One rifle."

But yeah, it was getting a bit confusing at times.

Chris

LittleLebowski
05-30-2018, 08:05 AM
So if I understand this you and JV have similar rifles, and using the same data your loads were slower in your rifle than his were in his rifle. That it?

If you want to compare his chrono data to yours, you really need to shoot his ammo in your rifle. Otherwise there are rifle variables you can't account for. If his ammo hits X velocity in yours, but your ammo doesn't reach X, it's something in your ammo.

I understand your conclusion and agree, but the real problem seems to be that I was using my chrono mounted to the suppressor. I will update this thread when I confirm.

Trigger
05-30-2018, 10:18 PM
More grist for the primer discussion:

https://rifleshooter.com/2018/05/does-primer-size-matter-6-5-creedmoor-small-v-large-primer-brass-comparisons/

BL, primers make a difference, but they are worth testing in your gun with your loads to decide. I know I’ve tested them in my rifles, and Wolf produced the largest groups, Federal next smaller, and CCI the smallest. All standard disclaimers apply.

SecondsCount
06-03-2018, 10:19 PM
More grist for the primer discussion:

https://rifleshooter.com/2018/05/does-primer-size-matter-6-5-creedmoor-small-v-large-primer-brass-comparisons/

BL, primers make a difference, but they are worth testing in your gun with your loads to decide. I know I’ve tested them in my rifles, and Wolf produced the largest groups, Federal next smaller, and CCI the smallest. All standard disclaimers apply.

Everything is a variable. Many claim that the Russian Tula and Wolf primers give good results and that has been my experience. I really like the small rifle magnum primers for 223 and 6x47L. Too bad you can't seem to find them any longer.

JFK
06-04-2018, 08:59 AM
I hope you figured it out. However for the sake of discussion and assessing variables....

I have found with compressed loads I have had more consistency with Magnum or BR primers. Logic would say the slightly hotter primer gives better initial ignition, but this could also be because of the burn rate of the powders that I use. When using uncompressed loads I have found little different in using standard or magnum primers, however I have found BR premiers are worth the extra if you are chasing low SD. When I refer to consistency, I mean not only SD over a single test, but a smaller and more predictable velocity change with environmental differences.

Also keep in mind that as a barrel ages and the throat wears it may be pertinent to address OAL periodically. If you have the bullet jammed to lands (more pressure) as the throat wears that extra space could change pressure, in turn velocity.

LittleLebowski
06-04-2018, 09:10 AM
Looks like I gained an easy 60FPS by removing the suppressor. I think that was the problem with the chrono.