Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

[dstewart51]

I sat down last night and measured and compared about 50 samples each of the Berger OTM's, Sierra MK's and Lapua Scenars. I checked weight and diameter.

Most consistent in weight where the Berger OTM's Rarely did they vary + or - .1gr with more then 90% hitting 300.0gr on the nose. The average diameter was the smallest of the three at .33750"

Next where the Sierra Match Kings. They stayed close to 300.0gr but there where more that where + or - .1gr. There where a few + or - .2 to .3gr. The average diameter was in the middle as well at .33780"

For as well as they shoot I was surprised to see the least consistent measurements with the Lapua Scenars. About as many where 299.9gr and 299.8 as there where 300.0gr. I had some come in as low as 299.4gr. Not too many where over, they tended to be a bit on the light side. They also had the largest diameter as well, averaging .33805"

So I had a question for Bryan, how much of an impact does the OD play in this? Is .0005" significant? What would be the reason for the smaller diameter on the OTM's if its designed to be so?

I know this is all kind of splitting hairs but it was interesting to see the differences.

 

[milo 2.0]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

Holy shit, if you have patience for this, you will adapt well to painting ceramic squirrels in some fucking nut house when you age.

 

[TwoGun]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

All the bullets are the same size when they exit the barrel. You could load a .308 bullet and it'd be .338 when it exited.

 

[dstewart51]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

Yes, but I was wondering if the larger dia Scenars would generate more pressure then the OTM's.

 

[Aimsmall55]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

Lmao! Thanks. Rough day.

 

[Blackbrush]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

Shit, there's a money saver. I'm gonna shoot 168SMKs in my 338LM!

 

[bas402]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TwoGun</div><div class="ubbcode-body">All the bullets are the same size when they exit the barrel. You could load a .308 bullet and it'd be .338 when it exited. </div></div>

Now That's Funny

 

[mrbig]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

it says on the box the Scenars are .339,,I havent measured them though,,

 

[milo 2.0]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dstewart51</div><div class="ubbcode-body">Yes, but I was wondering if the larger dia Scenars would generate more pressure then the OTM's. </div></div>

I apologize for my offbeat humor earlier in the thread.
To answer your question, you're just going to have shoot the bullets to find out. Even Litz couldn't predict barrel pressures, as all barrel manufacturers barrels are different.
And the reamer used to chamber it.

As for measuring and weighing bullets, I myself wouldn't even be looking there unless the gun wouldn't shoot them.

If I shot a .338 LP or Norma mag, I would be begging to get in on the 250gr Berger test bullet offer Michele Gallagher was offering in this forum earlier.

 

[Aimsmall55]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

Originally Posted By: TwoGun
All the bullets are the same size when they exit the barrel. You could load a .308 bullet and it'd be .338 when it exited.
That's is funny

 

[dstewart51]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: milo-2</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dstewart51</div><div class="ubbcode-body">Yes, but I was wondering if the larger dia Scenars would generate more pressure then the OTM's. </div></div>

I apologize for my offbeat humor earlier in the thread.
To answer your question, you're just going to have shoot the bullets to find out. Even Litz couldn't predict barrel pressures, as all barrel manufacturers barrels are different.
And the reamer used to chamber it.

As for measuring and weighing bullets, I myself wouldn't even be looking there unless the gun wouldn't shoot them.

If I shot a .338 LP or Norma mag, I would be begging to get in on the 250gr Berger test bullet offer Michele Gallagher was offering in this forum earlier.</div></div>

No apology necessary, I have a great sense of humor.

I was a strange child growing up. Wanted to be a Metrologist, http://en.wikipedia.org/wiki/Metrology. So measuring the differences was fun.

 

[BryanLitz]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

My reply is very close to Milo's statement (in his <span style="text-decoration: underline">second</span> post):

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">you'll just have to shoot them to find out</div></div>

I wouldn't say that +/-0.0005" is better or worse universally, but a little fatter or thinner might play better in a particular barrel, and that will be a case by case basis that you just have to shoot to find out. As he stated, at the end of the muzzle they're all obturated to the bore/groove diameter. The effect, if any, would be early in the bullets initial motion and engraving.

Having said all that, consistency is always a good thing and a high degree of consistency usually promotes better precision.

-Bryan

 

[dstewart51]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

Thanks Bryan, I was impressed the Bergers where the most consistent.

 

[bas402]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

I just came across this thread as I got the new 250gr Hybrids and I was taking some normal measurements. I didn't see any noticeable differences in dia when I tested between the 300 Scenars / Bergers/ Sierra's. All were in .337.5" to .338 and I observed the same with the 250gr Bergers/ Scenars. Both the 300gr and 250 weight comparison Berger came out on top then the Scenars then Sierra. Where the Berger's really shine is where I think is the most critical and that is base to ogive the Bergers in both the 250 and 300 came in @ +\- .0005 and the Scenars came in @ .00075 while the Sierra came in @ +\- .008. these were done on 100 lot ea. It's amazing but they all shoot. Wonder how much this effects velocity?

 

[esromvre]

Re: Ping Bryan Litz, 300gr .338" OTM vs SMK vs Scenar

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: milo-2</div><div class="ubbcode-body">Holy shit, if you have patience for this, you will adapt well to painting ceramic squirrels in some fucking nut house when you age.

</div></div>

You cracken on my Squirrels???

lol JK but I know what the time doing this test is like.