New rifle pressure signs with light loads

[pacer97]

Has any one had this happen? I loaded some what I thought were light loads to do a barrel breakin on my Rem. BDL SS 300 SAUM. The load was 130gr. sp Hornady over 53.5gr. H4895 and with some of the rounds the bolt lift seemed a little heavy but with such a mild load thought it was just me. So got to shooting 3 shot groups. Loaded up 3 180gr Nosler Accubonds over 58gr. of H4350, the start load in the Nosler #6. A great group - all three touching but the bolt is stiff. Anyone else have pressure signs at such mild loads? - my first time. Any suggestions appreciated.

Alan

 

[Desert Fox]

Check the primers. Are the edge flat or rounded? Do you own or have access to a chronograph? How is your seatting depth? Check the chamber. Remington are notorious for rough chamber. I don't think they polished the chamber well enough after reaming.

 

[pacer97]

Desert primers look fine. New Ced chrono Monday hopefully and chamber seems smooth to my eye but the local smith will be home from hunt trip Monday to. And I only have a stiff bolt lift the cases extract no problem.

Thanks Alan

 

[JD338]

What about the firing pin spring?
Might want to try some factory loads to check the bolt lift.

JD338

 

[pacer97]

JD338 if it was the firing pin spring would the bolt lift not stay the same it did get stiffer with the 180s. Factory loads I will try ones I get to a city to pick some up not available close.

Thanks Alan.

 

[Kimberman]

I know a guy who had a 700 in 7 SAUM that had the same problem. His smith said Remmy didnt run a finishing reamer deep enough in the chamber, and that it was rough around the shoulder of the chamber. He polished it out and all is well now.

 

[FOTIS]

Has any one had this happen? I loaded some what I thought were light loads to do a barrel breakin on my Rem. BDL SS 300 SAUM. The load was 130gr. sp Hornady over 53.5gr. H4895 and with some of the rounds the bolt lift seemed a little heavy but with such a mild load thought it was just me. So got to shooting 3 shot groups. Loaded up 3 180gr Nosler Accubonds over 58gr. of H4350, the start load in the Nosler #6. A great group - all three touching but the bolt is stiff. Anyone else have pressure signs at such mild loads? - my first time. Any suggestions appreciated.

Alan

Cartridge : .300 Rem SA Ultra Mag
Bullet : .308, 130, Hornady SP 3020
Cartridge O.A.L. L6: 2.825 inch or 71.76 mm
Barrel Length : 24.0 inch or 609.6 mm
Powder : Hodgdon H4895

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 58 37.45 2098 1270 16907 5604 82.9 1.698
-27.0 61 39.06 2175 1366 18368 5946 85.0 1.645
-24.0 63 40.66 2254 1466 19953 6285 87.0 1.596
-21.0 66 42.27 2332 1570 21660 6619 88.8 1.548
-18.0 68 43.87 2411 1677 23501 6945 90.6 1.501
-15.0 71 45.48 2489 1789 25489 7262 92.2 1.456
-12.0 73 47.08 2568 1903 27633 7567 93.7 1.413
-09.0 76 48.69 2646 2021 29944 7858 95.0 1.371
-06.0 78 50.29 2724 2142 32439 8134 96.2 1.332
-03.0 81 51.90 2801 2265 35129 8393 97.2 1.293
+00.0 83 53.50 2878 2391 38031 8632 98.1 1.252
+03.0 86 55.11 2954 2519 41162 8850 98.8 1.208
+06.0 88 56.71 3030 2649 44537 9046 99.3 1.165
+09.0 91 58.32 3104 2781 48141 9218 99.7 1.125
+12.0 93 59.92 3177 2914 52009 9365 99.9 1.087
+15.0 96 61.53 3250 3049 56174 9486 100.0 1.050 ! Near Maximum !

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 83 53.50 3010 2615 44876 8527 100.0 1.165
Data for burning rate decreased by 10% relative to nominal value:
-Ba 83 53.50 2705 2112 31580 8305 92.0 1.346





Cartridge : .300 Rem SA Ultra Mag
Bullet : .308, 180, Nosler AccuBond 54825
Cartridge O.A.L. L6: 2.825 inch or 71.76 mm
Barrel Length : 24.0 inch or 609.6 mm
Powder : Hodgdon H4350

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 69 40.60 2009 1614 21421 6553 84.3 1.807
-27.0 72 42.34 2092 1749 23572 6962 86.6 1.738
-24.0 75 44.08 2175 1891 25936 7363 88.8 1.673
-21.0 78 45.82 2259 2040 28534 7751 90.7 1.610
-18.0 81 47.56 2343 2195 31394 8124 92.6 1.549
-15.0 84 49.30 2428 2356 34542 8477 94.2 1.491
-12.0 87 51.04 2512 2523 38012 8807 95.7 1.433
-09.0 90 52.78 2597 2696 41843 9111 96.9 1.369
-06.0 93 54.52 2681 2873 46078 9386 98.0 1.310
-03.0 96 56.26 2765 3056 50766 9628 98.8 1.253
+00.0 99 58.00 2848 3243 55967 9836 99.4 1.200 ! Near Maximum !
+03.0 102 59.74 2931 3434 61752 10005 99.8 1.149 ! Near Maximum !
+06.0 105 61.48 3013 3629 68204 10134 100.0 1.101 !DANGEROUS LOAD-DO NOT USE!
+09.0 108 63.22 3094 3827 75419 10229 100.0 1.055 !DANGEROUS LOAD-DO NOT USE!
+12.0 111 64.96 3175 4029 83478 10315 100.0 1.011 !DANGEROUS LOAD-DO NOT USE!
+15.0 114 66.70 3255 4234 92497 10392 100.0 0.970 !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 99 58.00 2970 3525 67496 9478 100.0 1.114 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 99 58.00 2676 2863 45628 9701 94.5 1.312


As you can see no pressure to speak of with either load. The problem lies elsewhere. Get some factories.

 

[30-338]

How close you seating the bullets to the lands? Might want to load up some at factory OAL and try those.

 

[pacer97]

Kimber on Monday going to let the smith have a look. Pop have my brother looking for Factory loads in Calgary today and thanks for the quick load data. 30-338 the OAL is 2.80 with the 180s and well off the lands .
Thanks guys all good suggestions from ever one will look in to them all further.

Thanks Alan