87 V-Max/Dasher Issues

[762willdo]

I have run them over 3800 in a 12 twist. I don't have the 8 twist on yet.

In a dasher????

 

[CJ6]

In a dasher????

No..I was just relating velocity I've shot/shoot them at. Cartridge is 6-284. I haven't had one blow up yet.

 

[204 AR]

Yes, I've shot a lot of the 87 vmax, and yes they typically run slightly oversize ime. In fact it is close quarters in a dpms 243 I have, live rounds can be difficult to extract but they shoot very well. I thought maybe it was just the lots I've had as mostly I shoot blems.

 

[jaybray]

I had a real accurate load of 34 grains varget moving 3225 fps in my Dasher with the 87 V max using an old lot of bullets that were at least 10 or more years old. Ran out of them and bought some new 87's and they shot horrendous shotgun pattern groups with the same load and seating depth. With the difficulty of finding components at the moment I gave up trying to get these new ones to shoot. The 105 Amax with 31.6 varget at 2920 fps shoots lights out in my gun. Too bad as i liked them 87 vmax.

 

[urbanrifleman]

I'm confused.

 

[LRPV]

Guys, bullet manufactures will basically sell a 6mm bullet that measures from .243-.244 the diameter grows as the die wears till the point that it is out of spec and replaced. Different manufactures have different tolerances I’m sure. If the body (not the pressure ring) is larger than your freebore diameter, you’re probably gonna see some issues come up. It wouldn’t surprise me to even see some lots of 6mm bullets smaller than .243. I have a lot of 22cal 75 Amax that measure like .2237 or something like that. Just part of the game with bullets, especially off the shelf bullets.

 

[Linko]

If Jim Borden chambered the barrel he can tell you the chamber spec.

 

[AckleymanII]

RAG is right on the money with the measurement of .2435 on the shank dia. Problem is that reamer makers have a .0005 +/- on their dimensions, and I think that it is possible that RAG's is just a tad on the minus side. I am guessing of course.

My lot measured .2435 on the shank also with two very good micrometers that have been checked with gauge blocks.

In the right chamber/barrel, these "FAT" bullets should shoot like a house a fire!

I shoot these FAT bullets in a 6 BRX(10T) and a 6 Dasher(8T) with shortish throats, with some amazing accuracy.

 

[RAG]

If Jim Borden chambered the barrel he can tell you the chamber spec.

Yes, in fact he's been extremely helpful...I emailed him twice, and both times he promptly replied. Kudos to him on that. The diameter of the FB/Throat in the reamer used to make my chamber is in fact .2435. I received 8 different 6Dasher Reamer prints from PTG yesterday...they were all tight on this spec...one was as l low/tight as .2433, and none were over .2435, which surprised me.

 

[RAG]

Guys, bullet manufactures will basically sell a 6mm bullet that measures from .243-.244 the diameter grows as the die wears till the point that it is out of spec and replaced. Different manufactures have different tolerances I’m sure. If the body (not the pressure ring) is larger than your freebore diameter, you’re probably gonna see some issues come up. It wouldn’t surprise me to even see some lots of 6mm bullets smaller than .243. I have a lot of 22cal 75 Amax that measure like .2237 or something like that. Just part of the game with bullets, especially off the shelf bullets.

I'm sure you're right, but I measured 7 or 8 other 6mm bullets (including Hornady's 58 Vmax, 105 Amax and 108 ELD-M) I have, and all were right at .3430. And I now know of 3 people who have measured the 87 Vmax and all were "fat"...so I'm thinking it's possible they have done this on purpose?

 

[RAG]

I had a real accurate load of 34 grains varget moving 3225 fps in my Dasher with the 87 V max using an old lot of bullets that were at least 10 or more years old. Ran out of them and bought some new 87's and they shot horrendous shotgun pattern groups with the same load and seating depth. With the difficulty of finding components at the moment I gave up trying to get these new ones to shoot. The 105 Amax with 31.6 varget at 2920 fps shoots lights out in my gun. Too bad as i liked them 87 vmax.

Well, this would "potentially" support LRPVs theory, as maybe they had fresh dies 10 years ago and all of Hornady's 87 Vmax dies are now borderline worn out and producing fat bullets. I'd be curious to see, for those with good/calibrated micrometer, what other people measure on the 87 V-max and how old the bullets are.

 

[RAG]

In any case, it's well documented that many people seek/work to get the 87 Vmax to shoot well, for obviously reasons...inexpensive, good BC, and explosive. It's also well documented that many people fail at this goal and are forced to move on to another bullet, such as the Berger 88s, etc.

I surmise the reason so many people struggle to get the these bullets to shoot is because they are oversized, so pressure spikes abound with virtually no clearance in the FB/Throat, especially those shooting 6BRA/Dasher "match" chambers. My first group with these in my new Dasher printed a smidge over 1.5" at 500 yards (5 shots), and then quickly the residue/fouling starting to cause chambering issues and the groups went BAD...then, by 4th group, I couldn't even chamber the round at all.

 

[urbanrifleman]

In any case, it's well documented that many people seek/work to get the 87 Vmax to shoot well, for obviously reasons...inexpensive, good BC, and explosive. It's also well documented that many people fail at this goal and are forced to move on to another bullet, such as the Berger 88s, etc.

I surmise the reason so many people struggle to get the these bullets to shoot is because they are oversized, so pressure spikes abound with virtually no clearance in the FB/Throat, especially those shooting 6BRA/Dasher "match" chambers. My first group with these in my new Dasher printed a smidge over 1.5" at 500 yards (5 shots), and then quickly the residue/fouling starting to cause chambering issues and the groups went BAD...then, by 4th group, I couldn't even chamber the round at all.

What is the freebore of a PTG unithroater?

 

[SmokinJoe]

You set the FB on a Unithroater to get what you want/need. Don't know what throat diameter they are made to.

 

[urbanrifleman]

You set the FB on a Unithroater to get what you want/need. Don't know what throat diameter they are made to.

Right. I'm assuming the throat is larger. Just run a unithroater in there and kiss the freebore and now your freebore is larger.

 

[LRPV]

Right. I'm assuming the throat is larger. Just run a unithroater in there and kiss the freebore and now your freebore is larger.

Should be able to get one ground to whatever. Some guys use a pretty big number on their reamers.

 

[SmokinJoe]

Just mic'd some of my varmint bullets and found that V-Max 6mm 75 & 87 gr ran .2433/.2434, also checked some .224 & .204 V-Maxes and they ran .0002/.0003 over nominal, so maybe that is just the way Hornady makes them. BTW, my 6mm bullets are 20+ years old so probably from much earlier production than most of what has been discussed here.
Also looked at some of my reamer prints and found that the JGS 6mm prints show .2438 FB whereas PT&G reamers show .2435. Maybe this info might help the discussion.
One more thing, pulled out my 6mm Unithroater and measured FB diameter and best I can measure it is .2435. This is an off the shelf Unithroater with no special specs.

 

[alf]

PT&G reminds me of the restaurant we used to have in town.

You could order whatever your want, but no guarantee that's what you'd get.....

 

[RAG]

Should be able to get one ground to whatever. Some guys use a pretty big number on their reamers.

Right. This is exactly what I was thinking, thank you! I'm waiting for a smith to get back to me on his dimensions, but in all likelihood it's .2435 in diameter. I guess, for those that want to shoot these oversized bullets, you'd want to want to have a throater made/ground to a lot closer to .2440, so you have the normal .0005 or more clearance (at least), especially if you plan to dump 200 rounds down range before cleaning (as I do).

 

[RAG]

Like how they have a "Norma Dasher" reamer, I think they (PTG or other reamer makers) are going to need to have a "87 Vmax" reamer on file. or at least, an 87 V-Max Throater.