.338 M.O.A.G. (mother of all guns) pics and story

[257speed]

Which bearing surface comparator did you go with?

 

[abinok]

Whose comparitor did you decide to go with?
I just notticed david tubb has a new one out, ill scan and post the page if anybody is interested.

beat me to it by a few minutes 257, gotta quit messing around when im posting.... /ubbthreads/images/graemlins/grin.gif

 

[abinok]

I think the current theory is that bearing surface has the greatest effect on internal ballistics ie: more ES, and that base to ogive has more effect on external ie: inconsistant bc.
Im fighting the urge to sort by BS then base to ogive, after trimming meplats. Went through some bullets (46) I had sorted by BS yesterday, and there are still a few in there with inconsintant base to ogive, so there is still some inconsistancy with either measurement. Please don't tell me this is a good idea, then I might just have to do it.

 

[4ked Horn]

Hey Brian would you care to tell me what the difference is between base to ogive and bearing surface is when you subtract the boat tail portion of the bullet. I mean, I can see that finding the exact tangent spot where the cylindrical portion meets the ogive might be a challenge and would require special gear to get it down to the .001". But the distance from the bottom of the bullet to the largest diameter couldn't be off by much could it? I would guess it would be less than .001".

 

[goodgrouper]

It is one made by Bill Shehane. He does not advertise it on his website, but from the sound of it, it is a much more accurate way of eradicating those pesky vertical stringers. Time will tell in which way it affects internal ballistics as well.

 

[goodgrouper]

[ QUOTE ]
I think the current theory is that bearing surface has the greatest effect on internal ballistics ie: more ES, and that base to ogive has more effect on external ie: inconsistant bc.


[/ QUOTE ]

From what I have seen, I would buy that!
What is funny is that in my years of shooting out to 1500 and 1760 yards, this didn't show up near as much as it does with 2k shooting. The voodoo factor (difficulty level) multiplies exponentially from 1500 out!

 

[goodgrouper]

[ QUOTE ]
tell me what the difference is between base to ogive and bearing surface is when you subtract the boat tail portion of the bullet. I mean, I can see that finding the exact tangent spot where the cylindrical portion meets the ogive might be a challenge and would require special gear to get it down to the .001".

[/ QUOTE ]


That is in effect what this tool does. It will measure from the back of the bearing surface to the front. One can measure base to ogive with a S.P. tool, but there is another measurement in the middle-where the boat tail meets the shank or bearing surface. There is often huge variation in this area.

 

[abinok]

I thought you were using the sp comparitor for base to ogive? If so, you just need another body, and insert for your caliber... like the movie, for a few dollars more... Im sure Bill's tool is nice, maybe ive been doing this LR shooting thing on a college student budget too long.

 

[goodgrouper]

Yes, that would be about the same thing only Bill's is measuring just a bit farther down the ogive and hopefully is a little more precise.

 

[BountyHunter]

Bills is $275 and $80 for caliber conversion.

The Tubbs model is actually built for him by John Buhay in PA. RW Hart sells this also as the JB Ogive Indicator in their catalog on page 19 for $125 and $40 for caliber conversions. www.rwhart.com and 800-368-3656

BH

I got mine directly from John and have 4 caliber conversions. It actually is a product improvement off the BS model and more accurate.

BH

 

[goodgrouper]

I got a little antsy and decided to load up some more MOAGS today for the weekend shoot coming up. We haven't got Bills bs tool yet, so I improvised two sp comparators to check bs on the 300 grain MK's. Brian had already measured base to ogive length on the bullets and segregated them accordingly. So I measured bearing surface on all the bullets from the same group of ogive lengths. Wow, were they bad. I was getting variations of .002-.003" on bs. That would have to make at least a couple feet of impact difference at 2000 yards!

After Brian spent hours uniforming meplats and measuring base to ogive lengths, I spent 6 hours today measuring bs and assembling the rest of the rounds. I got 50 loaded in a combined time of about 20 minutes per round!
<font color="blue"> There has got to be a better way to do this! </font>

Come on Richard, lets get those Wildcatters here pronto! I know, I know, the die maker is holding us up.

<font color="red"> Why is it I always want what isn't made yet?!?! </font>

 

[4ked Horn]

One of Thomas Edisons more famous quotes: "There IS a better way. FIND IT!"

 

[jb1000br]

[ QUOTE ]
Bills is $275 and $80 for caliber conversion.

The Tubbs model is actually built for him by John Buhay in PA. RW Hart sells this also as the JB Ogive Indicator in their catalog on page 19 for $125 and $40 for caliber conversions. www.rwhart.com and 800-368-3656

BH

I got mine directly from John and have 4 caliber conversions. It actually is a product improvement off the BS model and more accurate.

BH

[/ QUOTE ]

BH -- glad you posted this cause i was feleing the urge -- so Bill dropped his price a bit i see /ubbthreads/images/graemlins/shocked.gif

Yep, Buhays tool is the deal, that is why Tubb is selling it as well /ubbthreads/images/graemlins/wink.gif

I'll stick with my 40$ double SP comparitor though /ubbthreads/images/graemlins/wink.gif

cheers,
JB

 

[ricka0]

goodgrouper - I can send (loan) you my 8-32x56 Benchrest with 1/8 MOA clicks, but u need a huge rail as it only has 50 MOA adjustment. the NP-R2 reticle is the best IMAO