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Post by Deleted on Feb 11, 2017 23:35:57 GMT -5
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Post by dennis on Feb 12, 2017 7:51:10 GMT -5
IT is about how deep you are seating your bullets. Some bullets shoot better .010-.015 off the lands and some are better at say .050 off the lands and even as stated in their write up even .150 off the lands. Get your best shooting powder figured out then seat same bullets at different depths to determine which is best with your barrel. So long as the right bullet to rate of twist is ok you should come up with something satisfactory.
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Post by Richard on Feb 12, 2017 15:43:21 GMT -5
If you are loading for a rifle with clip or magazine well you may be limited to to how "far out" you seat the bullet? The loaded round must fit into the magazine in order to function. If you go the single shot route then you have more lee way to seat the bullet further out so as to engage the rifling. What seating the bullet out to touch/engage the rifling does, is to hole the cartridge in alignment with the center of the bore. If you bullet is seated so as to NOT touch the rifling, you run the risk of the case and bullet not in alignment with the bore. This happens because the FACTORY chambers are generous and that "ejector" button in the bolt face........that is spring loaded?...........Guess what? It is pressing against the base of your cartridge on one side and pushing everything off to the other side.........moving the bullet out of alignment. Custom chambers and the way we size the brass body and neck help eliminate some of this. Sizing only part of the neck allows the expanded part of the neck to hold the case in alignment also.
Wow, my typewriter is running out of ink...........Give me a call sometime!
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Post by kai on Feb 16, 2017 14:19:01 GMT -5
Richard, thanks for the tips that you gave in your last post. I've learned a lot from your posts.
I've been trying to maximize the accuracy of Cutting Edge MTH bullets in .270 and 44 cal. and tend to load them pretty hot.
I've heard that having the bullets touching the lands can increase the pressure so I haven't tried loading the bullets out that far yet.
Do you know if having the bullets touching the lands really does increase pressures?
I also heard that monolithic, solid copper bullets like to have more jump than jacketed bullets.
Do you know if there's any truth to that in general? I like the idea you presented of having the bullet touching the lands to center them in the chamber and would like to try it but am concerned that one person told me that he thought it might cause excessive pressure.
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Post by Richard on Feb 16, 2017 17:28:29 GMT -5
I have never seen it to any degree. I have taken cup and core bullets and jammed them into the rifling and then pushed the bullets back into the case for a .010" jump and the velocity was only about 10 to 15 fps faster with the jam? One thing you need to have to prove or disprove this stuff is a chronograph. Take five cases and seat the bullet say........020" off the lands. Then .010" off, then just Kiss the lands with the next five (use a magnifying glass and look for just the slightest "nick" on the ojive of the bullet.) A good trick is to take some steel wool and twist a horizontal pattern on the bullet. That way when you chamber the bullet and then remove it (put your finger on the cartridge as you slowly open the bolt so the actual bullet does not scrape the inside of the action) You should be able to see if the bullet is touching the lands.
So go ahead and fire these rounds as record the velocities. I would almost guarantee there is not a big difference in all three groups. You can then seat the bullet say....010" further out. And then .020 out and these numbers would be how much "jam" you are putting on them.
When I am fireforming a case I always seat the bullet way out so that I have to almost pound the bolt handle in order to close it. That will usually produce about .030 to .040 jam. The reason being I want the case head to be firm up against the bolt face. This will then set the head space for my cartridge. This method is also done when forming ACKLEY cases.
So, will it produce more pressure? Maybe, but not enough to blow up your rifle. That bullet still has to engrave the rifling one way or the other.
If you ever have a question, let me know and I will "shoot" you my phone number.
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Post by kai on Feb 17, 2017 21:09:23 GMT -5
I have never seen it to any degree. I have taken cup and core bullets and jammed them into the rifling and then pushed the bullets back into the case for a .010" jump and the velocity was only about 10 to 15 fps faster with the jam? One thing you need to have to prove or disprove this stuff is a chronograph. Take five cases and seat the bullet say........020" off the lands. Then .010" off, then just Kiss the lands with the next five (use a magnifying glass and look for just the slightest "nick" on the ojive of the bullet.) A good trick is to take some steel wool and twist a horizontal pattern on the bullet. That way when you chamber the bullet and then remove it (put your finger on the cartridge as you slowly open the bolt so the actual bullet does not scrape the inside of the action) You should be able to see if the bullet is touching the lands. So go ahead and fire these rounds as record the velocities. I would almost guarantee there is not a big difference in all three groups. You can then seat the bullet say....010" further out. And then .020 out and these numbers would be how much "jam" you are putting on them. When I am fireforming a case I always seat the bullet way out so that I have to almost pound the bolt handle in order to close it. That will usually produce about .030 to .040 jam. The reason being I want the case head to be firm up against the bolt face. This will then set the head space for my cartridge. This method is also done when forming ACKLEY cases. So, will it produce more pressure? Maybe, but not enough to blow up your rifle. That bullet still has to engrave the rifling one way or the other. If you ever have a question, let me know and I will "shoot" you my phone number. Richard, thanks for your detailed and technical explanation. I'm trying to maximize the accuracy of Cutting Edge MTH bullets for my 270 Win and have only loaded them to the Cutting Edge recommended COAL of 3.265. The CEB MTH bullets have a raised "Seal-Tite" ring. CEB recommends against seating this ring out and away from the case mouth. Perhaps it would stick in the free bore if loaded out too far. I like the high BC of the CEB bullets but I'm not getting the accuracy with them that I do with some other bullets. I guess I'll call Cutting Edge and ask they why they recommend against loading longer than their recommended COAL. |
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Post by Richard on Feb 18, 2017 20:32:00 GMT -5
If you go to a long range BR match, you will not see competitors using monolithic bullets period! If they were that good, competitors would be using them.
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Post by Deleted on Feb 18, 2017 23:06:08 GMT -5
While I haven't traced any centerfire rifles YET, I understand the reason for the Wylde chamber in .223's is for the longer loaded .556 so that it isn't too close to the lands which is said to make more pressure. That said, unless it is a Berger VLD, I start at .020 off the lands.
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Post by Richard on Feb 19, 2017 14:49:36 GMT -5
Another part of that Jerry is the fact that there is SO MUCH .223 from all over the world you don't know to what extent it is loaded and with what. I have just found that using cartridges that I have personally loaded that this has not been an issue. Keeping in mind none of my cartridges are crimped and rarely have more than .002 to .003 grip on the bullets..............but take a .223 or other military round that has a steel case and some coated jacked bullet with a death grip plus bing crimped and who knows??? Part of the reasoning in the Wylde chamber. Again, JMHO?
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Post by kai on Feb 24, 2017 2:26:30 GMT -5
If you go to a long range BR match, you will not see competitors using monolithic bullets period! If they were that good, competitors would be using them. Richard, thanks for your comments and getting to the "bottom line" on monolithic bullets. |
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Post by nippernut on Aug 29, 2017 16:06:27 GMT -5
i seat all my loads with the current build .005 off the lands and adjusted the powder in .5 grain increments , i also shoot twice fired reconditioned brass very very happy with results using Berger 168 g VLD hunting bullets in 308
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AJ
Full Member
Meatasarus
Posts: 182
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Post by AJ on Aug 30, 2017 6:03:05 GMT -5
Here is a load I worked up for my 25-06 using 115 Bergers. I found the optimum charge then worked seating depth from touching the lands back to .120" from the lands (jumping). All loads were the same setup (powder/primer/case/bullet) the only change was seating depth. Groups were shot round Robin (1 shot from each group at a time) to eliminate fouling from biasing the results. There was a 105 fps reduction from touching to .120" jump. I settled on a jump of .090" and it shoots sub MOA out to 600 yards. The rifle is a Savage 110 with a Sharp Shooter barrel in a Boyd stock.  |
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Post by dannoboone on Aug 30, 2017 16:06:36 GMT -5
Thanks for that bit of info AJ. Going to see if I can get similar results
with the VLD's in my .25-06 VLP. It's one of the older models with
blind magazine, and the bullets clear that magazine no matter how
far out they are seated.
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