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Advice on bullet seating depth Berger 95 grain hybrid
- Thread starter merbeau
- Start date
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dakota1tn
It is amazing. I went into my local store and there was only one container of powder left on the shelf and all the ammunition was nearly sold out - even 416 Rigby!! I was fortuante enough to fnd one box of CCI primers and one box of Nosler 85 grain ammunition for base testing.
I am getting low on small pistol primers which is concerning since I shoot in competition.
Even Eley pistol match which I use in 22lr is sold out as well as Tenex which is really expensive. I have never seen that before.
I was going order new supplies around Christmas but spent that money on my wife and then chaos occurred. I read where since the Obama initiative over 70 millions firearms have been purchased.
Robert
It is amazing. I went into my local store and there was only one container of powder left on the shelf and all the ammunition was nearly sold out - even 416 Rigby!! I was fortuante enough to fnd one box of CCI primers and one box of Nosler 85 grain ammunition for base testing.
I am getting low on small pistol primers which is concerning since I shoot in competition.
Even Eley pistol match which I use in 22lr is sold out as well as Tenex which is really expensive. I have never seen that before.
I was going order new supplies around Christmas but spent that money on my wife and then chaos occurred. I read where since the Obama initiative over 70 millions firearms have been purchased.
Robert
Joe King
Well-Known Member
Berger only has 1 manual outmerbeau;775288[SIZE=3 said:
Hi merbeau.
I think everyone wants to help and they all have their versions on what works. You could simplify things.
You discovered where the bullet just kisses the rifling. Good to know as a reference.
Here is what I suggest for the hybrid:
Seat the bullet so it fits and feeds from magazine. Don't worry about the jump to rifling. IME most rifles will shoot just fine with a random seating depth. Make a dummy round with bullet seated that depth for future reference.
Load 6 rounds per powder charge incrementally increasing powder charge weight by 1 grain. Load charges up to suggested max from published charges listed on line for hodgdon or Alliant etc.
Go to the range and shoot three rounds at every target. Allow your barrel to cool to ambient temp as needed. As you get near the top end loads be aware that you could get some signs of pressure. Hard bolt lift, flattened primers, shiny spot on case head etc. (read up on signs of pressure). If rifle is sound you should find a one charge weight that gives the tightest group. Shoot three more rounds at the tighter targets. Choose the best load and shoot them a few more times on different days with a clean bore to verify you have a good load. At this point you may be done!
If necessary you can alter the seating depth of the best load by incrementally seating the bullet deeper in the case in .005" increments. This can be a real PITA if you don't have a competition seating die.
The problem is duplicating that seating depth later. If you don't remove your comparator from your caliper you can reference those values. Otherwise you will have to make a dummy for each increment to reference later.
Many of the hybrid loads I have made never needed a change in seating depth. Have loaded for 11 rifles with hybrids to date and only one required seating depth changes to tighten groups.
Good luck and let us know how it goes. Ask questions anytime.
Ross
I think everyone wants to help and they all have their versions on what works. You could simplify things.
You discovered where the bullet just kisses the rifling. Good to know as a reference.
Here is what I suggest for the hybrid:
Seat the bullet so it fits and feeds from magazine. Don't worry about the jump to rifling. IME most rifles will shoot just fine with a random seating depth. Make a dummy round with bullet seated that depth for future reference.
Load 6 rounds per powder charge incrementally increasing powder charge weight by 1 grain. Load charges up to suggested max from published charges listed on line for hodgdon or Alliant etc.
Go to the range and shoot three rounds at every target. Allow your barrel to cool to ambient temp as needed. As you get near the top end loads be aware that you could get some signs of pressure. Hard bolt lift, flattened primers, shiny spot on case head etc. (read up on signs of pressure). If rifle is sound you should find a one charge weight that gives the tightest group. Shoot three more rounds at the tighter targets. Choose the best load and shoot them a few more times on different days with a clean bore to verify you have a good load. At this point you may be done!
If necessary you can alter the seating depth of the best load by incrementally seating the bullet deeper in the case in .005" increments. This can be a real PITA if you don't have a competition seating die.
The problem is duplicating that seating depth later. If you don't remove your comparator from your caliper you can reference those values. Otherwise you will have to make a dummy for each increment to reference later.
Many of the hybrid loads I have made never needed a change in seating depth. Have loaded for 11 rifles with hybrids to date and only one required seating depth changes to tighten groups.
Good luck and let us know how it goes. Ask questions anytime.
Ross
westcliffe01
Well-Known Member
Robert, your description of the bullet does not match anything that Berger has on their website.
So do you mean "95 gr Match Grade Classic Hunter" part # 24570 ? 6mm 95 Grain Match Classic Hunter
Because if it is not that bullet you are unlikely to have success with any of the other 95 grainers in your 1:10 twist barrel.
I tried the "95 gr Match Grade VLD Hunting #24527" in my Savage 12 26" 1:9.25 barrel and they would not group better than 2" at 100 yards. I ran the calculation on the Berger website http://www.bergerbullets.com/litz/TwistRuleAlt.php and it confirmed the stability problem because of my twist rate. If you are shooting at much higher ambient temperatures and higher elevation (my parameters are 20F and 1000' asl) then your result may be better.
In the meantime I have a new Shilen 26" 1:8 chambered in 243 AI and it shoots the 95gr VLD's in 1/2" at 100 yards, capable of better since 2 of the 3 were touching and that is not even with a final load, thats while fireforming brass to the AI chamber. It will also shoot the 105gr VLD's and it sounds like it will shoot the 115gr DTAC bullets also. But the BC of the DTAC is close to the 105gr VLD so I might stick to the lighter one for now.
If you can shoot these bullets with a decent jump to the lands, it is better. First of all, it is safer for the case that you may need to unchamber a round after an unsuccessful hunt and leaving a bullet stuck in the barrel and the action full of powder is not a good thing. Particularly if you need to shoot a few seconds later and didn't realize the bullet was still in the bore... Secondly, having a bullet make a jump to the lands will lower your peak pressures and potentially allow higher max loads with less sensitivity. Max loads with bullets jammed into the lands could be far more sensitive to ambient temperature.
So specialized shooting sports like Benchrest may demand such a load configuration, but in general, one wants to avoid jamming the bullet into the lands under normal hunting conditions if at all possible. For berger bullets, jamming is a less reliable way to get repeatable loads and jumping is more consistent and today the recommended approach.
So do you mean "95 gr Match Grade Classic Hunter" part # 24570 ? 6mm 95 Grain Match Classic Hunter
Because if it is not that bullet you are unlikely to have success with any of the other 95 grainers in your 1:10 twist barrel.
I tried the "95 gr Match Grade VLD Hunting #24527" in my Savage 12 26" 1:9.25 barrel and they would not group better than 2" at 100 yards. I ran the calculation on the Berger website http://www.bergerbullets.com/litz/TwistRuleAlt.php and it confirmed the stability problem because of my twist rate. If you are shooting at much higher ambient temperatures and higher elevation (my parameters are 20F and 1000' asl) then your result may be better.
In the meantime I have a new Shilen 26" 1:8 chambered in 243 AI and it shoots the 95gr VLD's in 1/2" at 100 yards, capable of better since 2 of the 3 were touching and that is not even with a final load, thats while fireforming brass to the AI chamber. It will also shoot the 105gr VLD's and it sounds like it will shoot the 115gr DTAC bullets also. But the BC of the DTAC is close to the 105gr VLD so I might stick to the lighter one for now.
If you can shoot these bullets with a decent jump to the lands, it is better. First of all, it is safer for the case that you may need to unchamber a round after an unsuccessful hunt and leaving a bullet stuck in the barrel and the action full of powder is not a good thing. Particularly if you need to shoot a few seconds later and didn't realize the bullet was still in the bore... Secondly, having a bullet make a jump to the lands will lower your peak pressures and potentially allow higher max loads with less sensitivity. Max loads with bullets jammed into the lands could be far more sensitive to ambient temperature.
So specialized shooting sports like Benchrest may demand such a load configuration, but in general, one wants to avoid jamming the bullet into the lands under normal hunting conditions if at all possible. For berger bullets, jamming is a less reliable way to get repeatable loads and jumping is more consistent and today the recommended approach.
Ok, I am looking at the 2 boxes of bullets from Berger. The box reads 6mm 95 grain BTHP classic Hunter. G1 BC 0.427 and for 1 in 10: twist or faster. 100 CT. Lot 5185.
As far as the manual, I received a PDF file from Berger that was considered their manual at that point in time. Berger indicated they were working on a formal manual and would be released in the future which obviously has occurred..
In my mind with over several weeks of reading there seems to be two parts to the accuracy issue macro and micro. Macro variables would be those in which a change will make a significant improvement in accuracy. For example, going from a 2 moa group with factory ammunition to a 1 moa group by selected evaluation of various powders. Micro to me would be small changes on the order of 0.1 moa or less like cleaning primer pockets. For a bench shooter at long 1000 yd distances those micro changes can make the difference between winning and losing a match. For a person shooting at nominal distances from 100 to 300 yards and overal all less than 600 yards probably not so much.
As far as the manual, I received a PDF file from Berger that was considered their manual at that point in time. Berger indicated they were working on a formal manual and would be released in the future which obviously has occurred..
In my mind with over several weeks of reading there seems to be two parts to the accuracy issue macro and micro. Macro variables would be those in which a change will make a significant improvement in accuracy. For example, going from a 2 moa group with factory ammunition to a 1 moa group by selected evaluation of various powders. Micro to me would be small changes on the order of 0.1 moa or less like cleaning primer pockets. For a bench shooter at long 1000 yd distances those micro changes can make the difference between winning and losing a match. For a person shooting at nominal distances from 100 to 300 yards and overal all less than 600 yards probably not so much.
westcliffe01
Well-Known Member
Have you sat on those bullets for a while ?... I have the Berger reloading manual first edition, and it looks like it was printed in 2012. I picked it up at Cabelas a while ago after I had bought some of their VLD's.
There are 2 pages of loads for the 243 Win. Both pages recommend COAL of 2.710" which I believe is the SAMI standard, not anything that has bullets seated longer. I did all of my loads to that length and they shot beautifully. If one gets the throat lengthened, then it would allow seating the bullets longer, to the point that it would still fit in the magazine. My Savage magazine still has plenty of room so I can go 0.04-0.08" longer and it will still feed and function.
This list is just for information. It should match anything you got from Berger. The powders are listed by maximum charge weight. All assume the same COAL of 2.710"
There are 2 pages of loads for the 243 Win. Both pages recommend COAL of 2.710" which I believe is the SAMI standard, not anything that has bullets seated longer. I did all of my loads to that length and they shot beautifully. If one gets the throat lengthened, then it would allow seating the bullets longer, to the point that it would still fit in the magazine. My Savage magazine still has plenty of room so I can go 0.04-0.08" longer and it will still feed and function.
This list is just for information. It should match anything you got from Berger. The powders are listed by maximum charge weight. All assume the same COAL of 2.710"
Everybody to ther own opinions but I will say from over 25 yrs of reloading and the little I have learned..... Bullet seating depth is THE MOST CRITICAL THING!!!!!! Im not talking MOA groups. Im talking 1/2 or less MOA groups!!! Also you have to go by ogive!!!!! Tip to base means nothing because bullets are not uniform in that way!! Anyone tht says seating depth doesent mater either hasent set up many guns for long distance or has been lucky enough to have guns tht are great shooters ( I have seen a few of those). Every gun will not shoot the same bullet great!!! I have loaded enough to know certain calibers ( that I have set up) most likely shoot certain bullets best. This is not 100%. If you have a really great shooting gun!!! it will shoot a certain bullet within 1/2 moa with anything yo put in it(powder bullet amount of powder and seating dept).I have seen one of those in 25 yrs!!! Im sure there are several more. If yoiu are trying to find the best load (and I mean the very best load) its all trial and error with all components. IF your happy with 1 MOA then thats not to hard to get. Try going from 1 MOA to 1/4 moa and thats a different game!!! IF you want the best perfection you can achieve..... then every thing matters in every way!!!! Call me a perfectionist but its true!!!! I just want to be the best I can be at what ever I do!
ShootnMathews
Well-Known Member
I bought some of the Berger VLD 95 to try in my 243 1:10 twist. I don't know if they will shoot or not. The Berger calculator gave them a 1.09 factor using my info. 1.00 to 1.50 is moderately stable it says. I have only fired on test group so far. Measured 7/8". Will let you know if the next test groups shoot better.
westcliffe01
Well-Known Member
Robert, to verify which bullet you have, the "Classic Hunter" is 1.070" long, whereas the "VLD hunting" is 1.150" long. This is just a stability question, the same powder loads would work for either. The VLD has a longer point so would actually have a longer jump to the lands if loaded to the same COAL.
Only you can decide when enough is enough... My chamber is an Ackley Improved and there are no loads listed in the reloading handbook, but obviously they would be higher than the "regular" 243 Win. I am interested in seating my bullets longer, mainly to improve case capacity and reduce peak pressure. I do not want to be jamming my bullets into the lands, because that is exactly where it becomes imperative to have special bullet seaters which pick up the position of the bullet closer to the tangent point so that land engagement becomes more consistent. I think if my rifle consistently shoots 1/2 MOA it is enough for me at this point in my life.
If I run into the lands before I run out of magazine length, I will probably buy a throating reamer and lengthen the throat, since I have no interest in shooting light bullets in this rifle. Once you invest in a Savage barrel nut wrench and one of the NSS receiver wrenches, you will be able to do all of your own gunsmithing and it saves a ton of money. Many smiths charge nearly as much to fit your pre-machined barrel as what you paid for it !
Only you can decide when enough is enough... My chamber is an Ackley Improved and there are no loads listed in the reloading handbook, but obviously they would be higher than the "regular" 243 Win. I am interested in seating my bullets longer, mainly to improve case capacity and reduce peak pressure. I do not want to be jamming my bullets into the lands, because that is exactly where it becomes imperative to have special bullet seaters which pick up the position of the bullet closer to the tangent point so that land engagement becomes more consistent. I think if my rifle consistently shoots 1/2 MOA it is enough for me at this point in my life.
If I run into the lands before I run out of magazine length, I will probably buy a throating reamer and lengthen the throat, since I have no interest in shooting light bullets in this rifle. Once you invest in a Savage barrel nut wrench and one of the NSS receiver wrenches, you will be able to do all of your own gunsmithing and it saves a ton of money. Many smiths charge nearly as much to fit your pre-machined barrel as what you paid for it !
Hi Westcliffe01
The bullet I have mics to 1.070 inches which is the classic hunter. The box says for 1:10 twist or shorter. I did not purchase the VLD because of the stability issue. I used several tools from
http://www.jbmballistics.com/ballistics/calculators/calculators.shtml
to estimate the Miller Stability Coefficient and this bullet for my twist rate, elevation and mean temperature had a predicted value of 1.43 which according to the literature any number from 1.3 to 2.0 is acceptable. I understand the US Military uses a value from 1.5 to 2.0 for their work.
The area I live has a quite a few windy days so ballistic coefficient is important to me. I did a sensitivity analysis using the above web site for the published G1 value of 0.427 as compared to a much lighter bullet and there was a factor of 2 for bullet drop versus a factor of 4 for deflection. That is my rationale for choosing this bullet.
You quoted in your response
'I am interested in seating my bullets longer, mainly to improve case capacity and reduce peak pressure. I do not want to be jamming my bullets into the lands, because that is exactly where it becomes imperative to have special bullet seaters which pick up the position of the bullet closer to the tangent point so that land engagement becomes more consistent.'
That was my rationale. For volume I used the water technique and found a mean of 52.0 grains with a range of 52.2 to 52.3 grains which makes me wonder just how important this is for smaller cases. To obtain the volume occupied by the bullet I added the case length (2.032) and bullet length (1.07) then subtracted the overall COL (2.695) which is 0.407 inches for bullet seating. I used a blank case and cut two slits in the side inserted a bullet and closed the bolt slowly. I then removed the cartridge and measured the length and checked to make sure it would function in my magazine. There were light marks on the bullet and I used a bullet comparator to obtain a just touching the lands seating depth.
Next calculate the area of the bullet's cross section. For a .243 diameter bullet, that is (0.2432 ÷ 4) x 3.1416 = 0.0464 square inches. Multiply that area by the seating depth gives you the volume 0.0188 of the case occupied by the bullet, but it is in cubic inches. To convert cubic inches to grains of water, multiply by 252.8 grains of water per cubic inch which is 4.774 grains. Then subtract from case volume 52.0 – 4.774 = 47.23 grains. This a little off because the Berger bullet is a boat tail. I assume this is the maximum capacity before a compressed load is obtained. And from the literature at least 80% case capacity is necessary with powder so the minimum charge would be 47 x .8 or 38 grains.
Robert
The bullet I have mics to 1.070 inches which is the classic hunter. The box says for 1:10 twist or shorter. I did not purchase the VLD because of the stability issue. I used several tools from
http://www.jbmballistics.com/ballistics/calculators/calculators.shtml
to estimate the Miller Stability Coefficient and this bullet for my twist rate, elevation and mean temperature had a predicted value of 1.43 which according to the literature any number from 1.3 to 2.0 is acceptable. I understand the US Military uses a value from 1.5 to 2.0 for their work.
The area I live has a quite a few windy days so ballistic coefficient is important to me. I did a sensitivity analysis using the above web site for the published G1 value of 0.427 as compared to a much lighter bullet and there was a factor of 2 for bullet drop versus a factor of 4 for deflection. That is my rationale for choosing this bullet.
You quoted in your response
'I am interested in seating my bullets longer, mainly to improve case capacity and reduce peak pressure. I do not want to be jamming my bullets into the lands, because that is exactly where it becomes imperative to have special bullet seaters which pick up the position of the bullet closer to the tangent point so that land engagement becomes more consistent.'
That was my rationale. For volume I used the water technique and found a mean of 52.0 grains with a range of 52.2 to 52.3 grains which makes me wonder just how important this is for smaller cases. To obtain the volume occupied by the bullet I added the case length (2.032) and bullet length (1.07) then subtracted the overall COL (2.695) which is 0.407 inches for bullet seating. I used a blank case and cut two slits in the side inserted a bullet and closed the bolt slowly. I then removed the cartridge and measured the length and checked to make sure it would function in my magazine. There were light marks on the bullet and I used a bullet comparator to obtain a just touching the lands seating depth.
Next calculate the area of the bullet's cross section. For a .243 diameter bullet, that is (0.2432 ÷ 4) x 3.1416 = 0.0464 square inches. Multiply that area by the seating depth gives you the volume 0.0188 of the case occupied by the bullet, but it is in cubic inches. To convert cubic inches to grains of water, multiply by 252.8 grains of water per cubic inch which is 4.774 grains. Then subtract from case volume 52.0 – 4.774 = 47.23 grains. This a little off because the Berger bullet is a boat tail. I assume this is the maximum capacity before a compressed load is obtained. And from the literature at least 80% case capacity is necessary with powder so the minimum charge would be 47 x .8 or 38 grains.
Robert
westcliffe01
Well-Known Member
Do yourself a favor and get the Berger reloading manual. They have entire sections which discuss the problems of getting consistent bullet to land position, and also the importance of seating bullets long, since in doing so it is equivalent to working with a larger cartridge capacity. The book is well worth the money, there is a lot of historical stuff in it. Bear in mind that the company founder was a fanatical bench rest shooter where they are going for sub 1/4MOA grouping. I am not quite so fanatical, but if we use other peoples lessons we can save ourselves quite a bit of time and frustration.
