Newbie to reloading here, looking to do an incremental load development this weekend for the 7mm-08. I'm using Varget, 140 grain partitions and CCI 200 primers. Looking at the Hodgson data the minimum load comes up as 39.5 grains and the maximum at 42.2. What I was thinking of trying is a starting point of 38 grains and working my way up by .3 grains to 42.2. Any comments on this would be appreciated...
Incremental load development this weekend for 7mm-08
- Thread starter west250
- Start date
- Location
- Prince Albert, Sk
I do exactly that .3 or .5 depending on the spread between minimum and maximum charges.
Sounds like you will have no issues at all.
One thing I recommend is picking a seating depth and stay with it.If you change too many variable you will be chasing your tail.I tested Accubond's and set the COAL at 2.8" ( 5 out of 7 test groups were sub MOA), this does seem to be the sweet spot for 7-08 factory loads AND for many handloads, until of course you get into match bullets but for hunting the 2.8" will allow reliable feeding and be a good place to start.
Make sure you chronograph your loads so that you can see where your velocities are and where your load will settle in.
If you can get below MOA and repeat those results with a load, then you have a winner, once you have all your targets set side by each and your info laid out it will be very easy to interpret information.
Done lots of 7-08 testing so if you want to send me a PM feel free.
Sounds like you will have no issues at all.
One thing I recommend is picking a seating depth and stay with it.If you change too many variable you will be chasing your tail.I tested Accubond's and set the COAL at 2.8" ( 5 out of 7 test groups were sub MOA), this does seem to be the sweet spot for 7-08 factory loads AND for many handloads, until of course you get into match bullets but for hunting the 2.8" will allow reliable feeding and be a good place to start.
Make sure you chronograph your loads so that you can see where your velocities are and where your load will settle in.
If you can get below MOA and repeat those results with a load, then you have a winner, once you have all your targets set side by each and your info laid out it will be very easy to interpret information.
Done lots of 7-08 testing so if you want to send me a PM feel free.
With my .260 Remington using 120 grain Bergers, IMR 4064, starting at 38.0 and going up in .5 grain increments.
At 200 metres, the 7 loads from 38.5 to 41.5 produced a 1.5 inch group with #2 and #4 always being close together.
I decided to settle at 40.0 grains, and the other day a 3 shot group at 200 measured 1.07 c-c.
From Sierra VARGET 34.5 36.6 38.8 40.9 43.0
Accuracy Load: RE-15/ 39.6grs. 2700fps/ 2266ft. lbs.
Hunting Load: IMR-4350/ 45.7grs. 2800fps/ 2437ft. lbs.
With incremental loading, do not try to reinvent the wheel but start with a proven load.
I do not have my Nosler book handy but their accuracy loads, and most accurate powders are great starting points.
At 200 metres, the 7 loads from 38.5 to 41.5 produced a 1.5 inch group with #2 and #4 always being close together.
I decided to settle at 40.0 grains, and the other day a 3 shot group at 200 measured 1.07 c-c.
From Sierra VARGET 34.5 36.6 38.8 40.9 43.0
Accuracy Load: RE-15/ 39.6grs. 2700fps/ 2266ft. lbs.
Hunting Load: IMR-4350/ 45.7grs. 2800fps/ 2437ft. lbs.
With incremental loading, do not try to reinvent the wheel but start with a proven load.
I do not have my Nosler book handy but their accuracy loads, and most accurate powders are great starting points.
Snuck out of work early and went to the range to try these loads out yesterday. My results were not as expected: http://i1112.photobucket.com/albums/k494/west250/Laddertest1.jpg
It appeared that I would get one shot on paper, then the next charge would go lower, then the next higher etc. ... They were shot off shooting bags and I figured they went in reasonably well ( calling them, they all looked good at point of fire). The range was pretty quiet but with one other guy that came and went in the time I printed this. There was a slight side wind that generally came from the left. I'm not going to say that it's the nut behind the bolt as I have two other rifles that are accurate and I can shoot great groups most of the time with them.
All that being said I would assume that the erratic placement was due to fiddling around slightly with the seating depth. So made up a dummy round with bullet that slides with a little resistance in the case and proceeded to measure the overall chamber length for my particular rifle. After measuring 12 times I took the highest and lowest measurement out of play and averaged the ten which gave me a length of 2.862. I then proceeded to make up another ladder load with an overall length of 2.8050 and will try and get out on Sunday for another test. This one will be done from a lead sled to reduce human error further. Constructive comments anyone?
It appeared that I would get one shot on paper, then the next charge would go lower, then the next higher etc. ... They were shot off shooting bags and I figured they went in reasonably well ( calling them, they all looked good at point of fire). The range was pretty quiet but with one other guy that came and went in the time I printed this. There was a slight side wind that generally came from the left. I'm not going to say that it's the nut behind the bolt as I have two other rifles that are accurate and I can shoot great groups most of the time with them.
All that being said I would assume that the erratic placement was due to fiddling around slightly with the seating depth. So made up a dummy round with bullet that slides with a little resistance in the case and proceeded to measure the overall chamber length for my particular rifle. After measuring 12 times I took the highest and lowest measurement out of play and averaged the ten which gave me a length of 2.862. I then proceeded to make up another ladder load with an overall length of 2.8050 and will try and get out on Sunday for another test. This one will be done from a lead sled to reduce human error further. Constructive comments anyone?
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41.6 and 41.9 are close together.
That may be what you are looking for although I did not see 41.3.
If 42.2 is max, is that according to the book or were there pressure signs.
I think you are on the right track so now select the two loads that were closest together with the velocity that will be closest to your expectations.
I tried to bring up what I had on photobucket without success.
That may be what you are looking for although I did not see 41.3.
If 42.2 is max, is that according to the book or were there pressure signs.
I think you are on the right track so now select the two loads that were closest together with the velocity that will be closest to your expectations.
I tried to bring up what I had on photobucket without success.
Why are you starting 1.5 gr under the minimum? There is a reason that the minimum is called the MIMIMUM. In most cases it won't hurt anything to go there but there's no reason to go there in the first place.
I start at the minimum, work up in 1/2 gr increments and fire a 5 shot group at each increment. Usually a couple groups will be noticeably better and I will go back and reload some more of those to fire several more 5 shot groups to confirm which is better. Once I have that sorted out I might start playing with the seating depth to see if there is any improvement to be had there. Generally speaking using smaller increments has not made a great deal of difference most of the time.
Thanks for the comments all, it's giving me lots to think about. Here is today's ladder: http://s1112.beta.photobucket.com/user/west250/media/2012-11-18_14-08-37_507.jpg.html
Thinking I'm going to start with the 40.1 to 40.7 grain group and see where it goes...
Thinking I'm going to start with the 40.1 to 40.7 grain group and see where it goes...
