87 V-Max - Which Powder?

[urbanrifleman]

6 XC with .050 freebore should be excellent with the 87 V max! AA2700 would be my powder of choice with a large primer.

I am going to be working with RAG's load in one of Brad's 8T, 6 BRA's shortly with small primers, lucky I just found a brick of CCI 450's.

That is way to short of freebore. You need more like 140 or 160 to get away from the donut.

104 fb with 20 jump was into the donut on my brass. By a lot. It might be the reason it won't shoot.

That 87 vmax is an odd duck. It sits lower on the neck than a 108 Berger or 112 Barnes.

If you plan to jump the thing you better have some freebore.

160 freebore seems about ideal. I'm going to make a 6bra 160 freebore reamer and go to that. Anything less than that is for 80 and less.

 

[urbanrifleman]

For comparison.

 

[AckleymanII]

Brad, I would think that the .050 freebore would be perfect with the bullet shank/BT being barely above that shoulder/neck junction! Just a WAG on my part, sizing .001. Everything is new territory for me with the 87's.

I don't care where the bottom of the bullet is, just the junction of the boat tail/bullet shank is located.

My 7 mag, 280 AI, 7 STW shoot tiny groups with the bullet down in the case, seated way past the shoulder neck junction. You just have to monitor for the doughnuts by pushing a bullet back down in the case neck after firing...easy peasy!

Brad, that third picture down with the .050 freebore and the 87 is a wet dream come true. With this much contact with neck and bullet, less sizing would be better where sizing .002-.003 would screw the pooch, maybe....many factors.

I will have groups with the 87's in your 6 BRA,8T chamber coming very soon, and I will make notes on variations on ogive lengths. This 8T barrel of yours shoots the 70g TNT less than 3/8" on the first outing with no fiddling with powder charge or bullet seating depth, and the 75g V max shot a group in the 1's with no fiddling with bullet seating depth or powder charge...I bought a lottery ticket on the way home.

I seated the two above bullets .010 off the lands, 70g TNTwas 30.6g of 8208 with 7 1/2 and I lowered the powder charge to 30.2g for the 75g V max and hit a home run out of the park. I have a Harrells Tuner brake on this barrel, and tuned the load with the setting on the tuner set on zero for the 70g TNT, then moved to 3, then 5, then 7...load development is done at 7 for the 75g V max, will split to the number 4, 4 1/2 for the 70g tnt hoping to get a small bug hole. Dang, hard for me to believe just how small the groups are with so little load development using an 8 Twist on the 70g tnt and 75g V max. I was unsure if these two bullets would take the Rpm's.

87's maybe a challenge..

My 6 BRX-10 twist with some .030 freebore shoots these 87's into bug holes with IMR and H4895, 3200 fps. I have a RAS Tuner brake on this barrel, and it made short work of tuning the 87's.

 

[AckleymanII]

With Brad's thinking of the longer freebore, it could be that the case capacity is increased and this has a huge effect on the pressure curve. I saw this very thing on a 6 xc barrel of mine. So, we are talking two different things:
a. increasing case capacity by lengtheng the freebore
b. relationship of the shoulder/ neck junction in relation to the Bullet shank/ boat tail being out of Doughnut area.

 

[urbanrifleman]

With Brad's thinking of the longer freebore, it could be that the case capacity is increased and this has a huge effect on the pressure curve. I saw this very thing on a 6 xc barrel of mine. So, we are talking two different things:
a. increasing case capacity by lengtheng the freebore
b. relationship of the shoulder/ neck junction in relation to the Bullet shank/ boat tail being out of Doughnut area.

Wellllll....

I think the further down the neck the less consistent your seating tension is because the neck is being sized into a reverse funnel shape using bushing dies. The more you resize them the worse it gets. Your neck tension is increasing the further down the neck you go.

Most benchrest shooters have the bullet barely seated in a PPC. No more than halfway down the neck.

 

[AckleymanII]

I think that trial and error will be the key in this case with 87's.

 

[urbanrifleman]

I think that trial and error will be the key in this case with 87's.

I hope you find the secret. Because I don't know it!!

 

[Ackman]

Nothing wrong with 87's. My stuff is mostly slower twist and lighter bullets. However years ago I ordered a 13tw barrel and received a 9-1/2. Chambered for .243AI, 0 FB it was real pickly with 70's and light bullets. Howver with the right powder those 87's can shoot very well. I'm mentioning this because the 243AI case has a much shorter neck than a 6BR and with 0 FB an 87 just kissing seats well below the neck-shoulder junction. And those bullets group very tightly. I'm waiting to see how they do in an 8tw 6BRA. My 14tw 6BRA has 0 FB.......here's a picture of an 87 seated to just touch in that chamber. The dark line is where the boattail begins, just above the neck/shoulder radius. It would work fine with 0 FB. A .050" freebore as in Urbanrifleman's photo would also be just dandy.

 

[urbanrifleman]

Nothing wrong with 87's. My stuff is mostly slower twist and lighter bullets. However years ago I ordered a 13tw barrel and received a 9-1/2. Chambered for .243AI, 0 FB it was real pickly with 70's and light bullets. Howver with the right powder those 87's can shoot very well. I'm mentioning this because the 243AI case has a much shorter neck than a 6BR and with 0 FB an 87 just kissing seats well below the neck-shoulder junction. And those bullets group very tightly. I'm waiting to see how they do in an 8tw 6BRA. My 14tw 6BRA has 0 FB.......here's a picture of an 87 seated to just touch in that chamber. The dark line is where the boattail begins, just above the neck/shoulder radius. It would work fine with 0 FB. A .050" freebore as in Urbanrifleman's photo would also be just dandy.

In my opinion, that is too close to the donut. Way too close.

You haven't even started jumping it yet.

 

[urbanrifleman]

If you are messing around with the donut area, it will eventually jump up and be a problem. A really famous shooter once told me the only solution to donuts is to not be near them.

 

[Ackman]

In my opinion, that is too close to the donut. Way too close.

You haven't even started jumping it yet.

As I posted, that photo is where an 87 seats in my 14tw barrel and the boattail starts well above where the neck/shoulder radius begins. That barrel will never ever see one of those bullets anyway, picture was for illustration purposes. Also except for one chamber,I don't jump anything more than about .005". The 8 tw. has .050".

 

[urbanrifleman]

As I posted, that photo is where an 87 seats in my 14tw barrel and the boattail starts well above where the neck/shoulder radius begins. That barrel will never ever see one of those bullets anyway, picture was for illustration purposes. Also except for one chamber,I don't jump anything more than about .005". The 8 tw. has .050".

I am not being argumentative, but in your picture, if your brass had a few firings on it, you would be well into the donut.

 

[moorepower]

And to do that you better have a loooonnngggg freebore.

Not an issue.