Accumark .300 Bee Question #2 & #3

[elkeater2]

#2: Is there way to adjust or smith the Accumark trigger overtravel? I don't see it, and have it disassembled to replace the spring and polish sear surfaces. That all worked, but overtravel is pretty bad. BTW, I'm on the Weatherby forums too, I just like it here :lol:

Nobody on those forums has referenced Accumark trigger over-travel. The Accumark is similar but not identical to previous Mark V triggers.

#3 The owner wants to use Berger 210 Hunting VLD's. We started working up some loads until these other issues came up. Using RL25, H4831SC, and Retumbo. A Quickload run or any other load suggestions for this bullet would be great. A couple loads are right at 3000 fps without pressure signs. Likewise the Berger 185. That one we seated to ridiculous depth before it tightened up - but now we need to start over since we changed scopes, tuned trigger, etc.

Thanks everyone! EE2

 

[FOTIS]

I will Q/L when I get home.

overtravel? I suggest a good smith.

IMR 7828 always worked great for me.

200 grainers at 3000-3100

 

[DrMike]

Cartridge : .300 Weath. Mag.
Bullet : .308, 210, Berger VLD G7 #30415
Useable Case Capaci: 85.929 grain H2O = 5.579 cm³
Cartridge O.A.L. L6: 3.560 inch = 90.42 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Alliant Reloder-25

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% 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

-20.0 81 64.00 2403 2693 31652 10286 98.5 1.733
-18.0 83 65.60 2461 2825 33822 10514 99.2 1.690
-16.0 85 67.20 2519 2960 36142 10717 99.6 1.649
-14.0 87 68.80 2577 3096 38627 10894 99.9 1.599
-12.0 89 70.40 2634 3234 41284 11042 100.0 1.550
-10.0 91 72.00 2690 3374 44135 11170 100.0 1.502
-08.0 93 73.60 2745 3514 47188 11295 100.0 1.457
-06.0 95 75.20 2800 3656 50465 11416 100.0 1.413
-04.0 97 76.80 2854 3798 53980 11535 100.0 1.371
-02.0 100 78.40 2908 3943 57757 11650 100.0 1.330 ! Near Maximum !
+00.0 102 80.00 2961 4088 61815 11761 100.0 1.291 ! Near Maximum !
+02.0 104 81.60 3014 4235 66141 11869 100.0 1.253 !DANGEROUS LOAD-DO NOT USE!
+04.0 106 83.20 3066 4384 70765 11973 100.0 1.217 !DANGEROUS LOAD-DO NOT USE!
+06.0 108 84.80 3118 4535 75716 12073 100.0 1.182 !DANGEROUS LOAD-DO NOT USE!
+08.0 110 86.40 3170 4687 81025 12169 100.0 1.149 !DANGEROUS LOAD-DO NOT USE!
+10.0 112 88.00 3222 4841 86722 12260 100.0 1.116 !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 102 80.00 3059 4364 75624 11363 100.0 1.195 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 102 80.00 2810 3681 49009 12326 99.9 1.420

Cartridge : .300 Weath. Mag.
Bullet : .308, 210, Berger VLD G7 #30415
Useable Case Capaci: 85.929 grain H2O = 5.579 cm³
Cartridge O.A.L. L6: 3.560 inch = 90.42 mm
Barrel Length : 26.0 inch = 660.4 mm

Predicted Data for Indicated Charges of the Following Powders.
Matching Maximum Pressure: 55839 psi, or 385 MPa
or a maximum loading ratio or filling of 110 %
These calculations refer to your specified settings in QuickLOAD 'Cartridge Dimensions' window.
C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

34 loads produced a Loading Ratio below user-defined minimum of 90%. These powders have been skipped.
Powder type Filling/Loading Ratio Charge Charge Vel. Prop.Burnt P max P muzz B_Time
% Grains Gramm fps % psi psi ms
--------------------------------- -----------------------------------------------------------------
Vihtavuori N570 102.0 85.2 5.52 2959 97.5 55840 14023 1.346 ! Near Maximum !
Alliant Reloder-50 108.8 93.2 6.04 2948 97.3 55840 14224 1.372 ! Near Maximum !
Alliant Reloder 33 101.8 88.6 5.74 2947 98.1 55840 13830 1.349 ! Near Maximum !
Hodgdon H870 108.4 88.6 5.74 2942 98.8 55840 13584 1.350 ! Near Maximum !
Hodgdon Retumbo 105.5 84.0 5.44 2929 100.0 55840 12317 1.339 ! Near Maximum !
Ramshot Magnum 95.8 81.2 5.26 2895 99.9 55840 12373 1.346 ! Near Maximum !
Norma MRP 2 100.7 79.8 5.17 2892 99.8 55840 12534 1.364 ! Near Maximum !
Vihtavuori N560 92.8 75.1 4.87 2885 99.4 55840 12511 1.353 ! Near Maximum !
Accurate MAGPRO 93.3 78.5 5.09 2881 98.7 55840 12687 1.361 ! Near Maximum !
Alliant Reloder-25 98.5 77.6 5.03 2881 100.0 55840 11593 1.350 ! Near Maximum !
Norma MRP 91.1 75.3 4.88 2880 100.0 55840 12026 1.361 ! Near Maximum !
IMR 7828 SSC 91.9 74.8 4.85 2878 99.7 55840 12125 1.341 ! Near Maximum !
IMR 7828 97.1 74.8 4.85 2878 99.7 55840 12125 1.341 ! Near Maximum !
Hodgdon H1000 102.1 80.0 5.18 2870 99.8 55840 11912 1.334 ! Near Maximum !
ADI AR 2213 93.0 74.4 4.82 2867 99.6 55840 12038 1.338 ! Near Maximum !
Alliant Reloder-22 93.0 74.5 4.83 2859 100.0 55840 11937 1.359 ! Near Maximum !
Raufoss RA15 93.0 74.5 4.83 2859 100.0 55840 11937 1.359 ! Near Maximum !
Winchester WXR 95.5 74.9 4.85 2858 99.9 55840 11961 1.360 ! Near Maximum !
Vihtavuori 24N41 104.6 88.2 5.72 2853 92.1 55840 12751 1.339 ! Near Maximum !
Hodgdon US 869 110.0 92.8 6.01 2850 92.1 55722 12839 1.351 ! Near Maximum !
Hodgdon 50BMG 110.0 88.5 5.73 2846 88.2 55565 12965 1.351 ! Near Maximum !
Alliant Reloder-19 90.2 71.4 4.63 2819 99.9 55840 11379 1.353 ! Near Maximum !
Hodgdon H4831 95.5 73.5 4.76 2806 99.2 55840 11389 1.350 ! Near Maximum !
Hodgdon H4831 SC 91.8 73.5 4.76 2806 99.2 55840 11389 1.350 ! Near Maximum !
Vihtavuori N170 104.8 82.1 5.32 2803 96.0 55840 11943 1.372 ! Near Maximum !
Vihtavuori N165 95.5 74.8 4.85 2773 100.0 55840 10643 1.366 ! Near Maximum !
Vihtavuori 20N29 110.0 93.8 6.08 2771 93.0 49444 12733 1.431
Accurate 3100 98.7 73.9 4.79 2766 100.0 55840 10490 1.396 ! Near Maximum !
Vihtavuori N160 95.6 72.6 4.70 2763 99.5 55840 10744 1.357 ! Near Maximum !

Cartridge : .300 Weath. Mag.
Bullet : .308, 210, Berger VLD G7 #30415
Useable Case Capaci: 85.929 grain H2O = 5.579 cm³
Cartridge O.A.L. L6: 3.560 inch = 90.42 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Hodgdon Retumbo

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% 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

-20.0 87 69.20 2389 2661 30467 10783 96.5 1.754
-18.0 89 70.93 2453 2806 32651 11077 97.6 1.707
-16.0 91 72.66 2517 2955 35001 11341 98.5 1.662
-14.0 93 74.39 2581 3107 37535 11573 99.2 1.614
-12.0 96 76.12 2645 3262 40265 11770 99.6 1.560
-10.0 98 77.85 2708 3420 43214 11930 99.9 1.508
-08.0 100 79.58 2771 3580 46398 12053 100.0 1.459
-06.0 102 81.31 2833 3742 49841 12159 100.0 1.411
-04.0 104 83.04 2894 3905 53571 12261 100.0 1.364
-02.0 106 84.77 2955 4070 57615 12358 100.0 1.320 ! Near Maximum !
+00.0 109 86.50 3015 4238 62009 12451 100.0 1.277 ! Near Maximum !
+02.0 111 88.23 3074 4407 66786 12539 100.0 1.236 !DANGEROUS LOAD-DO NOT USE!
+04.0 113 89.96 3134 4579 71988 12622 100.0 1.196 !DANGEROUS LOAD-DO NOT USE!
+06.0 115 91.69 3193 4754 77673 12699 100.0 1.157 !DANGEROUS LOAD-DO NOT USE!
+08.0 117 93.42 3252 4931 83888 12770 100.0 1.120 !DANGEROUS LOAD-DO NOT USE!
+10.0 119 95.15 3311 5111 90704 12836 100.0 1.085 !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 109 86.50 3133 4576 77641 11954 100.0 1.174 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 109 86.50 2830 3735 49007 13056 99.3 1.414

 

[elkeater2]

Good info, thanks DrMike and Fotis! Wishing you could dial in the famous Weatherby freebore to QL - but anyone with sense knows even QL is ballpark and another reference. A pretty valuable one. Like I mentioned, the loads I have hit 3000 fps and that's all we want. No loads plateaued out, and they were all walking the QL line between !Near Maximum! and !DANGEROUS......!
Fotis, the Accumark bolt is removed by pulling the trigger harder and farther, so there isn't really a mechanical stop possible. I've been playing with different thickness circlip shims on the boltstop shaft. IF you can get the trigger travel timed so that the trigger fork wants to move the bolt stop and it's heavier spring immediately after the sear releases then you're close! It appears the only way to make it adjustable is to turn the circlips into shims by grinding them to different thicknesses. Maybe a heavier bolt stop spring would create more resistance and become in effect an overtravel stop. If the trigger breaks at 3 lbs., but moving the stop to release the bolt takes, say, 8 lbs. then I think that would help!
I haven't messed with sear engagement and don't want to for safety and other reasons. It breaks clean with minimal travel now.
Don't have any 7828 in town right now, and I don't either. H4831 kept up better than I thought it would. For now it's between RL25 and Retumbo. We tried 'recommended' starting loads w/Retumbo and the 185's and got really sooty necks. Upped the charge in increments but kept getting soot, even at book max. No soot with 215's though. Or way less. I think heavier bullets must help powders like Retumbo burn more efficiently.

Thanks again, I'll come up with question #4 shortly.
EE2

 

[FOTIS]

You should have no problems hitting 3K--- fed 215M caps

 

[elkeater2]

Yeah something about the 215's make them easier to push, some say the bearing surface creates less friction. Getting the 185's to published velocity is more difficult for sure.

 

[Guest]

I can't speak much to the loading except to say I've had good results with 180s over H1000, RL22, and IMR7828ssc. Nothing great (yet) but good. Around 1".

As for the trigger overtravel, there's no way to adjust it out. The design requires the trigger to be pulled fully to the rear to release the bolt from the action. All Mark Vs are that way, to my knowledge.

 

[elkeater2]

Dubyam,
I expanded on the overtravel thing earlier in the thread. There is a way to help the overtravel, but it requires planet alignment, soothsayers, a ouija board, and tea leaves. :lol:

If you are curious about that, PM me. I can take pictures if needed. As you said in the past,making the trigger crisper is more effective than making the pull lighter. I really put the polish on the sear surfaces and it made a big difference.

Elkeater 2

 

[Oldtrader3]

Addressing Question Number 2: The Weather by trigger is also the bolt release for removing the bolt from the action. Mechanically, the Mark V sear pin (a MIM's part) is factory adjusted with a set screw adjusted and Loctited into the trigger assembly which allows some overtravel in the sear pin on firing.

Weatherby has this set screw set in such a way that it is not adjusted down far enough to be a stop for sear pin travel. Weatherby prohibits adjusting this set screw by the customer because it has to have enough travel to also be a bolt release. That is why there is too much overtravel in the system. You have to have Weatherby adjust this set screw or your warranty is void.

As I comment, I am sitting here playing with an old Mark V trigger assembly. which I replaced with a Timney trigger.

 

[DrMike]

There is a way to help the overtravel, but it requires planet alignment, soothsayers, a ouija board, and tea leaves.

And I hate tea. It does sound complex.

 

[Oldtrader3]

Well you asked, said the White Rabbit.

 

[elkeater2]

Oldtrader3:
The Accumark trigger is different, or else the factory sear engagement screw is really well hidden, I haven't seen it. I don't really want to mess with sear engagement right now as the trigger is crisp and overtravel acceptable. Putting the micro-polish on all the engagement surfaces without stoning or changing angles was good enough.
Thanks for the input, we're now onto trying to get the 210's to group!!
EE2

 

[Oldtrader3]

That is okay, I would not touch it myself unless you know the tolerances for setting the screw or changing the sear extension limits. Weatherby only has one design of Mark V trigger, since the start of Japan manufacturing and now US production. The original US Mark V trigger was a different design.