Prepping the big 300gr SMK???

[lerch]

Me and Bill Bailey have recently ordered a 338 AM from ol' Montana boy, Kirby I am just jealous as hell because you get to live in that amazing state /ubbthreads/images/graemlins/grin.gif, and I am curious about the 300gr SMK.

I have 500 on hand right now and after a quick look at them I am curious how to organize them into groups. GG and Uncle B this is pointed toward you guys, congrats again on the recent chuck shootin.

The meplats on all the bullets are just uneven as hell and I have heard many stories about bearing surface differences. Do you need to trim meplats, and if you how much before we degrade BC???? Can you get by with true match ammo if you just sort by bearing surface?? If it is just bearing surface can you use the stoney point method or do we need to get a bearind surface sorter, UB I thought you showed one once.

I am not worried about case prep so much so the big question is how to sort out and/or create bullet consistancy.

I know a lot of you guys have experince with this big ol' boy ( Kirby, GG, UncleB,Mr.Carlock, ETC) so I am hoping you guys might chime in and help the new boys to the .338 family.

Thanks guys
steve

 

[Fiftydriver]

I will admit that so far I have simply grabbed one from the box and seated it everytime I loaded a round with no sorting.

From talking with Uncle B about this I will be ordering a tool to measure the bullets baring surface from Tubbs company. I think they run around $135 or so.

Uncle B will offer more information on measuring baring surface and measuring ogive lengths.

Again, I am not embarrased to say I have not sorted any of them yet. Obviously that will help consistancy but up till now they have been pretty **** consistant unsorted.

I may not be able to see the improvement in sorted bullets anyway /ubbthreads/images/graemlins/grin.gif!!

Kirby Allen(50)

 

[Roll-Yur-Own]

Guy's, I have never trimmed or sorted any MK's in any caliber and they still shoot lights out.

I do pick out the most even one I can find in the box to use when setting up my seater die to correct seating depth. When you measure your loaded rounds with your calipers, the variance with MK's is so much because of the meplats you THINK that they will shoot patterns. But, when you go to the range, they shoot lights out.

Hope this helps.

 

[Meister]

Well Fifty, I've loaded them the same way for many years. This year I went ultra picky and sorted them by weight and bearing surface. The groups were slightly smaller, but only by a few hundreths at 200y. At longer range they were nearly identical to the ones I loaded last year. To me the extra time and effort isn't worth the accuracy earned.

Not to get off the subject, but how consistant are Richards big 338 torpedo's?

 

[Fiftydriver]

Meister,

From the ones I have played with they were at least as consistant as the SMK and actually better in weight consistancy.

Lot to lot variations will be similiar to SMKs. The dies are all set up by hand each time a new lot of bullets is made. This is why the consistancy in a speicific lot of bullets is generally better then the SMKs but it can vary from lot to lot but I would not say much more if any more then Sierra bullets.

The cure, if you find a bullet of Richards that you like, order more then 100 at a time!!

Simply put I would say they are at least as consistant as SMKs and bullet weight generally is better from what I have measured in his 338 bullets.

Shot side by side, RIchards bullets averaged tighter groups at 500 yards then the SMK. Not dramatically different but for an average of five three shot groups out of my 338 Kahn with each bullet, the Wildcats averaged right at 1.3" ctc and the SMKs averaged 1.65".

Both shoot very well but my Kahn at least prefers the Wildcat. TO bad Richard does not have his dies back!!

This is just one rifle though and as we know all rifles have different personalities!!

Kirby Allen(50)

 

[Shawn Carlock]

I sort mine first by measuring from base to ogive, then take the biggest lot of the same and measure the bearing surface, I take the biggest lot of the same and trim them. These are the best of the best. I use these for anything important. I finally took some of the worst of the worst and shot some groups against the best of the best. Here is what I got.

W of W

ES - 16 fps

100 yds average 5, 3 shot groups .364"

300 yds average 5, 3 shot groups 1.089"

811 yds average 5, 3 shot groups 4.194"


B of B

ES - 6 fps ( this later turned out to be really important )

100 average 5, 3 shot groups .328"

300 average 5, 3 shot groups .891"

811 average 5, 3 shot groups 3.247"

I have not shot both at my 1276 yard plate but I believe that the vertical spreads I am getting are directly accountable to the small ES that is the product of the sorting process. You won't see a big difference until the ranges get long. I also shot some sorted but not trimmed bullets against sorted and trimmed bullets @ 811 yds. The group difference was none exsistant so from an accuracy stand point the sorting was worth it but trimming was not. I trim the best of the best because I use them for LRH and the open up more and more consistantly when you trim and clean the hollow point out. The trimmed bullets did drop .50 moa lower @ 811 yds. Now to the real question, is it worth it, that depends on your performance expectations. If you want to pull groups from 1200-1300 yds that are in the 5-6 " range I believe that you have to do everything you can to get there. If you simply want to lung a deer out to 800 yards sorting and trimming is a waste of time. Again this is what I found, if anyone has other data I love to see what they ended up with.

 

[goodgrouper]

Thanks Steve.

Congrats on the purchase of one of the most inconsistent bullets around and absolutely the worst MK ever made! Buying these bullets in 100 count boxes is an absolute waste of time and money. 500 is minimum with 1000 being even better. Maybe Sierra knows this and is making money off it!

Here is what I've found:

For shooting to 1k, you might not have to do anything but measure ogives from the base using a Sinclair, Stoney POint, or other comparator tool. Then again, if you need to shoot something up to or around 1k, using another gun is probably the wisest choice. No need to burn the barrel out on that big boy when a 6br will do 1k easily.

For 1500 yards to a mile, things get a little more tricky. Measuring the bearing surface and ogives in a manner like what Shawn mentioned is a must. I do the segregating exactly like his method. I have found that even bullets leaving the barrel at EXACTLY the same speed but having as little as .002" difference in bearing surface length can yeild as much as a minute and a half impact variation!

At 2000 yards, I do the same things as 1 mile shooting, but I pick out only the best bullets with the best meplats. If there are none, then trimming the meplats may be in order. I have shot the MK with meplats trimmed and untrimmed for comparison and there will be a 3-4 minute reduction in moa elevation needed at 2k with the untrimmed bullets. By far, the bullets critical lengths are more important than the condition of the meplats-probably 10 to 1.

If you do choose to trim meplats, Tubbs tool is probably the best although Sinclair's new tool looks to be very good as well.

As for the bearing surface tools, I prefer and use the double Stoney POint method and have found it to work as well as the more expensive tools. All the ammo I loaded for the Moag last year was done in this manner including the ammo used on UB's 2k chuck as well as my own. <font color="red"> It works and it's cheap. </font>


I think Wildcat bullets will probably end up making a much better 300 grain 338 than Sierra. I hope they make it to market soon. Kirby, any word on those pills yet?

Berger would also make a kick-butt 338 if they would try. A J4 jacketed 275 or 300 grain VLD would kill elk and deer way better than the MK and would have a higher bc probably too! COME ON BERGER!!

Good luck with that cannon. /ubbthreads/images/graemlins/wink.gif

 

[Guest]

[ QUOTE ]
I have found that even bullets leaving the barrel at EXACTLY the same speed but having as little as .002" difference in bearing surface length can yeild as much as a minute and a half impact variation!


[/ QUOTE ]

Great post! I'm guessing it's even worse than you suggest as a longer bearing surface (BS) would have more friction and yield a lower velocity. If longer BS increases BC the effect may be somewhat ameliorated (but my guess is the longer BS would lower the BC.

Here is a pic of my set up. Dual Banjo's -- oops Dual SP Bullet is a 190gr SMK .308

Not that I need to do this right now given my longest kill (717 yards) is exactly one mile behind Kirby, but I'm getting ready.

 

[uncleB]

I agree with GG and Shawn on every thing but one point the Tubbs bullet bearing surface comparitor is more precise than using 2 stoney point tools because it actualy measures the bearing surface of the bullet, the stoney point units are several thou under-sized and measure well ahead of the ogive and well behind the rear bearing surface. this is not really too much of a problem on most bullets as I use the 2 stoney points for every bullet I shoot EXCEPT the 300SMK, I think the BSC really makes a difference if shooting past a mile.
UB

 

[Meister]

I have considered having 2 Stoney Point guage dies made that more closely follow the Ogive. By lightly deburring the leading edge you would get a better reading on the Ogive's true length.

I have noticed a large BS variation going from lot to lot on the sierras since I have become more aware of the projectile's dimensions, but only on the 338c-300's and the 30c-220's.

The 220's I fire in my 300 whisper are, by nature, very picky with bearing surface variation. I've seen almost 150 fps variation in speed if I don't measure BS. With measurement I regularly get 30 fps max spread in the subsonic rounds.

Sounds like I need to try Richards' bullets. I'm resistant to change, unless I'm positive it will make things better. That and the fact that I hate shooting paper to re-ladder a gun that I already know what works in.

 

[jb1000br]

[ QUOTE ]
I agree with GG and Shawn on every thing but one point the Tubbs bullet bearing surface comparitor is more precise than using 2 stoney point tools because it actualy measures the bearing surface of the bullet, the stoney point units are several thou under-sized and measure well ahead of the ogive and well behind the rear bearing surface. this is not really too much of a problem on most bullets as I use the 2 stoney points for every bullet I shoot EXCEPT the 300SMK, I think the BSC really makes a difference if shooting past a mile.
UB

[/ QUOTE ]

The "bearing surface" is not the caliber sized part of the bullet...

the comparitors should be undersized like the SP inserts are since the BORE diameter (groove minus rifling depth) is what you really want to measure...

The part that actually touches the barrel is closer to .330" than .338"...

I will call John Buhay and see what diameter he makes the holes in the bushings that Tubb sells as the BSC...my bet is 8 thou under caliber size...

JB

 

[Shawn Carlock]

I built my own and built them like JB1000 described. I bored 2 bushings that were the bore diameter .331" of my barrel and used a throating reamer to open and set a shoulder in them. This seems to work very well, but buying a setup from stony point or tubb etc. is much easier.

 

[Guest]

[ QUOTE ]

The "bearing surface" is not the caliber sized part of the bullet...

the comparitors should be undersized like the SP inserts are since the BORE diameter (groove minus rifling depth) is what you really want to measure...

The part that actually touches the barrel is closer to .330" than .338"...


[/ QUOTE ]
My WASG is most of the transition area (.330 to .338)- ie is not touching at all to FULL .004 deformation is inconsequential in the frictional component. (I did say Wild Arse Scientific Guess and 40 hours of my scientific analysis is worth 4 seconds of Goodgroupers or Kirbys real experience).

What you say is true (the .330), but why do you think that is what you want to measure? At the .330 point (not touching, not deforming) there is no friction.

 

[jb1000br]

[ QUOTE ]
[ QUOTE ]

The "bearing surface" is not the caliber sized part of the bullet...

the comparitors should be undersized like the SP inserts are since the BORE diameter (groove minus rifling depth) is what you really want to measure...

The part that actually touches the barrel is closer to .330" than .338"...


[/ QUOTE ]
My WASG is most of the transition area (.330 to .338)- ie is not touching at all to FULL .004 deformation is inconsequential in the frictional component. (I did say Wild Arse Scientific Guess and 40 hours of my scientific analysis is worth 4 seconds of Goodgroupers or Kirbys real experience).

What you say is true (the .330), but why do you think that is what you want to measure? At the .330 point (not touching, not deforming) there is no friction.

[/ QUOTE ]

You want to measure the part of the bullet that is touching the bore bore right? Well, measuring closer to .338 than .330 is not doing that...

It probably makes no difference though, and I'd bet money it (method) gets lost in the noise...

JB