1200y+ Mosin Smyert Mk 3.7

[Grindl]

Once you change the OAL to facilitate achieving proper neck tension , will that cause you to have to "re-ladder" your load and / or , make a adjustment to the powder weight ?
When you ream the bore deeper , will you be trying to "hold" the same "jump" distance you are currently using , after adjusting the OAL ? Every tiny change seems to have a big effect when a rifle shoots as tight as you have this one shooting .

[ShootnMathews]

So lately I have been immensely frustrated as I try to get enough neck tension on these to hold the 190gr VLDs I am shooting. Now I know why. The bullet gas stop is almost .001 fatter then the portion of the bullet that my Improved brass is holding on to. Thus I am loosing virtually all neck tension. I am going to have the freed bore extended so that they can me loaded out much longer and thus this problem will go away.


You can see here a bullet on top seated to the needed OAL and below a bullet that very light finger pressure was able to push farther into the case because of no neck tension.




Bullets in the tray are ok. The rest on the table had no neck tension.



This is where the brass holds them. Its almost .001 smaller then the base where the grass seal is.


Once I ream out he freebore longer I will be able to seat them so the neck of the brass grabs here.

Before I cut the throat to seat the bullet that far out, I'd get a die that sized the brass to .002" neck tension at the length now. I had a rifle that I seated Bergers super long like you're thinking of doing and the results were not good. I worked up a load that shot 1/4" groups and was great. Then loaded a bunch of rounds. After a few range trips the load progressively opened up to almost 2". I had a friend check some rounds for concentricity and they were horrible. There was so little bullet in the case that just the vibration of driving around was enough to severely misalign the bullets.

[Grimstod]

Already have done this twice now. Its getting expensive at 35$ a bushing. I now have five bushings for this caliber. I think I will try my luck with the reamer. Its a free modification vs something that will cost another 35$.

[ShootnMathews]

Already have done this twice now. Its getting expensive at 35$ a bushing. I now have five bushings for this caliber. I think I will try my luck with the reamer. Its a free modification vs something that will cost another 35$. :wt*:

My thought is, if you throat it longer and then your bullets won't hold concentricity, then you are stuck buying the bushing anyways and you either have to jump them a long ways to the lands or go to bigger bullets. And a lot of high BC bullets don't like a lot of jump, so you'll have to step down to something more seating depth friendly. Like an SMK or some of the Berger 215 hybrids if you are can find some. Or have your barrel set back and re-chambered again to have the shorter throat again. To me it just seems that getting another bushing, although costly, would still be the more simplistic option. Just my 2¢

[Grimstod]

Bushed the bolt on my rifle. Did have over .009 of clearance on the firing pin and now it has about .002 and that should make it a lot easier to reacher greater velocities.

[ShootnMathews]

Very nice. Who did the work? I'd be interested in having it done

[Grimstod]

Did most of it myself but Chuck my Father in law made a few of the cuts.

[Grimstod]

My LotherWalther barrel is soon going to be back on Smyert 3.7 witch will sort of make it into 3.0 again

[Grimstod]

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Did some trying of the bolt face. Some work I had done on another lathe left the face a bit ruff. This six jaw is way nicer.

15726839_609874602530629_3470018121405692503_n.jpg

[iridium-192]

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