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Question for the guys that have played with A.I.
n/a
Member Posts: 168,427 ✭
calibers. I've read in the past that generally you can expect almost as good, if not as good accuracy with the parent cartridge as you can the with the loaded A.I. ammo. Has this been your experience???
I'm still working on breaking my barrel in, so I have not had the opportunity to put more than 5, and in one instance 6 rounds through it at a time (so I have not had a chance to fire some fouling shots before working on my groups). I know I really cannot expect a whole lot with regards to accuracy in this senario...but with that being said, I've tried 3 different loads and gone from seating .005 off the lands to .005 into the lands and the best groups I've seen are like 2.25" at 100 yards. This is horrible. Should this be expected??? I'm still fire forming my brass and working with the parent case, but this rifle was built by one of the top 1000 yard gunsmiths in the country and I was expecting it to do better with the parent cartridge from what I had read in the past. What has been your experience?
Are these the kind of results I should be expecting at this point in the game...or would you be concerned about the groups I'm getting at this point. Hell, factory ammo in a factory rifle will shoot better than this.
I'm still working on breaking my barrel in, so I have not had the opportunity to put more than 5, and in one instance 6 rounds through it at a time (so I have not had a chance to fire some fouling shots before working on my groups). I know I really cannot expect a whole lot with regards to accuracy in this senario...but with that being said, I've tried 3 different loads and gone from seating .005 off the lands to .005 into the lands and the best groups I've seen are like 2.25" at 100 yards. This is horrible. Should this be expected??? I'm still fire forming my brass and working with the parent case, but this rifle was built by one of the top 1000 yard gunsmiths in the country and I was expecting it to do better with the parent cartridge from what I had read in the past. What has been your experience?
Are these the kind of results I should be expecting at this point in the game...or would you be concerned about the groups I'm getting at this point. Hell, factory ammo in a factory rifle will shoot better than this.
Comments
I said this same thing to JustC once and he didn't believe me. He went out and tried and it worked.
So, to answer your question, yes, you should get very close to the same accuracy with the parent case as with the AI case. It's because of the tight headspace (.004" crush fit). However, because of what your gunsmith may have done to get your rifle to shoot better, it may not be so accurate. I would start judging the rifle when you start putting AI cases through it.
I'm on the run again but I really wanted to add a little bit to your thread.
I've probably cut more Ackley Improved or Improved chambers than most folks because I find them to be advantageous to my working and shooting practices. There is still a very simple statement regarding all rifles and all cartridges and all loads:
Treat each one as an individual and learn from the experience. Take copious notes and read them over several times when trying to find a solution to any problem.
You might be able to make some generalized statements about Improved cartridges as they relate to the parent case but not anything quite so clinical or specific. I have had excellent experiences with almost every Improved chamber except for a very few. Of those few, all were found to be flaws in execution not the cartridge itself. One in particular was very problematic when it came to working up a load. It only happened once and it was a cartridge that is normally brain-dead easy to develop loads. I finally got it but it was an arduous experience with no explanation as to the cause.
Accuracy is affected by numerous factors, not the least of which is the maker or the guy working up the loads. Accuracy is the culmination of dozens of the little details that make an average rifle a great rifle. No offense but even a 'top 1,000 yard gunsmith' can have an off day or make a tiny little error. Then too, sometimes the combination of load components are the problem, with no real reason as to why they don't behave in your rifle.
Scientific method of testing procedures always dictates changing one variable at a time in order to assess what changes occurred. Change your seating or change your powder charge but don't change both simultaneously.
Belted magnum cases often have an inconsistency in their dimensions for some odd reason. It's almost as if the manufacturers don't think it's important to make the same effort as with non-belted cases. The procedure I use does not include barrel break in as I have discussed on several other threads. I do however, make sure that I fireform my cases and get my dies meticulously set the way I want first thing. With Belted Magnums, it can be problematic to neck size only, especially with a hunting rifle. But careful manipulation of the dies should allow you to accomplishing this IF you work carefully. Feeding has been an issue sometimes but your gunsmith should have known this.
If all of your cases are exactly the same dimension from the rim to the belt, you might find that your accuracy improves by pushing the shoulder back a couple of thousandths. On the other hand, a tight fit between the shoulder and the chamber and the belt and the chamber can be equally accurate in other circumstance.
Neck wall thickness and concentricity are important. You have to know what size your chamber is first. Neck tension can also play a roll in accuracy but usually not in the type of chamber you're type of chamber.
Then you really need to check the bedding. You can't have all of this accuracy stuff done and have a mediocre bedding job. Be sure that all of the contact points in the bedding are clean and free of foreign matter. I found one problem with debris in the bottom of a the recoil lug area one time but it was enough to affect the accuracy and repeatability some.
I think that your load is on the low end and needs some work. Here is a little bit of reading about some personal loading experience with the .300 Win. Mag.:
http://www.reloadammo.com/300load.htm
Best.
NN...Do you have the spec's for the .300 Improved Case? I'm particularly looking for a case trim length.
I fire formed some RP brass first. Now I'm working with some Federal...it seems to be thicker, nicer brass.
The process of fireforming can create irregularities in the neck lengths so measuring the cases after fireforming will set the standard for trimming all of the cases. When working with fireformed brass, your best bet is to measure the cases and trim to the shortest case length after the fireforming.
Best.
ECC,
The process of fireforming can create irregularities in the neck lengths so measuring the cases after fireforming will set the standard for trimming all of the cases. When working with fireformed brass, your best bet is to measure the cases and trim to the shortest case length after the fireforming.
Best.
Thanks.