Question about 175 gr SMK

[alexdawg]

Question. I have a Remington 700P 308 and have been working on loads for it. I tried 100 rounds of 175gr SMK and it really likes those.
I set them at 2.808 COAL and the ogive was 2.128 with 42.2 grains of Varget in new win brass. OK so it likes the 175gr SMK so I order more, 2
boxes of 100. I did not realize there would be so much difference in ogive and overall lenght of these bullets. I did not measure the first
box either. I came to realize the differences when just seating these new bullets with the same settings on the die as I used with the first box.
There is no way I can set exactly to the original 2.808 coal or 2.128 ogive lenghts with these 2 new batches of bullets. Either the ogive length
is shorter or the coal length is longer.

Would you more experienced folks than me just set them to ogive length and live with coal? Man, I had just found something the gun really liked
too. I also assume I will be doing more OCW testing at 300 and also checking new bullets from now on.

Thanks in advance.

 

[FunkBass2008]

I set them by ogive. The COAL on SMK's can vary since they don't seem to have the most uniform meplats.

 

[FunkBass2008]

Also, look into 178 A-max bullets. The design of their meplat helps reduce the effect you are seeing with the SMK's open tips.

 

[Rotortuner]

As long as your not running into issues with fitting them into your magazine, just load them to ogive and they should still shoot fine. I shoot a lot of 175 SMK's and I dont really worry about the varience in OAL of the bullet.

CJG

 

[chefcam864]

What these guys said^

 

[scudzuki]

Being as the ogive is the part of the bullet that contacts the lands, always load to it, unless the resulting COL exceeds mag length. At that point COL is the limiting factor, like with a factory Remington .308 chamber.

Joe

 

[smschulz]

Base it on the OGIVE and just make sure the COAL fits in your mags.

 

[James n TN]

What you need look for is differences in length via bearing surface. This is what makes the difference in accuracy. What you need is two ogive comparator gauges and digital calipers and measure each of the bullets and separate in lengths via .0015 spread. If ya not real serious about accuracy you can do .003-.005 spread on bearing surface

 

[Red_SC]

If your 700P barrel is anything like mine was, then all this really doesn't matter. My jump to the lands was ridiculously long, but it was a hammer. I never touched my seating die between lots.

 

[alexdawg]

Thanks for the advise, I set them to the same ogive length and lived with coal and have found no differences while shooting. Still a sweet load for my rifle. Thanks again.

 

[sjb269]

I have found the SMKs are not affected by huge differences in COALs. I jump them a pretty astounding distance with great results.

 

[jkonzal]

These guys are right on. The important measurement is base to ogive. This is the one that will change your pressures.

 

[Pinecone]

I found in my 700, the longer I could seat the bullets, the smaller the groups.

42.2 gr of Varget is a pretty light load. 43.5 should be the next higher node and put you around 2600 fps.

 

[Rprecision]

Load for function you will be fine

Any change you may have will be inconsequential

 

[l115a3]

My 175 SMK

COAL 2.800"
CBTO 2.230"


Why your measure so short for CBTO?