Bearing surface length of Sierra 183gn 7mm?

[1KBR]

My gunsmith has asked what free bore I want for my new 284 and I was hoping to try the 183 Sierras. How do they compare to the 180 hybrids or 195gn in bearing surface/free bore needed?

 

[280man]

My reamer has a .200 FB and it works great with 180 Hybrids and 183 Sierras

 

[thomasholbrook43]

My gunsmith has asked what free bore I want for my new 284 and I was hoping to try the 183 Sierras. How do they compare to the 180 hybrids or 195gn in bearing surface/free bore needed?

220 freebore is perfect for 183's an 180 hybrids.

 

[1KBR]

My gunsmith has asked what free bore I want for my new 284 and I was hoping to try the 183 Sierras. How do they compare to the 180 hybrids or 195gn in bearing surface/free bore needed?

That will be handy. I suppose then that the bearing surface of the 195s will be too long to have a chamber set up to suit both the 183s and 195s? Has anyone here compared bearing surfaces with these 3 bullets using a comparator? I am still waiting for my 183s and 195s to arrive.

 

[thomasholbrook43]

183's about 50 thousand longer. You can set up reamer for both 180 hybrid/183 sierra. But it would be a little short for 195's ( still work but not optimum.)

 

[Dusty Stevens]

.220

 

[1KBR]

183's about 50 thousand longer. You can set up reamer for both 180 hybrid/183 sierra. But it would be a little short for 195's ( still work but not optimum.)

.050" longer than 180 hybrid, thanks for that.

 

[1KBR]

One more thing. I hear these bullets are pointed from the factory, but pictures of them don't really show this much. Are they pointed much? Will there be anything to be gained by pointing them further?

 

[thomasholbrook43]

Yes they are pointed very nicely. They have hit a home run with this bullet. It is very accurate. Tested in Shehane and soon to be tested in my saum.

 

[thomasholbrook43]

I'm currently having JGS Build a reamer in 7mm saum built around this bullet.

 

[1KBR]

Yes they are pointed very nicely. They have hit a home run with this bullet. It is very accurate. Tested in Shehane and soon to be tested in my saum.

In that case, I wonder if there is actually much difference in BC once the Berger Hybrid has been pointed?

 

[thomasholbrook43]

In that case, I wonder if there is actually much difference in BC once the Berger Hybrid has been pointed?

Have not tested drop. but wind drift difference is about 2 inchs at 600 yards. That is with non pointed hybrids vs 183's out of box Both running 2850fps . But for me I'm getting tired of sorting bearing surface and pointing. I just want to pull them out of box and shoot.There are a few custom bullet makers you can do that with plus the new senar-l's from lapua. So far 183's you can do that. I still need to more testing at 1000yards to see. I will be giving a full report once my 7mm saum is complete. My Shehane's freebore is not set up perfect for these bullets so I want to wait till saum is done.

 

[BIGMAC]

Have not tested drop. but wind drift difference is about 2 inchs at 600 yards. That is with non pointed hybrids vs 183's out of box Both running 2850fps . But for me I'm getting tired of sorting bearing surface and pointing. I just want to pull them out of box and shoot.There are a few custom bullet makers you can do that with plus the new senar-l's from lapua. So far 183's you can do that. I still need to more testing at 1000yards to see. I will be giving a full report once my 7mm saum is complete. My Shehane's freebore is not set up perfect for these bullets so I want to wait till saum is done.

Anxiously waiting for your full report!

 

[falconpilot]

I have drop tested them. There is between 1/3 to 1/2 moa difference in them at 600 yards. Both bullets, running the same speed, the 183's are requiring less come up than the 180 hybrids.

Running a .215 freebore. Seating both bullets to just touching the lands, I'm only seeing 5 thousands difference. Using my seating die which is set for my 183's to jus touch, I'm only having to go in 5 thous on the seating die to get the 180's to just touching.

Spent several days working with Kiff, measuring and figuring. .215 freebore' seating the 183's to just touching lands, keep the bullet 40 thous above the neck/shoulder junction. This allows you to jump the bullet up to 30 and still stay out the donut region of the case, while also allowing you plenty of neck to chase the lands as the barrel wears.

 

[bblackwell]

I sent a round with the 183 to JGS to measure with the bullet approx .050 above the neck/shoulder junction. It worked out to be .225 FB.

 

[savageshooter86]

I sent a round with the 183 to JGS to measure with the bullet approx .050 above the neck/shoulder junction. It worked out to be .225 FB.

How far up neck is bullet at this distance? About 1/4 ?

 

[bblackwell]

How far up neck is bullet at this distance? About 1/4 ?

It's close to 1/4 , might be a little shy. IMO 10-20 thou more FB won't hurt a thing......OAL is around 3.3