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Posted: 4/22/2014 8:20:38 AM EDT
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I've been reading up on improving my reloading. I have ordered a 300 win mag for long distance target shooting. I have read about chambering a dummy round to find the distance to the land and then backing the OAL back to improve accuracy. There are tools out there and then there is this article.
http://www.larrywillis.com/OAL.html I'd appreciate any pointers you have about finding the the most accurate OAL for a 300 win mag. Of course it will also have to do with what fits the magazine. I like the toolless method of chambering a round and having the bullet pushed back to find length. So far, I've been going by the book on my OAL according to my 223 and 300 AAc reloads. But I want to be better. Thoughts? |
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Don't have any experience with the 300 but I've just started using the Hornady tool with a 30/06 that I'm reloading for. It takes a while to develop a feel for its use but I think I've finally got the hang of it. Somewhere in the back of my mind I think I remember reading an article in Handloader that recommended setting the length at .010" back from direct contact of the bullet with the lands. In my rifle, use of the tool resulted in an average contact measure of 3.352 so I've loaded up some rounds at 3.342. Did this last night so I haven't had a chance to shoot them yet. You do have to keep track of the loads as they are chamber specific. Also, I found that the Hornady 150 gr. FMJ-BT's I had on hand from two different lots were not identical. Gauging them resulted in two different direct contact distances. So keep that in mind as well.
Good luck. |
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What do you mean by "long distance" shooting?
What group size do you currently get at 200 yards? Cartridges that are required to fit in the magazine, typically, do not get close to the lands. If you want to load to be close to the lands, typically, you are single loading rounds into the chamber. |
| I did my 243 with a fired round and a bullet. I tested 10 times and took the average, then loaded my rounds .030 shorter than that measurement (so .030 off the lands). Have had excellent accuracy at 100yrds, but don't have any longer ranges close where I can test out further yet. |
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Quoted:
What do you mean by "long distance" shooting? What group size do you currently get at 200 yards? Cartridges that are required to fit in the magazine, typically, do not get close to the lands. If you want to load to be close to the lands, typically, you are single loading rounds into the chamber. Greater than 100 yards. I have access to a 1000 yard range, so up to that. I don't have a group size at 200 yards. As I said, I have ordered the 300 win mag. I am just in the education phase of the "how to" find optimal OAL. There are a few techniques out there and I asked the question so I know how you guys do it. As far as magazine. I don't know that either. I haven't received the rifle yet. All this may be premature but I wanted to ask the questions here to see how optimal OAL is discovered. I'm ok with single loading for target shooting but will more than likely have an OAL for that and another if needed for hunting purposes so that the cartridges fit the magazine and give the closest best accuracy for that application. |
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Quoted:
Greater than 100 yards. I have access to a 1000 yard range, so up to that. I don't have a group size at 200 yards. As I said, I have ordered the 300 win mag. I am just in the education phase of the "how to" find optimal OAL. There are a few techniques out there and I asked the question so I know how you guys do it. As far as magazine. I don't know that either. I haven't received the rifle yet. All this may be premature but I wanted to ask the questions here to see how optimal OAL is discovered. I'm ok with single loading for target shooting but will more than likely have an OAL for that and another if needed for hunting purposes so that the cartridges fit the magazine and give the closest best accuracy for that application. Quoted:
Quoted:
What do you mean by "long distance" shooting? What group size do you currently get at 200 yards? Cartridges that are required to fit in the magazine, typically, do not get close to the lands. If you want to load to be close to the lands, typically, you are single loading rounds into the chamber. Greater than 100 yards. I have access to a 1000 yard range, so up to that. I don't have a group size at 200 yards. As I said, I have ordered the 300 win mag. I am just in the education phase of the "how to" find optimal OAL. There are a few techniques out there and I asked the question so I know how you guys do it. As far as magazine. I don't know that either. I haven't received the rifle yet. All this may be premature but I wanted to ask the questions here to see how optimal OAL is discovered. I'm ok with single loading for target shooting but will more than likely have an OAL for that and another if needed for hunting purposes so that the cartridges fit the magazine and give the closest best accuracy for that application. I asked about your group size because the effect of OAL on group size is usually small. When shooting longer ranges, it is the wind and range estimation errors that dominate group size. I would bet a reliable, match-quality trigger is more important than OAL. If you are buying a Remington 700 or other commercial rifle, you may find the chamber has been given a very long throat. As a result, it can be difficult to get to the lands. Even if you can, throat erosion will move the lands out in no time flat, especially in a magnum rifle. All in all, don't worry too much about it right now. Get your rifle. Get some sights on it (iron or telescopic) and go shooting. <-- do a really good job of this. Get zeroes using magazine length ammo (SAAMI spec OAL). This is probably not what you came to reloading forum to discuss but I think it's true/valid. 
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You will probably find quite a bit of distance to the lands. If I recall correctly (I'm at work) my .300 Wby Mag had about a 0.5" bullet jump (!!!), in a fairly light rifle (the Weatherby Mark V). It still grouped well, for 3 rounds (and then the heat of the barrel changed the way the gun shot). Pressure is a concern and was probably the reason behind so much free bore, so I would probably not venture too far from factory ammo specs unless you have a fairly heavy-duty action. Luckily, your magazine will probably keep the OAL down and the free bore up!
Just my recollection... I haven't loaded for .300 Wby Mag for some time now. |
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All true. Reason I ask is that it was recommended to me from the builder to get some Berger VLD hunting and they can be tricky. At any rate. I don't plan on buying much ammunition but rather loading components. Got to start somewhere in length. Trigger will be a jewel.
Good read on the Berger bullets http://www.bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/ |
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The Accuracy Sweet Spot distance from the lands is Bullet and Firearm Specific. What works for me may or may not work for you. What works with powder A may or may not work with powder B.
The only way to find that "Sweet Spot" is to experiment for yourself. You cannot find it from a web site or a forum. You can get recommendations and opinions galore, but they may not be what your bullet/powder/rifle combo likes. Range time, it's the only way. |
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Good read on the Berger bullets http://www.bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/ I used to love Berger's until they went big time. Put Sierra's bullets through a comparator and there will be much variation. It's because they went big time, LOL. I guess Berger's are adequate, but I sort the Sierra's. I only use Bart's for bench shooting, though. |
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Quoted:
All true. Reason I ask is that it was recommended to me from the builder to get some Berger VLD hunting and they can be tricky. At any rate. I don't plan on buying much ammunition but rather loading components. Got to start somewhere in length. Trigger will be a jewel. Good read on the Berger bullets http://www.bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/ VLD's and magazine length do not usually go together. To get good accuracy, VLD's are usually on or into the lands. Loaded that long, they will not fit in the magazine. Loaded to magazine length, they may be too far inside the case. |
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