Hey tnekkcc, A good many folks recognize the "Gas Handling" of the M70 as pitiful. Seems that a blown Primer or Casehead Separation results in a good bit of gas reaching which ever eye the person is aiming with due to the way the M70 is designed.

Am I missing something about them that you know?

HC,
I have a Win 70 pre 64 in 30-06.
It seems like some 98 Mauser design features have been lost when Winchester copied the master.
It has 3 screws on the bottom too

I got it when someone died, and the list of animals it took is impressive, even if the gas handling is poor. I will try to get around to testing it to see how it handles escaping gas.

Ackley sir: Please run this in your quickload program:
cartrige is 280 Ackley
Nosler Accubond 160 grain bullet
Reloder 22 powder 60.0 grains (this is 1.5 grain over Nosler #5 Max, although they do not specify accubond bullets)
barrel length is 24 inches
Fed 215 primer


also curious about a CCI 200 primer at 58.5 grains powder in a 26 inch barrel.

Both these loads shoot less .5 inch in different rifles.

I expect "book" velocity to be 2925-2975, based on my chrony readings

Thanks so much.

Jameister

Hey tnekkcc, Ah, the old pre-64 M70. I had a few of them long ago.

There have been some real interesting discussions on the GunSmith Board about the M70 Gas Handling. Their poor gas handling is just one more thing that I don't need to hassle with.

I may have saved a link to one of them:
https://forums.accuratereloading.com/eve/forums/a/tp...1043/m/183105923/p/1

Just tried it and it still works. I saved it because "bradly" sure made an "ad" of himself on that particular thread.

Matt Williams does an excellent job of describing the issue. And as a nice bonus, it also happens to blow bradly's "great wisdom(?)" completely out of the water.

Those QuickLOAD numbers in Cartridges of the World represent a mis-application of the software. The manual for QL tells you to always do the computations at a pressure 12 to 15% below the cartridge's spec. Those in CotW are usually done at the spec pressure, and the editor threw in slick bullets as well. Those numbers are worthless!

SO the very basis of the calculations is in error? can someone provide the pressures calc'd by quickload for the loads mentioned in COTW? they just looked a bit sketchy to me, but I would like to still know how far off, and I am too O/C to take a chance buying quickload for myself.

quote:

Originally posted by asdf:
Those QuickLOAD numbers in Cartridges of the World represent a mis-application of the software. The manual for QL tells you to always do the computations at a pressure 12 to 15% below the cartridge's spec. Those in CotW are usually done at the spec pressure, and the editor threw in slick bullets as well. Those numbers are worthless!

I am no expert, but I do have some anecdotal information on verifying Quickload:
1) The straightwall 9mm hot Power PIstol loads are predicted to be 1,000,000 psi and 2500 fps, but in reality do no pierce the primer and are 1500 fps. Per the QL manual, the powder gets blown out the muzzle unburned, and QL calculates the higher pressure as if it burned IN the barrel.
2) 8mm, 308, 30-06, 7mm mag, 300 win mag, 223, ect bottle necked cartridges will have a predicted velocity that is in the middle of the reality chrono string.
3) With bottle necked rifle cartridges, the overload required to make the primer pocket grow is at the same predicted pressure.
4) Bottle necked cartridge predictions are too low by ~~ 200 fps and ~~ 10,000 psi if the bullet is crammed into the lands.

Jameister:

I've never understood this aspect of QL. The author tells you to run the calculations at a pressure 15% below the cartridge's rating. When you run the software, it by default uses a working pressure 12.5% below the rating. Used in this way, the software generally matches the fps predicted in the new load books.

I can't say for the author, but I suspect he wants you to run a bit below average because normal shot-to-shot variations will cause a certain number of rounds to be over pressure. SAAMI allows for this with a margin stated in statistical terms. Note that load books which report pressure generally back off a bit from max. I've read that the amount they back off is a function of the pressure swings observed.

Anyway, that's my best guess.

(Oh, and my answer is based on what I've seen with my version of the software, 2.9 from 2002. He was hoping to change to an improved representation of the powder burning in later versions. I really ought to see if an update is in order.)

[quote]also curious about a CCI 200 primer at 58.5 grains powder in a 26 inch barrel.

Both these loads shoot less .5 inch in different rifles.

I expect "book" velocity to be 2925-2975, based on my chrony readings


Jameister,
Can't help you with a Quickload number. Loadtech gives 2875 at 58250psi. Your actual case capacity and COL will move these numbers up or down.

quote:

Ackley sir: Please run this in your quickload program:
cartrige is 280 Ackley
Nosler Accubond 160 grain bullet
Reloder 22 powder 60.0 grains (this is 1.5 grain over Nosler #5 Max, although they do not specify accubond bullets)
barrel length is 24 inches
Fed 215 primer

J, for the load above QL predicts 2890 fps at 55,000 PSI. Below is an analysis for the this set-up with various charges of Re22. J, I would buy a chronograph and not load this 160 gr. bullet with Re22 past 3050 fps.

Cartridge : .280 Ack Imp
Bullet : .284, 160, NOS AccuBond
Cartridge O.A.L. L6: 3.330 inch or 84.58 mm
Barrel Length : 24.0 inch or 609.6 mm
Powder : Alliant Reloder-22

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 !

%Fill./Charge/Vel./Pmax

98 / 58.80 / 2831 / 51615
100 / 60.00 / 2890 / 55164
102 / 61.20 / 2950 / 58952
104 / 62.40 / 3009 / 63013
106 / 63.60 / 3068 / 67369
108 / 64.80 / 3127 / 72048
110 / 66.00 / 3185 / 77080

J, also please note, results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge. Notice how much lot-to-lot variations can cause in PSI/Vel.

Data for burning rate increased by 10% relative to nominal value:

+Ba /100 /60.00 /3032 /67052

Data for burning rate decreased by 10% relative to nominal value:

-Ba /100 /60.00 /2580 /44031

What does quickload have as the case capacity? Or do you input? If so what are you using?

74 grs. of H20 - according to QL.

That explains a good part of the difference between QL and LT. LT show a capacity of 70.2. You have to go to the 7Gibbs to get 74. Even the 30-06AI only shows 72.5grs in Loadtech.

All the more reason to measure you own caces to obtain capacity.

quote:

I would buy a chronograph and not load this 160 gr. bullet with Re22 past 3050 fps.

THanks, I have used the chrono, on my 26 inch barrel, and it is right close. the pressure signs I was seeing, that made me wonder at COTW, were also in the "Plus 3050 fps range" and I backed off accordingly.

thanks again.

what a great information source this is!
Jmeister

J, glad to be of help. Regards, AIU