Strange (low) velocity readings while starting Ladder

[Alan Griffith]

You may have just viewed my post on a Ladder test I shot yesterday using Ramshot Hunter in my 30-06 and Nosler 180 Ballistic Tips.

Once I was done with the Hunter Ladder I started on a Reloader 22 Ladder using the same bullet. I start with 5 fouling shots from 58 to 61 grains. I know this particular rifle pretty intimately (much to my wife's chagrin /ubbthreads/images/graemlins/grin.gif) and have always been able to exceed book max prop charges. Not feeling too greedy I had only preloaded 1 round at 61 grains (60 is book max).

1. 58.0 gr = 2541 fps, .0001 expansion
2. 59.0 gr = 2590 fps, .0000 expansion
3. 60.0 gr = 2638 fps, .0000 expansion
4. 60.5 gr = 2649 fps, .0000 expansion
5. 61.0 gr = 2675 fps, .0000 expansion

I measure case head expansion just forward of the extractor groove with a .0001" mic and stop when I hit .0006".

Having run out of fouling/pressure rounds and wanting more velocity than 2675 (especially from Rel 22) I did not want to stop thier. I pulled out my Harrell's powder meter and began to single load upto 63.5 grains.

Here's the interesting point.

61.4 gr = 2639 fps, .0002" expansion
62.5 gr = 2662 fps, .0002" expansion
63.0 gr = 1418 fps, 0 expansion
63.0 gr = 1418 fps, 0 expansion
63.5 gr = 1412 fps, 0 expansion

Here is my guess. The WLR primer did not have enought "umph" to ignite that much powder in an '06 case.

Any opinions?

Big Al

 

[dakor]

Are you sure you did not have a low battery in your chronograph? Maybe your graph went a little crazy on you did you shoot anything else through it?

 

[Alan Griffith]

Dakor,

It could be a possiblity, I suppose. The chrono was running great the whole morning with nary a single bad reading. I'd have to check my owners manual but I believe the read out would indicate a low battery.

The one thing which makes me believe the total prop charge was not burning completly was the lack of case head expansion, zero, naughty!

Big Al

 

[Fiftydriver]

Could you tell a difference in recoil? It would be dramatic dropping from nearly 2700 fps down to 1400 fps. It would be easy to tell from felt recoil alone if you were actually getting these velocities.

Kirby Allen(50)

 

[jb1000br]

What chrony?

the folding ones im guessing...

Also, how far away from the muzzle?

I ran my shooting chrony in front of my oehler 35 last weekend...SC gave results from 1600fps-3400fps IIRC, while actual velocity was between 2800-3000

the 3400fps was most likely muzzle blast thru the screens (even at 10 feet...cause it happened before and was around 3400fps), but the low reading made no sense, and WAS NOT REAL -- evidenced by the impact where it was supposed to at 300yds.

JB

 

[Alan Griffith]

Kirby,

Now that I think of it, the recoil was less.

Big Al

 

[Alan Griffith]

JB,

Ohler M33, 5 foot spacing, 10 feet from muzzle, sky screens in place with light overcast.

Big Al

 

[41mag]

Hey Al,

Several years back, before I had anything that I thought was a LR rig, I loaded up some heavy 165gr '06 loads. I used the RL-22 and was getting right at 3000fps with the Nosler BT. The laod was 63grs, and it shot one hole at 100 and just under 3" at 450. The stuff rocked like a 300 mag as long as temps were above 60 degrees. Once below that, the load fell of to just what you described.

I found that the primer was just not up to lighting off that much compressed powder in the load. I switched over to RL-19 and got the velocities but the accuracy went south. THe last load I worked up, and stayed with, was using IMR 4350, and it has been great out of close to a dozen rifles. The velocity isn't anything amazing, but when you figure all of those rifles shot the same load into less than 1" at 100, it can't be all bad.

 

[Alan Griffith]

Mike,

Besides being an experimenter who likes to prove things to myself, I have powders which shoot dang near bugholes from this rifle. Especially this rifle. It was my dream rifle 24 years ago weighing only 6 lb 8 oz. The 'smith who built it for me took a bunch of metal from the action and bolt, glass bedded the action, free floated the barrel, turned down the barrel to toothpick (.550" muzzle) dimensions and gave it a supurb 3-lb trigger. It shoots H4350 and H4895 sub MOA. The best is .337" @ 100 Yds and 1.90" (5-shots) at 300 yds, and this with a Leupold M8 4x scope. The H4895 shoots tighter than the H4350 but only to about 2665 fps. Obviously the H4350 shoots faster but not as tight as the H4895. I wanted to try Hunter due to it's rep as being temperture insensitive and Rel 22 due to it's faster velocity potential.

If I wanted to live with 2675 fps, I'd just stay with H4895 (I still might settle on that powder) but I want to give Rel 22 it's full shot and see if a magnum primer, properly worked up, could beat H4895 in the velocity arena.

Big Al

 

[Alan Griffith]

I ran a back-up test this morning.
I believe it was the batteries. I inserted fresh ones and ran another 9 round test using WLR primers then a 9 round test using Fed 215 Mag primers.

Here is the results.

WLR primer pressure test
grains velocity Expansion in .0001"
57 2467 1
58 2502 1
59 power was off 2
60 2590 1
60.5 2605 1
61 2638 0
61.5 2655 0
62 2682 3
62.5 2696 0

New pressure test using Fed 215 mag primer
expansion in .0001"
57 2442 3
58 2487 0
59 2515 2
60 2577 2
60.5 2604 0
61 2628 0
61.5 2648 1
62 2649 1
62.5 2696 1

Something I've notices with this Rem 700. When I seat my Nosler 180 BT's, out touching the lands, I've got the bullet seated so 1/2 the neck has bearing surface seated. This give me extra case volume and I've been able to get about 3 grains of powder over any book max I've ever seen.

Big Al

 

[Jimm]

You have only mentioned using case head expansion as a over pressure test . What about flattened/cratered primers ,heavy bolt lift or hard extraction ? Have you experienced any of this with the loads you have worked up to ? Also what about loosened primer pockets ?

If you haven't then you may be still quite short of a "max" load for that rifle and RE 22.

Jim B.

 

[Alan Griffith]

Jim,

Yes, I do all the normal tests for pressure; primers look awesome, flatted a bit but not crattered. No heavy bolt lift or hard extraction. Primer pockets do not seem loose.

And, I agree.

Big Al