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Post by elkman1310 on Jun 28, 2020 17:04:19 GMT -5
After testing different calibers and a ton of different bullets in 1,000 yard competition one thing that has becoming glaringly clear is that super high BC bullets for any given caliber just won't win matches. Let me rephrase that they won't win benchrest matches where the goal is to shoot the smallest group possible. Super high Bc bullets should have a edge when it comes to scores but not groups. I score and measure our targets at our club along with three other guys and there is a clear pattern on all these targets especially in group size the 6mm and the 30Caliber dominate with more wins going to the 6mm because of more shooters using a Dasher or something very similar but all the 6mm bullets that are being used don't have a BC of more than .530. Yes there are new heavier high BC 6mm bullets but they don't group nearly as small at 1K.
I am a fan of the 7mm and it has a ton of new bullets that have come avaible but they all are on the very high end for caliber by weight and with some very hard to tune designs. You need to shoot a bullet that will stay in tune over a fairly broad range of temp ranges. For the 7mm the magic number has been the 180gr VLD and evening that one has not produced consistently small groups to win on our range the 30 caliber 300wsm will win with the 210vld or a similar weight bullet but I have not seen anyone win any of our matches for group with a bullet heavier than a Berger 215 hybrid even though their are bullets up to 250grs avaible.
The 6.5 has a ton of new offerings and I have tested 133gr through 155gr bullets and by far the only bullet weight that has proven good enough to win a relay for group or score is the Berger 140gr long range boat tail and sometimes the 142gr SMK the rest of them are good for shooting steel.
The 6mm has a lot of good custom bullets avaible which really helps its accuracy but the bullets that consistently win matches are the custom made 103gr Vapor trail bullet. For factory bullets the 105gr Berger VLD and Hybrid and the Sierra 107gr if your lucky enough to get a good lot will win on occasion all the rest bullets are for steel shooters.
Bottom line is you need a high quality made bullet with a good profile and center of gravity that is easy to tune. It is a one piece bullet not two piece designed bullets like Hornady plastic tips or A-tips or the Sierra tipped SMK they will not shoot consistently small enough to win a benchrest match. There are a lot of good bullets out there for all the different calibers but there are very few great bullets they are few and far between. |
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Post by smokelessk on Jun 29, 2020 3:15:26 GMT -5
Interesting perspective on bullets for sure. Not using a polymer tip bullet for best accuracy is something I've never heard before. Where I am located, and with the lack of spare time I have, learning at 1,000 yards is only something I can read about. Definitely is interesting.
Slightly more than 10 years ago I built a 6.5-284 on a quest for a 1k yard prairie dog. That was fulfilled with a 139 grain Lapua Scenar. Never shot paper at that distance with it, but sure turned up some dust on the South Dakota prairie and even turned over a prairie dog.
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Post by jims on Jun 29, 2020 6:28:45 GMT -5
The truth is the pudding I guess.
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Post by elkman1310 on Jun 29, 2020 7:30:39 GMT -5
Well after shooting long range benchrest for 30 years or more I have not seen a two part bullet ever win a match on our range. I know they have won 600 yard matches but not 1,000 yard matches.
We shoot 10 shot groups for both light gun and heavy gun IBS matches only shoot 5 for light and 10 for heavy. I see light gun targets all the time that would break the IBS world record for light gun on a regular bases. To get 10 shots to stay together at 1,000 yards is a very tall order conditions change so fast. The target I posted above shows the group moved out to the left my last three sighter shots where all in the 10X. But by the time they call cease fire and run the record target up and give the command to shoot can take 30 seconds or more so conditions can change.
When your sight in on the sight in target and your grouping say to the 9:00 clock side of the blue 9 ring and you adjust your scope to bring it into the center now you have cause another condition that will get you when the condition you corrected for lets off a little bit you won't stay centered up now you will be shooting to the left like my target shows. Its a never ending battle of conditions.
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Post by gd357 on Jun 29, 2020 12:36:10 GMT -5
Do you think there's a point of diminishing returns where there is a negative correlation between excessive bullet length vs caliber in the case of high b.c. bullets?
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Post by elkman1310 on Jun 29, 2020 16:47:25 GMT -5
Yes I do believe there is. A few shooters over the weekend talked about this exact thing. The bullet jackets are so long that its very hard to make them really concentric. The longer they get the more twist is required to stabilize them. Fast twist rates on these long bullets really can play hell with them. Berger uses J4 jackets that are softer than Sierra jackets The Berger's don't hold together very well above 3,000 fps there have been competitors that have lost one or two in a fast 10 shot string compared to the Sierra but usually you just slow the Berger down a little and they usually out shoot the Sierra.
Also when you compare the BC of a 180VLD and a 190gr Hybrid the 190gr looks much better on the BC number but you have to be able to push it fast enough to match what you can do with the 180gr bullet. The 180gr works great in a standard 1-9 twist barrel the 190gr really needs a 8.5 or 8 twist to get the job done so your better off using a 1-9 twist and shoot the slightly lower BC bullets. If you can't get the big 190gr bullet to shoot accurately all the BC in the world won't matter. This whole higher BC race is to sell more bullets and barrels.
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Post by gd357 on Jun 30, 2020 1:36:08 GMT -5
Yes, it seems like the higher rate of twist would exert exponentially more stress on the jacket, and if concentricity is already an issue, it's just wishful thinking.
While the thoery may have merit (assuming the issues you brought up could be overcome), they'd soon have us shooting projectiles longer than the casings...
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Post by aldeerhunter on Sept 19, 2020 16:37:41 GMT -5
Thanks for your post. Just getting in to the long range shooting game. The 103 VT bullets that you mentioned are not readily available. There is a waiting list that you may as well get on now if you plan on shooting them next year. I just got confirmation that my order from about six months ago is shipping.
I have tried their automated bullets called Vtacs. They shoot good but you have to sort them as there will be oddballs one the batch.
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Post by elkman1310 on Sept 21, 2020 14:41:33 GMT -5
When you get your 103VT measure the diameter right at the base of the pressure ring the old ones used to be .24335 it takes a good micrometer to accurately measure bullets a dial indicator won't do it. The first batch I had that shot so well measured .24335 the new ones are smaller. .24305 my barrels don't like them nearly as well. For bullets that are supposed to be made from the same dies you should not see that big of a difference. you will see only .00002 difference between a cold die and a warm die. I have been shoot the new 105gr JLK bullets which measure .24330 and my guns love them.
Not telling you that your going to get bad bullets from VT just ever barrel is different yours my shoot them really well. The hand pulled bullets do check out much better than the automated ones. But if your serious about shooting small groups at long range then you check everything no matter how redundant it may seem.
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Post by aldeerhunter on Feb 24, 2021 19:53:11 GMT -5
Just getting back into shooting. I have two different list of VT103s. Will measure them tonight and see what I come up with. Thanks
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Post by aldeerhunter on Feb 26, 2021 0:40:02 GMT -5
The base on both lots that I have are measuring .2433. I think I will change the freebore diameter on the dealer I am ordering to .2438.
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Post by elkman1310 on Feb 26, 2021 8:40:33 GMT -5
I know some shooters that run a little larger diameter freebore that's ok as long as you don't buy bullets that are under .243 at the pressure ring. I would stay with the standard spec FB diameter because all these .243 caliber bullets vary from lot to lot.
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Post by aldeerhunter on Mar 9, 2021 16:05:22 GMT -5
Thanks
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