Range Time

SingleShotLover · Posted: Thu Aug 27, 2015 4:23 pm Post subject: Range Time

I finally got the chance to fine-tune my Ruger #1B after replacing the old scope with the new Redfield Revenge 6X18. This was also a good opportunity to finish testing the new load I had been trying when the old scope died. Once I had sighted in the scope with another load, I settled in for serious work with the new one. Imagine my surprise when the first 3 made what looked through the scope to be a single hole. Taking a deep breath, I fired number 4...same result. Now we all know that we should always quit while we are ahead, but I sat back, relaxed and thought pure thoughts. Must not have been enough since, as everyone knows, there is always the shot that brings you back to earth.

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Guess those things happen to keep us humble. Obviously this load deserves serious investigation.

SSL

dhc4ever · Posted: Thu Aug 27, 2015 4:33 pm Post subject: Re: Range Time

I did a similar group without the flyer with the .222. 5 shots into .328".
Like you said yours was going extremely well until.......
Amazing how 1/4" can ruin your moment isnt it.

Gil Martin · Posted: Thu Aug 27, 2015 5:06 pm Post subject: Re: Range Time

Very nice group. Thanks for sharing. All the best...
Gil

slimjim · Posted: Thu Aug 27, 2015 7:25 pm Post subject: Re: Range Time

I found CFE to be pretty temperature sensitive. Hope you see a group like that through all the seasons.

Elvis · Posted: Fri Aug 28, 2015 2:51 am Post subject: Re: Range Time

wow hats fair honking along...AMax at that speed would be a grenade when it hits....very tidy wee group...what flyer???? thats just a chest/neck shot squirrel as apposed to the others who got frontal labotamy.

Vince · Posted: Fri Aug 28, 2015 4:31 am Post subject: Re: Range Time

That's a damn fine load SSL...put the rifle down and step away from the bench, there is nothing you need do there. Laughing

SingleShotLover · Posted: Fri Aug 28, 2015 4:49 am Post subject: Re: Range Time

Slimjim: I'm seeing a little sensitivity now. Ammunition left in the direct sunlight gets a little sticky extracting. I may see if I can get comparable accuracy dropping the load a grain or so. I should only lose about 50 fps at most, which is currently made up to some extent by the 26" barrel on my rifle. It will be interesting to see what cold weather does to it. 38 and 38.5 grains shot well, just not as well as the 39-grain load. Best accuracy in this rifle with any load is with the bullet just lightly touching the rifling. This of course means a delicate balancing act to keep pressure levels acceptable while maintaining accuracy. The speed is great for flattening extended -range trajectories (also why I'm sighted 2" high at 100 yards), but the goal is accuracy. In this case accuracy increased with speed.

Elvis: That flyer wouldn't have bothered me much if the first 4 hadn't been so danged cooperative! In the interest of full disclosure, other groups shot during that same session ran under .5" on average (all groups figured on centers) with most running a bit less unless I messed them up by wiggling when I should have wobbled or "jumped" on the trigger.

MacD · Posted: Fri Aug 28, 2015 4:50 am Post subject: Re: Range Time

Very nice. That load is one your rifle likes for sure. CFE is my second favourate powder. IMR8208 is #1.

SingleShotLover · Posted: Fri Aug 28, 2015 4:52 am Post subject: Re: Range Time

Vince wrote:

That's a damn fine load SSL...put the rifle down and step away from the bench, there is nothing you need do there. Laughing

But what's the fun in that? Sniper

slimjim · Posted: Fri Aug 28, 2015 6:28 am Post subject: Re: Range Time

SSL, changing you powder load will not compensate for temperature sensitivity. Keep your load where it shoots best. Even though CFE has exhibited the most consistent velocities for me of any powder, it has been one of the most temperature sensitive. When the temperature changes, its not just the velocity changes but you will have a POI change and so does the trajectory. Since its a velocity and POI change you just can't plug a different velocity into a ballistic calculator and see what your trajectory change will be. You don't have to what for colder weather to come. you can cool your rounds before you put them in the chamber and experience the effect now.

www.huntingnut.com/ind...c&start=45

I've been developing all my loads this summer with the the bullets sitting on ice (36F). I do my temperature testing with a cooler of frozen meet that gets the temp down to 15 to 25F. A meat thermometer in a case of powder provides truth as to what you powder temp is. Never leave cartridges in direct sunlight. Your powder temp was likely 120F. The temp of the powder changes more quickly than most realize.

SingleShotLover · Posted: Fri Aug 28, 2015 7:30 am Post subject: Re: Range Time

Slimjim: You are right on all points. I have gone through the various changes with other powders...most notably IMR 4064. Since I have my own range, when I have powders that show variations tied to temperature, I test them at various temperatures and record scope settings, velocity and trajectory tables for each condition. Kind of a pain, but at least I have a chance to compensate accordingly. I usually keep cartridges in the shade, but I got interrupted and didn't allow the box sitting out to cool. Just a lapse in procedure but a good reminder that cartridge temperature can lead to pressure increases. That's why I may test slightly lower loads - not to compensate but wondering if my experience isn't a sign that I am at that magical line on pressure limits...which I knew I was close to anyway.

slimjim · Posted: Fri Aug 28, 2015 7:45 am Post subject: Re: Range Time

SSL, I'm with you. I found that CFE worked better in the 6.8mm SPC with standard primers vs magnum primers. Cut temperature sensitivity in half. The standard primers worked fine in 25F conditions. Not sure that will help you. 1200R is a powder that is very temp sensitive and should never be run near max if you are shooting in warm conditions. It can really surprise you.

BigBlue · Posted: Sun Sep 06, 2015 2:27 pm Post subject: Re: Range Time

Just ordered a new reloading manual just so I can catch up on all these new powders that have come out. Great shooting!