Pressure too high

[Guest]

Update to the following post:
At the range yesterday attempting to break in a Rem Model 7 in 7 mm SAUM. Nosler # 6 manual shows 3 listings for RL19 of 58, 60 and 62 grains for a 140 grain bullet.

My load:
140 gr NBT
58 gr RL 19
Rem brass
Fed GM 210M match primers
OAL 2.82

The case is not full with this load. The bolt closes nicely before firing. First shot and the bolt was a little tight. Second shot and the bolt was tight, a slight extractor mark and there was a little black residue around the gas excape hole on the receiver = too hot for safety. I did not see any whiteness around the base of the cartridge. Tonight I plan to recheck the seating depth in relation to the lands. I will pull the rest of the bullets I have loaded and back off on the powder but I am a bit surprised at this since I started with the lowest load Nosler listed. Any thoughts or comments? Thanks.

update:Went back to the range yestereday with one loaded with 57 grains of powder. Everthing was fine .... no extractor mark or tight bolt. Next one was with 57.2 grains. Had a noticabley tight bolt and a slight but noticable extractor mark. Looks like the higher powder loads were too high for this rifle. I did not change the OAL. Sure seems odd to me but that is the results. Thanks. Al

 

[Guest]

At what range do you plan on hunting at?

 

[PGJPJ]

Same specs in the #5 manual.

140 grn BT
58, 60, 62 grn RL19.
Rem brass
They listed Rem9.5M for their primer

Don't know???

 

[Guest]

longranger, good question .... I mostly hunt in the east ... SC & TN. Ranges may be up to 500 yards here. Have always dreamed of hunting out west. Dreams do sometimes come true. Son in law & I are to go to WY in early Oct. to hunt pronghorn. I would like to think we may get to go back next year &/or the year after for mule deer and Elk. If so potential range will be up to ????? May not even get to go .... but dreams add a lot of spice to life and sometimes they come true.

 

[DrMike]

Just out of curiosity, have you checked your scale? Are you using digital or balance beam scale? If digital, do you calibrate and recheck calibration from time-to-time? If balance beam, do you tare your pan before beginning to weigh, and use check weights occasionally to ensure that the scale is not drifting. Also, is your scale level? Almost always when we find a deviation from anticipated results, there has been some minor step that was overlooked. Take it from someone who spent a fair amount of time in the laboratory that such mistakes happen more frequently than we like to admit.

 

[Guest]

It's time to step back, take a deep breath, and start from the beginning. Check everything. Dr. Mike is right - check the scale. Then check your rifle chamber and throat length to verify the chamber is not oily and your bullets aren't seated into the lands. Then consider that your lot of RL19 may be out of the norm in terms of burn rate, though I haven't heard anything about that with RL19 lately. Have you tried another powder? What other stuff do you have onhand you might work with to compare?

I suspect there's either oil in the chamber, or the throat is short versus your COL, or your powder is out of whack. Or I guess there's always the potential for some sort of bore fouling that is so severe it's causing spikes, but that'd have to be some serious fouling.

 

[Greg Nolan]

One of the most amazing things I've noticed with reloading is that most of the manuals are litigation conscious. I was lulled into that over a period of time(especially by Nosler manuals). Then One Day I discovered that I can't assume 2 grains more. At max load per Nosler #6 I was at "MAX". and I nearly blew up(really) my rifle by exceeding the max.
The moral of the story is that there is no absolutes in loading due to all the variables in all the rifles with all the bullets with all the primers with all the cases. I think you get the point. I don't like hanging my head and mumbleling to my local gunsmith about (But the manual said)
Greg

 

[Guest]

Good suggestions. I will recheck everthing during the coming week. I do land surveying and my work has really picked up (have to do it when I get it) so it may take a while to report back but I will.

Greg Nolan, Thanks for helping to make a dream come true... :grin: :grin: ..instead of early oct we leave Sept 25 for WY pronghorn hunt.

What a great group of guys on this board.

 

[1Shot]

Also the temp has really been hot. How hot was it when you were doing your load work up. I ran into the same thing using Retumbo in my 264 Win mag. with too much pressure. I got too much pressure 1 grain from max listed loads. It was 87* when I was doing the shooting.

 

[FOTIS]

Cartridge : 7 mm Rem SA Ultra Mag
Bullet : .284, 140, Nosler BalTip 28140
Cartridge O.A.L. L6: 2.820 inch or 71.63 mm
Barrel Length : 24.0 inch or 609.6 mm
Powder : Alliant Reloder-19

Predicted data by increasing and decreasing the given charge,
incremented in steps of 3.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-30.0 67 40.60 2066 1327 19807 6919 77.6 1.804
-27.0 70 42.34 2150 1437 21724 7383 79.9 1.740
-24.0 73 44.08 2235 1553 23821 7846 82.2 1.679
-21.0 76 45.82 2321 1675 26115 8305 84.4 1.619
-18.0 79 47.56 2408 1803 28626 8758 86.5 1.562
-15.0 82 49.30 2496 1936 31375 9201 88.5 1.508
-12.0 85 51.04 2584 2075 34387 9630 90.4 1.454
-09.0 88 52.78 2672 2220 37690 10042 92.1 1.400
-06.0 90 54.52 2761 2369 41314 10435 93.7 1.341
-03.0 93 56.26 2849 2524 45296 10803 95.1 1.284
+00.0 96 58.00 2938 2684 49673 11145 96.3 1.231
+03.0 99 59.74 3027 2848 54502 11458 97.4 1.180
+06.0 102 61.48 3115 3017 59807 11737 98.3 1.132 ! Near Maximum !
+09.0 105 63.22 3203 3190 65615 11980 99.0 1.086 !DANGEROUS LOAD-DO NOT USE!
+12.0 108 64.96 3291 3367 72022 12184 99.5 1.042 !DANGEROUS LOAD-DO NOT USE!
+15.0 111 66.70 3378 3547 79105 12347 99.9 1.000 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 96 58.00 3090 2969 59396 11189 99.7 1.139 ! Near Maximum !
Data for burning rate decreased by 10% relative to nominal value:
-Ba 96 58.00 2743 2339 40676 10551 89.0 1.348